Emit canonical tagged addresses

- Make `TCPAddress.unwrap()` emit `('tcp', host, port)` and
  `UDSAddress.unwrap()` emit `('unix', path)` while retaining the
  compatibility readers from the preceding change.

- Pass concrete TCP fields to Trio, compose multiaddrs from tagged
  values, and let `SpawnSpec` carry protocol-specific tuple shapes
  for validation by `wrap_address()`.

- Compare runtime, registry, bind, and tunnel addresses through
  canonical serialized forms and cover both TCP and UDS operation.

Prompt-IO: ai/prompt-io/opencode/20260820T033108Z_ba07e09d_prompt_io.md

(this patch was generated in some part by `opencode` using `gpt-5.6-sol` (`openai`))

ai/prompt-io/claude/20260813T001102Z_27c34aeb_prompt_io.md

@@ -3,8 +3,8 @@ model: claude-opus-5
 service: claude
 session: 7b9c97c4-fff7-4ac4-97fb-35720453308e
 timestamp: 2026-08-13T00:11:02Z
-git_ref: 27c34aeb
+git_ref: 27c34aebb615c30d4039fa399f4ce2766ed7ba2c
-scope: docs+code
+scope: code
 substantive: true
 raw_file: 20260813T001102Z_27c34aeb_prompt_io.raw.md
 ---

ai/prompt-io/claude/20260813T001102Z_27c34aeb_prompt_io.raw.md

@@ -2,15 +2,15 @@
 model: claude-opus-5
 service: claude
 timestamp: 2026-08-13T00:11:02Z
-git_ref: 27c34aeb
+git_ref: 27c34aebb615c30d4039fa399f4ce2766ed7ba2c
-diff_cmd: git diff main..ng_tpts_planning
+diff_cmd: git diff 3ad7e7e5dc28aa336499725a03744fc10c6c0026..27c34aebb615c30d4039fa399f4ce2766ed7ba2c
 ---
 
 # Raw output — next-gen tpt-backend implementation plans
 
 ## Generated planning docs
 
-> `git diff main..ng_tpts_planning -- ai/tpt-backends/`
+> `git diff 3ad7e7e5dc28aa336499725a03744fc10c6c0026..27c34aebb615c30d4039fa399f4ce2766ed7ba2c -- ai/tpt-backends/`
 
 Five markdown docs. `00_shared_backend_contract.md` is normative
 and the other three are written against it so they can be worked
@@ -43,7 +43,7 @@ independently:
 
 ## Generated example code
 
-> `git diff main..ng_tpts_planning -- examples/multihost/wg_lan/`
+> `git diff 3ad7e7e5dc28aa336499725a03744fc10c6c0026..27c34aebb615c30d4039fa399f4ce2766ed7ba2c -- examples/multihost/wg_lan/`
 
 - `wg_maddr.py` — `WGTunnelledAddr(msgspec.Struct, frozen=True)`
   carrying `bearer: tuple[str, int]`, `peer_pubkey: str`,

ai/prompt-io/opencode/20260818T021729Z_d9a6e2e9_prompt_io.md

@@ -0,0 +1,69 @@
+---
+model: gpt-5.6-sol
+service: opencode
+session: intercepted-claude-7b9c97c4-fff7-4ac4-97fb-35720453308e
+timestamp: 2026-08-18T02:17:29Z
+git_ref: d9a6e2e9
+scope: code
+substantive: true
+raw_file: 20260818T021729Z_d9a6e2e9_prompt_io.raw.md
+---
+
+## Prompt
+
+> Intercept Claude session
+> `7b9c97c4-fff7-4ac4-97fb-35720453308e`, pick up where it
+> stopped in its open worktree, finish the tunnelled-address change
+> and commit plan, and prepare any outstanding context for another
+> provider.
+
+The recovered final prompt specifically called out the `uds` versus
+`unix` boundary decision, absent concrete `Address.namespace`
+implementations, the corrected namespace test, and the passing
+focused and wider suites.
+
+During review, the human further required that tunnelled-maddr work
+delegate to `multiaddr`'s encapsulation APIs, challenged the premature
+transport-shaped listener hooks and directed their removal, corrected
+the long-term bearer provisioning model, and confirmed the intended
+split between discovery metadata and bindspace lifecycle code.
+
+## Response summary
+
+Recovered the transcript and matched it to `wkts/addr_unpacking`,
+audited the staged implementation, and completed the interrupted
+verification and commit-plan work. The audit removed premature
+transport-shaped listener hooks, widened the namespace identifier
+type, updated stale import documentation, and removed an
+invalid-escape warning from the maddr diagram. It also preserved the
+layer-C design where tractor provisions the kernel-owned tunnel
+bearer without treating it as a message transport.
+
+## Files changed
+
+- `tractor/discovery/_tunnel.py` - tunnel specs, address wrapper, and
+  peeling helpers.
+- `tractor/discovery/_addr.py` - wrapped-address recognition and
+  namespace typing.
+- `tractor/discovery/__init__.py` - public tunnel API exports.
+- `tests/discovery/test_tunnelled_addr.py` - delegation and boundary
+  regression coverage.
+- `ai/tpt-backends/03_wg_tunnel_bindspace.md` - distinguish
+  tractor-owned bindspace provisioning from kernel socket ownership.
+
+## Human edits
+
+Substantial human-directed editing occurred over several review turns:
+
+- required use of `multiaddr`'s `.encapsulate()`/`.decapsulate()`
+  family rather than a hand-rolled tunnel peeler
+- rejected the premature `start_listener()`/`close_listener()` hooks
+  and directed their removal from this foundational change
+- corrected the documentation so tractor retains ownership of future
+  bindspace provisioning while the kernel owns the bearer socket
+- reviewed and accepted the placement of declarative tunnel metadata
+  under `tractor.discovery`, with lifecycle code kept separate
+
+The final source lines were applied through the coding agents, but
+these design corrections and deletion decisions came from the human
+review and materially shaped the patch.

ai/prompt-io/opencode/20260818T021729Z_d9a6e2e9_prompt_io.raw.md

@@ -0,0 +1,66 @@
+---
+model: gpt-5.6-sol
+service: opencode
+timestamp: 2026-08-18T02:17:29Z
+git_ref: d9a6e2e9
+diff_cmd: git diff HEAD~1..HEAD
+---
+
+# Raw output - tunnelled-address handoff completion
+
+Recovered Claude Code session
+`7b9c97c4-fff7-4ac4-97fb-35720453308e` and continued its
+interrupted `wkts/addr_unpacking` changes.
+
+## Generated code
+
+> `git diff HEAD~1..HEAD -- tractor/discovery/_tunnel.py`
+
+Added frozen `WGTunnelSpec` and `TunnelledAddress` structs. The
+wrapper delegates transport identity, validity, bindspace, and wire
+serialization to its overlay while retaining tunnel metadata locally.
+Added pure helpers to peel nested wrappers and enumerate their tunnel
+specs. The module documents why wrappers must be peeled before
+`Endpoint` selects the overlay transport backend.
+
+> `git diff HEAD~1..HEAD -- tractor/discovery/_addr.py`
+
+Extended `is_wrapped_addr()` to recognize `TunnelledAddress` without
+registering tunnels as message transports, and widened the namespace
+identifier type to cover named network namespaces.
+
+> `git diff HEAD~1..HEAD -- tractor/discovery/__init__.py`
+
+Exported the tunnel address API from `tractor.discovery` and updated
+the eager-import documentation.
+
+> `git diff HEAD~1..HEAD -- tests/discovery/test_tunnelled_addr.py`
+
+Added focused coverage for delegation, serialization, rewrapping,
+namespace fallback, nested peeling order, and frozen structs.
+
+> `git diff HEAD~1..HEAD -- ai/tpt-backends/03_wg_tunnel_bindspace.md`
+
+Clarified that tractor owns the eventual bindspace lifecycle and may
+provision the WireGuard iface, routes, and kernel UDP listener through
+netlink/`pyroute2`. Kernel socket ownership does not make the bearer an
+application `MsgTransport` endpoint.
+
+## Verification
+
+Focused tests:
+
+```text
+9 passed in 0.03s
+```
+
+Discovery and IPC suites:
+
+```text
+67 passed, 2 xpassed
+```
+
+The audit removed premature module-level listener hooks. Runtime
+integration must peel the wrapper explicitly at bind and dial
+boundaries rather than make `._tunnel` impersonate a transport
+backend.

ai/prompt-io/opencode/20260818T075031Z_dd02c7c0_prompt_io.md

@@ -0,0 +1,50 @@
+---
+model: gpt-5.6-sol
+service: opencode
+session: tractor-addr-unpacking-followup
+timestamp: 2026-08-18T07:50:31Z
+git_ref: dd02c7c0
+scope: code
+substantive: true
+raw_file: 20260818T075031Z_dd02c7c0_prompt_io.raw.md
+---
+
+## Prompt
+
+The human requested the complete tunnelled-maddr parsing/composition
+slice as an unattended batch, with every numbered requirement finished
+and atomic commit plans prepared at the end. Existing human decisions
+required native `multiaddr` encapsulation APIs, no hand-written peeler,
+and preservation of tractor's future bindspace lifecycle ownership.
+
+## Response summary
+
+Implemented strict WG key codecs and native single/nested tunnel maddr
+parsing and composition, integrated them into discovery APIs, migrated
+the multihost example off its duplicate parser, corrected package
+dependency metadata, and added focused and end-to-end parser
+regressions. Verified the complete tractor suite and built both package
+artifacts.
+
+## Files changed
+
+- `tractor/discovery/` - WG codecs, parser/composer, wrapper typing,
+  public exports, and discovery dispatch.
+- `tests/discovery/` - key, grammar, nesting, round-trip, and public
+  boundary regressions.
+- `examples/multihost/wg_lan/` - production parser migration and
+  updated usage documentation.
+- `pyproject.toml`, `uv.lock` - reproducible WG codec and multibase
+  dependencies for checkout and package installs.
+- `ai/tpt-backends/03_wg_tunnel_bindspace.md` - current layer-A state
+  and future bindspace ownership.
+
+## Human edits
+
+The human selected the five-step scope and batch execution model,
+required delegation to `multiaddr`'s encapsulation APIs, rejected
+transport-shaped listener placeholders in the prerequisite commit, and
+clarified that tractor will eventually provision the kernel-owned
+bearer through its bindspace layer. The agent implemented and tested
+those decisions; no direct manual source edits were observed during
+this batch.

ai/prompt-io/opencode/20260818T075031Z_dd02c7c0_prompt_io.raw.md

@@ -0,0 +1,61 @@
+---
+model: gpt-5.6-sol
+service: opencode
+timestamp: 2026-08-18T07:50:31Z
+git_ref: dd02c7c0
+diff_cmd: git diff HEAD~1..HEAD
+---
+
+# Raw output - native WireGuard maddr integration
+
+The human requested completion of the five-step tunnelled-maddr slice:
+port the proven WireGuard parser, delegate to `py-multiaddr`'s native
+tunnel APIs, integrate public parse and composition entry points, add
+regressions, and return atomic commit plans after completing the batch.
+
+## Generated code
+
+> `git diff HEAD~1..HEAD -- tractor/discovery/_tunnel.py tractor/discovery/_multiaddr.py tractor/discovery/_addr.py tractor/discovery/__init__.py`
+
+Added strict WireGuard standard-base64/multibase key codecs and native
+WG maddr parsing/composition. Nested stacks peel the last `/wg/`
+repeatedly with `.decapsulate_code()`, isolate segments through
+`.split()`/`.join()`, and compose recursively with `.encapsulate()`.
+Public discovery parsing, wrapping, endpoint-table parsing, and maddr
+composition now preserve `TunnelledAddress` metadata locally.
+
+> `git diff HEAD~1..HEAD -- pyproject.toml uv.lock`
+
+Declared `py-multibase` directly and pinned the unreleased
+py-multiaddr#108 WG codec revision in distribution metadata. Enabled
+Hatch direct-reference metadata so editable, wheel, and sdist builds
+use the same dependency contract.
+
+> `git diff HEAD~1..HEAD -- tests/discovery/test_multiaddr.py tests/discovery/test_tunnelled_addr.py`
+
+Added key-codec, single/nested WG round-trip, malformed key, invalid
+bearer/overlay, missing codec, missing bearer, `wrap_address()`, and
+`parse_endpoints()` coverage while retaining plain TCP/UDS regressions.
+
+> `git diff HEAD~1..HEAD -- examples/multihost/wg_lan ai/tpt-backends/03_wg_tunnel_bindspace.md`
+
+Removed the duplicate example parser, migrated callers to production
+`TunnelledAddress`, retained only explicit `wg(8)` verification, and
+updated dependency and future bindspace ownership documentation.
+
+## Verification
+
+- focused discovery files: `45 passed`
+- discovery and IPC suites: `81 passed, 2 xpassed`
+- full suite: `443 passed, 9 skipped, 7 xfailed, 4 xpassed`
+- collection: `462 tests`
+- Ruff: clean
+- sdist and wheel builds: successful
+
+## Review corrections
+
+A review caught that `[tool.uv.sources]` alone would not constrain
+built-package consumers to a WG-capable py-multiaddr revision. The
+dependency was moved into PEP 621 metadata and the parser now converts
+missing-codec failures into an actionable tractor error without
+misclassifying Unix paths containing a `wg` directory.

ai/prompt-io/opencode/20260819T213144Z_f81fc5e5_prompt_io.md

@@ -0,0 +1,37 @@
+---
+model: gpt-5.6-sol
+service: opencode
+session: tractor-addr-unpacking-followup
+timestamp: 2026-08-19T21:31:44Z
+git_ref: f81fc5e5
+scope: code
+substantive: true
+raw_file: 20260819T213144Z_f81fc5e5_prompt_io.raw.md
+---
+
+## Prompt
+
+The human requested runtime boundary integration with the established
+per-step implementation and commit-plan workflow.
+
+## Response summary
+
+Kept `TunnelledAddress` available to callers while peeling it at the
+last outbound boundary before transport lookup and dialing. Added a
+regression which captures both transport arguments and confirms plain
+TCP behavior is unchanged.
+
+## Files changed
+
+- `tractor/ipc/_chan.py` - peel tunnel annotations before outbound
+  transport dispatch and connection.
+- `tests/ipc/test_channel_tunnel_boundary.py` - verify plain and
+  tunnelled channel inputs deliver only TCP overlays.
+
+## Human edits
+
+The human chose the runtime-boundary slice, required the existing
+per-step commit-plan flow, and previously established that wrappers
+must retain bindspace metadata without impersonating transports. The
+agent implemented those constraints; no direct manual source edits were
+observed during this step.

ai/prompt-io/opencode/20260819T213144Z_f81fc5e5_prompt_io.raw.md

@@ -0,0 +1,25 @@
+---
+model: gpt-5.6-sol
+service: opencode
+timestamp: 2026-08-19T21:31:44Z
+git_ref: f81fc5e5
+diff_cmd: git diff HEAD~1..HEAD
+---
+
+# Raw output - outbound tunnel boundary
+
+The human requested the next tunnelled-address slice using the same
+per-step commit-plan flow. Existing design decisions require retaining
+tunnel metadata until the narrow IPC transport boundary and never
+teaching exact-type transport tables about tunnel wrappers.
+
+> `git diff HEAD~1..HEAD -- tractor/ipc/_chan.py tests/ipc/test_channel_tunnel_boundary.py`
+
+Extended channel address inputs to accept tunnel declarations, then
+called `strip_tunnels()` immediately before exact-type transport lookup
+and `connect_to()`. Added plain/tunnel parameterized coverage proving
+both operations receive the identical TCP overlay while the original
+wrapper retains its tunnel spec.
+
+Verification included focused IPC tests, Ruff, discovery/IPC suites,
+and the full tractor suite.

ai/prompt-io/opencode/20260819T213145Z_f81fc5e5_prompt_io.md

@@ -0,0 +1,40 @@
+---
+model: gpt-5.6-sol
+service: opencode
+session: tractor-addr-unpacking-followup
+timestamp: 2026-08-19T21:31:45Z
+git_ref: f81fc5e5
+scope: code
+substantive: true
+raw_file: 20260819T213145Z_f81fc5e5_prompt_io.raw.md
+---
+
+## Prompt
+
+The human requested completion of inbound runtime peeling using the
+same per-step implementation and commit-plan workflow.
+
+## Response summary
+
+Preserved tunnel declarations through listener configuration, peeled
+them immediately before `Endpoint` construction, and used the overlay
+for backend-specific random listener allocation after registry
+discovery. Added a real listener regression for the reflection and
+exact-type boundary.
+
+## Files changed
+
+- `tractor/ipc/_server.py` - accept wrapper declarations and peel at
+  `Endpoint` construction.
+- `tractor/_root.py` - allocate random transport addresses from the
+  contacted registry's overlay.
+- `tests/ipc/test_server_tunnel_boundary.py` - verify a real listener
+  stores only TCP while preserving the source annotation.
+
+## Human edits
+
+The human selected the runtime-boundary work and previously corrected
+the architecture so tractor retains future bindspace provisioning
+ownership while `Endpoint` sees only application transports. The agent
+implemented and tested that direction; no direct manual source edits
+were observed during this step.

ai/prompt-io/opencode/20260819T213145Z_f81fc5e5_prompt_io.raw.md

@@ -0,0 +1,25 @@
+---
+model: gpt-5.6-sol
+service: opencode
+timestamp: 2026-08-19T21:31:45Z
+git_ref: f81fc5e5
+diff_cmd: git diff HEAD~1..HEAD
+---
+
+# Raw output - inbound tunnel boundary
+
+The human requested runtime boundary integration while preserving the
+future tractor-owned bindspace lifecycle.
+
+> `git diff HEAD~1..HEAD -- tractor/ipc/_server.py tractor/_root.py tests/ipc/test_server_tunnel_boundary.py`
+
+Broadened listener declarations to carry tunnel wrappers until
+`_serve_ipc_eps()` and peeled immediately before `Endpoint`
+construction. Also peeled a contacted tunnelled registry before
+backend-specific random listener allocation. Added a real TCP listener
+regression proving `Endpoint` stores only the resolved overlay while
+the original declaration retains bindspace metadata.
+
+Verification included `465` collected tests, `84` passing
+discovery/IPC tests with two xpasses, Ruff, and the full suite with
+`447` passes.

ai/prompt-io/opencode/20260820T021516Z_dfad66a0_prompt_io.md

@@ -0,0 +1,41 @@
+---
+model: gpt-5.6-sol
+service: opencode
+session: tractor-addr-unpacking-followup
+timestamp: 2026-08-20T02:15:16Z
+git_ref: dfad66a0
+scope: docs
+substantive: true
+raw_file: 20260820T021516Z_dfad66a0_prompt_io.raw.md
+---
+
+## Prompt
+
+The human requested that the bindspace plan preserve the agreed
+capability, spawn-bootstrap, endpoint-role, namespace augmentation,
+random-address, and teardown semantics, using `github/ns_aware` as
+prototype input.
+
+## Response summary
+
+Updated plan-03 and the shared backend contract to separate serializable
+bindspace declarations from scoped live capabilities, make namespace
+entry a pre-runtime spawn operation, keep maddr paths role-neutral, and
+define listen/dial provisioning plus ownership-sensitive teardown.
+
+## Files changed
+
+- `ai/tpt-backends/03_wg_tunnel_bindspace.md` - layer-C capability,
+  bootstrap, role, teardown, test, and risk model.
+- `ai/tpt-backends/00_shared_backend_contract.md` - distinguish
+  transport bind selectors from process namespace lifecycle.
+
+## Human edits
+
+The human supplied the core architecture: structured scoped
+capabilities, spawn-time namespace entry, orthogonal namespace
+augmentation, source/destination-dependent provisioning, and
+role-dependent teardown. They also rejected premature assumptions about
+`open_bindspace()` returning an address and requested grounding in the
+existing namespace prototype. The agent translated those decisions into
+the plan text; no direct manual source edits were observed.

ai/prompt-io/opencode/20260820T021516Z_dfad66a0_prompt_io.raw.md

@@ -0,0 +1,34 @@
+---
+model: gpt-5.6-sol
+service: opencode
+timestamp: 2026-08-20T02:15:16Z
+git_ref: dfad66a0
+diff_cmd: git diff HEAD~1..HEAD
+---
+
+# Raw output - bindspace capability design
+
+The human corrected the layer-C design around local network-stack
+realization. They established that bindspace state should be both
+structured and a scoped capability; namespace entry belongs in
+subactor bootstrap; maddrs can describe source or destination network
+paths while namespace selection augments them orthogonally; random
+address and teardown behavior depend on operation role and ownership.
+
+They directed comparison with the prototype on `github/ns_aware` and
+requested these decisions be preserved in the plan.
+
+> `git diff HEAD~1..HEAD -- ai/tpt-backends/03_wg_tunnel_bindspace.md ai/tpt-backends/00_shared_backend_contract.md`
+
+Reworked layer C around serializable `BindspaceSpec`, stable
+`BindspaceIdentity`, and scoped non-serializable `BindspaceHandle`
+concepts. Namespace FDs pin identity and lifetime; parent/supervisor
+provisioning transfers entry capability through spawn; the child enters
+before runtime, channels, listeners, sockets, or worker threads and then
+drops authority. Listen/dial roles and owned/borrowed teardown are
+explicit, while maddrs remain role-neutral network-path declarations.
+
+The shared backend contract now separates transport-level `.bindspace`
+selectors from process namespace lifecycle. Added tests/risks for FD
+identity, bootstrap ordering, privilege drop, role ownership, and
+shared-resource teardown.

ai/prompt-io/opencode/20260820T033107Z_ba07e09d_prompt_io.md

@@ -0,0 +1,41 @@
+---
+model: gpt-5.6-sol
+service: opencode
+session: tractor-addr-unpacking
+timestamp: 2026-08-20T03:31:07Z
+git_ref: ba07e09d
+scope: code
+substantive: true
+raw_file: 20260820T033107Z_ba07e09d_prompt_io.raw.md
+---
+
+## Prompt
+
+The human requested canonical tagged transport addresses with a
+reader-first migration. TCP should decode `('tcp', host, port)`, Unix
+should decode `('unix', path)`, `uds` should remain an accepted input
+alias and internal transport key, and legacy tuple/list inputs must keep
+working before writers switch formats.
+
+## Response summary
+
+Introduced canonical and compatibility address aliases, explicit tagged
+dispatch, transport-specific tagged readers, and focused serialization
+tests. Kept legacy pair inputs and native IPv6 socket values readable so
+this boundary can ship before tagged emission.
+
+## Files changed
+
+- `tractor/discovery/_addr.py` - address aliases and tagged dispatch.
+- `tractor/ipc/_tcp.py` - tagged, legacy, and IPv6 TCP decoding.
+- `tractor/ipc/_uds.py` - canonical Unix and UDS-alias decoding.
+- `tests/discovery/test_address_serialization.py` - reader compatibility
+  coverage.
+
+## Human edits
+
+The human supplied the canonical `tcp` and `unix` forms, chose `uds` as
+an input-only serialization alias while preserving it as the runtime
+transport key, and required a reader-first commit boundary. The agent
+implemented those decisions; no direct manual source edits were
+observed.

ai/prompt-io/opencode/20260820T033107Z_ba07e09d_prompt_io.raw.md

@@ -0,0 +1,25 @@
+---
+model: gpt-5.6-sol
+service: opencode
+timestamp: 2026-08-20T03:31:07Z
+git_ref: ba07e09d
+diff_cmd: git diff HEAD~1..HEAD
+---
+
+# Raw output - tagged address readers
+
+The human requested a migration away from ambiguous untagged transport
+tuples. They established `('tcp', host, port)` and `('unix', path)` as
+canonical forms, retained `('uds', path)` as an input alias, and required
+a reader-first compatibility boundary before changing emitted values.
+
+> `git diff HEAD~1..HEAD -- tractor/discovery/_addr.py tractor/ipc/_tcp.py tractor/ipc/_uds.py tests/discovery/test_address_serialization.py`
+
+Added explicit tagged address aliases and dispatch, taught TCP and UDS
+readers to decode tagged tuple/list payloads, preserved legacy pair input,
+and retained native IPv6 socket-address decoding. Added focused tests for
+canonical tags, the UDS alias, msgpack-style lists, legacy pairs, and IPv6
+socket values.
+
+Focused reader tests and Ruff checks passed before the writer migration
+was applied.

ai/prompt-io/opencode/20260820T033108Z_ba07e09d_prompt_io.md

@@ -0,0 +1,45 @@
+---
+model: gpt-5.6-sol
+service: opencode
+session: tractor-addr-unpacking
+timestamp: 2026-08-20T03:31:08Z
+git_ref: ba07e09d
+scope: code
+substantive: true
+raw_file: 20260820T033108Z_ba07e09d_prompt_io.raw.md
+---
+
+## Prompt
+
+The human asked the agent to continue after adding tagged readers,
+complete canonical address emission without dropping legacy input
+compatibility, verify the migration, and prepare a complete multi-commit
+package when the turn was done.
+
+## Response summary
+
+Changed `.unwrap()` to emit tagged TCP and Unix addresses, updated direct
+tuple consumers and spawn payload declarations, and aligned multiaddr,
+runtime, IPC, and discovery tests with canonical serialized equality.
+Kept untagged tuples and the `uds` spelling readable at input boundaries.
+
+## Files changed
+
+- `tractor/discovery/_addr.py` - canonical output alias.
+- `tractor/discovery/_multiaddr.py` - tagged address composition.
+- `tractor/ipc/_tcp.py` - tagged emission and direct socket dialing.
+- `tractor/ipc/_uds.py` - tagged full-path emission.
+- `tractor/msg/types.py` - protocol-neutral spawn tuple containers.
+- `tests/discovery/test_address_serialization.py` - writer assertions.
+- `tests/discovery/test_multiaddr.py` - canonical round-trip assertions.
+- `tests/discovery/test_tpt_bind_addrs.py` - tagged bind assertions.
+- `tests/ipc/test_each_tpt.py` - canonical runtime address assertions.
+- `tests/ipc/test_server_tunnel_boundary.py` - tagged TCP destructuring.
+- `tests/test_local.py` - canonical registry comparison.
+
+## Human edits
+
+The human established the reader-before-writer sequencing, canonical tag
+spellings, retained compatibility expectations, and requested final
+multi-commit packaging. The agent implemented and tested those choices;
+no direct manual source edits were observed.

ai/prompt-io/opencode/20260820T033108Z_ba07e09d_prompt_io.raw.md

@@ -0,0 +1,26 @@
+---
+model: gpt-5.6-sol
+service: opencode
+timestamp: 2026-08-20T03:31:08Z
+git_ref: ba07e09d
+diff_cmd: git diff HEAD~1..HEAD
+---
+
+# Raw output - canonical tagged address writers
+
+After the reader compatibility boundary, the human asked the agent to
+continue the migration and package the completed work as dependency-
+ordered commits.
+
+> `git diff HEAD~1..HEAD -- tractor/discovery/_addr.py tractor/discovery/_multiaddr.py tractor/ipc/_tcp.py tractor/ipc/_uds.py tractor/msg/types.py tests/discovery/test_address_serialization.py tests/discovery/test_multiaddr.py tests/discovery/test_tpt_bind_addrs.py tests/ipc/test_each_tpt.py tests/ipc/test_server_tunnel_boundary.py tests/test_local.py`
+
+Switched TCP and Unix `.unwrap()` output to canonical tagged tuples,
+updated direct transport and multiaddr consumers, widened spawn message
+tuple containers for protocol-specific shapes, and migrated runtime and
+test comparisons to serialized address equality. Legacy inputs remain
+accepted at `wrap_address()` and backend reader boundaries.
+
+Ruff and focused tests passed. The complete non-debugger TCP suite passed
+with 412 tests; the UDS suite reached 80% without failure before the
+harness timeout, then all 97 remaining tests passed on resume. Debugger
+PTY coverage was excluded after an unrelated timeout.

ai/prompt-io/opencode/20260828T003805Z_e40c39da_prompt_io.md

@@ -0,0 +1,45 @@
+---
+model: gpt-5.6-sol
+service: opencode
+session: addr-unpacking-rebase-conflict
+timestamp: 2026-08-28T00:38:05Z
+git_ref: e40c39da
+scope: code
+substantive: true
+raw_file: 20260828T003805Z_e40c39da_prompt_io.raw.md
+---
+
+## Prompt
+
+The human asked the agent to resolve the first conflict in the
+`wkt/addr_unpacking` rebase because the replayed history was primarily
+agent-generated.
+
+## Response summary
+
+Preserved the lazy-import and platform-aware behavior from the new
+base while restoring the replayed WireGuard address parsing and
+composition behavior. Reconciled the changed dependency lock with the
+replayed direct dependency contract and validated the combined result.
+
+## Files changed
+
+- `tractor/discovery/_addr.py` - combined address-platform and tunnel
+  typing changes.
+- `tractor/discovery/_multiaddr.py` - combined lazy imports with WG
+  parse and composition dispatch.
+- `tractor/discovery/_tunnel.py` - retained cold-import behavior for
+  the newly added WG implementation.
+- `tests/discovery/test_multiaddr.py` - adapted missing-codec
+  monkeypatching to the lazily imported upstream protocol module.
+- `uv.lock` - restored the WG-capable multiaddr source and direct
+  multibase metadata.
+
+## Human edits
+
+The human chose to abort the first rebase attempt, restart with an
+explicit old-base boundary, and delegated the conflict resolution to
+the agent. The human also chose not to preserve the superseded
+module-level protocol-lookup test seam; the agent redirected the test
+to the upstream protocol module. No direct manual source edits were
+observed during this resolution.

ai/prompt-io/opencode/20260828T003805Z_e40c39da_prompt_io.raw.md

@@ -0,0 +1,32 @@
+---
+model: gpt-5.6-sol
+service: opencode
+timestamp: 2026-08-28T00:38:05Z
+git_ref: e40c39da
+diff_cmd: git diff HEAD~1..HEAD
+---
+
+# Raw output - addr-unpacking rebase resolution
+
+The human delegated resolution of the first conflict while rebasing
+`wkt/addr_unpacking` from `d9a6e2e9` onto `85a44588`.
+
+## Generated code
+
+> `git diff HEAD~1..HEAD -- tractor/discovery/_addr.py tractor/discovery/_multiaddr.py tractor/discovery/_tunnel.py`
+
+Combined the rebased base's platform-aware address registries and lazy
+optional-dependency imports with the replayed `TunnelledAddress` typing
+and WireGuard multiaddr dispatch. Adapted the new tunnel module so
+importing tractor does not eagerly load `multiaddr`.
+
+> `git diff HEAD~1..HEAD -- uv.lock`
+
+Regenerated the lockfile to retain the replayed WG-capable
+`py-multiaddr` revision and direct `py-multibase` dependency after the
+new base's independently changed lockfile silently omitted that hunk.
+
+## Verification
+
+Conflict-marker, syntax, lock consistency, lint, collection, focused
+discovery, and cold-import checks were selected for the resolution.

ai/prompt-io/opencode/20260831T022317Z_768b5316_prompt_io.md

@@ -0,0 +1,72 @@
+---
+model: gpt-5.6-sol
+service: opencode
+session: f3a5eef0-9695-48ab-a336-861187473f8a
+timestamp: 2026-08-31T02:23:17Z
+git_ref: ng_tpts_planning
+diff_cmd: git diff 768b531662a88037e3988885102d2ff24a7ce34e..HEAD
+scope: code
+substantive: true
+raw_file: 20260831T022317Z_768b5316_prompt_io.raw.md
+---
+
+## Prompt
+
+The human asked to continue the retained PR landing sequence and
+selected "Repair all blockers" after a read-only review of PR #492.
+They then corrected the TIPC assessment:
+
+> oh one thing on the tipc findings, they may have already been
+> addressed in the downstream patch branch no?
+
+The repair therefore had to use downstream #493 as implementation
+evidence, avoid duplicating solved TIPC work, preserve the dirty
+downstream worktree, and repair the remaining shared, QUIC,
+WireGuard, lock, and provenance defects without committing,
+pushing, or publishing.
+
+## Response summary
+
+Reworked PR #492's plans and executable WireGuard example into a
+consistent landing candidate. The shared and TIPC documents now
+match current runtime/downstream behavior while naming remaining
+risks. The QUIC plan now defines transport ownership across the
+whole actor lifecycle. The WireGuard example validates keys and
+binds both hosts and the service actor correctly without elevating
+Tractor. The dependency lock and historical provenance pointers
+are synchronized.
+
+## Files changed
+
+- `ai/tpt-backends/00_shared_backend_contract.md` - current backend
+  contract, dispatch, capability, and locality rules.
+- `ai/tpt-backends/01_tipc_backend.md` - #493 reconciliation and
+  bounded unresolved work.
+- `ai/tpt-backends/02_quic_iroh_backend.md` - lifecycle-safe QUIC
+  and UniFFI implementation plan.
+- `ai/tpt-backends/03_wg_tunnel_bindspace.md` - corrected address
+  registry and privilege semantics.
+- `ai/tpt-backends/README.md` - refreshed plan summaries.
+- `examples/multihost/wg_lan/README.md` - unprivileged two-host
+  setup and accurate verification limits.
+- `examples/multihost/wg_lan/host_a_srv.py` - local key check,
+  overlay child bind, and stable RPC exposure.
+- `examples/multihost/wg_lan/host_b_client.py` - peer key check,
+  host-B bind, and explicit missing-service failure.
+- `examples/multihost/wg_lan/wg_maddr.py` - strict parsing and
+  asynchronous role-specific key inspection.
+- `uv.lock` - exact `py-multiaddr` Git source resolution.
+- `ai/prompt-io/claude/20260813T001102Z_27c34aeb_prompt_io.md` -
+  valid scope and immutable Git reference.
+- `ai/prompt-io/claude/20260813T001102Z_27c34aeb_prompt_io.raw.md`
+  - immutable historical diff pointers.
+
+## Human edits
+
+The human chose the full repair path rather than reducing the PR
+to planning documents or publishing the initial review. They also
+identified that the initial TIPC review had not accounted for the
+downstream implementation branch. That correction materially
+changed the work: solved TIPC items were backported into the plan,
+remaining defects were separated from implemented behavior, and
+the dirty downstream worktree was kept read-only.

ai/prompt-io/opencode/20260831T022317Z_768b5316_prompt_io.raw.md

@@ -0,0 +1,60 @@
+---
+model: gpt-5.6-sol
+service: opencode
+timestamp: 2026-08-31T02:23:17Z
+git_ref: ng_tpts_planning
+diff_cmd: git diff 768b531662a88037e3988885102d2ff24a7ce34e..HEAD
+---
+
+# Raw output - repair PR #492 for landing
+
+## Generated changes
+
+> `git diff 768b531662a88037e3988885102d2ff24a7ce34e..HEAD -- ai/tpt-backends/`
+
+- Reconciled the shared backend contract with current address,
+  dispatch, capability, locality, and listener-rebind APIs.
+- Updated the TIPC plan from downstream #493 implementation and
+  tests, preserving unresolved registrar election, collision,
+  locality, and socket-cleanup work as explicit follow-ups.
+- Reworked the QUIC plan around a launch-time transport bootstrap,
+  one actor-owned endpoint, a transport nursery spanning parent
+  dial through deregistration, supervised UniFFI cleanup, complete
+  routable addresses, connection leases, and listener-owned tasks.
+- Corrected the WireGuard bindspace plan to distinguish the
+  build-registered address registry from runtime capability.
+
+> `git diff 768b531662a88037e3988885102d2ff24a7ce34e..HEAD -- examples/multihost/wg_lan/`
+
+- Hardened WireGuard key conversion and parsing with strict
+  32-byte validation, lazy protocol lookup, and explicit rejection
+  of unsupported nested tunnel descriptors.
+- Made interface inspection asynchronous, bounded at its
+  cancellation request, role-specific, and separable from
+  privileged preflight commands.
+- Corrected host-local binds, subactor overlay publication, stable
+  RPC module exposure, and missing-actor handling in the two-host
+  example.
+- Updated the README so Tractor remains unprivileged and the local
+  versus remote overlay roles are explicit.
+
+> `git diff 768b531662a88037e3988885102d2ff24a7ce34e..HEAD -- pyproject.toml uv.lock ai/prompt-io/`
+
+- Regenerated `uv.lock` for the exact merged `py-multiaddr` WireGuard
+  codec revision.
+- Replaced mutable historical prompt diff pointers with immutable
+  refs and normalized the substantive scope without rewriting the
+  historical raw response.
+
+## Verification output
+
+- `git diff --check`: passed.
+- `uv lock --check`: passed.
+- Ruff on the WireGuard example directory: passed.
+- Python compilation of the WireGuard example directory: passed.
+- Tractor imported from the PR worktree's existing environment.
+- WireGuard address round-trip, local/peer role checks, malformed
+  base64 rejection, and nested-tunnel rejection: passed.
+- Three independent final re-reviews reported no actionable
+  findings in the shared/TIPC, QUIC, or WireGuard slices.
+- No live TIPC, iroh/UniFFI, or WireGuard network test was run.

ai/tpt-backends/00_shared_backend_contract.md

@@ -33,19 +33,35 @@ doc in the same PR.
 
 ## 1. The backend duck-type (empirical, from `_tcp.py`/`_uds.py`)
 
-A transport backend is **one module** under `tractor/ipc/`
+A transport backend is **one module** under `tractor/ipc/`.
-exposing exactly four things. There is no ABC to subclass and no
+There is no ABC to subclass and no plugin entrypoint; wiring is by
-plugin entrypoint; wiring is by explicit table registration
+explicit table registration (§2) plus one piece of reflection
-(§2) plus one piece of reflection (§1.3).
+(§1.3).
+
+Keep two contracts distinct:
+
+- `tractor.discovery._addr.Address` is a static `Protocol`. It
+  declares address-wrapper members including `namespace`,
+  `open_listener()` and `close_listener()`.
+- the runtime's empirical contract is what `_tcp.py`, `_uds.py`
+  and `_server.py` actually call. The current address classes do
+  not implement every declared `Address` member: listener
+  lifecycle is module-level, `def_bindspace` is used despite not
+  being declared by the `Protocol`, and `namespace` remains
+  aspirational.
+
+Until those surfaces are deliberately reconciled, implement the
+empirical module contract below and update the static `Protocol`
+only when the runtime really consumes the new member. Do not claim
+that structural conformance alone defines a backend.
 
 ### 1.1 `class <Proto>Address(msgspec.Struct, frozen=True)`
 
-Structurally conforms to the `Address` `Protocol` in
+The runtime-consumed address-wrapper surface is:
-`tractor/discovery/_addr.py:82`. Required surface:
 
 | member | kind | notes |
 | --- | --- | --- |
-| `proto_key` | `ClassVar[str]` | the wire/registry key, e.g. `'tcp'`, `'uds'` |
+| `proto_key` | `ClassVar[str]` | internal transport key, e.g. `'tcp'`, `'uds'` |
 | `unwrapped_type` | `ClassVar[type]` | the primitive tuple shape |
 | `def_bindspace` | `ClassVar` | default bindspace value |
 | `is_valid` | `@property -> bool` | "is this a *dialable/bindable* addr" |
@@ -81,22 +97,32 @@ Hard constraints learned from the existing two:
   paper over it at best.
 
   **The fix, and the recommended prerequisite for all three
-  backends: make the unwrapped form carry an explicit
+  backends: make the unwrapped form carry an explicit internal
-  proto-key, using the `multiaddr` protocol name as the
+  proto-key** — `('tcp', host, port)`,
-  canonical spelling** — `('tcp', host, port)`,
+  `('uds', filedir, filename)`, `('tipc', stype, inst, scope)`.
-  `('unix', path)`, `('udp', ...)`, `('tipc', stype, inst,
+  The tag must be a `TransportProtocolKey`/registry key. In
-  scope)`. Then `wrap_address()` collapses from an
+  particular it is **`'uds'`, not the external multiaddr spelling
-  order-sensitive `match` to `_address_types[addr[0]]`, and the
+  `'unix'`**. If a wire or display format uses a different name,
-  whole collision class stops existing. Note this *also* aligns
+  name that translation explicitly; today `_multiaddr.py` maps
-  the on-wire form with `mk_maddr()`/`parse_maddr()`, so the two
+  internal `uds` to external `/unix/`. Then `wrap_address()` can
-  representations stop being independent inventions.
+  dispatch through `_address_types[addr[0]]` without an
+  order-sensitive shape match.
 
   Two consequences to plan for:
-  - it's a **wire-format change** (`SpawnSpec`,
+  - it's a **wire-format change**. Widen and keep synchronized
-    `_root_mailbox`, `_registry_addrs`) plus every test fixture
+    `discovery._addr.UnwrappedAddress` and the duplicate wire
-    and downstream config (`piker`'s `[network]` table). It
+    alias in `msg.types`; change `SpawnSpec.reg_addrs` and
-    wants its **own migration commit, landed before any new
+    `.bind_addrs`, not only `_root_mailbox` and
-    backend**, not smuggled into one.
+    `_registry_addrs`. Audit the related `RuntimeVars`
+    `_root_mailbox`/`_root_addrs` annotations, `Actor.reg_addrs`
+    and accept-address annotations, channel/spawn signatures,
+    fixtures, and downstream config (`piker`'s `[network]`
+    table). `msgspec` rejects a union containing multiple
+    array-like tuple shapes, so #493 used
+    `tuple[str|int, ...]` as the truthful transitional wire type;
+    the complete proto-key migration can restore per-proto
+    validation. This wants its **own migration commit, landed
+    before any new backend**, not smuggled into one.
   - it's the moment to **stop handing raw unwrapped tuples to
     users at all.** The long-term shape is: `Address` subtypes
     are the public currency and `UnwrappedAddress` becomes an
@@ -104,15 +130,20 @@ Hard constraints learned from the existing two:
     `ipaddress` uses (you pass `IPv4Address`, not a 4-tuple).
     Public API should accept `Address|maddr-str` and treat bare
     tuples as legacy-tolerated input, ideally deprecated.
-- **`.get_random()` must be collision-free without a live
+- **`.get_random()` must not deterministically alias without a
-  runtime.** See the `UDSAddress.get_random()` uuid-token
+  live runtime.** See the `UDSAddress.get_random()` uuid-token
   comment (`_uds.py:207-220`): with no `current_actor()` the
   sockname degenerates to a pure fn of `(prefix, pid)` and two
   calls in one proc alias. Mix in a `uuid4().hex[:8]` token.
 - **`.bindspace` semantics**: "the address' bindable space" —
   ip/host for `tcp`, the socket-file *directory* for `uds`. For
   the new backends: the TIPC *scope* (§1 of plan 01), the iroh
-  *ALPN + relay/discovery realm* (plan 02), the netns (plan 03).
+  *ALPN + relay/discovery realm* (plan 02). Do not overload this
+  transport-level bind selector with process namespace lifecycle.
+  Plan 03 augments an maddr/address declaration with a serializable
+  `BindspaceSpec` and a scoped, non-serializable `BindspaceHandle`;
+  the latter owns namespace identity/FD/lifetime and is consumed at
+  spawn bootstrap before a concrete address reaches transport bind.
   `Address.namespace` is already spec'd in the Protocol as
   "the if-available OS-specific network namespace key" and is
   currently unimplemented by both backends — plan 03 is the
@@ -162,10 +193,11 @@ if (unwrapped := lstnr.socket.getsockname()) != self.addr.unwrap():
 ```
 
 i.e. it assumes `lstnr.socket.getsockname()` exists and that its
-return value is a valid `from_addr()` input. This is fine for
+return value is a valid `from_addr()` input. That is false for
-TIPC (§3 of plan 01) and **is the main integration hazard for
+TIPC, whose listener sockname is an undialable port ID, and for
-iroh** (§3 of plan 02) — plans that break it must say so
+non-socket iroh. Both plans must use the explicit backend rebind
-explicitly and propose the upstream `_server.py` patch.
+policy added at this integration point rather than pretending a
+sockname is always an address replacement.
 
 ### 1.4 `class Msgpack<Proto>Stream(MsgpackTransport)`
 
@@ -224,20 +256,26 @@ path.** This is why plan 01 is small and plan 02 is not.
 
 ---
 
-## 2. Registration tables (the full wiring checklist)
+## 2. Registration and policy wiring
 
-Adding a backend touches these and only these:
+Adding a backend requires this complete audit. Not every item
+changes for every backend, but none may be assumed from the others:
 
 1. `tractor/runtime/_state.py:46`
    `TransportProtocolKey = Literal['tcp', 'uds', ...]` — add the
-   key. This `Literal` is the canonical set; `_testing/pytest.py`
+   internal key. This `Literal` is the **declared protocol-key
-   drives `--tpt-proto` validation off `_addr._address_types`,
+   set**, not proof that a backend is usable on this host.
-   and the spawn-backend fixture already models the
+2. `tractor/discovery/_addr.py` `_address_protos` and
-   "drive-the-set-from-the-Literal" pattern
+   `_address_types: dict[str, Type[Address]]` — register
-   (`pytest.py:870-880`) — do the same rather than hardcoding.
+   `'<key>': <Proto>Address`. `_address_types` is a plain
-2. `tractor/discovery/_addr.py:173` `_address_types: bidict` —
+   **`dict`, not a `bidict`**, and represents the backends this
-   `{'<key>': <Proto>Address}`. Note it is a **`bidict`**, so
+   build registers for import and dispatch. UDS is conditional on
-   the mapping must stay 1:1.
+   `HAS_UDS`, while TIPC can remain registered on a host where its
+   kernel support is unavailable. An importable backend with a
+   runtime capability requirement therefore needs a separate
+   availability check. Never conflate this dispatch registry with
+   either host usability or the declared `TransportProtocolKey`
+   universe.
 3. `tractor/discovery/_addr.py:181` `_default_lo_addrs` —
    `'<key>': <Proto>Address.get_root().unwrap()`.
    ⚠️ this dict is built at **import time**, so
@@ -250,7 +288,7 @@ Adding a backend touches these and only these:
    add a case iff your `unwrapped_type` isn't already uniquely
    matched. **Preferably do the proto-key migration in §1.1
    first**, after which this step becomes a one-line
-   `_address_types` entry instead of an order-sensitive `case`.
+    `_address_types` lookup instead of an order-sensitive `case`.
 5. `tractor/ipc/_types.py` — `Address` union alias,
    `_msg_transports` list, `_key_to_transport[('msgpack', key)]`,
    `_addr_to_transport[<Proto>Address]`.
@@ -262,9 +300,17 @@ Adding a backend touches these and only these:
    `parse_maddr()`.
 8. `tractor/ipc/__init__.py` — re-export if the backend has a
    public surface.
-9. `tractor/_testing/addr.py::get_rando_addr()` — per-proto
+9. `tractor/discovery/_api.py::_is_local_addr()` and
+   `prefer_addr()` — define and test the backend's locality and
+   selection tier. The current order is UDS, local TCP, then
+   remote. A new backend must not silently fall into `remote` by
+   accident: for example TIPC node scope is local, cluster scope
+   is not known-local, and an observed address with unknown scope
+   must not be promoted. Preserve the last-registered tie-break
+   unless intentionally changing policy.
+10. `tractor/_testing/addr.py::get_rando_addr()` — per-proto
     branch so the whole suite can run under `--tpt-proto <key>`.
-10. `pyproject.toml` — new deps go in an **optional extra**, never
+11. `pyproject.toml` — new deps go in an **optional extra**, never
     in `[project].dependencies`. See §5.
 
 ## 3. Where the `trio.SocketListener` assumption is load-bearing
@@ -339,7 +385,10 @@ dep-free, or make that table lazy.
   `_state._def_tpt_proto` + `_runtime_vars['_enable_tpts']`
   (`pytest.py:807-835`). Adding the key to `_address_types` is
   what makes `--tpt-proto <key>` legal (`pytest.py:795-800`
-  asserts the lookup).
+  asserts the lookup). Thus CLI acceptance follows the
+   build-registered `_address_types`, while type-level declarations
+   follow `TransportProtocolKey` and host usability follows each
+   backend's capability probe; test all three layers separately.
 - The **acceptance bar** for every backend is: the *entire*
   existing suite passes under `--tpt-proto <key>`, unmodified.
   That is the whole point of the abstraction. Backend-specific
@@ -353,8 +402,11 @@ dep-free, or make that table lazy.
   `OSError(97, 'Address family not supported by protocol')`
   because the `tipc` module isn't loaded. Put the predicate in
   the backend module (so apps can use it too), not in the test.
-- New pytest marks must be registered in `pyproject.toml`, per
+- New pytest marks must be registered in
-  the project's fix-warnings-at-source rule (gh #469).
+  `_testing/pytest.py::pytest_configure()` with
+  `config.addinivalue_line()`, alongside the existing custom
+  marks. The repo has no `pyproject.toml` marker table. This is
+  still part of the fix-warnings-at-source rule (gh #469).
 
 ## 7. Code style (non-negotiable, matches the repo)
 

ai/tpt-backends/01_tipc_backend.md

@@ -4,13 +4,18 @@ Tracks gh [#378]. Prereq reading:
 [`00_shared_backend_contract.md`](./00_shared_backend_contract.md).
 
 **Thesis**: TIPC is the *cheapest* new backend we can add and
-simultaneously the only one that gives us cluster-wide service
+gives us kernel-native service-name publication, known-address
-discovery **for free, in the kernel**, replacing (for
+dialling, and topology events. Those are primitives for reducing
-TIPC-capable deployments) the whole `tractor.discovery`
+registrar traffic; they do **not** by themselves replace
-registrar round-trip with a `bind()`/`connect()` on a
+`tractor.discovery`, derive an actor's address from its name, or
-*service name*. It is stdlib-only: zero new dependencies.
+elect one registrar. It is stdlib-only: zero new dependencies.
+
+This plan is reconciled against downstream PR [#493]'s code and
+tests. Treat that implementation as prior art without mistaking
+implemented transport primitives for completed discovery policy.
 
 [#378]: https://github.com/goodboy/tractor/issues/378
+[#493]: https://github.com/goodboy/tractor/pull/493
 
 ---
 
@@ -74,10 +79,12 @@ The design decision that makes this backend coherent:
 > ever an *observed* address (`getpeername()`), never a
 > user-facing one.**
 
-This is exactly the "leverage the built-in discovery machinery"
+This is the "leverage the built-in discovery machinery" part of
-ask in #378: publishing a bind *is* registration, and
+#378: publishing a bind is kernel name-table registration and
-`connect()` on a name *is* a lookup, with no registrar actor in
+`connect()` on an already-known name is a kernel lookup, with no
-the loop.
+registrar actor on that **dial** path. Mapping an application name
+to that address and maintaining Tractor's actor registry remain
+separate work (§5).
 
 ### 2.2 the struct
 
@@ -89,12 +96,12 @@ class TIPCAddress(
     _stype: int                    # TIPC "type" == service class
     _instance: int                 # service instance within the type
     _scope: int = TIPC_CLUSTER_SCOPE
-    # observed-only, never part of identity/equality-by-intent
+    # observed-only, excluded from the unwrapped service identity
     maybe_node: int|None = None    # from TIPC_ADDR_ID getpeername()
     maybe_ref: int|None = None
 
     proto_key: ClassVar[str] = 'tipc'
-    unwrapped_type: ClassVar[type] = tuple[str, int]
+    unwrapped_type: ClassVar[type] = tuple[str, int, int, int]
     def_bindspace: ClassVar[int] = TIPC_CLUSTER_SCOPE
 ```
 
@@ -106,8 +113,8 @@ shape as `TCPAddress`*, so `wrap_address()`'s
 `case (str(), int())` steals it. This backend is therefore the
 forcing function for the contract-doc's conclusion (§1.1):
 
-> **make the unwrapped form carry an explicit proto-key, spelled
+> **make the unwrapped form carry the explicit internal
-> with the `multiaddr` protocol name.**
+> `TransportProtocolKey`.**
 
 ```python
 def unwrap(self) -> tuple[str, int, int, int]:
@@ -115,11 +122,31 @@ def unwrap(self) -> tuple[str, int, int, int]:
 ```
 
 `wrap_address()` then dispatches `_address_types[addr[0]]` and
-the collision class disappears. **This is a prerequisite
+the collision class disappears. The complete all-backend change
-migration commit, not part of this backend** — see contract §1.1
+is a prerequisite migration; #493 necessarily carried the
-for its blast radius (wire format + every fixture + `piker`
+transitional `UnwrappedAddress`/`SpawnSpec.reg_addrs`/
-config) and for the follow-on "stop handing raw tuples to users
+`.bind_addrs` widening needed for TIPC. See contract §1.1 for the
-at all, à la `ipaddress`" direction.
+remaining runtime annotations, fixtures and `piker` config. Here
+`tipc` is both the internal and external spelling; UDS remains
+internally `uds` and translates explicitly to external `/unix/`.
+
+`msgpack` decodes tuples as lists, so both forms are part of the
+round-trip contract. Match only the exact three- or four-element
+tagged shapes and test all four routes:
+
+```python
+case (
+    ('tipc', int() as stype, int() as inst, int() as scope)
+    |
+    ['tipc', int() as stype, int() as inst, int() as scope]
+):
+    ...
+```
+
+Also test the scope-defaulted three-element form through
+`TIPCAddress.from_addr()`, and tuple/list forms through the global
+`wrap_address()`. A normal two-element TCP/UDS address whose first
+element happens to be `'tipc'` must retain its classic dispatch.
 
 ⚠️ an earlier revision of this plan proposed a self-tagging
 `('tipc:<stype>:<scope>', instance)` string-prefix hack with an
@@ -150,25 +177,28 @@ treatment (`_uds.py:242`).
 - `_instance` for `get_random()`: TIPC gives us no
   kernel-assigned-instance analogue of `port=0`, so we must
   choose. Use a *pure* fn of the actor identity so it is
-  reproducible and collision-free:
+  reproducible and well-distributed, **not collision-free**:
   ```python
-  # 32-bit instance derived from the actor's uuid4 (+ pid when
+  # 32-bit instance derived from the actor's Aid.uid, or from a
-  # there's no live runtime, per the UDS precedent).
+  # per-call token + pid when there is no live runtime.
   inst: int = int.from_bytes(
       blake2b(seed.encode(), digest_size=4).digest(),
       'big',
   )
   ```
-  where `seed = f'{actor.aid.name}@{pid}'` if
+  where `seed = '.'.join(actor.aid.uid)` if
   `current_actor(err_on_no_runtime=False)` else
   `f'{prefix}.{uuid4().hex[:8]}@{pid}'`. Must avoid the reserved
   low range: `inst = 64 + (inst % (2**32 - 64))`.
+  The UUID is load-bearing because TIPC names are cluster-wide
+  while PIDs are only host-local: `(actor name, pid)` can alias on
+  different hosts.
   ⚠️ *unlike* `port=0`, a collision here surfaces as a
   successful-but-shared publication (TIPC allows multiple
   binders on the same name and round-robins!) rather than
   `EADDRINUSE`. That is a silent-crosstalk failure mode; §7 has
-  the test that proves the 4-byte digest is enough and §9 has
+  a statistical test and §9 records the unresolved recovery work
-  the mitigation if it isn't.
+  in [#501].
 - `_scope`: `TIPC_NODE_SCOPE` for a same-host-only actor (the
   UDS-equivalent), `TIPC_CLUSTER_SCOPE` (default) for
   cluster-visible. **This is `.bindspace`**:
@@ -189,7 +219,9 @@ treatment (`_uds.py:242`).
 @property
 def is_valid(self) -> bool:
     return (
-        self._instance != 0
+        self._instance > 0
+        and
+        self._stype > 0
         and
         self._stype not in _tipc_reserved_stypes  # {0, 1, ...}
         and
@@ -236,10 +268,11 @@ Notes / hazards:
 - **no `close_listener()` needed** — nothing to unlink. Omit the
   function entirely (contract §1.2: absence means implicit).
   Withdrawal of the published name happens on socket close.
-- ⚠️ `SocketListener.__init__` will try
+- `SocketListener.__init__` calls
-  `getsockopt(SOL_SOCKET, SO_ACCEPTCONN)`. If TIPC rejects it,
+  `getsockopt(SOL_SOCKET, SO_ACCEPTCONN)`. The live-kernel probe
-  trio's `except OSError: pass` covers us. Assert this in a
+  used by #493 answers `1`; retain the unit test so a kernel-side
-  unit test rather than assuming.
+  change is visible rather than relying on trio's suppressed-
+  `OSError` carve-out.
 - Wrap the bind in a `_reraise_as_connerr()`-style `@cm` (copy
   the `_uds.py:256` pattern) so `EADDRINUSE`-ish and
   `EAFNOSUPPORT` become `ConnectionError` with the addr in the
@@ -258,33 +291,31 @@ returns a `TIPC_ADDR_ID`-flavoured 5-tuple (the port id), *not*
 the name-seq we bound. So the `!=` is **always true** and
 `from_addr()` will be handed a 5-tuple.
 
-Handle it inside `TIPCAddress.from_addr()` — do **not** patch
+`TIPCAddress.from_addr()` must accept only proto-keyed service
-`_server.py`:
+names. It must reject a bare port ID because no conversion can
+recover `(stype, instance)`:
 
 ```python
 @classmethod
 def from_addr(cls, addr) -> TIPCAddress:
     match addr:
-        # our own unwrapped form
+        # our proto-keyed tuple or decoded-list wire form
-        case (str() as tag, int() as inst) if tag.startswith('tipc:'):
+        case (
-            _, stype, scope = tag.split(':')
+            ('tipc', int() as stype, int() as inst, int() as scope)
-            return TIPCAddress(int(stype), inst, int(scope))
+            |
+            ['tipc', int() as stype, int() as inst, int() as scope]
+        ):
+            return TIPCAddress(stype, inst, _norm_scope(scope))
 
-        # a kernel-observed TIPC_ADDR_ID 5-tuple: keep the
+        # a bare kernel-observed TIPC_ADDR_ID 5-tuple has no
-        # *service* identity we already know and only annotate
+        # service identity to annotate.
-        # the observed port-id.
         case (int() as atype, *rest) if atype == socket.TIPC_ADDR_ID:
-            ...
+            raise ValueError(...)
 ```
 
-The `TIPC_ADDR_ID` case cannot reconstruct `(stype, instance)`
+The `TIPC_ADDR_ID` case cannot reconstruct `(stype, instance)`.
-— that info isn't in a port id. So `from_addr()` alone is
+The resolution is the explicit listener-rebind policy added ahead
-insufficient for the reconciliation path. **Resolution**: make
+of the backend in #493:
-`from_addr()` raise a clear `ValueError` for the bare
-`TIPC_ADDR_ID` case, and instead prevent the reconciliation
-from firing by having `start_listener()` return a listener
-whose `getsockname()` we never need — i.e. land this two-line
-upstream fix in `_server.py:664`:
 
 ```python
 if (
@@ -300,12 +331,13 @@ behaviour exactly). Rationale: the reconciliation exists *only*
 to learn the kernel-assigned port for `port=0` TCP binds (its
 own comment says so, `_server.py:662`); TIPC has no such
 late-binding, so opting out is semantically right rather than a
-hack. **Land this as its own commit, ahead of the backend**,
+hack. Keep the guard test that TCP's `port=0` behaviour is
-with a test that `tcp`'s `port=0` behaviour is unchanged.
+unchanged.
 
-Keep the observed port-id available anyway: annotate
+Do **not** annotate `Endpoint.addr` from `getsockname()`: the
-`ep.addr = ep.addr.with_port_id(*getsockname()[1:3])` (a pure
+listener endpoint must remain the dialable service name. Port IDs
-`msgspec.structs.replace()` helper) purely for logging/repr.
+are observed only on connected streams and may annotate a copy via
+`with_port_id()` purely for logging/repr.
 
 ### 3.3 `MsgpackTIPCStream`
 
@@ -340,8 +372,9 @@ class MsgpackTIPCStream(MsgpackTransport):
                 0,              # domain: 0 == "anywhere in scope"
                 destaddr._scope,
             ))
+            stream = trio.SocketStream(sock)
             return cls(
-            trio.SocketStream(sock),
+                stream,
                 prefix_size=prefix_size,
                 codec=codec,
             )
@@ -363,11 +396,11 @@ class MsgpackTIPCStream(MsgpackTransport):
     leave at default, we have `trio` cancel scopes.
   - `TIPC_DEST_DROPPABLE = 0` on the connection so undeliverable
     msgs come back as errors rather than being silently dropped.
-- **`connect_to()` on a name with no publisher**: TIPC returns
+- **`connect_to()` on a name with no publisher**: the live-kernel
-  `ECONNREFUSED`/`EHOSTUNREACH` promptly (no SYN-timeout wait),
+  result is immediate `EHOSTUNREACH`. Python exposes that as a
-  which is *better* discovery-ping behaviour than TCP. Confirm
+  bare `OSError`, not a `ConnectionError` subtype, so
-  the errno and make sure it surfaces as `ConnectionError`
+  `_reraise_as_connerr()` is load-bearing for contract §4. Keep
-  (contract §4 — the registrar ping path depends on it).
+  the exact errno and normalization under test.
 
 ### 3.4 `get_stream_addrs()`
 
@@ -385,29 +418,27 @@ Problem: neither end's port-id tells us the *service name*. The
 `laddr`/`raddr` are used for logging, `Channel.raddr`,
 `Server._peers` keying-adjacent repr, and `maddr`. Design:
 
-- the **connecting** side knows the destaddr it dialled →
+- `get_stream_addrs()` converts both socket results into
-  `connect_to()` overrides `_raddr` after construction with the
+  **observed-only** addresses: `_stype`/`_instance` use the
-  known-good `TIPCAddress`, exactly as
+  `TIPC_NAME_UNKNOWN = -1` sentinel and `maybe_node`/`maybe_ref`
-  `MsgpackUDSStream.connect_to()` does for the peer-pid case
+  carry the port ID. Such addresses are invalid for dialling.
-  (`_uds.py:539-543`).
+- the **connecting** side knows the service name it dialled, so
-- the **accepting** side does not know the peer's service name
+  `connect_to()` replaces `_raddr` after construction with that
-  from the socket. Two honest options:
+  known `TIPCAddress` while retaining the constructor's one
-  - **(a) accept it: `raddr` carries only `(node, ref)`** via
+  tolerant port-ID observation. Do not call `getpeername()` a
-    `maybe_node`/`maybe_ref`, `_stype/_instance` set to a
+  second time: the peer can withdraw between the two calls.
-    sentinel `-1`, and `__repr__` renders
+- the **accepting** side genuinely cannot recover the peer's
-    `TIPCAddress[<peer-node:0x...>:<ref>]`. The `Aid` from the
+  service name from a port ID. Keep the observed-only `raddr`;
-    handshake already gives us the peer's logical identity, so
+  the handshake's `Aid` supplies logical identity. Piggybacking a
-    nothing in the runtime actually *needs* the peer's service
+  bound name in the handshake is outside this backend.
-    name. **Recommended.**
+- `laddr` is observed-only as well. It is used for repr/logging,
-  - (b) piggyback the peer's own bound name in the handshake.
+  not to replace the endpoint's known service name.
-    Rejected for this PR: touches `Aid`/msg-spec.
+- unlike TCP/UDS, TIPC can answer `ENOTCONN` from
-- `laddr` on the accepting side: the `Endpoint` knows its own
+  `getpeername()` after a connect-then-drop. This lookup happens
-  `addr`; but `get_stream_addrs()` is a `@classmethod` with only
+  during `MsgpackTransport` construction, before handshake error
-  the stream. Use `TIPC_ADDR_ID` for `laddr` too and let
+  tolerance. Wrap `getsockname()` and `getpeername()` in a
-  `Endpoint.peer_tpts` keying (which is by *peer* addr) still
+  tolerant helper and degrade to a port-ID-less observed address;
-  work. Verify nothing asserts `laddr == ep.addr` — grep for
+  a dropped peer must cost an observation, not kill the actor.
-  `.laddr` uses before committing (`_server.py`'s
-  `con_status` logging, `Channel.pformat()`).
 
 ---
 
@@ -444,43 +475,47 @@ the maddr stays 2-segment like `/unix/...`.
 
 ---
 
-## 5. Discovery: the actually-interesting part
+## 5. Discovery primitives and explicit limits
 
-Two independently-shippable layers. **Layer A is in scope for
+The backend provides independently-shippable kernel primitives.
-the first PR; layer B is a fast-follow.**
+Neither primitive alone implements Tractor's actor-name discovery,
+registry ownership, or registrar election.
 
 ### 5.1 Layer A — "discovery by bind" (free)
 
 Because `bind(TIPC_ADDR_NAMESEQ)` publishes and
-`connect(TIPC_ADDR_NAME)` resolves, a `tractor` tree whose
+`connect(TIPC_ADDR_NAME)` resolves, a caller that **already knows**
-`registry_addrs` are TIPC service names needs **no registrar
+a TIPC service address can dial it without a registrar lookup.
-liveness at all** for the connect path: `find_actor()`'s
+This is narrower than registrar-less `find_actor(name)`:
-"connect to the registrar and ask" becomes "connect to the
-service name directly". Concretely:
 
-- `tractor.discovery._api.find_actor()` etc. keep working
+- `tractor.discovery._api.find_actor()` and peers still query a
-  unchanged (they go through the registrar), *and*
+  registrar; #493 does not change them.
-- a new, TIPC-only fast path becomes possible: derive an actor's
+- deriving a stable service address from `(name, uuid)` and
-  service name from its `(name, uuid)` and dial it without any
+  dialling it directly is follow-up [#499]. The mapping must be
-  registrar hop.
+  documented and cross-language stable.
+- `registry_addrs` still identify registrars. Connecting to a
+  known registrar by TIPC name removes no registrar bookkeeping
+  or ownership semantics.
 
-Do **not** build the fast path in PR 1. Instead, prove the
+There is also an unresolved **split-brain election** problem.
-property with a test (§7.4) and file the follow-up: it changes
+Duplicate TIPC name publication succeeds and round-robins, so two
-`discovery` semantics (name→instance derivation must be a
+roots can both probe an unoccupied registrar name, both bind it,
-documented, stable, cross-language-able hash) and deserves its
+and both believe they won. The backend provides no atomic
-own design.
+compare-and-publish, lease, quorum, or deterministic winner. A
+topology subscription can reveal multiple publisher port IDs but
+does not elect or fence one. Do not describe registrar election as
+solved until a separate protocol closes this race.
 
 ### 5.2 Layer B — the topology service (`TIPC_TOP_SRV`)
 
-This is what makes #378's "end game cluster proto" claim real:
+This is the push primitive behind #378's "end game cluster proto"
-a *subscription* to name-table events, i.e. push-based
+direction: a subscription to kernel name-table publish/withdraw
-`register`/`deregister` for free, replacing the registrar's
+events. #493 implements `open_topology_events()`; consuming that
-polled `find_actor()`.
+feed in `discovery._registry` is follow-up [#496]. Until then it
+does not replace registrar state or `find_actor()`.
 
-Mechanics (verify each field against
+Mechanics, verified against `linux/include/uapi/linux/tipc.h`,
-`linux/include/uapi/linux/tipc.h` + `net/tipc/topsrv.c` at
+`net/tipc/topsrv.c` and #493's live-kernel probe:
-implementation time — the struct layout below is from the uapi
-header and the byte-order caveat is real):
 
 ```python
 # SOCK_SEQPACKET connected to the topology server
@@ -498,22 +533,25 @@ await sock.connect((
 #   __u32 filter;              /* TIPC_SUB_{PORTS,SERVICE,CANCEL} */
 #   char  usr_handle[8];
 # }                            /* == 28 bytes */
-_SUBSCR_FMT: str = '=IIIII8s'   # ⚠ 5*I is 20 -> use '=5I8s'
+_SUBSCR_FMT: str = '=5I8s'
 ```
 
-- **byte order**: the topology server historically accepts both
+- **byte order**: #493's live-kernel probe verified native
-  host and swapped order and auto-detects; modern kernels are
+  standard-size (`'='`) packing for publish and withdraw events.
-  strict-ish. Pack native (`'='`) first, and if the server
+  Use `'=5I8s'` for the 28-byte subscription. Do not retain the
-  closes the connection immediately, retry with `'>'`. Encode
+  speculative `'>'` retry/probe as if it were required. Preserve
-  that as a one-time probe helper
+  the earlier `# ?TODO` to verify the deterministic rule directly
-  `_detect_topsrv_endianness()` cached at module level — and
+  against `net/tipc/topsrv.c`; it is source-audit work, not a
-  put a `# ?TODO` pointing at `net/tipc/topsrv.c` for someone
+  runtime retry requirement.
-  to make it deterministic.
 - **events**: `struct tipc_event` is `event: u32`,
   `found_lower: u32`, `found_upper: u32`,
   `port: {ref: u32, node: u32}`, then the 28-byte subscription
-  echo → 40 bytes. `event ∈ {TIPC_PUBLISHED, TIPC_WITHDRAWN,
+  echo: **48 bytes** (`4 + 4 + 4 + 8 + 28`), not 40. Use
-  TIPC_SUBSCR_TIMEOUT}`.
+  `'=10I8s'` and assert `struct.calcsize(...) == 48`.
+  `event ∈ {TIPC_PUBLISHED, TIPC_WITHDRAWN,
+  TIPC_SUBSCR_TIMEOUT}`. Python exposes `TIPC_WAIT_FOREVER` as
+  `-1`, so mask it with `& 0xFFFF_FFFF` before packing an
+  unsigned `I`.
 - **trio shape** — this is where the "nearly-functional,
   modern-async" style pays off; expose it as an `@acm` yielding
   a `trio` receive-channel of typed events, *not* a class:
@@ -538,14 +576,22 @@ async def open_topology_events(
   `kind: Literal['published','withdrawn','timeout']`,
   `addr: TIPCAddress`, `node: int`, `ref: int`. One
   `trio.lowlevel`-free implementation: a nursery-spawned reader
-  task doing `await sock.recv(40)` in a loop and
+  task doing `await sock.recv(48)` in a loop. The feed is
-  `send_nowait()`ing decoded events, with the `@acm` closing the
+  authoritative and may neither block the socket reader nor drop
-  socket on exit → reader gets `ClosedResourceError` → cancel
+  transitions silently. Use `send_nowait()` and, on
-  scope collapses. Standard `tractor` `@acm` discipline.
+  `trio.WouldBlock`, raise a dedicated
-- **consumer**: `tractor/discovery/_registry.py` gains an
+  `TIPCNameEventOverflow` that aborts the subscription and tells
-  optional "watch" mode so a registrar (or any actor) can keep
+  the consumer to resubscribe and rebuild its view. A timeout
-  a live view of the actor set without polling. Sketch the
+  event is delivered once and then closes the channel. The
-  integration in the follow-up issue; do not wire it in PR 1.
+  `@acm` cancels its reader before closing the fd so teardown
+  cannot race a retried `recv()` into `EBADF`.
+- **scope**: topology events carry no publication scope. Use an
+  explicit unknown-scope sentinel and keep the resulting address
+  non-dialable; never copy caller/subscription context into
+  supposedly observed data.
+- **consumer**: [#496] owns the optional watch mode and the
+  decision whether the feed subsumes or merely accelerates
+  existing registrar bookkeeping.
 - **`SOCK_SEQPACKET` is fine here** because this socket never
   goes through `MsgpackTransport` — it's a plain trio socket
   used with `recv()`. The contract's "`SOCK_STREAM` only"
@@ -561,14 +607,16 @@ async def open_topology_events(
 2. `tractor/ipc/_tipc.py`: `TIPCAddress` + `is_tipc_available()`
    predicate + `start_listener()`. No transport yet.
    Tests: address round-trip (`unwrap`/`from_addr`/`wrap_address`),
-   `get_random()` uniqueness, bind/listen + `SO_ACCEPTCONN`
+   `get_random()` distribution, bind/listen + `SO_ACCEPTCONN`
    tolerance, `EAFNOSUPPORT` → actionable `ConnectionError`.
 3. `MsgpackTIPCStream` + `connect_to()` + `get_stream_addrs()`.
    Test: two `trio` tasks in one proc exchange a msg over
    `Msgpack` framing (no `tractor` runtime).
-4. registration tables (contract §2 items 1-6, 9) +
+4. registration tables (contract §2 items 1-8 and 10) +
    `pyproject.toml` mark/extra. Test: full suite under
-   `--tpt-proto tipc` (§7.3).
+   `--tpt-proto tipc` (§7.3). Keep TIPC in the conservative remote
+   preference tier until a follow-up implements and tests contract
+   item 9's node-scope locality policy.
 5. maddr support (`str` form + prefix special-case) + docs.
 6. `open_topology_events()` @acm + its tests (layer B).
 7. docs page + `docs/` example.
@@ -589,6 +637,8 @@ def is_tipc_available() -> bool:
     the `tipc` module is loaded.
 
     '''
+    if sys.platform != 'linux':
+        return False
     try:
         socket.socket(socket.AF_TIPC, socket.SOCK_STREAM).close()
         return True
@@ -596,17 +646,22 @@ def is_tipc_available() -> bool:
         return False
 ```
 
-Cache it in a module global (it can't change without a
+Do not permanently memoize the result: `modprobe tipc` and module
-`modprobe`, and a cold call costs a syscall). Pure predicate, no
+removal can change it during a long-lived process. Probe once per
-side effects, no logging.
+runtime startup, or use an explicitly refreshable cache whose
+owner invalidates it after module-management operations. The
+predicate itself remains side-effect-free and silent.
 
 ### 7.2 gating
 
-- `pytest.mark.tipc` registered in `pyproject.toml`.
+- `pytest.mark.tipc` registered in
-- module-level
+  `_testing/pytest.py::pytest_configure()` via
-  `pytestmark = pytest.mark.skipif(not is_tipc_available(),
+  `config.addinivalue_line()`, where this repo declares its other
-  reason='`tipc` kernel module not loaded (`modprobe tipc`)')`
+  custom marks. Do not invent a `pyproject.toml` marker table.
-  in `tests/ipc/test_tipc.py`.
+- keep pure address, serialization, and topology-codec tests
+  runnable on every host. Apply a shared `requires_tipc` marker
+  only to tests that create sockets or otherwise touch the kernel;
+  do not module-skip `tests/ipc/test_tipc.py`.
 - `--tpt-proto tipc` with no module must fail **loudly and
   early** with the actionable message, not with 400 confusing
   timeouts. Add the check to the `tpt_protos` fixture's existing
@@ -622,23 +677,29 @@ side effects, no logging.
   `sudo modprobe tipc` in a `before` step. GH's
   `ubuntu-latest` runners do allow `modprobe tipc` (the module
   ships with the standard Ubuntu kernel package); verify in a
-  throwaway workflow before wiring the matrix. If it turns out
+  throwaway workflow before wiring the matrix. #493's TIPC leg
-  to be unavailable, fall back to a container job with
+  is now blocking. If runners cease permitting the module load,
-  `--privileged`/`--cap-add NET_ADMIN`, and mark the job
+  fix the environment or use a suitable container rather than
-  `continue-on-error` until it's proven stable.
+  silently restoring `continue-on-error`.
 - cross-node TIPC (bearer) cannot be CI'd; cover it with a
   documented manual smoke test in the docs page, in the style
   of gh #482's LAN examples.
 
 ### 7.4 backend-specific tests worth writing
 
-- **name-publication is discovery**: bind a listener on
+- **known-name publication/resolution**: bind a listener on
   `(stype, inst)`, then from a second task `connect()` by name
   and assert it lands — *without* any `tractor` registrar.
-- **`get_random()` collision resistance**: 10k `get_random()`
+- **`get_random()` distribution**: 10k `get_random()` calls with
-  calls with no live runtime → 10k distinct `_instance`s.
+  no live runtime. Do **not** assert 10k distinct values: the
-  (This is the silent-crosstalk risk from §2.3; if the 4-byte
+  no-runtime seeds and outputs are both only 32 bits. Including
-  digest ever collides in this test, escalate to §9.)
+  duplicate seeds plus distinct-seed hash collisions puts the
+  modeled chance of at least one duplicate near 2.3% for 10k
+  calls. #493 uses `>= n - 2` (modeled probability of more than
+  two collisions around `2e-6`) and separately proves
+  `instance_from_seed()` is a pure function. Also hold actor
+  name/PID fixed while varying only `Aid.uuid` to prove live
+  actors seed from `Aid.uid`.
 - **round-robin surprise**: two listeners bound to the *same*
   `(stype, inst)` both succeed (TIPC allows it) and connects
   distribute. Assert the observed behaviour and reference it
@@ -678,14 +739,61 @@ single best demo this backend has; lead with it.
 
 ## 9. Known risks + escalations
 
-| risk | mitigation |
+- **Instance collision / silent crosstalk remains unresolved.**
-| --- | --- |
+  `Aid.uid` seeding and §7.4 tests reduce and measure risk, but
-| `_instance` hash collision → silent crosstalk (two actors share a service name, TIPC round-robins connects between them) | §7.4 test; if it bites, add a post-bind verification handshake, or bump to a 6-byte digest folded into `(stype_low, instance)` |
+  the instance field is still a hard 32 bits. [#501] owns
-| kernel/module unavailability everywhere (dev boxes, macOS, CI) | hard gating (§7.2); TIPC is explicitly an *opt-in cluster* transport, never a default |
+  post-bind verification and recovery. Do not fold bits into
-| `getsockname()` returns port-id not name | the `rebind_from_sockname` opt-out (§3.2), landed first |
+  `_stype`: topology can watch only one service type.
-| unregistered `/tipc` multiaddr proto | `str` maddr fallback (§4) + upstream track gh #483 |
+- **Concurrent registrar startup can split brain.** Topology can
-| stale docs (#378 notes tipc.io docs may be out of date) | treat `include/uapi/linux/tipc.h` + `net/tipc/` as the only normative source; cite file+symbol in code comments |
+  observe duplicate publisher port IDs but cannot elect or fence
-| `SOCK_SEQPACKET` topology framing byte-order | probe helper + `?TODO` (§5.2) |
+  a winner; a separate election protocol is required (§5.1).
+- **Kernel/module availability is opt-in.** Keep the hard gate in
+  §7.2; TIPC is never the default transport.
+- **A listener sockname is a port ID, not its service name.** Keep
+  the `rebind_from_sockname` opt-out (§3.2).
+- **`/tipc` is not yet a registered multiaddr protocol.** Keep
+  the interim `str` maddr fallback (§4) and upstream gh #483.
+- **The public TIPC docs can be stale.** Treat
+  `include/uapi/linux/tipc.h` and `net/tipc/` as normative and
+  cite file/symbol names in code comments.
+- **A slow topology consumer loses continuity.** Fail fast with
+  `TIPCNameEventOverflow`; resubscribe and rebuild rather than
+  block the reader or retain stale state (§5.2).
+- **TIPC locality preference is not implemented.** Current
+  `_is_local_addr()` handles only UDS and TCP, so node- and
+  cluster-scope TIPC both remain in the conservative remote tier.
+  Add explicit scope-aware policy and multihomed selection tests
+  before claiming node-scope preference (contract §2.9).
+
+### 9.1 remaining constructor/error cleanup
+
+#493 closes the peer-withdrawal race in transport construction,
+but it is not a blanket error-path cleanup. Keep these gaps
+explicit rather than reporting the backend as fully hardened:
+
+- direct `TIPCAddress(...)` construction bypasses
+  `from_addr()` scope normalization; `is_valid` is queried later
+  rather than enforcing validity at construction. Decide whether
+  constructors should reject bad service types/instances/scopes
+  or document direct construction as trusted-internal.
+- `maybe_node`/`maybe_ref` are excluded from `.unwrap()` but, as
+  `msgspec.Struct` fields, still participate in structural
+  equality/hash. If service-name identity must ignore observation
+  metadata, represent or compare it explicitly instead of relying
+  on the current "observed-only" description.
+- `start_listener()` must keep ownership of the raw socket through
+  `bind()`, `listen()` and `SocketListener(...)`. The downstream
+  implementation normalizes bind errors but does not yet wrap the
+  complete listener-construction sequence in close-on-error, so a
+  later setup failure can leak the fd.
+- `_maybe_sockaddr()` currently degrades every `OSError` to an
+  unknown observed address. Narrow that tolerance to expected
+  peer-withdrawal errors (notably `ENOTCONN`) so unrelated bad-fd
+  or programming failures remain visible.
+- error normalization is intentionally required for an
+  unpublished-name `EHOSTUNREACH`, but setup `setsockopt`,
+  listener-constructor, and topology setup failures still need a
+  consistent policy and focused regression tests.
 
 ## 10. Follow-up issue seeds
 
@@ -695,9 +803,11 @@ single best demo this backend has; lead with it.
   `py-multiaddr`, then drop our `str`-maddr fallback (§4). Worth
   filing *alongside* the `wg` spec-submission issue so both
   proposals go up together rather than as one-offs.
-- registrar-less discovery fast path via name derivation (§5.1)
+- registrar-less discovery fast path via name derivation ([#499],
+  §5.1)
 - `TIPC_TOP_SRV`-driven push registry in
-  `discovery/_registry.py` (§5.2)
+  `discovery/_registry.py` ([#496], §5.2)
+- post-bind collision verification and recovery ([#501], §9)
 - `TIPC_IMPORTANCE` for the parent<->child lifetime channel
   (§3.3) — genuinely novel supervision QoS, no other backend
   can do it
@@ -705,3 +815,7 @@ single best demo this backend has; lead with it.
   for `tractor.trionics` fan-out (explicitly not `MsgTransport`)
 - dual-link resiliency / multi-homing (#378's "hybrid dual link")
   once bearers are scripted in the docs
+
+[#496]: https://github.com/goodboy/tractor/issues/496
+[#499]: https://github.com/goodboy/tractor/issues/499
+[#501]: https://github.com/goodboy/tractor/issues/501

ai/tpt-backends/02_quic_iroh_backend.md

@@ -3,6 +3,12 @@
 Tracks gh [#353]. Prereq reading:
 [`00_shared_backend_contract.md`](./00_shared_backend_contract.md).
 
+**External-fact rule**: every claim here about `iroh`, UniFFI,
+generated bindings, QUIC wire/security behavior, or multiaddr
+support is provisional until the step-0 API-truth pass records a
+source or probe. Tractor/Trio behavior read from this checkout is
+the only locally proven basis for the plan.
+
 **Thesis**: the value of `iroh` over "just QUIC" is
 `NodeId`-addressed, NAT-traversing, relay-fallback endpoints —
 i.e. a `tractor` actor tree that spans hosts *without* a
@@ -49,20 +55,22 @@ relitigate:
   **But**: build it first as the throwaway spike (§6 step 0) to
   de-risk the iroh API surface before writing the bridge.
 
-Version pinning: `iroh` moves fast and has had breaking
+Version pinning: treat API stability across `iroh` minors as an
-API renames across minors. Pin `iroh>=X.Y,<X.Y+1` in a `quic`
+**unverified external constraint** until step 0. Pin the version
-extra, and **write down the exact resolved version + the
+exercised by the spike to `iroh>=X.Y,<X.Y+1` in a `quic` extra,
-generated `iroh/_uniffi*` module layout** in the module
+and **write down the exact resolved version + generated
-docstring, because §2 depends on generated-code internals.
+`iroh/_uniffi*` module layout** in the module docstring, because
+§2 depends on generated-code internals.
 
 **Step 0 of implementation is an API-truth pass**: install the
-pinned `iroh`, `python -c "import iroh; help(iroh)"`, and record
+pinned `iroh`, inspect both its generated Python and loaded FFI
-in this doc's §1.1 the real names of: endpoint builder, secret
+symbols, and run the throwaway two-process spike. Record in
-key type, `connect`/`accept`, bi-stream open/accept, the
+§1.1 the real names and observed contracts. Every statement
-send/recv methods and their exact signatures/return types, and
+below about `iroh`, UniFFI, Rust callbacks, or generated symbols
-whether they're `async def`. Everything below uses *provisional*
+is a **step-0 hypothesis**, not a locally proven fact, unless it
-names and must be reconciled. Do not skip this; do not guess
+is copied into the completed API-truth table with a source or
-from memory.
+probe. Tractor and Trio behavior cited from this checkout is not
+subject to that qualifier.
 
 ### 1.1 API-truth table (fill in during step 0)
 
@@ -79,122 +87,120 @@ from memory.
 | send | `await send_stream.write_all(b)` | |
 | recv | `await recv_stream.read(n) -> bytes\|None` | |
 | half-close | `await send_stream.finish()` | |
+| endpoint close + completion | `close()` / `await closed()` | |
+| resolved node address | relay URL + direct socket addrs | |
+| future start/poll callback ABI | generated symbols + args | |
+| future cancel/complete/free | generated symbols + ordering | |
+| callback quiescence guarantee | after poll/complete/free? | |
+| cancellation terminal poll code | generated enum/value | |
+| iroh exception/status taxonomy | per operation | |
 
 ---
 
 ## 2. The `trio`-native uniffi future bridge (`tractor/ipc/_uniffi_trio.py`)
 
-### 2.1 what uniffi actually generates
+### 2.1 Step-0 generated-ABI gate
 
-`uniffi`'s async support does not use asyncio *semantically* —
+The expected generated shape is: start an opaque Rust future,
-it uses asyncio only as the *executor* for a poll loop. The
+poll it with a C callback, cancel through a generated cancel
-generated python for an `async fn` is, in shape:
+symbol, consume its terminal value/status through `complete`,
+then call `free`. The expected callback may arrive on a foreign
+Rust thread. **All of that is external and provisional.** Step 0
+must identify the exact generated driver and prove, from its
+template/source plus probes:
 
-1. call `_uniffi_..._<method>(...)` → returns an opaque
+1. the start, poll, cancel, complete, and free signatures for
-   `RustFuture` handle (a `void*`/`u64`).
+   every return-type family used by `iroh`;
-2. loop: call
+2. poll result values and whether callbacks can be synchronous,
-   `ffi_..._rust_future_poll_<T>(handle, callback, callback_data)`.
+   concurrent, repeated, or late;
-   The callback is a C-ABI fn pointer invoked **from an
+3. which terminal state permits `complete`, when `free` is
-   arbitrary rust thread** with a poll-result code
+   legal, and when no callback can still reference Python;
-   (`READY`/`MAYBE_READY`).
+4. whether generated callback-data and call-status objects must
-3. the generated glue's callback resolves an
+   remain alive, and how generated lifting/errors are applied;
-   `asyncio.Future` via `loop.call_soon_threadsafe(...)`; the
+5. whether one narrow generated async-driver entrypoint can be
-   coroutine awaits it, then re-polls.
+   replaced without importing or requiring an asyncio loop.
-4. on ready: `ffi_..._rust_future_complete_<T>(handle,
-   &call_status)` → the value; then
-   `ffi_..._rust_future_free_<T>(handle)`.
 
-**The asyncio dependency is confined to step 3.** That is the
+Do not implement from a remembered UniFFI version. If cancel
-whole insight: the bridge is ~40 lines.
+does not have a documented path to a terminal, safely freeable
+state, the native Trio bridge fails the spike gate and the first
+backend uses the infected-asyncio fallback.
 
-### 2.2 the trio version
+### 2.2 Cancellation-safe ownership
 
-```python
+Do not let the caller task own a raw handle across an `await`.
-async def await_rust_future(
+Introduce an actor-scoped `UniffiFutureSupervisor` running in the
-    poll: Callable,      # ffi_..._rust_future_poll_<T>
+dedicated transport nursery specified in §3.2.1. That nursery
-    complete: Callable,  # ffi_..._rust_future_complete_<T>
+must span parent bootstrap, the service nurseries, and final
-    free: Callable,      # ffi_..._rust_future_free_<T>
+deregistration. For each call, its operation task owns the
-    handle: int,
+**entire** generated lifecycle:
-    lift: Callable[[Any], Any],
-) -> Any:
-    '''
-    Drive a `uniffi` rust-future to completion on the current
-    `trio` task, bridging rust-thread wakeups via
-    `TrioToken.run_sync_soon()`.
 
-    '''
+```text
-    token = trio.lowlevel.current_trio_token()
+create handle -> poll/callback loop -> complete -> lift/status
-    while True:
+              -> free -> publish result
-        wake = trio.Event()
+                 ^
-        # NOTE, invoked from a *rust* thread!
+                 cancel request uses generated cancel, then follows
-        def _cb(_data, poll_code):
+                 the verified terminal poll/complete/free protocol
-            token.run_sync_soon(wake.set)
-
-        cb = _UNIFFI_FUTURE_CALLBACK(_cb)   # keep a strong ref!
-        poll(handle, cb, 0)
-        await wake.wait()
-        if <poll_code was READY>:
-            break
-    try:
-        status = _UniffiRustCallStatus.default()
-        res = complete(handle, status)
-        _uniffi_check_call_status(status)   # reuse generated helper
-        return lift(res)
-    finally:
-        free(handle)
 ```
 
-Critical details, each a real bug if missed:
+The operation task, not the awaiting caller, creates the handle.
+Creation and insertion in the supervisor's live-operation set
+must have no cancellation checkpoint between them. The operation
+retains strong references to the C callback trampoline, callback
+data, wake state, call status, and handle until step 0 proves all
+callbacks are quiescent and `free` has returned. Use one stable
+callback per operation unless the verified ABI requires a fresh
+one per poll; in either case, retain every potentially callable
+trampoline. Capture `current_trio_token()` in the Trio owner and
+schedule the wake into Trio with `token.run_sync_soon(...)`; the
+foreign callback only stores its poll result and schedules that
+wake.
 
-- **`token.run_sync_soon()` is the only trio API callable from a
+Caller cancellation is a request, not handle ownership transfer:
-  foreign thread**, and it is documented as such. Use it; do
+
-  *not* use `trio.from_thread.run_sync` (requires a trio thread
+1. the caller sends an idempotent cancel request and waits under
-  context) and do not touch the `Event` directly from the
+   a short shield for the operation to acknowledge it;
-  callback.
+2. the owner invokes the generated cancel function exactly once
-- **the poll code must reach the trio side.** Capture it in a
+   and continues the **verified** poll/complete/free sequence;
-  `nonlocal`/1-slot list written by the callback *before*
+3. once caller cancellation is observed, cleanup completion never
-  `run_sync_soon`, since the callback owns the value. Handle
+   wins the race by returning a value. After acknowledgement the
-  `MAYBE_READY` by re-polling (the loop above does).
+   caller continues propagating its original Trio cancellation;
-- **keep the `ctypes` callback object alive** across the await —
+   if cleanup outlives the grace period it first abandons its
-  a GC'd `CFUNCTYPE` trampoline is a segfault. Bind it to a
+   result channel while the actor supervisor keeps ownership;
-  local *and* make sure the local outlives the `poll()` call
+4. actor endpoint teardown stops accepting new calls, requests
-  window.
+   cancellation of all live operations, and joins the supervisor
-- **cancellation.** `await wake.wait()` is a trio checkpoint, so
+   before destroying endpoint/key state.
-  a `Cancelled` can fire while rust still owns the future. On
+
-  cancel we must still `free(handle)` — and per uniffi, the
+There is deliberately no `move_on_after(...): free(handle)`
-  correct sequence is to call the generated
+path. A timeout proves only that cleanup is slow; it does not
-  `ffi_..._rust_future_cancel_<T>(handle)` then continue
+prove that callbacks are quiescent or that `free` is legal. A
-  polling to completion before `free`. Wrap the whole thing so
+wedged operation therefore remains visible in the supervisor and
-  the cancel path does:
+can delay graceful actor shutdown; process-level termination is
-  `with trio.CancelScope(shield=True): cancel(handle); <drain
+the final escalation, not an unsafe FFI free.
-  poll loop>; free(handle)`. **Bounded** shield (add a
+
-  `trio.move_on_after()` with a module-level constant) so a
+Structured-concurrency race to test: caller cancellation may land
-  wedged rust future can't make an actor un-cancellable —
+after handle creation, after each poll, during callback delivery,
-  `tractor` is SC-first and an unbounded shield here would
+after terminal readiness, during `complete`, and before result
-  violate that.
+publication. At every checkpoint exactly one operation task owns
-- **`trio.lowlevel.current_trio_token()`** must be captured on
+the handle, exactly one `free` is possible, and the supervisor
-  the trio side (not in the callback).
+cannot exit while that task or a callable trampoline remains.
 
 ### 2.3 how to apply it to the generated bindings
 
-Do **not** fork/vendor the generated `iroh` python. Instead ship
+Do **not** fork/vendor the generated `iroh` Python. Subject to the
-a *narrow* re-dispatch shim:
+step-0 gate, ship a *narrow* re-dispatch shim:
 
-- write `tractor/ipc/_uniffi_trio.py` with `await_rust_future()`
+- write `tractor/ipc/_uniffi_trio.py` with the supervisor and a
-  plus a `@cm patch_uniffi_for_trio()` that monkey-patches the
+  `@cm patch_uniffi_for_trio()` that patches only the generated
-  generated module's single async-driver entrypoint (in current
+  async-driver entrypoint recorded in §1.1;
-  uniffi that's `_uniffi_rust_call_async` / `_rust_call_async`,
-  one function) to the trio implementation.
 - verify at import time that the expected symbol exists and
   raise a clear, actionable error naming the pinned `iroh`
   version if not. A silent fallback to asyncio would be a
   nightmare to debug.
-- **plan for this to break on `iroh`/`uniffi` upgrades.** Mitigate
+- treat every `iroh`/UniFFI upgrade as requiring the step-0 ABI
-  with (a) a unit test that drives one trivial `iroh` async call
+  gate again. Keep a test that drives one trivial call under bare
-  under bare `trio.run()` and asserts no event loop was ever
+  `trio.run()`, asserts no asyncio loop, and injects cancellation
-  created (`asyncio.get_event_loop_policy()` untouched /
+  at every lifecycle checkpoint. Point the module docstring at
-  `asyncio._get_running_loop() is None`), and (b) a docstring
+  the exact generated template/revision mirrored by the shim.
-  pointing at the uniffi codegen template this mirrors.
 
 If step 0 reveals the generated code is *structurally* hostile
 to this (e.g. `asyncio` imported and used at module scope for
@@ -228,18 +234,52 @@ iroh bi-stream     ==  one `Channel`/`MsgTransport`  -> 1:1
 - `layer_key: int = 4` still (QUIC is L4-ish); note in a comment
   that this backend is really 4+security+multiplex.
 
-**Connection pooling** is the one place we add state the other
+**Connection pooling** is actor-endpoint state, never module
-backends don't have: dialing the same peer twice should reuse
+state. Its key is exactly
-the `Connection` and open a second bi-stream. Implement as a
+`(local_endpoint_identity, remote_node_id, alpn)`, where local
-module-level `dict[NodeId, Connection]` guarded by a
+endpoint identity is the local NodeId derived from the actor key.
-`trio.Lock`... **no** — that's a per-process cache with
+Remote NodeId alone would incorrectly share connections across
-lifetime/teardown hazards. Instead reuse the codebase's existing
+local keys or protocol epochs. Build it over the codebase's
-idiom: `tractor.trionics.maybe_open_context()` keyed on the
+`maybe_open_context()` idiom only after a concurrency review of
-node-id, which already solves exactly this (one-cached-resource-
+its actual last-user teardown behavior in the implementation
-per-key, refcounted, teardown-on-last-exit) and whose teardown
+revision. Do not assume an issue reference proves the required
-semantics were just hardened (gh #488). Use it; do not hand-roll
+ordering.
-a cache. Anything concurrency-subtle here should get the
+
-`conc-anal` skill run over it.
+`acquire_connection()` returns a `ConnectionLease`, not a bare
+connection. An outgoing `QuicMsgStream` owns that entered lease
+for its whole lifetime; `connect_to()` must not exit the cached
+context immediately after `open_bi()`. Exact transfer paths:
+
+- dial/acquire or `open_bi()` failure releases the lease in a
+  shielded `finally` before raising;
+- successful stream construction atomically transfers the lease
+  to `QuicMsgStream` before the first cancellation checkpoint;
+- `send_eof()` closes only the send half and does not release;
+- clean receive EOF closes only the receive half and does not
+  release while the send half remains usable;
+- one guarded terminal-state transition releases exactly once
+  when both halves have become terminal, in either order;
+- `aclose()`, reset, or terminal connection failure closes both
+  halves as applicable and idempotently releases exactly once;
+- a stream queued by `QuicListener` already owns its lease; if
+  never accepted, listener draining closes it and releases it.
+
+After `accept()` returns, the server dispatch path owns the stream
+until a handler task starts and must close it if task start fails.
+The handler then takes ownership, with an outer `finally` that
+calls `stream.aclose()` on normal return, handshake failure, and
+cancellation. Lease release itself is an idempotent pool state
+transition; if last-user connection teardown awaits FFI, the actor
+endpoint's pool supervisor owns that await so cancellation of the
+handler cannot strand the lease.
+
+For inbound connections, the connection-feeder owns a base lease
+while accepting streams and each queued/returned stream gets a
+child lease. The base lease is released only after the accept
+loop ends; the pool closes the connection after the base and all
+stream leases are gone. Reject or deterministically reconcile a
+simultaneous inbound/outbound duplicate for the same full key;
+record the chosen iroh-compatible rule during step 0.
 
 ### 3.2 `IrohAddress`
 
@@ -248,29 +288,29 @@ class IrohAddress(
     msgspec.Struct,
     frozen=True,
 ):
-    _node_id: str                 # 32B ed25519 pubkey, hex or z32
+    _node_id: str
-    _alpn: str = 'tractor/0'      # the bindspace!
+    _alpn: str
-    # optional dial hints; NOT part of identity
+    _relay_url: str|None
-    maybe_relay_url: str|None = None
+    _direct_addrs: tuple[str, ...]
-    maybe_direct_addrs: tuple[str, ...] = ()
 
-    proto_key: ClassVar[str] = 'iroh'   # ?or 'quic'; see §3.2.1
+    proto_key: ClassVar[str] = 'quic'
-    unwrapped_type: ClassVar[type] = tuple[str, str]
+    unwrapped_type: ClassVar[type] = tuple
     def_bindspace: ClassVar[str] = 'tractor/0'
 ```
 
-- **`.unwrap() -> (node_id_str, alpn_str)`** — a `(str, str)`
+- **`.unwrap()` is the complete, tagged wire descriptor**:
-  tuple, which is *unambiguously distinct* from
+  `('quic', node_id, alpn, relay_url, direct_addrs)`. All values
-  `TCPAddress`'s `(str, int)`. But careful:
+  are msgpack-native and `direct_addrs` is canonicalized to a
-  `wrap_address()`'s UDS case is
+  tuple. `from_addr()` requires that exact tag and shape; never
-  `case (_, filename) if type(filename) is str` — which
+  infer QUIC from a `(str, str)` pair. This depends on the shared
-  **already catches `(str, str)`**. So the iroh `case` MUST be
+  contract's tagged-address migration and removes the UDS
-  ordered *before* the UDS case and guarded, e.g.
+  collision rather than ordering around it.
-  `case (str() as nid, str() as alpn) if _is_node_id(nid):`
+- The descriptor always carries NodeId, ALPN, and both route-hint
-  with `_is_node_id()` a cheap length+alphabet check. Add a
+  fields. For this discovery-free first backend, `.is_valid`
-  regression test asserting a UDS `(dir, filename)` pair still
+  requires a parseable NodeId, non-empty ALPN, and at least one
-  wraps to `UDSAddress` — this is the exact "wrong transport
+  relay URL or direct address. Whether NodeId-only dialing works
-  loaded" hazard `_addr.py:214` warns about.
+  through optional iroh discovery is a step-0 API check and is
+  not part of the first implementation.
 - `.bindspace` → `self._alpn`. This is the honest analogue:
   the ALPN is the set of endpoints willing to talk to you, and
   two `tractor` deployments sharing an iroh network are
@@ -278,39 +318,80 @@ class IrohAddress(
   separated by directory. Include a `tractor` version/proto
   epoch in the default ALPN so incompatible runtimes can't
   handshake.
-- `.is_valid` → node-id parses, alpn non-empty.
-- **`get_root()` is the hard one.** There is no
-  well-known-port analogue: an iroh node id is a *keypair*, so
-  "the host's default registrar addr" requires a *persisted
-  secret key*. Design:
-  - the root/registrar's secret key lives at
-    `get_rt_dir() / 'iroh_registrar.key'` (0600), created on
-    first use.
-  - `get_root()` must stay **pure and import-time-safe**
-    (contract §2.3: `_default_lo_addrs` is built at import!).
-    So `get_root()` *reads* the key file if present and
-    otherwise returns an `IrohAddress` with
-    `_node_id=''`/sentinel, and the **generation** happens in
-    an explicit sibling — `ensure_registrar_key() ->
-    IrohAddress` — called from the listen path. Pure getter,
-    explicit setter; do not smuggle key generation into
-    `get_root()`.
-  - this almost certainly means `_default_lo_addrs` must become
-    lazy for this backend. **Land that refactor as its own prep
-    commit** (a `default_lo_addrs()` that computes per-call
-    instead of the import-time dict) — it also unblocks plan
-    03's netns-scoped defaults.
-- `get_random()`: generate a fresh `SecretKey` per subactor and
-  return its node-id. Note this runs post-fork pre-listen
-  (contract §4) and costs an ed25519 keygen (~µs, fine). The
-  *secret* can't live in a frozen `Address`, so it must be
-  stashed where the listen path can find it: a module-level
-  `dict[node_id, SecretKey]` populated by `get_random()` and
-  consumed+popped by `start_listener()`. Ugly but honest;
-  document it and note the alternative (thread the key through
-  `Endpoint`) as a follow-up.
 
-#### 3.2.1 `proto_key`: `'iroh'` vs `'quic'`
+### 3.2.1 One actor endpoint and key
+
+Add an actor-scoped `QuicActorEndpoint` resource containing the
+secret key, one bound iroh endpoint, the UniFFI supervisor, the
+connection pool, and its latest resolved `IrohAddress`. It cannot
+live in `_service_tn`: a child dials its parent before that nursery
+opens, while final deregistration may dial after it closes.
+
+Add a dedicated `transport_tn` around the complete actor runtime:
+the task that opens this nursery must start the complete
+`async_main` sequence as a **child** of it and wait for that child.
+That makes `transport_tn` an ancestor of every parent-dial,
+service, and deregistration caller, satisfying
+`maybe_open_context(tn=transport_tn)` rather than asking the
+nursery-opening task to use its own child nursery. The child keeps
+the nursery around `_root_tn` and `_service_tn`, performs final
+deregistration while it remains open, then returns so the owner can
+close the transport resource and nursery. Root startup needs the
+equivalent outer owner around actor construction, service, and
+teardown. If this shape cannot be preserved, the connection pool
+must stop depending on `maybe_open_context()`'s ancestor-nursery
+contract. No path creates a second endpoint for the actor.
+
+The child currently receives transport configuration only in the
+`SpawnSpec` sent over its already-open parent channel. QUIC cannot
+derive its local key, ALPN, or requested bind policy from that late
+message. Add a small msgpack/pickle-native
+`ChildTransportBootstrap` to every process-launch path. It carries
+the selected protocol and the QUIC-local key reference/generation
+policy, ALPN, relay policy, and requested bind constraints. It is
+available before `_from_parent()`; the later `SpawnSpec` repeats
+the public configuration and startup rejects any mismatch. Root
+actors derive the same bootstrap record directly from
+`open_root_actor()` inputs before address selection.
+
+With that prep in place, the order is:
+
+1. consume the launch-time bootstrap record, select one key
+   (persisted and explicitly provisioned for a registrar, fresh
+   for an ordinary actor), and construct/bind the endpoint in the
+   transport owner task;
+2. await the step-0-verified address-ready API and build a valid
+   descriptor from the endpoint's NodeId, ALPN, relay URL, and
+   direct addresses;
+3. only then dial `_from_parent()` through this endpoint;
+4. start `QuicListener` over this endpoint's accept API;
+5. publish the resolved descriptor as `Endpoint.addr` and
+   `Actor.accept_addrs` before parent/registrar registration;
+6. after service nurseries close, keep the endpoint available for
+   deregistration; then close listeners and streams, drain
+   connection leases and FFI operations, close/join the endpoint,
+   and release key state.
+
+`IrohAddress.get_random()` is therefore a descriptor lookup on
+the active actor transport resource, not key generation. Broaden
+the shared `get_random()` contract for resource-backed transports
+and make root/subactor address selection consume the bootstrap
+resource instead of calling it before that resource exists. Do not
+hide a secret in a module-level side table. Calls without an active
+resource fail clearly rather than allocating an unowned key.
+
+`get_root()` never returns an empty/sentinel NodeId. Make default
+addresses lazy, and have QUIC load a provisioned public registrar
+descriptor. Registrar provisioning writes its secret separately
+with mode 0600 and writes the matching complete public descriptor
+atomically; endpoint startup verifies the derived NodeId. If no
+descriptor exists, default QUIC registrar discovery fails with an
+actionable configuration error. Automatic first-process election
+is deferred until a safe key-file locking and endpoint-binding
+protocol is proven; key generation never occurs in the listen
+path.
+
+#### 3.2.2 `proto_key`: `'iroh'` vs `'quic'`
 
 Use **`'quic'`** for the `proto_key`/`--tpt-proto` name and
 name the module `_quic.py`, with `iroh` as the *implementation*.
@@ -357,7 +438,7 @@ class QuicMsgStream(trio.abc.HalfCloseableStream):
     '''
     tpt_key: ClassVar[MsgTransportKey] = ('msgpack', 'quic')
 
-    def __init__(self, conn, send, recv) -> None: ...
+    def __init__(self, conn, send, recv, lease) -> None: ...
     async def send_all(self, data: bytes) -> None: ...
     async def wait_send_all_might_not_block(self) -> None: ...
     async def receive_some(self, max_bytes: int|None = None) -> bytes: ...
@@ -379,17 +460,38 @@ already exists in `_transport.py` and must keep working):
   absent, so the `raise_on_report` branch at
   `_transport.py:290` stays quiet).
 - `send_all()` on a closed peer → `trio.BrokenResourceError`.
-- honour `trio`'s one-task-per-direction rule: guard with
+- honour Trio's one-task-per-direction rule with public,
-  `trio._util.ConflictDetector` equivalents (or just document +
+  implementation-local guards that raise
-  assert), because `MsgpackTransport` already serializes sends
+  `trio.BusyResourceError`; do not depend on `trio._util`.
-  with a `StrictFIFOLock` but recvs are single-task by
+  `MsgpackTransport` already serializes sends, while receives are
-  construction.
+  single-task by construction.
 - **buffering**: if iroh's `read()` doesn't support
   "read up to n", `receive_some()` must maintain an internal
   leftover buffer. Note `MsgpackTransport` wraps us in
   `tricycle.BufferedReceiveStream` anyway, so `receive_some()`
   just needs *some* nonzero-progress contract.
 
+Centralize exception translation at every iroh/UniFFI boundary;
+no generated exception may escape into `Channel` or server code.
+Step 0 must record actual exception classes/status payloads and
+build an exhaustive operation-specific mapping:
+
+| observed condition | adapter result |
+| --- | --- |
+| receive clean EOF | `b''` |
+| local stream/listener/endpoint already closed | `trio.ClosedResourceError` |
+| concurrent same-direction operation | `trio.BusyResourceError` |
+| peer reset, stopped stream, lost connection | `trio.BrokenResourceError` |
+| dial rejected or no usable route | `ConnectionRefusedError` or `ConnectionError` |
+| caller's Trio deadline/cancellation | preserve Trio cancellation semantics |
+| unexpected FFI status/panic | chained `RuntimeError` identifying operation and pinned version |
+
+Preserve the original exception as `__cause__`, but sanitize
+messages so `_transport.py` sees stable Trio/Tractor categories,
+not version-specific iroh text. Endpoint accept failure becomes a
+listener `BrokenResourceError`; normal endpoint shutdown becomes
+`ClosedResourceError`. Add one test per observed step-0 status.
+
 ```python
 class QuicListener(trio.abc.Listener):
     '''
@@ -402,41 +504,63 @@ class QuicListener(trio.abc.Listener):
     async def aclose(self) -> None: ...
 ```
 
-The accept-side subtlety: `trio.abc.Listener.accept()` yields
+The accept-side subtlety is fan-out: one actor transport accepts
-one stream per call, but iroh gives us *connections* which then
+connections and each connection accepts streams, while
-yield *streams*. So `QuicListener` needs an internal
+`Listener.accept()` returns one stream. Give **each** listener a
-`trio.MemoryReceiveChannel[QuicMsgStream]` fed by a background
+supervisor task started with
-task-pair (one task accepting connections, one per connection
+`await server_ep.listen_tn.start(...)`.
-accepting bi-streams). `trio.abc.Listener` has no nursery, so:
+That task creates and owns a cancel scope, a child nursery for the
-make the listener **constructed by an `@acm`** that owns the
+endpoint feeder plus per-connection feeders, a guarded stream
-nursery, and have `start_listener()` be that `@acm`'s driver.
+queue, and a completion event.
+`start_listener(addr=, server_ep=, actor_tpt=)` does not return
+until the supervisor has reported all of those ready.
+Do not borrow an implicit parent nursery or spawn feeders lazily
+from `accept()`.
 
-⚠️ this collides with `Endpoint.start_listener()` being a plain
+The queue is a guarded `deque`, not an unowned memory-channel
-`async def` returning a listener. Two options:
+buffer. A feeder transfers a fully constructed, lease-owning
-- **(a)** hang the nursery off the `Endpoint`'s existing
+stream into it only while the listener is open; if close wins the
-  `listen_tn` — `_serve_ipc_eps()` already creates `listen_tn`
+race, the feeder closes the stream itself. `accept()` atomically
-  and passes it into every `Endpoint` (`_server.py:1063-1074`),
+pops one item or waits on the queue condition. Once close is
-  and `Endpoint.listen_tn` is right there. So
+marked and the queue is empty, it raises
-  `start_listener()` can `self.listen_tn.start_soon(...)` the
+`trio.ClosedResourceError`.
-  acceptor tasks. **Recommended**: no upstream signature change,
-  correct lifetime (dies with the ep group), and it's why
-  `listen_tn` is on the struct in the first place.
-- (b) change `start_listener()` to a `@acm`. Bigger blast
-  radius; only if (a) proves insufficient.
 
-Since `start_listener()` is called via
+`QuicListener.aclose()` is idempotent and has this exact order:
-`inspect.getmodule(addr)` with only `addr=` (contract §1.3),
+
-option (a) needs the `Endpoint` itself. Either add `ep=` to the
+1. under the queue guard, mark closed and wake all `accept()`
-module-level `start_listener()` call signature (all backends
+   waiters without a checkpoint between the state change and
-ignore it except quic → small upstream change, do it as part of
+   notification;
-the prep PR and make it keyword-only with a default) or have
+2. cancel the listener-owned supervisor scope;
-`QuicListener.accept()` lazily spawn via
+3. the supervisor's shielded `finally` joins the endpoint and all
-`trio.lowlevel.current_task().parent_nursery` (**rejected** —
+   connection feeders, atomically detaches the queue, closes every
-fragile, implicit). Do the explicit `ep=` kwarg.
+   queued stream, releases their leases, and closes the queue;
+4. only after that finalizer finishes, the supervisor sets its
+   completion event;
+5. `aclose()` waits under a shield for that event and returns;
+   concurrent closers wait for the same event.
+
+The same supervisor finalizer runs if its parent nursery is
+cancelled before someone calls `aclose()`. This makes the
+supervisor, not an arbitrarily cancelled caller, the sole final
+cleanup owner. Test cancellation at feeder accept, stream
+construction, queue transfer, `accept()` wakeup, and each close
+checkpoint; no feeder may outlive the listener and no queued
+lease may survive completion.
+
+This needs two explicit, typed references in the module-level
+listener call: `server_ep=` is the IPC server `Endpoint` that owns
+`listen_tn`, while `actor_tpt=` is the already-open
+`QuicActorEndpoint` whose iroh accept API supplies connections.
+Store `actor_tpt` on the server endpoint during actor transport
+bootstrap and pass both keyword-only arguments; socket backends
+ignore `actor_tpt`. `Endpoint.start_listener()` then stores the
+listener's already-resolved address instead of calling
+`getsockname()`.
 
 ### 3.4 `maddr`
 
-Multiaddr already standardizes the pieces:
+Expected multiaddr spellings for direct QUIC and relay routes are
+**step-0 verification items**, not assumptions:
 
 ```
 /ip4/<h>/udp/<p>/quic-v1                     # direct
@@ -444,19 +568,16 @@ Multiaddr already standardizes the pieces:
 /dns/<relay-host>/tcp/443/tls/ws/p2p/<node>  # relay-ish
 ```
 
-- primary form: `/p2p/<node-id>` alone is a legal maddr and is
+- Do not emit NodeId alone in the first backend: without enabled
-  the *only* required component for iroh dialling — relay +
+  discovery it would discard the route required by the complete
-  direct addrs are discovery hints. So `mk_maddr()` emits
+  `IrohAddress`. `mk_maddr()` must preserve NodeId, ALPN, relay
-  `/p2p/<node_id>` and, when known, prefixes the direct
+  URL, and all direct addresses, or return a canonical Tractor
-  `/ip4/../udp/../quic-v1/`.
+  string form that does until a multiaddr grammar can round-trip
-- `/p2p/` values are multihash-encoded peer ids; an iroh node-id
+  every field.
-  is a raw ed25519 key. Converting requires the identity
+- Verify whether an iroh NodeId can losslessly map to `/p2p/`.
-  multihash + libp2p key protobuf wrapper. **Decide**: emit the
+  If not, use a tractor-local `/iroh/<node-id>` segment rather
-  raw node-id under a *tractor-local* `/iroh/<node-id>` segment
+  than pretending to be a libp2p peer-id. This needs upstream
-  (needs upstream registration, same track as `wg`/`tipc`,
+  registration, on the same track as `wg`/`tipc` (gh #483).
-  gh #483) rather than pretending to be a libp2p peer-id we
-  can't round-trip. Return the `str` form until upstream lands
-  (`MsgTransport.maddr` is `Multiaddr|str`).
 - this backend is the strongest argument for gh #443's
   **tunnelled/composed maddr** item: `/ip4/../udp/../quic-v1/..`
   *is* a composed stack. Cross-reference plan 03 §5 so the two
@@ -466,24 +587,25 @@ Multiaddr already standardizes the pieces:
 
 ## 4. Discovery integration
 
-- iroh's node-id addressing means the `tractor` registrar can
+- The registrar stores the complete `IrohAddress`, not only a
-  hold `IrohAddress`es that are **reachable from anywhere** with
+  NodeId. Registration is forbidden until endpoint address
-  no port-forwarding — that is the headline feature. The
+  resolution has produced that descriptor. If route hints change
-  registrar itself works unchanged.
+  later, dynamic re-registration is a follow-up; the spike uses
-- iroh has its own discovery (DNS/pkarr/mdns). **Out of scope**;
+  the pre-registration snapshot.
-  note in the follow-up that `tractor.discovery` could
+- Optional iroh discovery mechanisms and their names/capabilities
-  eventually delegate to it, which would be the direct analogue
+  are step-0 verification items and out of scope for the first
-  of plan 01's TIPC-topology idea.
+  backend. No NodeId-only reachability claim is made.
-- relay servers: default to n0's public relays for the demo,
+- Relay configuration belongs to `QuicActorEndpoint` creation,
-  document self-hosting (docs.iroh.computer's dedicated-infra
+  not `start_listener()`, because dialing and listening reuse the
-  page is linked from #353), and make the relay set a
+  same endpoint. The demo's relay choice and self-hosted option
-  `start_listener()` kwarg.
+  are selected only after step 0 verifies the pinned API.
 
 ## 5. Security note
 
-QUIC is TLS-1.3-always and iroh authenticates by node-id, so
+The transport-security and NodeId-authentication properties of the
-this backend is the first `tractor` transport with real
+pinned iroh stack are **step-0 documentation-verification items**.
-transport security and peer authentication. Two things follow:
+Claim only the properties supported by that version's source and
+docs. Two design consequences remain:
 1. an **allowlist hook** — an actor should be able to reject
    inbound connections from unknown node-ids *before* the
    `Aid` handshake. Natural home: a predicate kwarg on
@@ -497,59 +619,72 @@ transport security and peer authentication. Two things follow:
 
 0. **spike (throwaway, not committed)**: drive iroh under
    `trio-asyncio`/`tractor.to_asyncio`, echo bytes over a
-   bi-stream between two procs. Fills in §1.1. Timebox it.
+   bi-stream between two processes. Fill §1.1 with generated ABI,
-1. prep PR: annotation widening + `rebind_from_sockname` gate +
+   endpoint resolution, close/join, and error observations. Probe
-   `transport_from_stream()` `tpt_key` dispatch + `ep=` kwarg on
+   cancel at every generated lifecycle phase. Timebox it and use
-   `start_listener()` + lazy `default_lo_addrs()`. **No new
+   the fallback if any mandatory ownership fact stays unknown.
-   backend.** Full suite green on tcp *and* uds.
+1. prep PR: tagged address migration, annotation widening,
-2. `_uniffi_trio.py` + its tests (drive one iroh async call
+   non-socket listener reconciliation, `tpt_key` dispatch,
-   under bare `trio.run()`; assert no asyncio loop; assert
+   typed `server_ep=`/`actor_tpt=` listener inputs, and lazy
-   cancellation frees the future).
+   default addresses. **No new backend.** Keep tcp and uds
-3. `QuicMsgStream` + tests against a *loopback* iroh endpoint
+   behavior unchanged.
-   pair in one process (no `tractor` runtime): send/recv, clean
+2. bootstrap prep: pass `ChildTransportBootstrap` through every
-   EOF → `b''`, reset → `BrokenResourceError`, use-after-close
+   process-launch path and add the transport nursery around child
-   → `ClosedResourceError`.
+   parent-dial, service, deregistration, and teardown. Resolve the
-4. `QuicListener` + `start_listener()` + `IrohAddress` +
+   endpoint address before registration. Add no iroh-specific
-   key-file mgmt.
+   global state.
-5. `MsgpackQuicStream(MsgpackTransport)` + `connect_to()` +
+3. `_uniffi_trio.py` supervisor + lifecycle fault-injection tests:
-   `maybe_open_context()` connection pooling.
+   no asyncio loop, one owner/complete/free, callback retention,
-6. registration tables + `--tpt-proto quic` + full suite.
+   bounded caller handoff, and joined durable cleanup.
-7. maddr + docs + a two-host example (pairs with #482's format).
+4. `QuicActorEndpoint` + provisioned registrar descriptor +
+   loopback direct-address tests; prove one endpoint handles dial,
+   listen, address lookup, and ordered teardown.
+5. `QuicMsgStream` + exhaustive error-normalization and lease
+   release tests against the loopback endpoint pair.
+6. `QuicListener` supervisor + cancellation-at-every-checkpoint
+   tests, including queued-stream draining and feeder joins.
+7. `MsgpackQuicStream`, full-key connection pooling, registration
+   tables, and `--tpt-proto quic`; then run the full suite.
+8. routable maddr/string form + docs + a two-host example (pairs
+   with #482's format).
 
 ## 7. Testing
 
 - capability predicate `is_quic_available()` → `iroh` importable
-  *and* the uniffi driver symbol present at the pinned version.
+  *and* every step-0-recorded driver symbol present at the pinned
-  Same `pytest.fail`-early hook as plan 01 §7.2.
+  version. Same `pytest.fail`-early hook as plan 01 §7.2.
 - **the acceptance bar is the same**: whole suite green under
   `--tpt-proto quic`. Expect this to shake out real bugs in the
   adapters (esp. teardown ordering and `TransportClosed`
   classification) — that's the point.
-- expect to need **timeout headroom**: iroh endpoint bind +
+- Measure endpoint bind and first-connect latency in step 0; do
-  first connect (relay discovery) is orders of magnitude slower
+  not assume a multiplier. Before changing a deadline, rule out
-  than a UDS bind. Before touching any test deadline, rule out
+  the project's CPU-throttle false-positive, then prefer one
-  the CPU-throttle false-positive (see the project's
+  per-proto harness multiplier over individual-test edits.
-  `env_cpu_throttle_masquerades_as_regression` note); then, if
+- Use the step-0-verified relay-disable configuration with direct
-  real, add a per-proto timeout multiplier to the test harness
+  loopback addresses for default CI. Mark separately verified
-  rather than editing individual tests.
+  relay tests `pytest.mark.net` and keep them out of default CI.
-- a no-network test mode: iroh with relays disabled +
+- leak checks: assert the actor has one key/endpoint, every FFI
-  loopback direct addrs only, so CI doesn't depend on n0's
+  operation completed/freed once, all listener feeders joined,
-  infra. **Make this the default in CI**; mark the relay tests
+  all queued streams closed, every connection lease released,
-  `pytest.mark.net` and keep them out of the default run.
+  and endpoint close completion observed before actor teardown.
-- leak checks: assert every `SecretKey`/`Endpoint` is closed on
+- address-ordering check: block registration until a descriptor
-  actor teardown (an `Endpoint` left open holds UDP sockets and
+  with NodeId, ALPN, and at least one route is published; reject
-  relay connections; a leak here shows up as hung tests, not
+  sentinel, NodeId-only, and post-registration mutation cases.
-  errors).
 
 ## 8. Risks
 
 | risk | mitigation |
 | --- | --- |
 | uniffi codegen internals shift on upgrade | pinned minor, symbol assertion at import, the "no asyncio loop" test, documented fallback to `to_asyncio` |
-| rust-thread callback → trio wakeup mishandled (segfault / lost wakeup / un-cancellable task) | strong ref on the ctypes trampoline; `run_sync_soon` only; **bounded** shielded cancel-drain; run the `conc-anal` skill over the bridge |
+| callback wakeup/lifetime semantics differ from the hypothesis | step-0 source + probe gate; retain callback/data through verified quiescence; durable owner; never timeout-free |
+| cancelled foreign future never reaches a freeable state | bounded caller handoff to visible actor supervisor; joined graceful shutdown or process-level escalation; never speculative free |
 | `iroh` wheel availability for 3.13/3.14 on linux+macos | verify in step 0; if missing, that alone may force the `aioquic` fallback |
-| QUIC latency/jitter destabilizes the existing suite's timing assumptions | per-proto timeout multiplier, relay-less CI mode |
+| endpoint or route resolution is not ready before parent dial/registration | actor endpoint bootstrap barrier; publish only a complete resolved descriptor |
-| `(str, str)` unwrapped form collides with UDS in `wrap_address()` | guarded case ordered first + explicit regression test (§3.2) |
+| connection closes while a stream still uses it | full-key pool + stream-held leases + exact-once release tests |
+| listener close strands feeder tasks or queued streams | listener-owned scope/completion event; cancel, join, drain, then return |
+| QUIC latency/jitter destabilizes suite timing assumptions | measure first; per-proto multiplier only if demonstrated; relay-less CI mode |
+| address tuple collides with another backend | required `'quic'` tag and exact-shape dispatch |
 | scope creep into iroh's docs/blobs/gossip crates | this backend is `Endpoint`+`Connection`+bi-streams only; anything else is a separate issue |
 
 ## 9. Follow-up issue seeds

ai/tpt-backends/03_wg_tunnel_bindspace.md

@@ -19,35 +19,35 @@ onto `trio` as the library's sans-io layer allows.
 
 ---
 
-## 1. What exists today (verified, per #482)
+## 1. What exists today (derived from #482)
 
 - `wrap_address()` accepts maddr `str`s (leading-`/` dispatch,
-  `_addr.py:262`) but `parse_maddr()` only knows
+  `_addr.py:262`). `parse_maddr()` and `mk_maddr()` support plain
-  `/ip4|ip6/<h>/tcp/<p>` and `/unix/<p>`; a `.../wg/u<key>`
+  TCP/UDS addresses plus nested, canonical bearer-first `/wg/`
-  maddr raises `ValueError('Unsupported multiaddr protocol
+  stacks represented locally as `TunnelledAddress` wrappers.
-  combo')`.
 - there is no `wg` proto in the multiaddr *spec* yet, but
   multiformats/py-multiaddr#108 (key form `u<base64url>`) is
   **merged** as of 2026-07-28 (`f86519da`) — and unreleased, the
   latest `0.2.0` predating it. Spec registration is still tracked
   by multiformats/py-multiaddr#107 and gh #483.
-- so **today's deployable story is declarative**: run `wg-quick`
+- **today's deployable story remains declarative**: run `wg-quick`
-  out-of-band, parse the maddr, strip to the overlay
+  out-of-band, parse the maddr, strip its wrapper to the overlay
-  `(host, port)`, verify the pubkey against the live tunnel,
+  `(host, port)`, verify the pubkey in its host-specific role,
   hand the overlay addr to `registry_addrs=`/`tpt_bind_addrs=`.
-  #482 already contains working example code for exactly this.
+  The repaired `examples/multihost/wg_lan/` implementation derives
+  from and supersedes #482's original example.
 - `Address.namespace` exists in the Protocol
   (`_addr.py:94-101`, "the if-available OS-specific network
-  namespace key") and **no backend implements it**. This plan is
+  namespace key"). `TunnelledAddress` implements it from its spec;
-  its first consumer.
+  no concrete transport backend implements it yet.
 
 ## 2. Three layers, three PRs
 
 | layer | what | dep | ships |
 | --- | --- | --- | --- |
-| **A. declarative** | commit #482's examples; `parse_maddr()` learns `/wg/u<key>` → overlay `Address` + verified pubkey | `multiaddr` (already), `wg(8)` CLI | first |
+| **A. declarative** | land repaired examples derived from #482; `parse_maddr()` learns `/wg/u<key>` → `TunnelledAddress` wrappers carrying overlay `Address` values and declared WG pubkeys | `multiaddr`, `py-multibase`, `wg(8)` CLI | first |
-| **B. `pyroute2` read/verify** | replace the `subprocess.run(['sudo','wg','show'])` shelling with netlink queries | `pyroute2` extra | second |
+| **B. `pyroute2` read/verify** | replace the example-local, role-aware async `wg(8)` verification probe with netlink queries | `pyroute2` extra | second |
-| **C. `@acm` lifecycle** | create/configure/tear down wg ifaces + netns *from the runtime*, as nested bindspaces; implement `Address.namespace` | `pyroute2` + `CAP_NET_ADMIN` | third |
+| **C. `@acm` lifecycle** | create/configure/tear down wg ifaces + netns *from the runtime*, consume `Address.namespace` for nested bindspaces, and implement explicit `None` on concrete transports | `pyroute2` + `CAP_NET_ADMIN` + `CAP_SYS_ADMIN` or a userns/helper equivalent | third |
 
 Each is independently valuable and independently reviewable.
 **Do not attempt C first** — the interesting design (nested
@@ -73,28 +73,24 @@ does not create a new address type.** Two candidate encodings;
       overlay: Address         # e.g. TCPAddress
       tunnel: WGTunnelSpec     # proto-specific, frozen
   ```
-  with `.proto_key` **delegating to `overlay.proto_key`** so every
+  with `.proto_key`, `.bindspace`, and `.unwrap()` delegating to
-  existing table lookup (`_addr_to_transport`,
+  the overlay so transport guards retain their existing meaning
-  `enable_transports` guard at `_root.py:391`,
+  and **nothing new crosses the wire**. `.namespace` derives from
-  `transport_from_addr()`) keeps working untouched, and
+  the tunnel spec. Exact-type dispatch through
-  `.unwrap()` delegating to `overlay.unwrap()` so **nothing new
+  `_addr_to_transport`/`transport_from_addr()` still requires the
-  crosses the wire**. `.namespace` and `.bindspace` come from
+  wrapper to be stripped (`→ .overlay`) at bind/connect time.
-  the tunnel spec. The wrapper is stripped (`→ .overlay`) at the
+  - ⚠️ `is_wrapped_addr()` explicitly recognizes
-  moment of bind/connect.
+    `TunnelledAddress` even though the wrapper is deliberately not
-  - ⚠️ `is_wrapped_addr()` (`_addr.py:194`) tests
+    in `_address_types`: it has no `MsgTransport` of its own and
-    `type(addr) in _address_types.values()` — a `bidict` of
+    therefore gets no build-registered proto-key entry.
-    proto_key→type. `TunnelledAddress` isn't in it and must not
-    be (it's not 1:1 with a proto). So either add an explicit
-    `isinstance(addr, TunnelledAddress)` clause there, or give
-    the wrapper a marker and test structurally. Do the former;
-    it's two lines and honest.
   - the reflection in `Endpoint.start_listener()`
     (`inspect.getmodule(self.addr)`) would resolve to the
     *wrapper's* module, not the transport's. **So the wrapper
     must be unwrapped before it reaches `Endpoint`** — i.e. by
-    the bindspace `@acm` (layer C) or by `parse_maddr()`
+    the bindspace `@acm` (layer C) or explicitly via `.overlay`
-    (layer A). State this loudly in the docstring; it's the #1
+    or `strip_tunnels()` at each bind/dial boundary (layer A).
-    way to get this wrong.
+    State this loudly in the docstring; it's the #1 way to get
+    this wrong.
 - (b) add fields to each existing `Address` type. Rejected:
   duplicates tunnel logic per-backend and pollutes `.unwrap()`.
 
@@ -104,10 +100,10 @@ class WGTunnelSpec(
     frozen=True,
 ):
     peer_pubkey: str          # std-base64 `wg(8)` form
+    bearer: tuple[str, int]|None = None
     iface: str = 'wg0'
     netns: str|None = None
     # layer-C-only fields, unset in layer A
-    maybe_endpoint: tuple[str, int]|None = None
     maybe_allowed_ips: tuple[str, ...] = ()
 ```
 
@@ -123,7 +119,7 @@ that the key decodes to exactly 32 bytes, so a truncated key is a
 ```
 /ip4/192.168.1.50/udp/51820/wg/u<A_pub>/ip4/10.0.11.1/tcp/1616
 \_______ bearer __________/\__ key __/\______ overlay ______/
- underlay, wg `ListenPort`             the ONLY part we bind
+ underlay, wg `ListenPort`             the `MsgTransport` bind
 ```
 
 The `/wg/` segment is **infix, not suffix** — the segments
@@ -137,9 +133,8 @@ examples in gh #482) used a *suffix* form
 `/ip4/10.0.11.1/tcp/1616/wg/u<key>`. That parses, but it is
 semantically inverted: it puts the overlay addr where the bearer
 belongs, `tcp` where wg's `udp` `ListenPort` goes, and declares
-no overlay endpoint at all. `parse_wg_maddr()` in
+no overlay endpoint at all. `tractor.discovery.parse_wg_maddr()`
-`examples/multihost/wg_lan/` now rejects it with an actionable
+now rejects it with an actionable error.
-error.
 Observed protocol-name lists, for writing the `match`:
 
 | maddr | `[p.name for p in m.protocols()]` |
@@ -150,11 +145,11 @@ Observed protocol-name lists, for writing the `match`:
 - so the three parts have **three different owners**, and only the
   third is an `Endpoint`:
 
-  | part | bound by | in the runtime? |
+  | part | socket owner / provisioner | runtime role |
   | --- | --- | --- |
-  | bearer | kernel, via `wg-quick`/`pyroute2` | no |
+  | bearer | kernel-owned; externally provisioned in layer A, tractor bindspace-provisioned in layer C | control-plane metadata, never an `Endpoint` |
-  | `/wg/u<key>` | nothing — it's an identity | no, verified out-of-band |
+  | `/wg/u<key>` | nothing — it's an identity | parsed and explicitly verified |
-  | overlay | `tractor`'s `IPCServer` | **yes**, as `.overlay` |
+  | overlay | `tractor`'s `IPCServer` | application `MsgTransport`, as `.overlay` |
 
   This owner-split is the real axis of the design, *not* whether
   the maddr stack is "composed" (it is).
@@ -168,7 +163,7 @@ Observed protocol-name lists, for writing the `match`:
 
   | need | API |
   | --- | --- |
-  | isolate the bearer | `ma.decapsulate_code(P_WG)` |
+  | isolate the bearer | `ma.decapsulate_code(_wg_proto_code())` |
   | drop the overlay, keep bearer+key | `ma.decapsulate(overlay_ma)` |
   | per-seg maddrs | `ma.split()` |
   | rejoin a seg tail | `Multiaddr.join(*segs)` |
@@ -184,22 +179,18 @@ Observed protocol-name lists, for writing the `match`:
   silently returns the **first** match, i.e. the bearer's host.
   Always call it on a peeled sub-maddr, never the whole stack.
 
-- `parse_maddr()` gains a case on
+- keep the existing 2-proto cases byte-identical; add
-  `[('ip4'|'ip6'), 'udp', 'wg', ('ip4'|'ip6'), <overlay-l4>]` →
+  `case _ if 'wg' in proto_names:` after them.
-  peel w/ the API above, decode the multibase key to std-base64,
+- that case delegates to `parse_wg_maddr()`, which repeatedly
-  and return `TunnelledAddress(overlay=..., tunnel=WGTunnelSpec(
+  peels the last `/wg/`, decodes its key to std-base64, records
-  ...))` w/ the bearer recorded in the spec.
+  its bearer in `WGTunnelSpec`, and wraps the overlay in one
-- keep the existing 2-proto cases byte-identical; add the new
+  `TunnelledAddress` per segment.
-  case *after* them.
-- nesting (wg-in-wg) falls out of `.decapsulate_code()` cutting
-  at the *last* occurrence — peel repeatedly rather than
-  recursing through a bespoke splitter.
 - `mk_maddr()` inverse for `TunnelledAddress` is just
   `.encapsulate()` composition; don't rebuild `str`s by hand.
 - **pending an upstream release**: py-multiaddr#108 is merged, so
-  `Multiaddr('/…/wg/u…')` parses — but off a `[tool.uv.sources]`
+  `Multiaddr('/…/wg/u…')` parses off a PEP 621 direct-revision pin,
-  `rev` pin, since no release carries the codec. Gate the tests
+  since no release carries the codec. Gate parser entry on
-  on `_have_wg_maddr_proto()`, implemented as
+  `_wg_proto_code()`, implemented as
   `protocols.protocol_with_name('wg')` under
   `except ProtocolNotFoundError`. Do **not** probe by parsing a
   dummy like `Multiaddr('/wg/uAAAA')` — the codec enforces a
@@ -207,20 +198,33 @@ Observed protocol-name lists, for writing the `match`:
   **not** hand-roll a `wg` parser in `tractor` — the whole point
   of #429 was dropping the NIH parser.
 
-### 3.3 verification helper (pure, composable)
+### 3.3 pure parser helpers + explicit verification
 
-Port #482 §2's helpers into `tractor/discovery/_tunnel.py` as
+The parser/key-codec helpers live in
-*pure functions* + one impure probe, cleanly separated:
+`tractor/discovery/_tunnel.py`; the impure verifier remains
+example-local until layer B:
 
 ```python
-def parse_wg_maddr(maddr: str) -> TunnelledAddress: ...   # pure
+def parse_wg_maddr(maddr: str|Multiaddr) -> TunnelledAddress: ...
-def wg8_pubkey(multibase_key: str) -> str: ...            # pure
+def mb_pubkey(wg8_key: str) -> str: ...
-def verify_wg_peer(spec: WGTunnelSpec) -> bool: ...       # impure probe
+def wg8_pubkey(multibase_key: str) -> str: ...
+async def verify_wg_key(
+    addr: TunnelledAddress,
+    role: Literal['local', 'peer'],
+    iface: str|None = None,
+    timeout: float = 5,
+    inspection: str|None = None,
+) -> bool: ...  # example-local impure probe
 ```
 
-In layer A `verify_wg_peer()` may shell out (`wg show <if>
+In layer A `verify_wg_key()` may shell out to role-specific
-peers`), but it must be a *single* function so layer B swaps
+`wg show <if> public-key|peers` queries, but it must be a *single*
-only its body. Never call it implicitly from
+async, time-bounded function so it never blocks trio's run thread
+and layer B swaps only its body. It verifies key presence only,
+not `Endpoint`, `AllowedIPs`, handshake state, or routing. Never
+run `tractor` as root: privileged inspection stays a separate
+step whose public-key output can be passed as `inspection`. Never
+call it implicitly from
 `wrap_address()`/`parse_maddr()` — parsing must stay pure and
 side-effect-free; verification is the *caller's* explicit step
 (and later, the bindspace `@acm`'s).
@@ -281,7 +285,7 @@ Three integration options, in increasing trio-nativeness:
 - (3) reimplement the codecs. Never.
 
 **Recommended split**: ship (1) first so layer B is a small,
-reviewable, behaviour-preserving swap of `verify_wg_peer()`'s
+reviewable, behaviour-preserving swap of `verify_wg_key()`'s
 body; then land (2) as a follow-up commit for the read path
 (`wg get`, `link get`) where the sans-io surface is smallest,
 and keep (1) for the privileged mutating ops. Measure before
@@ -306,7 +310,7 @@ async def read_wg_peers(
 async def read_wg_pubkey(iface: str = 'wg0', ...) -> str: ...
 ```
 
-and `verify_wg_peer()` becomes a thin composition over the two.
+and `verify_wg_key()` becomes a thin composition over the two.
 Note the pure-getter rule: no `read_wg_peers(..., create=True)`.
 
 ---
@@ -319,40 +323,117 @@ data-structure which can easily be passed to nested `@acm`s
 which consecutively setup nested net bindspaces for binding the
 endpoint addrs"*.
 
+Layer C is where tractor takes ownership of bindspace orchestration.
+For a fully bootstrapped deployment it may create the netns and wg
+iface, configure peers/routes, and ask the kernel to establish the
+bearer's UDP `ListenPort` through netlink/`pyroute2`. "Kernel-owned"
+describes the data-plane socket, not who provisions it: tractor owns
+the lifecycle while `Endpoint`/`MsgTransport` remain responsible only
+for the overlay application socket.
+
 ### 5.1 the composition
 
+The maddr describes the composed network path and can be used as
+either a source/listen or destination/dial handle. It does **not**
+select the local instance of that network stack. A netns, VRF,
+interface, user namespace, or equivalent platform resource is
+orthogonal augmentation carried alongside/below the maddr.
+
+Keep two bindspace representations with deliberately different
+lifetimes:
+
 ```python
+class BindspaceSpec(msgspec.Struct, frozen=True):
+    '''Serializable spawn/config declaration.'''
+    kind: str                 # `netns`, later `vrf`, ...
+    key: str|None             # requested name/key, if any
+
+
+class BindspaceIdentity(msgspec.Struct, frozen=True):
+    '''Stable identity of the realized platform resource.'''
+    kind: str
+    key: str|None
+    inode: int|None           # Linux namespace identity
+
+
+class BindspaceHandle:
+    '''Scoped, non-serializable capability for one live bindspace.'''
+    spec: BindspaceSpec
+    identity: BindspaceIdentity
+    namespace_fd: int|None
+    ownership: Literal['owned', 'borrowed']
+
+
 @acm
 async def open_bindspace(
-    addr: TunnelledAddress,
+    spec: BindspaceSpec,
-) -> AsyncGenerator[Address, None]:
+    *,
+    role: Literal['listen', 'dial'],
+) -> AsyncGenerator[BindspaceHandle, None]:
     '''
-    Enter the net-bindspace implied by `addr`'s tunnel stack,
+    Provision/borrow one bindspace and yield its live capability.
-    yielding the *overlay* `Address` ready to bind/connect.
-
-    Nests: one `@acm` per tunnel segment, outermost-first, so
-    a 2-deep stack is just two nested `async with`s and the
-    teardown order is guaranteed by `trio`.
 
     '''
 ```
 
-with per-tunnel-kind implementations:
+The exact field set remains design work; the required split does not:
+`BindspaceSpec` crosses config/spawn serialization, while
+`BindspaceHandle` contains live OS resources (especially an open
+namespace FD), pins identity/lifetime, and must never cross msgpack.
+An FD is a stronger capability than a namespace name: it avoids
+name-resolution TOCTOU, survives rename/unlink, and identifies the
+exact namespace the parent provisioned.
+
+`open_bindspace()` is **not** an address factory and does not return a
+`TunnelledAddress`. At the declaration layer, listener allocation can
+use the handle to replace an overlay while preserving every tunnel:
+
+```python
+async with open_bindspace(
+    bindspace_spec,
+    role='listen',
+) as bindspace:
+    listen_decl = declared_addr.get_random(
+        bindspace=bindspace,
+    )
+    transport_addr = strip_tunnels(listen_decl)
+```
+
+That sketch intentionally leaves the `.get_random()`/bindspace value
+contract open. A concrete transport call returns a concrete overlay;
+a declaration-level call may replace the overlay and return a new
+`TunnelledAddress`. In either case wrappers remain until the final
+transport bind/dial boundary, where `strip_tunnels()` is mandatory.
+
+Per-platform provisioning still composes one resource context per
+tunnel/bindspace layer:
 
 ```python
 @acm
-async def open_netns(name: str) -> AsyncGenerator[None, None]: ...
+async def open_netns(
+    spec: BindspaceSpec,
+    role: Literal['listen', 'dial'],
+) -> AsyncGenerator[BindspaceHandle, None]: ...
+
 @acm
-async def open_wg_iface(spec: WGTunnelSpec) -> AsyncGenerator[WGTunnelSpec, None]: ...
+async def open_wg_iface(
+    spec: WGTunnelSpec,
+    bindspace: BindspaceHandle,
+    role: Literal['listen', 'dial'],
+) -> AsyncGenerator[WGTunnelSpec, None]: ...
 ```
 
 and a driver that folds a list of specs into nested contexts
 (`contextlib.AsyncExitStack` for the N-deep case). The
-`parse_endpoints()` API (`_multiaddr.py:153`) is the front door:
+`parse_endpoints()` API (`_multiaddr.py:189`) is the front door:
-it already returns `dict[name, list[Address]]` and the
+its `ParsedEndpoints` values already contain
-`multiaddr_declare_eps.md` sketch anticipates the recursive
+`Address|TunnelledAddress` declarations and preserve each tunnel
-`dict[str, list[Address]]|dict[...]` return for tunnelled
+stack for the eventual bindspace handler. It carries declarations;
-entries. Extend it to carry the tunnel stack, not to *enter* it.
+it does not *enter* their bindspaces.
+
+The caller supplies `role`; do not infer it from maddr shape. The same
+composed maddr can name a server source or client destination, and the
+required local provisioning/ownership differs (§5.3).
 
 ### 5.2 `Address.namespace`, at last
 
@@ -369,6 +450,13 @@ entries. Extend it to carry the tunnel stack, not to *enter* it.
   `Endpoint.pformat()`, `_server.py:645`). Fill that in; it's
   the cheapest possible proof the layer is wired.
 
+Use `github/ns_aware@e4688cad` as prototype evidence, not code to
+cherry-pick unchanged. Its `/proc/<pid>/ns/<type>` inode reader and
+`ip netns identify` probe establish the useful `(key, inode)` identity
+pair. Layer C should move that shape into `BindspaceIdentity`, avoid a
+subprocess where netlink/procfs suffices, and hold the namespace FD in
+`BindspaceHandle` to pin the identity.
+
 ### 5.3 the netns/process reality — read this before designing
 
 **The headline consequence, stated up front**: netns is a
@@ -396,26 +484,52 @@ server bound in the old namespace.
 - entering a netns is *process-global-ish and irreversible-ish*
   in practice. Therefore: **netns membership belongs to the
   actor process, decided before the runtime binds**, not to a
-  mid-life `@acm`. Design:
+  mid-life actor API. Design:
-  - the root/parent decides the netns for a subactor and passes
+  - the root/parent decides the `BindspaceSpec`, provisions or
-    it in the spawn spec (there's already
+    borrows it, and passes the spec plus an inherited/transferred
+    namespace-FD capability through the spawn backend (there's already
     `enable_transports`/`accept_addrs` plumbing at
     `_runtime.py:1595-1615` — the netns rides alongside).
-  - the child, in `_runtime.async_main()` **before**
+  - the child spawn/bootstrap trampoline calls `setns()` **before**
-    `IPCServer.listen_on()`, enters it.
+    `_runtime.async_main()`, `IPCServer.listen_on()`, parent-channel
-  - the mid-life `@acm` form is then only for the *root* /
+    connection, or creation of any worker thread/socket.
-    single-actor case, and for iface creation (which is
+  - only after successful entry does the child drop namespace-entry
-    genuinely scoped).
+    privileges and initialize the actor runtime.
+  - a root/single-actor process follows the same ordering: enter during
+    root bootstrap, never after actor runtime startup.
+  - iface/route/WG provisioning is genuinely scoped and remains under
+    the parent/supervisor's `BindspaceHandle` context.
   - document the constraint rather than hiding it; a
-    `RuntimeError` if `open_netns()` is entered after any
+    `RuntimeError` if namespace entry is attempted after bootstrap.
-    listener exists.
+- capabilities: iface/route/WG configuration needs `CAP_NET_ADMIN`;
-- privileges: iface/netns creation needs `CAP_NET_ADMIN`.
+  creating or entering a Linux network namespace normally requires
-  Never `sudo` from inside the runtime. Two supported modes:
+  `CAP_SYS_ADMIN` in the owning user namespace. Never `sudo` from
+  inside the runtime. A privileged parent/helper should provision the
+  stack and open the namespace FD; the child receives only the scoped
+  capability and temporary authority needed to enter it, then drops
+  that authority before actor code runs. This separates create/config
+  authority from enter/use authority and fits user-namespace/capability
+  deployments without granting every actor broad ambient caps.
+  Two supported modes remain:
   (i) pre-provisioned out-of-band (layers A/B — the default,
-  and what #482 documents), (ii) runtime-managed when the
+  and what #482 documents), (ii) runtime-managed when the supervising
-  process already holds the cap. Detect with a cheap
+  process/helper holds the required caps. Probe exact required caps and
-  `os.geteuid()==0 or CAP_NET_ADMIN in /proc/self/status`
+  *fail loudly with an actionable message* otherwise.
-  probe and *fail loudly with an actionable message* otherwise.
+- role semantics are explicit:
+  - `listen`: may create/own the local bindspace, iface, routes, WG
+    peer/listener state, and random local overlay; lifetime normally
+    extends through all listeners and the actor process.
+  - `dial`: may borrow an actor-wide bindspace or ensure local routing
+    and tunnel state reaches the remote stack; it does not own the
+    remote maddr and may need no new local resource at all.
+  - source/destination use is an operation property, never permanently
+    encoded into the maddr or inferred from segment ordering.
+- teardown follows capability ownership, not just address type:
+  - owned listener bindspaces tear down after endpoints/channels and
+    the actor process have exited;
+  - borrowed dial/actor-wide bindspaces only release their handle;
+  - nested resources exit inside-out, but shared resources remain until
+    their owning supervisor drops the final capability.
 - teardown must be idempotent and tolerant: an iface/netns
   already gone must not strand the rest of the teardown — the
   exact lesson `_uds.close_listener()`'s `FileNotFoundError`
@@ -426,14 +540,22 @@ server bound in the old namespace.
 
 - unit: fold-N-tunnel-specs-into-nested-`@acm`s, with fakes; assert
   enter/exit ordering (outermost-last-out) via a trace list.
-- integration, gated on `CAP_NET_ADMIN` (skip otherwise, and in
+- integration, gated on `CAP_NET_ADMIN` plus `CAP_SYS_ADMIN` in the
-  CI run it in a `--cap-add NET_ADMIN` container job): create two
+  owning user namespace (or a tested userns/helper equivalent; skip
-  netns + a wg pair entirely in-process, boot a `tractor` root in
+  otherwise). In CI, grant both capabilities explicitly. Create two
-  one and a subactor in the other, `find_actor()` across the
+  netns + a wg pair entirely in-process, boot a `tractor` root in one
-  tunnel. This is a *fantastic* test to have and is fully
+  and a subactor in the other, then `find_actor()` across the tunnel.
-  self-contained — no second host, no `sudo` in the test body.
+  This is fully self-contained — no second host and no `sudo` in the
+  test body.
 - the `to_thread`-netns-mismatch regression from §5.3, written
   **first** (red), then the fix (green), per project convention.
+- bootstrap ordering: assert the child reports the expected namespace
+  inode before parent-channel connect and listener creation.
+- FD capability: rename/unlink the namespace name after opening its FD
+  and prove child entry still selects the pinned inode.
+- privilege drop: prove actor code lacks provisioning caps after entry.
+- role/ownership: fake listen/dial resources and assert owned listener
+  teardown versus borrowed dial-handle release.
 
 ---
 
@@ -467,8 +589,12 @@ consider doing it *first* for exactly that reason.
 | risk | mitigation |
 | --- | --- |
 | `to_thread` worker runs in the wrong netns | §5.3; pass `netns=` to pyroute2 or pin a worker; test-first |
-| py-multiaddr#108 merged but unreleased | `[tool.uv.sources]` `rev` pin + `_have_wg_maddr_proto()` gate; layer A's overlay-addr path works regardless |
+| namespace name is renamed/replaced between provision and spawn | pass an open namespace FD; verify `(key, inode)` after child entry |
-| `TunnelledAddress` leaks into `Endpoint` and breaks `inspect.getmodule()` | unwrap at parse/bindspace boundary; assert `not isinstance(ep.addr, TunnelledAddress)` in `Endpoint.__post_init__` |
+| child starts sockets/threads before `setns()` | enter in the spawn bootstrap trampoline before `_runtime.async_main()`; assert inode ordering |
+| ambient capabilities leak into actor app code | split provision/enter authority and drop caps before runtime initialization |
+| dial path tears down a shared actor bindspace | encode ownership in `BindspaceHandle`; borrowed handles never remove resources |
+| py-multiaddr#108 merged but unreleased | PEP 621 direct-revision pin + `_wg_proto_code()` gate; replace with a release floor once published |
+| `TunnelledAddress` leaks into transport reflection/type dispatch | keep wrappers through declaration/bindspace handling, call `strip_tunnels()` at channel/endpoint boundaries, and retain the boundary regressions |
 | privileged ops in a library | never `sudo`; explicit cap probe + actionable error; pre-provisioned is the default |
 | pyroute2 0.9 asyncio core drags a loop into the actor | option (1) is a *thread*, not a loop; forbid `trio-asyncio` here (§4.1) |
 | netns teardown strands actor teardown | idempotent/tolerant teardown mirroring `_uds.close_listener()` |

ai/tpt-backends/README.md

@@ -7,9 +7,9 @@ different model/provider) without design or lib-selection drift.
 **Read [`00_shared_backend_contract.md`](./00_shared_backend_contract.md)
 first** — it is the normative description of what a `tractor`
 transport backend *is* as of `main@83b34884` (the backend
-duck-type, the 10-item registration checklist, the test-harness
+duck-type, registration and address-selection wiring, the
-plumbing, the code-style rules). The three plans assume it and
+test-harness plumbing, the code-style rules). The three plans
-document only their own deltas.
+assume it and document only their own deltas.
 
 | plan | issue | dep | size | lands |
 | --- | --- | --- | --- | --- |
@@ -23,10 +23,12 @@ Headline conclusions:
   `trio.SocketListener` are address-family agnostic (only
   `SOCK_STREAM` + a trio socket), and CPython ships `AF_TIPC` +
   23 `TIPC_*` constants. So the backend is ~one module of
-  contract boilerplate, zero new deps, and it buys
+  contract boilerplate, zero new deps, and it buys kernel-native
-  *kernel-native* service discovery: `bind()` publishes,
+  service primitives: `bind()` publishes, known-address
-  `connect()`-by-name resolves — no registrar in the loop.
+  `connect()` resolves, and topology events report publication
-  (`modprobe tipc` is required; hard-gate everything.)
+  changes. Actor-name lookup, registrar state and split-brain-safe
+  election remain separate work. (`modprobe tipc` is required;
+  hard-gate everything.)
 - **QUIC's cost is entirely in two adapters**, not in QUIC. The
   `iroh` python bindings are `uniffi`-generated asyncio, but the
   asyncio dependency is confined to *one* future-poll callback —

examples/multihost/wg_lan/README.md

@@ -21,16 +21,16 @@ Supersedes the example set in gh
 /ip4/192.168.1.50/udp/51820/wg/u<A_pub>/ip4/10.0.11.1/tcp/1616
 \____ wg bearer ___________/\__ key __/\____ tractor ep _____/
  underlay, wg `ListenPort`              overlay, on the wg iface
- (kernel/`wg(8)` owns it)               (the ONLY part tractor binds)
+ (kernel owns the socket)               (`MsgTransport` binds this)
 ```
 
 Three parts, three different owners:
 
-| part | who binds it | in the runtime? |
+| part | socket owner / provisioner | runtime role |
 | --- | --- | --- |
-| `/ip4/../udp/51820` bearer | kernel via `wg-quick`/`pyroute2` | no |
+| `/ip4/../udp/51820` bearer | kernel-owned; `wg-quick` now, tractor bindspace later | control-plane metadata |
-| `/wg/u<key>` | nothing — it's an identity | no, verified out-of-band |
+| `/wg/u<key>` | nothing — it's an identity | parsed, verified explicitly |
-| `/ip4/../tcp/1616` overlay | `tractor`'s `IPCServer` | **yes**, as `.overlay` |
+| `/ip4/../tcp/1616` overlay | `tractor`'s `IPCServer` | application `MsgTransport` |
 
 Verified against py-multiaddr
 [#108](https://github.com/multiformats/py-multiaddr/pull/108):
@@ -41,31 +41,29 @@ this composed form parses and round-trips
 
 py-multiaddr #108 is **merged** (2026-07-28) but ships in no
 release yet — the latest `0.2.0` (2026-03-17) predates it and has
-no `wg` codec. So `pyproject.toml` carries a temporary
+no `wg` codec. So `pyproject.toml` temporarily pins the merge commit
-`[tool.uv.sources]` `rev` pin at the merge commit, and a plain
+in its PEP 621 dependency metadata, and a plain
 
 ```bash
 uv sync
 ```
 
 gets you a `wg`-aware `multiaddr`. That pin goes away once a
-release carries the codec. You also need `multibase`:
+release carries the codec. `py-multibase` is a direct project
-
+dependency, so no separate install command is needed.
-```bash
-uv pip install multibase
-```
 
 Without the codec `parse_wg_maddr()` raises immediately with an
 actionable message — there is deliberately **no** degraded
-hand-split fallback. `_have_wg_maddr_proto()` is the predicate.
+hand-split fallback. `_wg_proto_code()` performs the capability
+check before parsing.
 
 Every peel and re-compose here goes through `py-multiaddr`'s own
 tunnel API (`.decapsulate_code()`, `.split()`, `.join()`,
 `.encapsulate()`, `.value_for_protocol()`) rather than any
 bespoke segment slicing — see its README "En/decapsulate" and
 "Tunneling" sections. gh #429 was about *dropping* our NIH
-parser, and that applies to peeling a tunnel stack just as much
+parser, and that applies to peeling nested tunnel stacks just as
-as to decoding one proto.
+much as to decoding one proto.
 
 ## 0. tunnel setup (out-of-band, both hosts)
 
@@ -106,8 +104,11 @@ AllowedIPs = 10.0.11.1/32
 PersistentKeepalive = 25
 ```
 
-Note how `ListenPort` and `Endpoint` are exactly the maddr's
+This example configures host A's `ListenPort` and host B's
-bearer segment, and `[Interface] Address` is its overlay host.
+`Endpoint` from the maddr bearer, and configures host A's
+`[Interface] Address` from its overlay host. The verification
+step below checks keys only; it does not inspect those fields or
+either peer's `AllowedIPs`.
 
 ```bash
 sudo wg-quick up wg0   # both hosts
@@ -118,16 +119,40 @@ ping -c1 10.0.11.1     # from B
 
 ```bash
 python -c "
-import base64, multibase
+from tractor.discovery import mb_pubkey
 key = open('wg_pub.key').read().strip()
-print(multibase.encode('base64url', base64.b64decode(key)).decode())
+print(mb_pubkey(key))
 "
 ```
 
 Paste the `u...` output into `WG_MADDR` in both scripts (they use
 the same string — A's bearer, A's key, A's overlay ep).
 
-## 2. run
+## 2. verify the keys
+
+Interface inspection commonly needs `CAP_NET_ADMIN`. Keep that
+privileged operation separate from the `tractor` processes:
+
+```bash
+# host A: output must equal the maddr's A_pub key
+export WG_KEY_INSPECTION="$(sudo wg show wg0 public-key)"
+
+# host B: output must contain the maddr's A_pub key
+export WG_KEY_INSPECTION="$(sudo wg show wg0 peers)"
+```
+
+These checks establish only that host A uses the declared local
+key and host B has that key as a configured peer. They do not
+verify `Endpoint`, `AllowedIPs`, a recent handshake, or routing.
+The exported text contains public keys only. Each script passes it
+to `verify_wg_key()` with its host-specific role before starting
+`tractor`. Callers that already have permission to inspect the
+interface may omit that argument; the helper's direct query is
+async and requests cancellation after five seconds. Trio's
+subprocess termination escalation can make final process cleanup
+take longer than that cancellation deadline.
+
+## 3. run
 
 ```bash
 # host A
@@ -137,6 +162,17 @@ python host_a_srv.py
 python host_b_client.py
 ```
 
+Run both `tractor` programs as the normal application account,
+not as root. Privilege is needed only for tunnel setup and the
+separate inspection above. If using that preflight, keep the
+host-specific `WG_KEY_INSPECTION` value exported in each
+program's shell.
+
+The client binds its own actor listener to `10.0.11.2:0`, while
+the service actor binds to host A's `10.0.11.1` overlay host with
+a random port. Keep `LOCAL_OVERLAY_BIND` aligned with host B's
+WireGuard interface address if adapting this example.
+
 `host_a_srv.py` must be importable on host B too, since
 `portal.run()` refs the fn by module path — standard `tractor`
 RPC semantics.
@@ -153,24 +189,23 @@ Four corrections, all from
    all. `parse_wg_maddr()` now rejects it with an actionable
    error.
 2. **parsing is pure.** #482's helper had the key-check adjacent
-   to the parse; `verify_wg_peer()` is now a separate, explicitly
+   to the parse; `verify_wg_key()` is now a separate, explicitly
-   composed step that the caller invokes. A parser that shells
+   composed step for inspection-capable callers. A parser that
-   out is a nasty surprise.
+   shells out is a nasty surprise.
 3. **no `sudo`.** #482 ran `sudo wg show`; a library/example must
-   never escalate. `wg show` works unprivileged for read on most
+   never escalate or run `tractor` as root. Privileged tunnel
-   setups; if yours needs root, run the script as root rather
+   setup and key inspection are separate shell steps.
-   than embedding `sudo`.
 4. **no new `Address` proto-type.** The tunnel rides *beside* the
-   overlay addr in a frozen `WGTunnelledAddr`, and only `.overlay`
+   overlay addr in a frozen `TunnelledAddress`, and only `.overlay`
    crosses into `open_nursery()`. #482 §6 floated a `WGAddress`
-   registered in `_address_types` — that table is a `bidict`
+   registered in `_address_types` — that registry maps available
-   (1:1 proto-key↔type) and `_addr_to_transport` wants a
+   transport keys to concrete address types, and
-   `MsgTransport` per addr-type, which `wg` doesn't have.
+   `_addr_to_transport` wants a `MsgTransport` per addr-type,
+   which `wg` doesn't have.
 
 ## next
 
-`WGTunnelledAddr` is deliberately example-local. Promoting it to
+Layer A's `TunnelledAddress` and native maddr parser now live in
-`tractor.discovery` as a `TunnelledAddress` whose
+`tractor.discovery`. Next, replace this example's `wg(8)` verification
-`.proto_key`/`.unwrap()` delegate to `.overlay`, plus
+probe with `pyroute2`, then add `open_bindspace()` `@acm`s which
-`open_bindspace()` `@acm`s that create/tear down the iface +
+create/tear down the iface and netns.
-netns via `pyroute2`, is layers A→C of the plan doc.

examples/multihost/wg_lan/host_a_srv.py

@@ -8,15 +8,18 @@ tunnel's *overlay* addr, declared as a single `wg` maddr.
 '''
 from __future__ import annotations
 
+import os
+
 import tractor
 import trio
-
+from tractor.discovery import (
-from wg_maddr import (
+    TunnelledAddress,
+    mk_maddr,
     parse_wg_maddr,
-    verify_wg_peer,
-    WGTunnelledAddr,
 )
 
+from wg_maddr import verify_wg_key
+
 # bearer = host A's underlay `(ip, wg ListenPort)`
 # key    = host A's OWN tunnel pubkey
 # overlay = the ep `tractor` binds, on the wg iface's addr
@@ -33,27 +36,36 @@ async def echo(msg: str) -> str:
 
 
 async def main():
-    addr: WGTunnelledAddr = parse_wg_maddr(WG_MADDR)
+    addr: TunnelledAddress = parse_wg_maddr(WG_MADDR)
-    assert verify_wg_peer(addr), (
+    inspection: str | None = os.environ.get('WG_KEY_INSPECTION')
-        f'wg pubkey from maddr not active on wg0 !\n'
+    if not await verify_wg_key(
+        addr,
+        role='local',
+        inspection=inspection,
+    ):
+        raise RuntimeError(
+            f'Maddr key is not wg0 local public key!\n'
             f'maddr: {WG_MADDR}\n'
-        f'key: {addr.peer_pubkey}\n'
+            f'key: {addr.tunnel.peer_pubkey}\n'
         )
     print(
-        f'wg bearer (kernel-owned): {addr.bearer}\n'
+        f'wg bearer (kernel-owned): {addr.tunnel.bearer}\n'
         f'tractor overlay ep: {addr.overlay}\n'
     )
     async with tractor.open_nursery(
         # XXX only `.overlay` crosses into the runtime; the bearer
-        # + key are iface-layer concerns `tractor` never binds.
+        # + key are bindspace metadata, never `Endpoint` addrs.
         registry_addrs=[addr.overlay],
-        enable_transports=[addr.overlay_proto],
+        enable_transports=[addr.overlay.proto_key],
     ) as an:
+        overlay_host, _ = addr.unwrap()
         await an.start_actor(
             'echo_srv',
-            enable_modules=[__name__],
+            bind_addrs=[(overlay_host, 0)],
+            enable_transports=[addr.overlay.proto_key],
+            enable_modules=['host_a_srv'],
         )
-        print(f'echo_srv up on\n  {addr.maddr}\n')
+        print(f'echo_srv up on\n  {mk_maddr(addr)}\n')
         await trio.sleep_forever()
 
 

examples/multihost/wg_lan/host_b_client.py

@@ -6,15 +6,17 @@ Host B: workstation dialing host A's actor tree through the
 '''
 from __future__ import annotations
 
+import os
+
 import tractor
 import trio
+from tractor.discovery import (
+    TunnelledAddress,
+    parse_wg_maddr,
+)
 
 from host_a_srv import echo  # noqa: F401  (RPC refs it by mod path)
-from wg_maddr import (
+from wg_maddr import verify_wg_key
-    parse_wg_maddr,
-    verify_wg_peer,
-    WGTunnelledAddr,
-)
 
 # same maddr as host A: A's bearer, A's key, A's overlay ep
 WG_MADDR: str = (
@@ -22,23 +24,33 @@ WG_MADDR: str = (
     '/wg/u<A_pub_b64url>'
     '/ip4/10.0.11.1/tcp/1616'
 )
+LOCAL_OVERLAY_BIND: tuple[str, int] = ('10.0.11.2', 0)
 
 
 async def main():
-    addr: WGTunnelledAddr = parse_wg_maddr(WG_MADDR)
+    addr: TunnelledAddress = parse_wg_maddr(WG_MADDR)
-    assert verify_wg_peer(addr), (
+    inspection: str | None = os.environ.get('WG_KEY_INSPECTION')
-        f'wg pubkey from maddr not a peer on wg0 !\n'
+    if not await verify_wg_key(
+        addr,
+        role='peer',
+        inspection=inspection,
+    ):
+        raise RuntimeError(
+            f'Maddr key is not a configured wg0 peer!\n'
             f'maddr: {WG_MADDR}\n'
+            f'key: {addr.tunnel.peer_pubkey}\n'
         )
     async with (
         tractor.open_root_actor(
             name='wg_client',
+            tpt_bind_addrs=[LOCAL_OVERLAY_BIND],
             registry_addrs=[addr.overlay],
-            enable_transports=[addr.overlay_proto],
+            enable_transports=[addr.overlay.proto_key],
         ),
         tractor.find_actor(
             'echo_srv',
             registry_addrs=[addr.overlay],
+            raise_on_none=True,
         ) as portal,
     ):
         res: str = await portal.run(

examples/multihost/wg_lan/wg_maddr.py

@@ -1,299 +1,85 @@
 # tractor: distributed structured concurrency.
 r'''
-Parse `wg`-tunnelled multiaddrs into `tractor`-ready addrs.
+Verify `wg` keys declared by tractor's multiaddr parser.
 
-The canonical form (per py-multiaddr #108, verified against its
+`tractor.discovery.parse_wg_maddr()` owns pure parsing and delegates
-upstream merge) nests the *overlay* endpoint **after** the `/wg/`
+all tunnel peeling to `py-multiaddr`. This example keeps only the
-segment:
+explicit impure probe used by the two-host demo; parsing never shells
+out or verifies local interface state implicitly.
+
+The canonical maddr form is:
 
     /ip4/10.0.0.1/udp/51820/wg/u<key>/ip4/10.0.11.1/tcp/1616
     \_______ wg bearer ______/\_ key _/\____ tractor ep _____/
-      (underlay, wg
-       `ListenPort`)
 
-Naming follows `py-multiaddr`'s own encapsulation model, where
+The kernel owns the bearer socket. A future tractor bindspace may
-earlier segments *wrap* later ones (`.encapsulate()` appends), so
+provision it through netlink, but only the overlay is an application
-the two roles are:
+`MsgTransport` endpoint.
-
-- **bearer**: the segs *before* `/wg/`, i.e. the underlay
-  `(ip, udp-port)` that `wg(8)` itself listens on. Nothing in
-  `tractor` ever binds this — the kernel/`wg` iface owns it.
-- **overlay**: the segs *after*, i.e. the addr `tractor` actually
-  binds/dials. The only part the runtime ever sees.
-
-We deliberately avoid `inner`/`outer` for these two: in a *call*
-stack "inner" reads as higher-up and later-called, whereas here
-the encapsulated addr is bound *first* and sits deeper in the
-maddr — two opposite intuitions on one word.
-
-`/wg/u<key>` itself carries the tunnel peer's Curve25519 pubkey
-as multibase base64url (std base64 from `wg(8)` contains `/` and
-so can't go in a `/`-delimited maddr). It binds nothing at all;
-it's an identity, verified out-of-band.
-
-XXX NOTE, `tractor`'s own `parse_maddr()` can't parse this yet
-(`ValueError('Unsupported multiaddr protocol combo')`), which is
-why this module exists: peel here, hand `.overlay` to the
-runtime.
-
-Design rules this module follows (see
-`ai/tpt-backends/03_wg_tunnel_bindspace.md`):
-
-- **let `py-multiaddr` do the parsing**. Every peel/compose goes
-  through `.decapsulate_code()`, `.split()`, `.join()`,
-  `.encapsulate()` and `.value_for_protocol()`. We hand-roll no
-  segment splitting whatsoever — the whole point of gh #429 was
-  dropping the NIH parser, and that applies to *peeling a tunnel
-  stack* every bit as much as to decoding a single proto.
-- **parsing is pure**. `parse_wg_maddr()` does no I/O, no
-  `subprocess`, no netlink. A parser that shells out is a nasty
-  surprise.
-- **verification is an explicit, separate step**. The caller
-  composes `verify_wg_peer()` when it wants it; nothing implicit.
-- **no new `Address` proto-type**. `wg` gets no entry in
-  `tractor.discovery._addr._address_types` (a `bidict`, so 1:1
-  proto-key<->type) bc it has no `MsgTransport` of its own. The
-  tunnel is a *bindspace*, so we carry it beside the overlay
-  addr and strip to `.overlay` at bind/dial time.
 
 '''
 from __future__ import annotations
-import base64
-import subprocess
 from typing import Literal
 
-import msgspec
+import trio
-from multiaddr import Multiaddr
-from multiaddr.protocols import P_WG
 
-
+from tractor.discovery import (
-IPProto = Literal['ip4', 'ip6']
+    TunnelledAddress,
-
+    WGTunnelSpec,
-
-class WGTunnelledAddr(
-    msgspec.Struct,
-    frozen=True,
-):
-    '''
-    A `wg`-tunnelled endpoint: the underlay bearer, the tunnel
-    peer key, and the overlay addr `tractor` binds/dials.
-
-    '''
-    # underlay, owned by `wg(8)`/the kernel — NEVER bound by us
-    bearer: tuple[str, int]
-
-    # tunnel peer pubkey in the std-base64 `wg(8)` form, i.e.
-    # directly comparable to `wg show <if> peers` output
-    peer_pubkey: str
-
-    # overlay ep: an `UnwrappedAddress` as accepted by
-    # `tractor.discovery.wrap_address()`
-    overlay: tuple[str, int]
-    overlay_proto: Literal['tcp'] = 'tcp'
-
-    # kept so `.as_multiaddr()` re-renders the same ip family it
-    # was parsed from, rather than assuming v4
-    bearer_ip: IPProto = 'ip4'
-    overlay_ip: IPProto = 'ip4'
-
-    def as_multiaddr(self) -> Multiaddr:
-        '''
-        Re-compose the canonical `Multiaddr`, bearer outward-in,
-        using `.encapsulate()` exactly as py-multiaddr's own
-        tunneling example does.
-
-        '''
-        b_host, b_port = self.bearer
-        o_host, o_port = self.overlay
-        return (
-            Multiaddr(f'/{self.bearer_ip}/{b_host}/udp/{b_port}')
-            .encapsulate(
-                Multiaddr(f'/wg/{mb_pubkey(self.peer_pubkey)}')
-            )
-            .encapsulate(
-                Multiaddr(
-                    f'/{self.overlay_ip}/{o_host}'
-                    f'/{self.overlay_proto}/{o_port}'
-                )
-            )
-        )
-
-    @property
-    def maddr(self) -> str:
-        '''
-        The canonical maddr `str` form.
-
-        '''
-        return str(self.as_multiaddr())
-
-
-def mb_pubkey(wg8_key: str) -> str:
-    '''
-    `wg(8)` std-base64 pubkey -> multibase base64url (`u`-prefixed).
-
-    '''
-    import multibase
-    raw: bytes = base64.b64decode(wg8_key)
-    return multibase.encode('base64url', raw).decode('ascii')
-
-
-def wg8_pubkey(mb_key: str) -> str:
-    '''
-    Inverse of `mb_pubkey()`: multibase -> `wg(8)` std-base64.
-
-    '''
-    import multibase
-    raw: bytes = multibase.decode(mb_key)
-    return base64.b64encode(raw).decode('ascii')
-
-
-_wg_proto_known: bool|None = None
-
-
-def _have_wg_maddr_proto() -> bool:
-    '''
-    True iff the installed `py-multiaddr` knows the `/wg/` proto,
-    i.e. carries py-multiaddr#108.
-
-    Merged upstream 2026-07-28 (`f86519da`) but in no release as
-    of `0.2.0`, hence the `[tool.uv.sources]` `rev` pin in
-    `pyproject.toml`.
-
-    Pure predicate; result cached since it can't change without a
-    reinstall.
-
-    '''
-    global _wg_proto_known
-    if _wg_proto_known is None:
-        from multiaddr.protocols import protocol_with_name
-        from multiaddr.exceptions import ProtocolNotFoundError
-        try:
-            protocol_with_name('wg')
-            _wg_proto_known = True
-        except ProtocolNotFoundError:
-            _wg_proto_known = False
-
-    return _wg_proto_known
-
-
-def parse_wg_maddr(
-    maddr: str|Multiaddr,
-) -> WGTunnelledAddr:
-    '''
-    Peel a `wg`-tunnelled maddr into its bearer/key/overlay
-    parts. Pure — no I/O.
-
-    Every cut is made by `py-multiaddr`, so a malformed maddr
-    (incl. a `wg` key that isn't exactly 32B) raises out of
-    `Multiaddr()` rather than yielding a struct quietly built
-    from garbage segs.
-
-    '''
-    if not _have_wg_maddr_proto():
-        raise RuntimeError(
-            f'Installed `py-multiaddr` has no `/wg/` proto!\n'
-            f'Needs py-multiaddr#108, merged upstream but not\n'
-            f'yet released; a `uv sync` picks up the pinned rev.\n'
-            f'maddr: {maddr!r}\n'
-        )
-
-    ma: Multiaddr = (
-        maddr
-        if isinstance(maddr, Multiaddr)
-        else Multiaddr(maddr)
-    )
-    segs: list[Multiaddr] = ma.split()
-    names: list[str] = [
-        proto.name
-        for seg in segs
-        for proto in seg.protocols()
-    ]
-    if 'wg' not in names:
-        raise ValueError(
-            f'Not a `wg`-tunnelled maddr, no `/wg/` segment ??\n'
-            f'maddr: {ma}\n'
-        )
-
-    # NOTE, `.decapsulate_code()` cuts at the LAST occurrence of
-    # the proto and keeps the *prefix*, which is exactly the
-    # bearer. It handles `/wg/` cleanly precisely bc it cuts on
-    # proto-code and never tries to match an addr value — the
-    # key seg has no addr of its own.
-    bearer_ma: Multiaddr = ma.decapsulate_code(P_WG)
-    overlay_ma: Multiaddr = Multiaddr.join(
-        *segs[names.index('wg') + 1:]
-    )
-
-    match [proto.name for proto in bearer_ma.protocols()]:
-        case [('ip4' | 'ip6') as b_ip, 'udp']:
-            bearer = (
-                bearer_ma.value_for_protocol(b_ip),
-                int(bearer_ma.value_for_protocol('udp')),
-            )
-        case _:
-            raise ValueError(
-                f'Bad `wg` bearer, expected `/ip4|ip6/<h>/udp/<p>`\n'
-                f'got: {bearer_ma}\n'
-                f'from maddr: {ma}\n'
-            )
-
-    match [proto.name for proto in overlay_ma.protocols()]:
-        case [('ip4' | 'ip6') as o_ip, ('tcp') as l4]:
-            overlay = (
-                overlay_ma.value_for_protocol(o_ip),
-                int(overlay_ma.value_for_protocol(l4)),
-            )
-        case []:
-            raise ValueError(
-                f'`wg` maddr declares no overlay endpoint!\n'
-                f'A bare `/…/wg/<key>` names only the tunnel; '
-                f'append the ep `tractor` should bind, e.g.\n'
-                f'  {ma}/ip4/10.0.11.1/tcp/1616\n'
-            )
-        case _:
-            raise ValueError(
-                f'Unsupported `wg` overlay proto combo\n'
-                f'got: {overlay_ma}\n'
-                f'from maddr: {ma}\n'
-            )
-
-    return WGTunnelledAddr(
-        bearer=bearer,
-        peer_pubkey=wg8_pubkey(ma.value_for_protocol('wg')),
-        overlay=overlay,
-        overlay_proto=l4,
-        bearer_ip=b_ip,
-        overlay_ip=o_ip,
 )
 
 
-def verify_wg_peer(
+async def verify_wg_key(
-    addr: WGTunnelledAddr,
+    addr: TunnelledAddress,
-    iface: str = 'wg0',
+    role: Literal['local', 'peer'],
+    iface: str | None = None,
+    timeout: float = 5,
+    inspection: str | None = None,
 ) -> bool:
     '''
-    True iff `addr.peer_pubkey` is a configured peer (or our own
+    Verify the declared key in the role required on this host.
-    pubkey) on `iface`.
 
-    IMPURE + explicit by design: never called from
+    A bearer host uses `role='local'`; a dialer uses `role='peer'`.
-    `parse_wg_maddr()`.
+    This verifies only key presence. It does not inspect the peer's
+    endpoint, AllowedIPs, handshake state, or iface addresses.
+
+    `inspection` accepts output captured by a separate privileged
+    `wg show` step. Without it, query asynchronously for callers
+    which already have interface-inspection permission.
+
+    IMPURE + explicit by design: neither `parse_wg_maddr()` nor
+    `tractor.discovery.parse_maddr()` calls this probe.
 
     ?TODO, per plan-03 layer B, swap this body for `pyroute2`
-    (keeping the signature) — and note `setns(2)` is *per-thread*,
+    while retaining the explicit verification boundary.
-    so a query issued via `trio.to_thread` lands in the ORIGINAL
-    netns unless `netns=` is passed down.
 
     '''
-    def _wg(*args: str) -> str:
+    spec = addr.tunnel
-        return subprocess.run(
+    if not isinstance(spec, WGTunnelSpec):
-            ['wg', 'show', iface, *args],
+        raise TypeError(
-            capture_output=True,
+            f'Unsupported tunnel spec: {type(spec)!r}'
-            text=True,
-            check=True,
-        ).stdout
-
-    return (
-        addr.peer_pubkey in _wg('peers').split()
-        or
-        addr.peer_pubkey == _wg('public-key').strip()
         )
+
+    iface = iface or spec.iface
+
+    match role:
+        case 'local':
+            field = 'public-key'
+        case 'peer':
+            field = 'peers'
+        case _:
+            raise ValueError(
+                f'Unknown WireGuard key role: {role!r}'
+            )
+
+    if inspection is None:
+        with trio.fail_after(timeout):
+            proc = await trio.run_process(
+                ['wg', 'show', iface, field],
+                capture_stdout=True,
+                check=True,
+            )
+        inspection = proc.stdout.decode()
+
+    if role == 'local':
+        return spec.peer_pubkey == inspection.strip()
+    return spec.peer_pubkey in inspection.split()

pyproject.toml

@@ -48,7 +48,10 @@ dependencies = [
   # typed IPC msging
   "msgspec>=0.20.0",
   "bidict>=0.23.1",
-  "multiaddr>=0.2.0",
+  # unreleased `/wg/` codec from py-multiaddr#108
+  "multiaddr @ git+https://github.com/multiformats/py-multiaddr.git@f86519daaa21699023d0037c58cdff600313dd09",
+  # encode/decode `wg` pubkeys carried by multiaddrs
+  "py-multibase>=2.0.0,<3",
   "platformdirs>=4.4.0",
   # per-actor `argv[0]` proc-title for OS-level diag tools
   # (`ps`, `top`, `psutil`-backed tooling like `acli.pytree`).
@@ -169,17 +172,6 @@ sync_pause = {requires-python = ">=3.13, <3.14"}
 # linux kernel networking
 # 'pyroute2
 
-# XXX TEMP, the `/wg/u<key>` maddr proto is MERGED upstream (in
-# py-multiaddr#108, 2026-07-28) but is in NO release yet; the
-# latest `0.2.0` (2026-03-17) predates the merge by ~4 months.
-# Pinned by `rev` (not `branch`) so CI stays reproducible.
-#
-# Drop this pin (and bump the `multiaddr` dep floor above) the
-# moment a release carries the `wg` codec; the only consumer is
-# `examples/multihost/wg_lan/`.
-# |_https://github.com/multiformats/py-multiaddr/pull/108
-multiaddr = { git = 'https://github.com/multiformats/py-multiaddr.git', rev = 'f86519daaa21699023d0037c58cdff600313dd09' }
-
 # ------ tool.uv.sources ------
 
 [tool.uv]
@@ -194,6 +186,9 @@ python-preference = 'system'
 
 # ------ tool.uv ------
 
+[tool.hatch.metadata]
+allow-direct-references = true
+
 [tool.hatch.build.targets.sdist]
 include = ["tractor"]
 

tests/discovery/test_address_serialization.py

@@ -0,0 +1,100 @@
+'''
+Canonical tagged-address decoding and legacy input compatibility.
+
+'''
+from pathlib import Path
+
+import pytest
+
+from tractor.discovery._addr import wrap_address
+from tractor.ipc._tcp import TCPAddress
+from tractor.ipc._uds import UDSAddress
+
+
+@pytest.mark.parametrize(
+    'value',
+    [
+        ('tcp', '127.0.0.1', 1616),
+        ['tcp', '127.0.0.1', 1616],
+    ],
+)
+def test_decode_tagged_tcp_address(value):
+    '''
+    Shape-only decoding cannot distinguish future transport address
+    forms. Feed canonical tuple and msgpack-style list values through
+    the compatibility boundary and prove the explicit `tcp` tag
+    selects the TCP backend and emits the canonical tagged form.
+
+    '''
+    addr = wrap_address(value)
+
+    assert type(addr) is TCPAddress
+    assert addr.unwrap() == ('tcp', '127.0.0.1', 1616)
+
+
+@pytest.mark.parametrize(
+    'tag',
+    ['unix', 'uds'],
+)
+@pytest.mark.parametrize('container', [tuple, list])
+def test_decode_tagged_unix_address(
+    tag: str,
+    container: type,
+):
+    '''
+    Multiaddr calls the protocol `unix` while tractor's transport key
+    remains `uds`. Decode both spellings from tuple/list containers,
+    normalize them to one `UDSAddress`, and emit the canonical `unix`
+    spelling.
+
+    '''
+    value = container((tag, '/tmp/tractor/registry.sock'))
+    addr = wrap_address(value)
+
+    assert type(addr) is UDSAddress
+    assert addr.sockpath == Path('/tmp/tractor/registry.sock')
+    assert addr.unwrap() == (
+        'unix',
+        '/tmp/tractor/registry.sock',
+    )
+
+
+@pytest.mark.parametrize(
+    'value, expected_type',
+    [
+        (('127.0.0.1', 1616), TCPAddress),
+        (['127.0.0.1', 1616], TCPAddress),
+        (('/tmp/tractor', 'registry.sock'), UDSAddress),
+        (['/tmp/tractor', 'registry.sock'], UDSAddress),
+    ],
+)
+def test_decode_legacy_address_forms(
+    value,
+    expected_type: type,
+):
+    '''
+    Existing callers, config, and older msgpack payloads still
+    provide untagged pairs. Keep tuple/list forms readable while
+    canonical tagged emission is introduced, proving the writer
+    migration does not break shipped input behavior.
+
+    '''
+    addr = wrap_address(value)
+
+    assert type(addr) is expected_type
+    assert addr.unwrap()[0] in {'tcp', 'unix'}
+
+
+def test_tcp_from_native_ipv6_sockname():
+    '''
+    `socket.getsockname()` returns a four-item IPv6 sockaddr which is
+    neither a wire form nor a legacy two-item pair. Preserve it as an
+    OS compatibility boundary and intentionally ignore unsupported
+    flow-info/scope-id fields when constructing `TCPAddress`.
+
+    '''
+    addr = TCPAddress.from_addr(
+        ('::1', 1616, 0, 0)
+    )
+
+    assert addr.unwrap() == ('tcp', '::1', 1616)

tests/discovery/test_multiaddr.py

@@ -10,6 +10,14 @@ from types import SimpleNamespace
 import pytest
 from multiaddr import Multiaddr
 
+from tractor.discovery import (
+    TunnelledAddress,
+    WGTunnelSpec,
+    mb_pubkey,
+    mk_wg_maddr,
+    parse_wg_maddr,
+    tunnels_of,
+)
 from tractor.ipc._tcp import TCPAddress
 from tractor.ipc._uds import UDSAddress
 from tractor.discovery._multiaddr import (
@@ -22,6 +30,19 @@ from tractor.discovery._multiaddr import (
 from tractor.discovery._addr import wrap_address
 
 
+_WG_PUBKEY: str = (
+    'g3x7z0AdV1rM6UQU22CC7IL3/ivn4DzrE7ikDhCZ/Dc='
+)
+_WG_PUBKEY_2: str = (
+    'AAECAwQFBgcICQoLDA0ODxAREhMUFRYXGBkaGxwdHh8='
+)
+_WG_MADDR: str = (
+    f'/ip4/192.168.1.50/udp/51820'
+    f'/wg/{mb_pubkey(_WG_PUBKEY)}'
+    f'/ip4/10.0.11.1/tcp/1616'
+)
+
+
 def test_tpt_proto_to_maddr_mapping():
     '''
     `_tpt_proto_to_maddr` maps all supported `proto_key`
@@ -167,7 +188,7 @@ def test_parse_maddr_tcp_ipv4():
     result = parse_maddr('/ip4/127.0.0.1/tcp/1234')
 
     assert isinstance(result, TCPAddress)
-    assert result.unwrap() == ('127.0.0.1', 1234)
+    assert result.unwrap() == ('tcp', '127.0.0.1', 1234)
 
 
 def test_parse_maddr_tcp_ipv6():
@@ -179,7 +200,7 @@ def test_parse_maddr_tcp_ipv6():
     result = parse_maddr('/ip6/::1/tcp/5678')
 
     assert isinstance(result, TCPAddress)
-    assert result.unwrap() == ('::1', 5678)
+    assert result.unwrap() == ('tcp', '::1', 5678)
 
 
 def test_parse_maddr_uds():
@@ -192,9 +213,10 @@ def test_parse_maddr_uds():
     result = parse_maddr('/unix/tmp/tractor_test/test.sock')
 
     assert isinstance(result, UDSAddress)
-    filedir, filename = result.unwrap()
+    assert result.unwrap() == (
-    assert filename == 'test.sock'
+        'unix',
-    assert str(filedir) == '/tmp/tractor_test'
+        '/tmp/tractor_test/test.sock',
+    )
 
 
 def test_parse_maddr_unsupported():
@@ -210,6 +232,181 @@ def test_parse_maddr_unsupported():
         parse_maddr('/ip4/127.0.0.1/udp/1234')
 
 
+def test_parse_wg_maddr():
+    '''
+    `parse_maddr()` previously rejected the canonical infix `/wg/`
+    grammar even though `py-multiaddr` parsed it. Feed a bearer,
+    identity, and TCP overlay through both the WG-specific and public
+    parsers, then prove they produce the same local-only tunnel
+    annotation without changing the bindable overlay.
+
+    '''
+    parsed = parse_wg_maddr(_WG_MADDR)
+
+    assert parse_maddr(_WG_MADDR) == parsed
+    assert isinstance(parsed, TunnelledAddress)
+    assert parsed.tunnel == WGTunnelSpec(
+        peer_pubkey=_WG_PUBKEY,
+        bearer=('192.168.1.50', 51820),
+    )
+    assert isinstance(parsed.overlay, TCPAddress)
+    assert parsed.overlay.unwrap() == ('tcp', '10.0.11.1', 1616)
+
+
+def test_mk_wg_maddr_roundtrip():
+    '''
+    `mk_maddr()` previously saw only the wrapper's delegated TCP
+    proto-key and silently dropped all tunnel metadata. Parse the
+    canonical maddr, compose it through both public entry points, and
+    prove bearer, key, and overlay survive byte-for-byte.
+
+    '''
+    parsed = parse_wg_maddr(_WG_MADDR)
+
+    assert str(mk_wg_maddr(parsed)) == _WG_MADDR
+    assert str(mk_maddr(parsed)) == _WG_MADDR
+
+
+def test_nested_wg_maddr_roundtrip():
+    '''
+    A single first-match lookup confuses nested WG keys and bearers.
+    Arrange an IPv4 outer bearer around an IPv6 inner bearer, parse
+    from the last `/wg/` outward, and assert tunnel ordering plus an
+    exact re-composition of the original stack.
+
+    '''
+    nested_maddr: str = (
+        f'/ip4/192.168.1.50/udp/51820'
+        f'/wg/{mb_pubkey(_WG_PUBKEY)}'
+        f'/ip6/2001:db8::2/udp/51821'
+        f'/wg/{mb_pubkey(_WG_PUBKEY_2)}'
+        f'/ip4/10.0.11.1/tcp/1616'
+    )
+
+    parsed = parse_maddr(nested_maddr)
+    specs = tunnels_of(parsed)
+
+    assert len(specs) == 2
+    assert specs[0].peer_pubkey == _WG_PUBKEY
+    assert specs[0].bearer == ('192.168.1.50', 51820)
+    assert specs[1].peer_pubkey == _WG_PUBKEY_2
+    assert specs[1].bearer == ('2001:db8::2', 51821)
+    assert str(mk_maddr(parsed)) == nested_maddr
+
+
+@pytest.mark.parametrize(
+    'maddr, match',
+    [
+        pytest.param(
+            (
+                f'/ip4/192.168.1.50/tcp/51820'
+                f'/wg/{mb_pubkey(_WG_PUBKEY)}'
+                f'/ip4/10.0.11.1/tcp/1616'
+            ),
+            'Bad `wg` bearer',
+            id='non-udp-bearer',
+        ),
+        pytest.param(
+            (
+                f'/ip4/192.168.1.50/udp/51820'
+                f'/wg/{mb_pubkey(_WG_PUBKEY)}'
+            ),
+            'no overlay endpoint',
+            id='missing-overlay',
+        ),
+        pytest.param(
+            (
+                f'/ip4/192.168.1.50/udp/51820'
+                f'/wg/{mb_pubkey(_WG_PUBKEY)}'
+                f'/ip4/10.0.11.1/udp/1616'
+            ),
+            'Unsupported `wg` overlay',
+            id='non-tcp-overlay',
+        ),
+    ],
+)
+def test_parse_wg_maddr_rejects_bad_grammar(
+    maddr: str,
+    match: str,
+):
+    '''
+    Accepting an invalid bearer or overlay assigns an endpoint to the
+    wrong runtime owner. Exercise parseable but unsupported protocol
+    combinations and prove each fails before constructing a wrapper,
+    with an error identifying the violated WG grammar boundary.
+
+    '''
+    with pytest.raises(ValueError, match=match):
+        parse_maddr(maddr)
+
+
+def test_parse_wg_maddr_rejects_malformed_key():
+    '''
+    A truncated multibase key used to be vulnerable to silent
+    identity corruption in hand-written parsers. Give the upstream
+    `/wg/` codec a short key and prove `Multiaddr()` rejects it
+    before tractor's wrapper parser runs.
+
+    '''
+    maddr: str = (
+        '/ip4/192.168.1.50/udp/51820'
+        '/wg/udG9vIHNob3J0'
+        '/ip4/10.0.11.1/tcp/1616'
+    )
+    with pytest.raises(ValueError):
+        parse_maddr(maddr)
+
+
+def test_parse_wg_maddr_reports_missing_codec(
+    monkeypatch,
+):
+    '''
+    Released `multiaddr==0.2.0` does not know `/wg/` and emits an
+    opaque unknown-protocol parse error. Simulate that registry and
+    prove an actual WG stack reports the dependency action while a
+    Unix path containing a `wg` directory remains ordinary UDS data.
+
+    '''
+    from multiaddr.exceptions import ProtocolNotFoundError
+    from multiaddr import protocols
+
+    def no_wg_proto(name: str):
+        raise ProtocolNotFoundError(name)
+
+    monkeypatch.setattr(
+        protocols,
+        'protocol_with_name',
+        no_wg_proto,
+    )
+    uds = parse_maddr('/unix/tmp/wg/service.sock')
+    assert isinstance(uds, UDSAddress)
+
+    with pytest.raises(
+        RuntimeError,
+        match='py-multiaddr#108',
+    ):
+        parse_maddr(_WG_MADDR)
+
+
+def test_mk_wg_maddr_requires_bearer():
+    '''
+    A key-only tunnel spec relies on local configuration and cannot
+    be reconstructed as the canonical bearer-first maddr. Build that
+    incomplete annotation and prove composition raises instead of
+    emitting a misleading overlay-only address.
+
+    '''
+    addr = TunnelledAddress(
+        overlay=TCPAddress('10.0.11.1', 1616),
+        tunnel=WGTunnelSpec(peer_pubkey=_WG_PUBKEY),
+    )
+    with pytest.raises(
+        ValueError,
+        match='without a bearer',
+    ):
+        mk_maddr(addr)
+
+
 @pytest.mark.parametrize(
     'addr',
     [
@@ -249,7 +446,22 @@ def test_wrap_address_maddr_str():
     result = wrap_address('/ip4/127.0.0.1/tcp/9999')
 
     assert isinstance(result, TCPAddress)
-    assert result.unwrap() == ('127.0.0.1', 9999)
+    assert result.unwrap() == ('tcp', '127.0.0.1', 9999)
+
+
+def test_wrap_address_wg_maddr_str():
+    '''
+    `wrap_address()` delegates slash-prefixed strings to
+    `parse_maddr()`. Pass a canonical WG maddr through that public
+    boundary and prove it preserves the tunnel annotation rather than
+    rejecting the protocol stack or returning only its TCP overlay.
+
+    '''
+    result = wrap_address(_WG_MADDR)
+
+    assert isinstance(result, TunnelledAddress)
+    assert result.tunnel.peer_pubkey == _WG_PUBKEY
+    assert result.overlay.unwrap() == ('tcp', '10.0.11.1', 1616)
 
 
 # ------ parse_endpoints() tests ------
@@ -270,11 +482,11 @@ def test_parse_endpoints_tcp_only():
 
     reg_addr = result['registry'][0]
     assert isinstance(reg_addr, TCPAddress)
-    assert reg_addr.unwrap() == ('127.0.0.1', 1616)
+    assert reg_addr.unwrap() == ('tcp', '127.0.0.1', 1616)
 
     feed_addr = result['data_feed'][0]
     assert isinstance(feed_addr, TCPAddress)
-    assert feed_addr.unwrap() == ('0.0.0.0', 5555)
+    assert feed_addr.unwrap() == ('tcp', '0.0.0.0', 5555)
 
 
 def test_parse_endpoints_mixed_tpts():
@@ -294,12 +506,37 @@ def test_parse_endpoints_mixed_tpts():
 
     assert len(addrs) == 2
     assert isinstance(addrs[0], TCPAddress)
-    assert addrs[0].unwrap() == ('127.0.0.1', 4040)
+    assert addrs[0].unwrap() == ('tcp', '127.0.0.1', 4040)
 
     assert isinstance(addrs[1], UDSAddress)
-    filedir, filename = addrs[1].unwrap()
+    assert addrs[1].unwrap() == (
-    assert filename == 'broker.sock'
+        'unix',
-    assert str(filedir) == '/tmp/tractor'
+        '/tmp/tractor/broker.sock',
+    )
+
+
+def test_parse_endpoints_wg_maddr():
+    '''
+    Service endpoint tables previously rejected WG protocol stacks.
+    Put a tunnelled maddr beside a plain TCP address and prove
+    `parse_endpoints()` retains input order while delivering the
+    wrapper needed by the future bindspace lifecycle.
+
+    '''
+    table = {
+        'registry': [
+            _WG_MADDR,
+            '/ip4/127.0.0.1/tcp/1616',
+        ],
+    }
+    addrs = parse_endpoints(table)['registry']
+
+    assert isinstance(addrs[0], TunnelledAddress)
+    assert addrs[0].tunnel.bearer == (
+        '192.168.1.50',
+        51820,
+    )
+    assert isinstance(addrs[1], TCPAddress)
 
 
 def test_parse_endpoints_unwrapped_tuples():
@@ -315,7 +552,7 @@ def test_parse_endpoints_unwrapped_tuples():
 
     addr = result['ems'][0]
     assert isinstance(addr, TCPAddress)
-    assert addr.unwrap() == ('127.0.0.1', 6666)
+    assert addr.unwrap() == ('tcp', '127.0.0.1', 6666)
 
 
 def test_parse_endpoints_mixed_str_and_tuple():
@@ -335,10 +572,10 @@ def test_parse_endpoints_mixed_str_and_tuple():
 
     assert len(addrs) == 2
     assert isinstance(addrs[0], TCPAddress)
-    assert addrs[0].unwrap() == ('127.0.0.1', 7777)
+    assert addrs[0].unwrap() == ('tcp', '127.0.0.1', 7777)
 
     assert isinstance(addrs[1], TCPAddress)
-    assert addrs[1].unwrap() == ('127.0.0.1', 8888)
+    assert addrs[1].unwrap() == ('tcp', '127.0.0.1', 8888)
 
 
 def test_parse_endpoints_unsupported_proto():

tests/discovery/test_tpt_bind_addrs.py

@@ -371,7 +371,7 @@ def test_non_registrar_root_tpt_bind_addrs(
             for uw_addr in bound:
                 w = wrap_address(uw_addr)
                 if w.proto_key == 'tcp':
-                    _host, port = uw_addr
+                    _, _host, port = uw_addr
                     assert port > 0
 
     trio.run(_main)
@@ -443,7 +443,7 @@ def test_tpt_bind_addrs_as_maddr_str(
             for uw_addr in actor.accept_addrs:
                 w = wrap_address(uw_addr)
                 if w.proto_key == 'tcp':
-                    _host, port = uw_addr
+                    _, _host, port = uw_addr
                     assert port > 0
 
     trio.run(_main)
@@ -475,7 +475,7 @@ def test_registrar_merge_binds_union(
     # actually differ (always true for TCP, may
     # collide for UDS).
     expect_disjoint: bool = (
-        tuple(reg_addr) != rando.unwrap()
+        reg_wrapped.unwrap() != rando.unwrap()
     )
 
     async def _main():

tests/discovery/test_tunnelled_addr.py

@@ -0,0 +1,234 @@
+'''
+`TunnelledAddress` delegation + peeling semantics.
+
+A tunnel annotates an existing L4 addr rather than being its own
+transport, so the contract under test is mostly *delegation*: the
+runtime must not be able to tell a tunnelled addr from its
+overlay, and **nothing** about the tunnel may cross the wire.
+
+See `ai/tpt-backends/03_wg_tunnel_bindspace.md` §3.1/§3.4.
+
+'''
+from __future__ import annotations
+
+import msgspec
+import pytest
+
+from tractor.discovery import (
+    TunnelledAddress,
+    WGTunnelSpec,
+    mb_pubkey,
+    strip_tunnels,
+    tunnels_of,
+    wg8_pubkey,
+)
+from tractor.discovery._addr import (
+    is_wrapped_addr,
+    wrap_address,
+)
+from tractor.ipc._tcp import TCPAddress
+
+
+# a valid-looking std-base64 `wg(8)` pubkey (32B -> 44 chars)
+_PUBKEY: str = 'g3x7z0AdV1rM6UQU22CC7IL3/ivn4DzrE7ikDhCZ/Dc='
+
+
+@pytest.fixture
+def overlay() -> TCPAddress:
+    return TCPAddress('10.0.11.1', 1616)
+
+
+@pytest.fixture
+def spec() -> WGTunnelSpec:
+    return WGTunnelSpec(
+        peer_pubkey=_PUBKEY,
+        bearer=('192.168.1.50', 51820),
+    )
+
+
+@pytest.fixture
+def tunnelled(
+    overlay: TCPAddress,
+    spec: WGTunnelSpec,
+) -> TunnelledAddress:
+    return TunnelledAddress(overlay=overlay, tunnel=spec)
+
+
+def test_wg_pubkey_codec_roundtrip():
+    '''
+    Standard `wg(8)` base64 keys can contain `/`, which cannot be
+    embedded unchanged in a slash-delimited maddr. Prove the helper
+    emits `u`-prefixed multibase base64url without `/` and decodes
+    it back to the exact original 32-byte key.
+
+    '''
+    mb_key: str = mb_pubkey(_PUBKEY)
+
+    assert mb_key.startswith('u')
+    assert '/' not in mb_key
+    assert wg8_pubkey(mb_key) == _PUBKEY
+
+
+@pytest.mark.parametrize(
+    'key, converter',
+    [
+        pytest.param(
+            'dG9vIHNob3J0',
+            mb_pubkey,
+            id='wg8-base64',
+        ),
+        pytest.param(
+            'udG9vIHNob3J0',
+            wg8_pubkey,
+            id='multibase',
+        ),
+    ],
+)
+def test_wg_pubkey_codec_rejects_wrong_size(
+    key: str,
+    converter,
+):
+    '''
+    WireGuard silently-corrupt key handling would let an invalid
+    identity reach peer verification. Exercise both input encodings
+    with a short payload and prove conversion rejects it before a
+    tunnel spec or maddr can be constructed.
+
+    '''
+    with pytest.raises(
+        ValueError,
+        match='must decode to 32 bytes',
+    ):
+        converter(key)
+
+
+def test_proto_key_delegates(
+    tunnelled: TunnelledAddress,
+    overlay: TCPAddress,
+):
+    '''
+    A tunnel has no transport of its own, so every table lookup
+    must see the *overlay's* proto-key.
+
+    '''
+    assert tunnelled.proto_key == overlay.proto_key == 'tcp'
+
+
+def test_unwrap_is_identical_to_overlay(
+    tunnelled: TunnelledAddress,
+    overlay: TCPAddress,
+):
+    '''
+    The whole point: nothing new crosses the wire, so a peer
+    never has to understand tunnels.
+
+    '''
+    assert tunnelled.unwrap() == overlay.unwrap()
+
+    # and it must survive msgpack as-is
+    enc: bytes = msgspec.msgpack.encode(tunnelled.unwrap())
+    assert msgspec.msgpack.decode(enc) == list(overlay.unwrap())
+
+
+def test_unwrap_roundtrips_back_to_plain_overlay(
+    tunnelled: TunnelledAddress,
+    overlay: TCPAddress,
+):
+    '''
+    `wrap_address()` on a tunnelled addr's unwrapped form yields
+    the *plain* overlay type — the tunnel is simply absent, which
+    is correct: it was never on the wire.
+
+    '''
+    rewrapped = wrap_address(tunnelled.unwrap())
+    assert type(rewrapped) is TCPAddress
+    assert rewrapped == overlay
+    assert not isinstance(rewrapped, TunnelledAddress)
+
+
+def test_bindspace_and_validity_delegate(
+    tunnelled: TunnelledAddress,
+    overlay: TCPAddress,
+):
+    assert tunnelled.bindspace == overlay.bindspace
+    assert tunnelled.is_valid == overlay.is_valid
+
+
+def test_is_wrapped_addr_accepts_tunnelled(
+    tunnelled: TunnelledAddress,
+    overlay: TCPAddress,
+):
+    '''
+    `TunnelledAddress` is deliberately absent from
+    `_address_types`, so `is_wrapped_addr()` needs its own
+    clause.
+
+    '''
+    assert is_wrapped_addr(overlay)
+    assert is_wrapped_addr(tunnelled)
+    # the unwrapped form is NOT a wrapped addr
+    assert not is_wrapped_addr(tunnelled.unwrap())
+
+
+def test_namespace_comes_from_the_tunnel(
+    overlay: TCPAddress,
+):
+    '''
+    First real consumer of `Address.namespace`, spec'd in the
+    protocol since day one and implemented by no backend.
+
+    '''
+    # XXX, "no backend implements it" is literal — the member
+    # isn't even declared, so this is `AttributeError` not `None`.
+    # This assert is the guard: when a backend finally declares
+    # `.namespace`, it fails and the `getattr()` fallback in
+    # `TunnelledAddress.namespace` can go.
+    assert not hasattr(overlay, 'namespace')
+
+    no_ns = TunnelledAddress(
+        overlay=overlay,
+        tunnel=WGTunnelSpec(peer_pubkey=_PUBKEY),
+    )
+    assert no_ns.namespace is None
+
+    in_ns = TunnelledAddress(
+        overlay=overlay,
+        tunnel=WGTunnelSpec(peer_pubkey=_PUBKEY, netns='wg-test'),
+    )
+    assert in_ns.namespace == ('netns', 'wg-test')
+
+
+def test_strip_tunnels(
+    tunnelled: TunnelledAddress,
+    overlay: TCPAddress,
+    spec: WGTunnelSpec,
+):
+    # idempotent on a plain addr
+    assert strip_tunnels(overlay) is overlay
+    # peels one
+    assert strip_tunnels(tunnelled) is overlay
+    # and collapses a nested stack in one call
+    nested = TunnelledAddress(overlay=tunnelled, tunnel=spec)
+    assert strip_tunnels(nested) is overlay
+
+
+def test_tunnels_of_is_outermost_first(
+    tunnelled: TunnelledAddress,
+    overlay: TCPAddress,
+):
+    assert tunnels_of(overlay) == ()
+    assert tunnels_of(tunnelled) == (tunnelled.tunnel,)
+
+    inner_spec = WGTunnelSpec(peer_pubkey=_PUBKEY, iface='wg1')
+    nested = TunnelledAddress(
+        overlay=tunnelled,
+        tunnel=inner_spec,
+    )
+    assert tunnels_of(nested) == (inner_spec, tunnelled.tunnel)
+
+
+def test_frozen(
+    tunnelled: TunnelledAddress,
+):
+    with pytest.raises(AttributeError):
+        tunnelled.overlay = TCPAddress('127.0.0.1', 1)

tests/ipc/test_channel_tunnel_boundary.py

@@ -0,0 +1,91 @@
+'''
+Tunnel annotation peeling at the outbound IPC transport boundary.
+
+'''
+from __future__ import annotations
+
+import pytest
+import trio
+
+from tractor.discovery import (
+    TunnelledAddress,
+    WGTunnelSpec,
+    tunnels_of,
+)
+from tractor.ipc import _chan
+from tractor.ipc._tcp import TCPAddress
+
+
+_PUBKEY: str = 'g3x7z0AdV1rM6UQU22CC7IL3/ivn4DzrE7ikDhCZ/Dc='
+
+
+@pytest.fixture
+def overlay() -> TCPAddress:
+    return TCPAddress('127.0.0.1', 0)
+
+
+@pytest.fixture
+def tunnelled(
+    overlay: TCPAddress,
+) -> TunnelledAddress:
+    return TunnelledAddress(
+        overlay=overlay,
+        tunnel=WGTunnelSpec(
+            peer_pubkey=_PUBKEY,
+            bearer=('192.168.1.50', 51820),
+        ),
+    )
+
+
+@pytest.mark.parametrize('use_tunnel', [False, True])
+def test_channel_peels_before_transport_dispatch(
+    monkeypatch,
+    overlay: TCPAddress,
+    tunnelled: TunnelledAddress,
+    use_tunnel: bool,
+):
+    '''
+    Exact-type transport lookup cannot dispatch a `TunnelledAddress`,
+    and passing one onward would make TCP dial the wrong object. Feed
+    both a plain overlay and its annotated wrapper into
+    `Channel.from_addr()`, capture lookup and connect arguments, and
+    prove both transport operations receive only the same bindable
+    TCP address while the caller's tunnel metadata remains intact.
+
+    '''
+    seen: list[tuple[str, TCPAddress]] = []
+
+    class FakeTransport:
+        @classmethod
+        async def connect_to(
+            cls,
+            addr: TCPAddress,
+            **kwargs,
+        ) -> FakeTransport:
+            seen.append(('connect', addr))
+            return cls()
+
+    def fake_transport_from_addr(
+        addr: TCPAddress,
+    ) -> type[FakeTransport]:
+        seen.append(('lookup', addr))
+        return FakeTransport
+
+    monkeypatch.setattr(
+        _chan,
+        'transport_from_addr',
+        fake_transport_from_addr,
+    )
+
+    async def main() -> None:
+        declared = tunnelled if use_tunnel else overlay
+        chan = await _chan.Channel.from_addr(declared)
+        assert isinstance(chan.transport, FakeTransport)
+
+    trio.run(main)
+
+    assert seen == [
+        ('lookup', overlay),
+        ('connect', overlay),
+    ]
+    assert tunnels_of(tunnelled) == (tunnelled.tunnel,)

tests/ipc/test_each_tpt.py

@@ -703,17 +703,20 @@ def test_uds_bindspace_created_implicitly(
 
             root: Actor = tractor.current_actor()
             assert root.is_registrar
+            canonical_addr = _addr.wrap_address(
+                registry_addr,
+            ).unwrap()
 
-            assert registry_addr in root.reg_addrs
+            assert canonical_addr in root.reg_addrs
             assert (
-                registry_addr
+                canonical_addr
                 in
                 _state._runtime_vars['_registry_addrs']
             )
             assert (
-                _addr.wrap_address(registry_addr)
+                canonical_addr
                 in
-                root.registry_addrs
+                [addr.unwrap() for addr in root.registry_addrs]
             )
 
     trio.run(main)

tests/ipc/test_server_tunnel_boundary.py

@@ -0,0 +1,59 @@
+'''
+Tunnel annotation peeling at the inbound IPC transport boundary.
+
+'''
+from __future__ import annotations
+
+import trio
+
+from tractor.discovery import (
+    TunnelledAddress,
+    WGTunnelSpec,
+    tunnels_of,
+)
+from tractor.ipc._server import open_ipc_server
+from tractor.ipc._tcp import TCPAddress
+
+
+_PUBKEY: str = 'g3x7z0AdV1rM6UQU22CC7IL3/ivn4DzrE7ikDhCZ/Dc='
+
+
+def test_server_peels_before_endpoint_construction():
+    '''
+    `Endpoint.start_listener()` reflects on its address's declaring
+    module, so retaining a tunnel wrapper there selects `._tunnel`
+    instead of the TCP backend. Start a real listener from the
+    wrapper, assert the resulting `Endpoint` contains only a resolved
+    `TCPAddress`, and prove the original declaration still carries
+    its tunnel spec for the future bindspace lifecycle.
+
+    '''
+    overlay = TCPAddress('127.0.0.1', 0)
+    tunnelled = TunnelledAddress(
+        overlay=overlay,
+        tunnel=WGTunnelSpec(
+            peer_pubkey=_PUBKEY,
+            bearer=('192.168.1.50', 51820),
+        ),
+    )
+
+    async def main() -> None:
+        async with open_ipc_server() as server:
+            eps = await server.listen_on(
+                accept_addrs=[tunnelled],
+            )
+            assert len(eps) == 1
+            endpoint = eps[0]
+
+            assert type(endpoint.addr) is TCPAddress
+            _, host, port = endpoint.addr.unwrap()
+            assert host == overlay.unwrap()[1]
+            assert port > 0
+            assert endpoint.addr is not tunnelled
+            assert tunnels_of(tunnelled) == (
+                tunnelled.tunnel,
+            )
+
+            server.cancel()
+
+    trio.run(main)

tests/test_local.py

@@ -8,6 +8,7 @@ import trio
 import tractor
 
 from tractor._testing import tractor_test
+from tractor.discovery._addr import wrap_address
 
 
 def test_no_runtime():
@@ -48,7 +49,7 @@ async def test_self_is_registered_localportal(reg_addr):
         with trio.fail_after(0.2):
             sockaddr = await portal.run_from_ns(
                     'self', 'wait_for_actor', name='root')
-            assert sockaddr[0] == reg_addr
+            assert sockaddr[0] == wrap_address(reg_addr).unwrap()
 
 
 def test_local_actor_async_func(reg_addr):

tractor/_root.py

@@ -55,6 +55,7 @@ from .discovery._addr import (
     mk_uuid,
     wrap_address,
 )
+from .discovery._tunnel import strip_tunnels
 from .trionics import (
     is_multi_cancelled,
     collapse_eg,
@@ -505,6 +506,7 @@ async def open_root_actor(
             # proto if not already provided.
             if not tpt_bind_addrs:
                 for addr in ponged_addrs:
+                    bindable_addr: Address = strip_tunnels(addr)
                     tpt_bind_addrs.append(
                         # XXX, these are `Address` NOT `UnwrappedAddress`.
                         #
@@ -512,8 +514,8 @@ async def open_root_actor(
                         # protos we allocate port=0 such that the system
                         # allocates a random value at bind time; this
                         # happens in the `.ipc.*` stack's backend.
-                        addr.get_random(
+                        bindable_addr.get_random(
-                            bindspace=addr.bindspace,
+                            bindspace=bindable_addr.bindspace,
                         )
                     )
 

tractor/discovery/__init__.py

@@ -18,11 +18,10 @@
 Discovery (protocols) API for automatic addressing
 and location management of (service) actors.
 
-NOTE: this ``__init__`` only eagerly imports the
+NOTE: this ``__init__`` only eagerly imports the lightweight
-``._multiaddr`` submodule (for public re-exports).
+``._multiaddr`` and ``._tunnel`` submodules for public re-exports.
-Heavier submodules like ``._addr`` and ``._api``
+Heavier submodules like ``._addr`` and ``._api`` are NOT imported
-are NOT imported here to avoid circular imports;
+here to avoid circular imports; use direct module paths for those.
-use direct module paths for those.
 
 '''
 from ._multiaddr import (
@@ -30,3 +29,14 @@ from ._multiaddr import (
     parse_maddr as parse_maddr,
     mk_maddr as mk_maddr,
 )
+from ._tunnel import (
+    TunnelledAddress as TunnelledAddress,
+    TunnelSpec as TunnelSpec,
+    WGTunnelSpec as WGTunnelSpec,
+    mb_pubkey as mb_pubkey,
+    mk_wg_maddr as mk_wg_maddr,
+    parse_wg_maddr as parse_wg_maddr,
+    strip_tunnels as strip_tunnels,
+    tunnels_of as tunnels_of,
+    wg8_pubkey as wg8_pubkey,
+)

tractor/discovery/_addr.py

@@ -19,7 +19,9 @@ from typing import (
     Any,
     Protocol,
     ClassVar,
+    Literal,
     Type,
+    TypeAlias,
     TYPE_CHECKING,
 )
 
@@ -40,9 +42,13 @@ from ..ipc._uds import (
 if TYPE_CHECKING:
     # ONLY type-annots, the eager import costs ~4.5ms
     # of `import tractor` wall-time (gh #470).
+    from ._tunnel import (
+        TunnelledAddress,
+    )
     from ..runtime._runtime import Actor
 else:
     Actor = Any
+    TunnelledAddress = Any
 
 log = get_logger()
 
@@ -69,25 +75,44 @@ log = get_logger()
 #    seems like the right name as per,
 #    https://www.geeksforgeeks.org/introduction-to-address-descriptor/
 #
-UnwrappedAddress = (
+TaggedTCPAddress: TypeAlias = tuple[
-    # tcp/udp/uds
+    Literal['tcp'],
-    tuple[
+    str,
-        str,  # host/domain(tcp), filesys-dir(uds)
+    int,
-        int|str,  # port/path(uds)
 ]
-    # ?TODO? should we also include another 2 fields from
+TaggedUnixAddress: TypeAlias = tuple[
-    # our `Aid` msg such that we include the runtime `Actor.uid`
+    Literal['unix'],
-    # of `.name` and `.uuid`?
+    str,
-    # - would ensure uniqueness across entire net?
+]
-    # - allows for easier runtime-level filtering of "actors by
+TaggedUDSAlias: TypeAlias = tuple[
-    #   service name"
+    Literal['uds'],
+    str,
+]
+TaggedAddress: TypeAlias = (
+    TaggedTCPAddress
+    |TaggedUnixAddress
 )
 
+# Input-only compatibility forms retained for older callers and
+# serialized payloads.
+LegacyTCPAddress: TypeAlias = tuple[str, int]
+LegacyUDSAddress: TypeAlias = tuple[str, str]
+LegacyUnwrappedAddress: TypeAlias = (
+    LegacyTCPAddress
+    |LegacyUDSAddress
+)
+UnwrappedAddress = TaggedAddress
+# ?TODO? should we also include another 2 fields from our `Aid` msg
+# such that we include the runtime `Actor.uid` of `.name` and `.uuid`?
+# - would ensure uniqueness across entire net?
+# - allows for easier runtime-level filtering of "actors by service
+#   name"
+
 
 # TODO, maybe rename to `SocketAddress`?
 class Address(Protocol):
     proto_key: ClassVar[str]
-    unwrapped_type: ClassVar[UnwrappedAddress]
+    unwrapped_type: ClassVar[type]
 
     # TODO, i feel like an `.is_bound()` is a better thing to
     # support?
@@ -99,7 +124,7 @@ class Address(Protocol):
 
     # TODO, maybe `.netns` is a better name?
     @property
-    def namespace(self) -> tuple[str, int]|None:
+    def namespace(self) -> tuple[str, str|int]|None:
         '''
         The if-available, OS-specific "network namespace" key.
 
@@ -209,7 +234,16 @@ def get_address_cls(name: str) -> Type[Address]:
 
 
 def is_wrapped_addr(addr: any) -> bool:
-    return type(addr) in _address_types.values()
+    # XXX NOTE, a `TunnelledAddress` is genuinely "wrapped" but is
+    # deliberately NOT in `_address_types`: it has no
+    # `MsgTransport` of its own (a tunnel is transparent to
+    # `socket(2)`), so it gets no proto-key entry. See `._tunnel`.
+    from ._tunnel import TunnelledAddress
+    return (
+        type(addr) in _address_types.values()
+        or
+        isinstance(addr, TunnelledAddress)
+    )
 
 
 def mk_uuid() -> str:
@@ -223,8 +257,16 @@ def mk_uuid() -> str:
 
 
 def wrap_address(
-    addr: UnwrappedAddress|str,
+    addr: (
-) -> Address:
+        TaggedAddress
+        |TaggedUDSAlias
+        |LegacyUnwrappedAddress
+        |list[str|int]
+        |str
+        |Address
+        |TunnelledAddress
+    ),
+) -> Address|TunnelledAddress:
     '''
     Wrap an `UnwrappedAddress` as an `Address`-type based
     on matching builtin python data-structures which we adhoc
@@ -246,6 +288,20 @@ def wrap_address(
     #     import pdbp; pdbp.set_trace()
     match addr:
 
+        case (
+            ('tcp', str(), int())
+            |
+            ['tcp', str(), int()]
+        ):
+            return TCPAddress.from_addr(addr)
+
+        case (
+            (('unix' | 'uds'), str())
+            |
+            [('unix' | 'uds'), str()]
+        ):
+            return UDSAddress.from_addr(addr)
+
         # classic network socket-address as tuple/list
         case (
             (str(), int())

tractor/discovery/_multiaddr.py

@@ -38,9 +38,13 @@ if TYPE_CHECKING:
     # `import tractor` path (gh #470).
     from multiaddr import Multiaddr
     from tractor.discovery._addr import Address
+    from tractor.discovery._tunnel import (
+        TunnelledAddress,
+    )
 else:
     Multiaddr = Any
     Address = Any
+    TunnelledAddress = Any
 
 # map from tractor-internal `proto_key` identifiers
 # to the standard multiaddr protocol name strings.
@@ -57,7 +61,7 @@ _maddr_to_tpt_proto: dict[str, str] = {
 
 
 def mk_maddr(
-    addr: 'Address',
+    addr: 'Address|TunnelledAddress',
 ) -> Multiaddr:
     '''
     Construct a `Multiaddr` from a tractor `Address` instance,
@@ -67,6 +71,13 @@ def mk_maddr(
     '''
     from multiaddr import Multiaddr
 
+    from ._tunnel import (
+        TunnelledAddress,
+        mk_wg_maddr,
+    )
+    if isinstance(addr, TunnelledAddress):
+        return mk_wg_maddr(addr)
+
     proto_key: str = addr.proto_key
     maddr_proto: str|None = _tpt_proto_to_maddr.get(proto_key)
     if maddr_proto is None:
@@ -76,7 +87,7 @@ def mk_maddr(
 
     match proto_key:
         case 'tcp':
-            host, port = addr.unwrap()
+            _, host, port = addr.unwrap()
             ip = ipaddress.ip_address(host)
             net_proto: str = (
                 'ip4' if ip.version == 4
@@ -87,13 +98,12 @@ def mk_maddr(
             )
 
         case 'uds':
-            filedir, filename = addr.unwrap()
+            _, sockpath = addr.unwrap()
-            filepath = Path(filedir) / filename
             # NOTE, strip any leading `/` to avoid
             # double-slash `/unix//run/..` which the
             # multiaddr parser rejects as "empty
             # protocol path".
-            fpath_str: str = str(filepath).lstrip('/')
+            fpath_str: str = sockpath.lstrip('/')
             return Multiaddr(
                 f'/{maddr_proto}/{fpath_str}'
             )
@@ -101,7 +111,7 @@ def mk_maddr(
 
 def parse_maddr(
     maddr_str: str,
-) -> 'Address':
+) -> 'Address|TunnelledAddress':
     '''
     Parse a multiaddr string into a tractor `Address`.
 
@@ -113,7 +123,16 @@ def parse_maddr(
     from tractor.ipc._tcp import TCPAddress
     from tractor.ipc._uds import UDSAddress
 
+    try:
         maddr = Multiaddr(maddr_str)
+    except ValueError:
+        # Diagnose an unavailable WG codec after upstream parsing
+        # fails. Pre-checking the raw string would misclassify valid
+        # values such as `/unix/tmp/wg/service.sock`.
+        if '/wg/' in maddr_str:
+            from ._tunnel import _wg_proto_code
+            _wg_proto_code()
+        raise
     proto_names: list[str] = [
         p.name for p in maddr.protocols()
     ]
@@ -136,6 +155,10 @@ def parse_maddr(
                 filename=sockpath.name,
             )
 
+        case _ if 'wg' in proto_names:
+            from ._tunnel import parse_wg_maddr
+            return parse_wg_maddr(maddr)
+
         case _:
             raise ValueError(
                 f'Unsupported multiaddr protocol combo: '
@@ -154,11 +177,11 @@ EndpointsTable = dict[
     list[str|tuple],        # maddr strs or UnwrappedAddress
 ]
 
-# output table: actor/service name -> list of wrapped
+# output table: actor/service name -> list of wrapped address
-# `Address` instances ready for transport binding.
+# declarations ready for bindspace handling.
 ParsedEndpoints = dict[
     str,                    # actor/service name
-    list['Address'],
+    list['Address|TunnelledAddress'],
 ]
 
 
@@ -167,7 +190,7 @@ def parse_endpoints(
 ) -> ParsedEndpoints:
     '''
     Parse a service-endpoint config table into wrapped
-    `Address` instances suitable for transport binding.
+    address declarations suitable for bindspace handling.
 
     Each key is an actor/service name and each value is
     a list of addresses in any format accepted by
@@ -179,6 +202,8 @@ def parse_endpoints(
       ``/uds/`` proto_key)
     - raw unwrapped tuples: ``('127.0.0.1', 1616)``
     - pre-wrapped `Address` objects (passed through)
+    - `wg` maddrs, returned as `TunnelledAddress` wrappers which
+      must be peeled at the eventual bind/dial boundary
 
     Returns a new `dict` with the same keys, where each
     value list contains the corresponding `Address`

tractor/discovery/_tunnel.py

@@ -0,0 +1,502 @@
+# tractor: structured concurrent "actors".
+# Copyright 2018-eternity Tyler Goodlet.
+
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Affero General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Affero General Public License for more details.
+
+# You should have received a copy of the GNU Affero General Public License
+# along with this program.  If not, see <https://www.gnu.org/licenses/>.
+r'''
+Tunnelled addresses: an `Address` that rides *inside* a tunnel.
+
+A tunnel (`wg`, and later plain ip-in-udp, `veth`-in-netns, ..) is
+**not** a `MsgTransport`. Its data plane is transparent to the
+application's `socket(2)`, so it never gets its own entry in
+`._addr._address_types` nor a `MsgpackTransport` impl. Instead it
+*annotates* an existing L4 addr, and this module carries that
+annotation beside it.
+
+That does not mean tractor can never provision the tunnel. Layer A
+assumes an externally configured iface; a later bindspace lifecycle
+may create its iface, netns, routes, and kernel-owned UDP listener
+through netlink/`pyroute2`. The distinction is that this
+control-plane work does not turn the bearer into an application
+`Endpoint`.
+
+Naming follows `py-multiaddr`'s encapsulation model, where earlier
+maddr segs wrap later ones (`.encapsulate()` appends):
+
+    /ip4/192.168.1.50/udp/51820/wg/u<key>/ip4/10.0.11.1/tcp/1616
+    \_______ bearer __________/\__ key __/\______ overlay ______/
+
+- **bearer**: the underlay ep the tunnel iface listens on
+  (`wg(8)`'s `ListenPort`). The kernel owns this data-plane socket;
+  tractor may later provision it through a bindspace lifecycle but
+  never treats it as a `MsgTransport` listener.
+- **overlay**: the ep `tractor` actually binds/dials, i.e. the
+  application IPC endpoint handled by `Endpoint`/`MsgTransport`.
+
+We avoid `inner`/`outer` deliberately: in a *call* stack "inner"
+reads as higher-up and later-called, whereas here the
+encapsulated addr is bound *first* and sits deeper in the maddr.
+
+XXX XXX READ THIS BEFORE USING XXX XXX
+--------------------------------------
+A `TunnelledAddress` **must be unwrapped to `.overlay` before it
+reaches `Endpoint`**. `Endpoint.start_listener()` resolves its
+listener fns by `inspect.getmodule(self.addr)`, so a wrapper
+would resolve to *this* module rather than the transport's and
+silently fail to find `start_listener()`.
+
+If a wrapper reaches `Endpoint`, its backend lookup resolves this
+module instead of the overlay transport module:
+
+    tpt_mod = inspect.getmodule(self.addr)
+    await tpt_mod.start_listener(addr=self.addr)
+
+This module intentionally does not impersonate that transport API.
+Unwrap at the parse or bindspace boundary; see `.overlay` and
+`strip_tunnels()`.
+
+'''
+from __future__ import annotations
+import base64
+import ipaddress
+from typing import (
+    Any,
+    ClassVar,
+    TYPE_CHECKING,
+)
+
+import msgspec
+import multibase
+
+if TYPE_CHECKING:
+    from multiaddr import Multiaddr
+
+    from ._addr import (
+        Address,
+        UnwrappedAddress,
+    )
+else:
+    Address = Any
+    Multiaddr = Any
+    UnwrappedAddress = Any
+
+
+class WGTunnelSpec(
+    msgspec.Struct,
+    frozen=True,
+):
+    '''
+    The `wg`-specific half of a tunnel annotation.
+
+    Everything here is an *interface-layer* concern owned by
+    `wg(8)`/the kernel. A later tractor bindspace lifecycle may
+    provision it through netlink, but it is never an application
+    `MsgTransport` endpoint.
+
+    '''
+    # tunnel peer pubkey in the std-base64 `wg(8)` form, i.e.
+    # directly comparable to `wg show <if> peers` output
+    peer_pubkey: str
+
+    # the underlay `(ip, udp-port)` the wg iface listens on, i.e.
+    # wg's `ListenPort`. The kernel owns the socket even when a
+    # tractor bindspace lifecycle provisions it. `None` when the
+    # maddr declared only a key (identity) and the bearer is
+    # implied by local cfg.
+    bearer: tuple[str, int]|None = None
+
+    iface: str = 'wg0'
+    netns: str|None = None
+
+    # layer-C-only fields, unset in layer A
+    maybe_allowed_ips: tuple[str, ...] = ()
+
+    # the `multiaddr` proto name for this tunnel kind
+    tunnel_key: ClassVar[str] = 'wg'
+
+
+# the tunnel-spec union; grows as new tunnel kinds land
+# (plain ip-in-udp, `veth`-in-netns, ..)
+TunnelSpec = WGTunnelSpec
+
+
+def mb_pubkey(
+    wg8_key: str,
+) -> str:
+    '''
+    Encode a `wg(8)` public key as multibase base64url.
+
+    WireGuard public keys are exactly 32 bytes. Enforce that here
+    before handing the `u`-prefixed result to `py-multiaddr`'s
+    `/wg/` codec.
+
+    '''
+    raw: bytes = base64.b64decode(
+        wg8_key,
+        validate=True,
+    )
+    if (nbytes := len(raw)) != 32:
+        raise ValueError(
+            f'A `wg` public key must decode to 32 bytes, '
+            f'not {nbytes}!'
+        )
+
+    return multibase.encode(
+        'base64url',
+        raw,
+    ).decode('ascii')
+
+
+def wg8_pubkey(
+    mb_key: str,
+) -> str:
+    '''
+    Decode a multibase public key to `wg(8)` standard base64.
+
+    '''
+    raw: bytes = multibase.decode(mb_key)
+    if (nbytes := len(raw)) != 32:
+        raise ValueError(
+            f'A `wg` public key must decode to 32 bytes, '
+            f'not {nbytes}!'
+        )
+
+    return base64.b64encode(raw).decode('ascii')
+
+
+def _wg_proto_code() -> int:
+    '''
+    Deliver the installed `py-multiaddr` `/wg/` protocol code.
+
+    `wg` support is merged upstream but not yet in a release, so
+    fail clearly when tractor was installed without the pinned rev.
+
+    '''
+    from multiaddr.exceptions import ProtocolNotFoundError
+    from multiaddr.protocols import protocol_with_name
+
+    try:
+        return protocol_with_name('wg').code
+    except ProtocolNotFoundError as exc:
+        raise RuntimeError(
+            'Installed `py-multiaddr` has no `/wg/` protocol!\n'
+            'Install py-multiaddr#108 or use tractor\'s pinned '
+            'dependency revision.\n'
+        ) from exc
+
+
+class TunnelledAddress(
+    msgspec.Struct,
+    frozen=True,
+):
+    '''
+    An `Address` annotated with the tunnel it must be reached
+    *through*.
+
+    Address-level properties delegate to `.overlay`, so proto-key
+    guards and `.unwrap()` retain their existing meaning and
+    **nothing new crosses the wire**. Transport boundaries which
+    dispatch on exact type or declaring module must first call
+    `strip_tunnels()`.
+
+    '''
+    overlay: Address|TunnelledAddress
+    tunnel: TunnelSpec
+
+    # ---- delegated, so the runtime can't tell the difference ----
+
+    @property
+    def proto_key(self) -> str:
+        '''
+        The *overlay's* proto-key — a tunnel has no transport of
+        its own.
+
+        NOTE, this is a property whereas `Address.proto_key` is
+        spec'd as a `ClassVar`. That's deliberate: the value is
+        only knowable per-instance here, and this type is never
+        registered in `_address_types`, so no class-level access
+        of it should ever occur.
+
+        '''
+        return self.overlay.proto_key
+
+    @property
+    def is_valid(self) -> bool:
+        return self.overlay.is_valid
+
+    @property
+    def bindspace(self) -> str:
+        return self.overlay.bindspace
+
+    def unwrap(self) -> UnwrappedAddress:
+        '''
+        Delegate to `.overlay`, so the tunnel annotation is
+        **not** serialized and no peer needs to understand it.
+
+        '''
+        return self.overlay.unwrap()
+
+    # ---- the tunnel's own contribution ----
+
+    @property
+    def namespace(self) -> tuple[str, str|int]|None:
+        '''
+        The tunnel's netns, when it declares one.
+
+        This is the first real consumer of `Address.namespace`,
+        spec'd in the `Address` protocol since day one and
+        implemented by no backend.
+
+        XXX NOTE, "implemented by no backend" is literal: neither
+        `TCPAddress` nor `UDSAddress` defines `.namespace` at all,
+        so a plain attr access on an overlay raises
+        `AttributeError` rather than yielding `None`. Hence the
+        `getattr()` — drop it once the backends actually declare
+        the member.
+
+        '''
+        if (netns := self.tunnel.netns) is None:
+            return getattr(self.overlay, 'namespace', None)
+
+        return ('netns', netns)
+
+    def __repr__(self) -> str:
+        return (
+            f'{type(self).__name__}(\n'
+            f'  overlay={self.overlay!r},\n'
+            f'  via={self.tunnel.tunnel_key!r} '
+            f'iface={self.tunnel.iface!r},\n'
+            f')'
+        )
+
+
+def _wg_bearer(
+    bearer_ma: Multiaddr,
+    source_ma: Multiaddr,
+) -> tuple[str, int]:
+    '''
+    Parse one kernel-owned `wg` bearer endpoint.
+
+    '''
+    proto_names: list[str] = [
+        proto.name
+        for proto in bearer_ma.protocols()
+    ]
+    match proto_names:
+        case [('ip4' | 'ip6') as ip_proto, 'udp']:
+            return (
+                bearer_ma.value_for_protocol(ip_proto),
+                int(bearer_ma.value_for_protocol('udp')),
+            )
+
+        case _:
+            raise ValueError(
+                f'Bad `wg` bearer, expected '
+                f'`/ip4|ip6/<host>/udp/<port>`\n'
+                f'got: {bearer_ma}\n'
+                f'from maddr: {source_ma}\n'
+            )
+
+
+def parse_wg_maddr(
+    maddr: str|Multiaddr,
+) -> TunnelledAddress:
+    '''
+    Parse a `wg` maddr stack into nested tunnel annotations.
+
+    Pure: every segment operation delegates to `py-multiaddr`.
+    Repeated `.decapsulate_code()` calls peel the last `/wg/`
+    first, while `.split()` and `.join()` isolate that tunnel's
+    bearer without parsing slash-delimited strings ourselves.
+
+    '''
+    from multiaddr import Multiaddr
+
+    ma: Multiaddr = (
+        maddr
+        if isinstance(maddr, Multiaddr)
+        else Multiaddr(maddr)
+    )
+    wg_code: int = _wg_proto_code()
+    segs: list[Multiaddr] = ma.split()
+    proto_names: list[str] = [
+        proto.name
+        for seg in segs
+        for proto in seg.protocols()
+    ]
+    if 'wg' not in proto_names:
+        raise ValueError(
+            f'Not a `wg`-tunnelled maddr; no `/wg/` segment!\n'
+            f'maddr: {ma}\n'
+        )
+
+    final_wg_i: int = len(proto_names) - 1
+    final_wg_i -= proto_names[::-1].index('wg')
+    overlay_ma: Multiaddr = Multiaddr.join(
+        *segs[final_wg_i + 1:]
+    )
+    overlay_names: list[str] = [
+        proto.name
+        for proto in overlay_ma.protocols()
+    ]
+    match overlay_names:
+        case [('ip4' | 'ip6'), 'tcp']:
+            from ._multiaddr import parse_maddr
+            overlay: Address|TunnelledAddress = parse_maddr(
+                str(overlay_ma)
+            )
+
+        case []:
+            raise ValueError(
+                f'`wg` maddr declares no overlay endpoint!\n'
+                f'Append the endpoint tractor should bind.\n'
+                f'maddr: {ma}\n'
+            )
+
+        case _:
+            raise ValueError(
+                f'Unsupported `wg` overlay protocol combo: '
+                f'{overlay_names!r}\n'
+                f'overlay: {overlay_ma}\n'
+                f'from maddr: {ma}\n'
+            )
+
+    cursor: Multiaddr = ma
+    while any(
+        proto.name == 'wg'
+        for proto in cursor.protocols()
+    ):
+        cursor_segs: list[Multiaddr] = cursor.split()
+        cursor_names: list[str] = [
+            proto.name
+            for seg in cursor_segs
+            for proto in seg.protocols()
+        ]
+        wg_i: int = len(cursor_names) - 1
+        wg_i -= cursor_names[::-1].index('wg')
+        mb_key: str = cursor_segs[wg_i].value_for_protocol('wg')
+
+        bearer_prefix: Multiaddr = cursor.decapsulate_code(
+            wg_code
+        )
+        prefix_segs: list[Multiaddr] = bearer_prefix.split()
+        prefix_names: list[str] = [
+            proto.name
+            for seg in prefix_segs
+            for proto in seg.protocols()
+        ]
+        prior_wg_i: int = (
+            len(prefix_names) - 1
+            - prefix_names[::-1].index('wg')
+            if 'wg' in prefix_names
+            else -1
+        )
+        bearer_ma: Multiaddr = Multiaddr.join(
+            *prefix_segs[prior_wg_i + 1:]
+        )
+        overlay = TunnelledAddress(
+            overlay=overlay,
+            tunnel=WGTunnelSpec(
+                peer_pubkey=wg8_pubkey(mb_key),
+                bearer=_wg_bearer(bearer_ma, ma),
+            ),
+        )
+        cursor = bearer_prefix
+
+    return overlay
+
+
+def mk_wg_maddr(
+    addr: TunnelledAddress,
+) -> Multiaddr:
+    '''
+    Compose nested tunnel annotations as a canonical `wg` maddr.
+
+    Only the peer key and bearer have maddr representations. Local
+    interface, namespace, and allowed-IP config remains local.
+
+    '''
+    from multiaddr import Multiaddr
+
+    _wg_proto_code()
+    if (bearer := addr.tunnel.bearer) is None:
+        raise ValueError(
+            f'Can not compose a `wg` maddr without a bearer!\n'
+            f'tunnel: {addr.tunnel!r}\n'
+        )
+
+    bindable: Address = strip_tunnels(addr)
+    if bindable.proto_key != 'tcp':
+        raise ValueError(
+            f'Unsupported `wg` overlay proto-key: '
+            f'{bindable.proto_key!r}\n'
+            f'overlay: {bindable!r}\n'
+        )
+
+    host, port = bearer
+    ip = ipaddress.ip_address(host)
+    ip_proto: str = (
+        'ip4'
+        if ip.version == 4
+        else 'ip6'
+    )
+    bearer_ma = Multiaddr(
+        f'/{ip_proto}/{host}/udp/{port}'
+    )
+    key_ma = Multiaddr(
+        f'/wg/{mb_pubkey(addr.tunnel.peer_pubkey)}'
+    )
+
+    from ._multiaddr import mk_maddr
+    overlay_ma: Multiaddr = mk_maddr(addr.overlay)
+    return (
+        bearer_ma
+        .encapsulate(key_ma)
+        .encapsulate(overlay_ma)
+    )
+
+
+def strip_tunnels(
+    addr: Address|TunnelledAddress,
+) -> Address:
+    '''
+    Deliver the bindable `Address`, peeling any tunnel
+    annotation(s).
+
+    Pure. Idempotent on an un-tunnelled `Address`, and loops so
+    a nested (tunnel-in-tunnel) stack collapses in one call.
+
+    Call this at every bind/dial boundary.
+
+    '''
+    while isinstance(addr, TunnelledAddress):
+        addr = addr.overlay
+
+    return addr
+
+
+def tunnels_of(
+    addr: Address|TunnelledAddress,
+) -> tuple[TunnelSpec, ...]:
+    '''
+    Deliver every tunnel spec wrapping `addr`, outermost first.
+
+    Pure; empty for an un-tunnelled `Address`.
+
+    '''
+    specs: list[TunnelSpec] = []
+    while isinstance(addr, TunnelledAddress):
+        specs.append(addr.tunnel)
+        addr = addr.overlay
+
+    return tuple(specs)

tractor/ipc/_chan.py

@@ -46,6 +46,10 @@ from tractor.discovery._addr import (
     Address,
     UnwrappedAddress,
 )
+from tractor.discovery._tunnel import (
+    TunnelledAddress,
+    strip_tunnels,
+)
 from tractor.log import get_logger
 from tractor._exceptions import (
     MsgTypeError,
@@ -182,16 +186,17 @@ class Channel:
     @classmethod
     async def from_addr(
         cls,
-        addr: UnwrappedAddress,
+        addr: UnwrappedAddress|Address|TunnelledAddress,
         **kwargs
     ) -> Channel:
 
         if not is_wrapped_addr(addr):
-            addr: Address = wrap_address(addr)
+            addr = wrap_address(addr)
 
-        transport_cls = transport_from_addr(addr)
+        transport_addr: Address = strip_tunnels(addr)
+        transport_cls = transport_from_addr(transport_addr)
         transport = await transport_cls.connect_to(
-            addr,
+            transport_addr,
             **kwargs,
         )
         # XXX, for UDS *no!* since we recv the peer-pid and build out
@@ -551,7 +556,7 @@ class Channel:
 
 @acm
 async def _connect_chan(
-    addr: UnwrappedAddress,
+    addr: UnwrappedAddress|Address|TunnelledAddress,
     close_timeout: float|None = None,
 ) -> typing.AsyncGenerator[Channel, None]:
     '''

tractor/ipc/_server.py

@@ -59,12 +59,16 @@ from ..msg import (
 from ..trionics import maybe_open_nursery
 from ..runtime import _state
 from .. import log
-from ..discovery._addr import Address
+from ..discovery._addr import (
+    Address,
+    UnwrappedAddress,
+)
 from ._chan import Channel
 from ._transport import MsgTransport
 
 
 if TYPE_CHECKING:
+    from ..discovery._tunnel import TunnelledAddress
     from ..runtime._runtime import Actor
     from ..runtime._supervise import ActorNursery
 
@@ -965,7 +969,9 @@ class Server(Struct):
     async def listen_on(
         self,
         *,
-        accept_addrs: list[tuple[str, int|str]]|None = None,
+        accept_addrs: list[
+            UnwrappedAddress|Address|TunnelledAddress
+        ]|None = None,
         stream_handler_nursery: Nursery|None = None,
     ) -> list[Endpoint]:
         '''
@@ -1048,7 +1054,7 @@ async def _serve_ipc_eps(
     *,
     server: IPCServer,
     stream_handler_tn: Nursery,
-    listen_addrs: list[tuple[str, int|str]],
+    listen_addrs: list[Address|TunnelledAddress],
 
     task_status: TaskStatus[
         Nursery,
@@ -1064,6 +1070,8 @@ async def _serve_ipc_eps(
     `.cancel_server()` is called.
 
     '''
+    from ..discovery._tunnel import strip_tunnels
+
     try:
         listen_tn: Nursery
         async with trio.open_nursery() as listen_tn:
@@ -1072,7 +1080,8 @@ async def _serve_ipc_eps(
             # XXX NOTE, required to call `serve_listeners()` below.
             # ?TODO, maybe just pass `list(eps.values()` tho?
             listeners: list[trio.abc.Listener] = []
-            for addr in listen_addrs:
+            for declared_addr in listen_addrs:
+                addr: Address = strip_tunnels(declared_addr)
                 ep = Endpoint(
                     addr=addr,
                     listen_tn=listen_tn,

tractor/ipc/_tcp.py

@@ -47,8 +47,10 @@ if TYPE_CHECKING:
     # ONLY type-annots, the eager import costs
     # `import tractor` wall-time (gh #470).
     from multiaddr import Multiaddr
+    from tractor.discovery._addr import TaggedTCPAddress
 else:
     Multiaddr = Any
+    TaggedTCPAddress = Any
 
 
 log = get_logger()
@@ -70,7 +72,7 @@ class TCPAddress(
             ) from valerr
 
     proto_key: ClassVar[str] = 'tcp'
-    unwrapped_type: ClassVar[type] = tuple[str, int]
+    unwrapped_type: ClassVar[type] = tuple
     def_bindspace: ClassVar[str] = '127.0.0.1'
 
     # ?TODO, actually validate ipv4/6 with stdlib's `ipaddress`
@@ -112,19 +114,35 @@ class TCPAddress(
     @classmethod
     def from_addr(
         cls,
-        addr: tuple[str, int]
+        addr: tuple|list,
     ) -> TCPAddress:
         match addr:
-            case (str(), int()):
+            case (
-                return TCPAddress(addr[0], addr[1])
+                ('tcp', str() as host, int() as port)
+                |
+                ['tcp', str() as host, int() as port]
+                |
+                (str() as host, int() as port)
+                |
+                [str() as host, int() as port]
+                |
+                (
+                    str() as host,
+                    int() as port,
+                    int(),
+                    int(),
+                )
+            ):
+                return TCPAddress(host, port)
             case _:
                 raise ValueError(
                     f'Invalid unwrapped address for {cls}\n'
                     f'{addr}\n'
                 )
 
-    def unwrap(self) -> tuple[str, int]:
+    def unwrap(self) -> TaggedTCPAddress:
         return (
+            self.proto_key,
             self._host,
             self._port,
         )
@@ -223,7 +241,8 @@ class MsgpackTCPStream(MsgpackTransport):
         **kwargs
     ) -> MsgpackTCPStream:
         stream = await trio.open_tcp_stream(
-            *destaddr.unwrap(),
+            destaddr._host,
+            destaddr._port,
             **kwargs
         )
         return MsgpackTCPStream(

tractor/ipc/_uds.py

@@ -77,10 +77,12 @@ if TYPE_CHECKING:
     # ONLY type-annots, the eager import costs
     # `import tractor` wall-time (gh #470).
     from multiaddr import Multiaddr
+    from tractor.discovery._addr import TaggedUnixAddress
     from tractor.runtime._runtime import Actor
 else:
     Multiaddr = Any
     Actor = Any
+    TaggedUnixAddress = Any
 
 
 # Platform-specific credential passing constants
@@ -147,7 +149,7 @@ class UDSAddress(
     # -[ ] need to check what other mult-transport frameworks do
     #     like zmq, nng, uri-spec et al!
     proto_key: ClassVar[str] = 'uds'
-    unwrapped_type: ClassVar[type] = tuple[str, int]
+    unwrapped_type: ClassVar[type] = tuple
     def_bindspace: ClassVar[Path] = get_rt_dir()
 
     @property
@@ -165,7 +167,7 @@ class UDSAddress(
 
     @property
     def sockpath(self) -> Path:
-        return self.bindspace / self.filename
+        return Path(self.bindspace) / self.filename
 
     @property
     def is_valid(self) -> bool:
@@ -179,16 +181,26 @@ class UDSAddress(
     def from_addr(
         cls,
         addr: (
-            tuple[Path|str, Path|str]|Path|str
+            tuple|list|Path|str
         ),
     ) -> UDSAddress:
         match addr:
-            case tuple()|list():
+            case (
-                filedir = Path(addr[0])
+                (('unix' | 'uds'), str()|Path() as sockpath)
-                filename = Path(addr[1])
+                |
+                [('unix' | 'uds'), str()|Path() as sockpath]
+            ):
+                path = Path(sockpath)
+                return UDSAddress(*unwrap_sockpath(path))
+
+            case (
+                (str()|Path() as filedir, str()|Path() as filename)
+                |
+                [str()|Path() as filedir, str()|Path() as filename]
+            ):
                 return UDSAddress(
-                    filedir=filedir,
+                    filedir=Path(filedir),
-                    filename=filename,
+                    filename=Path(filename),
                     # maybe_pid=pid,
                 )
             # NOTE, in case we ever decide to just `.unwrap()`
@@ -203,12 +215,10 @@ class UDSAddress(
                     f'{addr!r}\n'
                 )
 
-    def unwrap(self) -> tuple[str, int]:
+    def unwrap(self) -> TaggedUnixAddress:
-        # XXX NOTE, since this gets passed DIRECTLY to
-        # `.ipc._uds.open_unix_socket_w_passcred()`
         return (
-            str(self.filedir),
+            'unix',
-            str(self.filename),
+            str(self.sockpath),
         )
 
     @classmethod

tractor/msg/types.py

@@ -213,10 +213,11 @@ class SpawnSpec(
     # module import capability
     enable_modules: dict[str, str]
 
-    # TODO: not just sockaddr pairs?
+    # Tagged addresses have protocol-specific tuple shapes which
-    # -[ ] abstract into a `TransportAddr` type?
+    # msgspec cannot express as one decodable union. `wrap_address()`
-    reg_addrs: list[tuple[str, str|int]]
+    # validates each tuple at the transport boundary.
-    bind_addrs: list[tuple[str, str|int]]|None
+    reg_addrs: list[tuple]
+    bind_addrs: list[tuple]|None
 
 
 # TODO: caps based RPC support in the payload?

uv.lock

@@ -273,9 +273,9 @@ name = "greenback"
 version = "1.2.1"
 source = { registry = "https://pypi.org/simple" }
 dependencies = [
-    { name = "greenlet", marker = "python_full_version < '3.14'" },
+    { name = "greenlet" },
-    { name = "outcome", marker = "python_full_version < '3.14'" },
+    { name = "outcome" },
-    { name = "sniffio", marker = "python_full_version < '3.14'" },
+    { name = "sniffio" },
 ]
 sdist = { url = "https://files.pythonhosted.org/packages/dc/c1/ab3a42c0f3ed56df9cd33de1539b3198d98c6ccbaf88a73d6be0b72d85e0/greenback-1.2.1.tar.gz", hash = "sha256:de3ca656885c03b96dab36079f3de74bb5ba061da9bfe3bb69dccc866ef95ea3", size = 42597, upload-time = "2024-02-20T21:23:13.239Z" }
 wheels = [
@@ -518,7 +518,7 @@ wheels = [
 [[package]]
 name = "multiaddr"
 version = "0.2.0"
-source = { registry = "https://pypi.org/simple" }
+source = { git = "https://github.com/multiformats/py-multiaddr.git?rev=f86519daaa21699023d0037c58cdff600313dd09#f86519daaa21699023d0037c58cdff600313dd09" }
 dependencies = [
     { name = "base58" },
     { name = "dnspython" },
@@ -533,10 +533,6 @@ dependencies = [
     { name = "trio-typing" },
     { name = "varint" },
 ]
-sdist = { url = "https://files.pythonhosted.org/packages/c7/10/4e26a8577cfce1c0febc8d83087e1373e93c695c6e73ad010546fb67e229/multiaddr-0.2.0.tar.gz", hash = "sha256:acb6b25c332ec1b2f1f8fef8d03a8c63385d34a87d690df0f4bba43cdf6efe8d", size = 58356, upload-time = "2026-03-17T21:51:00.274Z" }
-wheels = [
-    { url = "https://files.pythonhosted.org/packages/b5/13/56e503d01218d1ca27ea9fda862045a4b400cae5e756f47315f5aaba0eee/multiaddr-0.2.0-py3-none-any.whl", hash = "sha256:bcff7bf3d7de3d6da0b865b25423bcb411de1d20d70cc6abfacf75170d17866c", size = 40424, upload-time = "2026-03-17T21:50:58.833Z" },
-]
 
 [[package]]
 name = "mypy-extensions"
@@ -1193,7 +1189,7 @@ requires-dist = [
     { name = "bidict", specifier = ">=0.23.1" },
     { name = "colorlog", specifier = ">=6.8.2,<7" },
     { name = "msgspec", specifier = ">=0.20.0" },
-    { name = "multiaddr", specifier = ">=0.2.0" },
+    { name = "multiaddr", git = "https://github.com/multiformats/py-multiaddr.git?rev=f86519daaa21699023d0037c58cdff600313dd09" },
     { name = "pdbp", specifier = ">=1.8.2,<2" },
     { name = "platformdirs", specifier = ">=4.4.0" },
     { name = "setproctitle", specifier = ">=1.3,<2" },