diff --git a/ai/prompt-io/claude/20260413T192116Z_f851f28_prompt_io.md b/ai/prompt-io/claude/20260413T192116Z_f851f28_prompt_io.md
new file mode 100644
index 00000000..8c1e1519
--- /dev/null
+++ b/ai/prompt-io/claude/20260413T192116Z_f851f28_prompt_io.md
@@ -0,0 +1,74 @@
+---
+model: claude-opus-4-6
+service: claude
+session: (ad-hoc, not tracked via conf.toml)
+timestamp: 2026-04-13T19:21:16Z
+git_ref: f851f28
+scope: code
+substantive: true
+---
+
+## Prompt
+
+User provided a detailed implementation plan for
+a new `test_tpt_bind_addrs.py` test suite covering
+`open_root_actor(tpt_bind_addrs=...)` — the three
+runtime code paths in `_root.py:385-450`:
+
+1. Non-registrar, no explicit bind -> random addrs
+2. Registrar, no explicit bind -> registry_addrs
+3. Explicit bind given -> `wrap_address()` + merge
+
+Plan specified 6 test functions (~10 parametrized
+variants), predicted a type-mixing bug at line 446,
+and asked for an in-flight fix if confirmed.
+
+## Response summary
+
+Created `tests/discovery/test_tpt_bind_addrs.py`
+with 9 collected test variants across 6 functions:
+
+- `test_registrar_root_tpt_bind_addrs` (3 variants:
+  `bind-eq-reg`, `bind-subset-reg`,
+  `bind-disjoint-reg`)
+- `test_non_registrar_root_tpt_bind_addrs`
+  (2 variants: `bind-same-bindspace`,
+  `bind-disjoint`)
+- `test_non_registrar_default_random_bind`
+  (baseline, no explicit bind)
+- `test_tpt_bind_addrs_as_maddr_str`
+  (multiaddr string input)
+- `test_registrar_merge_binds_union`
+  (registrar + disjoint bind -> union)
+- `test_open_nursery_forwards_tpt_bind_addrs`
+  (`open_nursery(**kwargs)` forwarding)
+
+Confirmed and fixed the predicted bug at
+`_root.py:446`: the registrar merge path mixed
+`Address` objects (`tpt_bind_addrs`) with raw tuples
+(`uw_reg_addrs`) inside `set()`, preventing
+deduplication and causing double-bind `OSError`.
+
+Fix: wrap `uw_reg_addrs` before the set union:
+```python
+# before (broken)
+tpt_bind_addrs = list(set(
+    tpt_bind_addrs + uw_reg_addrs
+))
+# after (fixed)
+tpt_bind_addrs = list(set(
+    tpt_bind_addrs
+    + [wrap_address(a) for a in uw_reg_addrs]
+))
+```
+
+All 9 tests pass after the fix.
+
+## Files changed
+
+- `tests/discovery/test_tpt_bind_addrs.py` (new)
+- `tractor/_root.py:446` (bug fix, 1 line)
+
+## Human edits
+
+N/A — pending review.
diff --git a/ai/prompt-io/prompts/multiaddr_declare_eps.md_ b/ai/prompt-io/prompts/multiaddr_declare_eps.md_
new file mode 100644
index 00000000..dcd07cb8
--- /dev/null
+++ b/ai/prompt-io/prompts/multiaddr_declare_eps.md_
@@ -0,0 +1,76 @@
+ok now i want you to take a look at the most recent commit adding
+a `tpt_bind_addrs` to `open_root_actor()` and extend the existing
+tests/discovery/test_multiaddr* and friends to use this new param in
+at least one suite with parametrizations over,
+
+- `registry_addrs == tpt_bind_addrs`, as in both inputs are the same.
+- `set(registry_addrs) >= set(tpt_bind_addrs)`, as in the registry
+  addrs include the bind set.
+- `registry_addrs != tpt_bind_addrs`, where the reg set is disjoint from
+  the bind set in all possible combos you can imagine.
+
+All of the ^above cases should further be parametrized over,
+- the root being the registrar,
+- a non-registrar root using our bg `daemon` fixture.
+
+once we have a fairly thorough test suite and have flushed out all
+bugs and edge cases we want to design a wrapping API which allows
+declaring full tree's of actors tpt endpoints using multiaddrs such
+that a `dict[str, list[str]]` of actor-name -> multiaddr can be used
+to configure a tree of actors-as-services given such an input
+"endpoints-table" can be matched with the number of appropriately
+named subactore spawns in a `tractor` user-app.
+
+Here is a small example from piker,
+
+- in piker's root conf.toml we define a `[network]` section which can
+  define various actor-service-daemon names set to a maddr
+  (multiaddress str).
+
+- each actor whether part of the `pikerd` tree (as a sub) or spawned
+  in other non-registrar rooted trees (such as `piker chart`) should
+  configurable in terms of its `tractor` tpt bind addresses via
+  a simple service lookup table,
+
+  ```toml
+  [network]
+  pikerd = [
+    '/ip4/127.0.0.1/tcp/6116',  # std localhost daemon-actor tree
+    '/uds/run/user/1000/piker/pikerd@6116.sock',  # same but serving UDS
+  ]
+  chart = [
+    '/ip4/127.0.0.1/tcp/3333',  # std localhost daemon-actor tree
+    '/uds/run/user/1000/piker/chart@3333.sock',
+  ]
+  ```
+
+We should take whatever common API is needed to support this and
+distill it into a
+```python
+tractor.discovery.parse_endpoints(
+) -> dict[
+  str,
+  list[Address]
+  |dict[str, list[Address]]
+  # ^recursive case, see below
+]:
+```
+
+style API which can,
+
+- be re-used easily across dependent projects.
+- correctly raise tpt-backend support errors when a maddr specifying
+  a unsupport proto is passed.
+- be used to handle "tunnelled" maddrs per
+  https://github.com/multiformats/py-multiaddr/#tunneling such that
+  for any such tunneled maddr-`str`-entry we deliver a data-structure
+  which can easily be passed to nested `@acm`s which consecutively
+  setup nested net bindspaces for binding the endpoint addrs using
+  a combo of our `.ipc.*` machinery and, say for example something like
+  https://github.com/svinota/pyroute2, more precisely say for
+  managing tunnelled wireguard eps within network-namespaces,
+  * https://docs.pyroute2.org/
+  * https://docs.pyroute2.org/netns.html
+
+remember to include use of all default `.claude/skills` throughout
+this work!
diff --git a/tests/discovery/test_tpt_bind_addrs.py b/tests/discovery/test_tpt_bind_addrs.py
new file mode 100644
index 00000000..61baecda
--- /dev/null
+++ b/tests/discovery/test_tpt_bind_addrs.py
@@ -0,0 +1,337 @@
+'''
+`open_root_actor(tpt_bind_addrs=...)` test suite.
+
+Verify all three runtime code paths for explicit IPC-server
+bind-address selection in `_root.py`:
+
+1. Non-registrar, no explicit bind -> random addrs from registry proto
+2. Registrar, no explicit bind -> binds to registry_addrs
+3. Explicit bind given -> wraps via `wrap_address()` and uses them
+
+'''
+from functools import partial
+
+import pytest
+import trio
+import tractor
+from tractor.discovery._addr import (
+    wrap_address,
+)
+from tractor.discovery._multiaddr import mk_maddr
+from tractor._testing.addr import get_rando_addr
+
+
+# ------------------------------------------------------------------
+# helpers
+# ------------------------------------------------------------------
+def _bound_bindspaces(
+    actor: tractor.Actor,
+) -> set[str]:
+    '''
+    Collect the set of bindspace strings from the actor's
+    currently bound IPC-server accept addresses.
+
+    '''
+    return {
+        wrap_address(a).bindspace
+        for a in actor.accept_addrs
+    }
+
+
+def _bound_wrapped(
+    actor: tractor.Actor,
+) -> list:
+    '''
+    Return the actor's accept addrs as wrapped `Address` objects.
+
+    '''
+    return [
+        wrap_address(a)
+        for a in actor.accept_addrs
+    ]
+
+
+# ------------------------------------------------------------------
+# 1) Registrar + explicit tpt_bind_addrs
+# ------------------------------------------------------------------
+@pytest.mark.parametrize(
+    'addr_combo',
+    [
+        'bind-eq-reg',
+        'bind-subset-reg',
+        'bind-disjoint-reg',
+    ],
+    ids=lambda v: v,
+)
+def test_registrar_root_tpt_bind_addrs(
+    reg_addr: tuple,
+    tpt_proto: str,
+    debug_mode: bool,
+    addr_combo: str,
+):
+    '''
+    Registrar root-actor with explicit `tpt_bind_addrs`:
+    bound set must include all registry + all bind addr bindspaces
+    (merge behavior).
+
+    '''
+    reg_wrapped = wrap_address(reg_addr)
+
+    if addr_combo == 'bind-eq-reg':
+        bind_addrs = [reg_addr]
+        # extra secondary reg addr for subset test
+        extra_reg = []
+
+    elif addr_combo == 'bind-subset-reg':
+        second_reg = get_rando_addr(tpt_proto)
+        bind_addrs = [reg_addr]
+        extra_reg = [second_reg]
+
+    elif addr_combo == 'bind-disjoint-reg':
+        # port=0 on same host -> completely different addr
+        rando = wrap_address(reg_addr).get_random(
+            bindspace=reg_wrapped.bindspace,
+        )
+        bind_addrs = [rando.unwrap()]
+        extra_reg = []
+
+    all_reg = [reg_addr] + extra_reg
+
+    async def _main():
+        async with tractor.open_root_actor(
+            registry_addrs=all_reg,
+            tpt_bind_addrs=bind_addrs,
+            debug_mode=debug_mode,
+        ):
+            actor = tractor.current_actor()
+            assert actor.is_registrar
+
+            bound = actor.accept_addrs
+            bound_bs = _bound_bindspaces(actor)
+
+            # all registry bindspaces must appear in bound set
+            for ra in all_reg:
+                assert wrap_address(ra).bindspace in bound_bs
+
+            # all bind-addr bindspaces must appear
+            for ba in bind_addrs:
+                assert wrap_address(ba).bindspace in bound_bs
+
+            # registry addr must appear verbatim in bound
+            # (after wrapping both sides for comparison)
+            bound_w = _bound_wrapped(actor)
+            assert reg_wrapped in bound_w
+
+            if addr_combo == 'bind-disjoint-reg':
+                assert len(bound) >= 2
+
+    trio.run(_main)
+
+
+@pytest.mark.parametrize(
+    'addr_combo',
+    [
+        'bind-same-bindspace',
+        'bind-disjoint',
+    ],
+    ids=lambda v: v,
+)
+def test_non_registrar_root_tpt_bind_addrs(
+    daemon,
+    reg_addr: tuple,
+    tpt_proto: str,
+    debug_mode: bool,
+    addr_combo: str,
+):
+    '''
+    Non-registrar root with explicit `tpt_bind_addrs`:
+    bound set must exactly match the requested bind addrs
+    (no merge with registry).
+
+    '''
+    reg_wrapped = wrap_address(reg_addr)
+
+    if addr_combo == 'bind-same-bindspace':
+        # same bindspace as reg but port=0 so we get a random port
+        rando = reg_wrapped.get_random(
+            bindspace=reg_wrapped.bindspace,
+        )
+        bind_addrs = [rando.unwrap()]
+
+    elif addr_combo == 'bind-disjoint':
+        rando = reg_wrapped.get_random(
+            bindspace=reg_wrapped.bindspace,
+        )
+        bind_addrs = [rando.unwrap()]
+
+    async def _main():
+        async with tractor.open_root_actor(
+            registry_addrs=[reg_addr],
+            tpt_bind_addrs=bind_addrs,
+            debug_mode=debug_mode,
+        ):
+            actor = tractor.current_actor()
+            assert not actor.is_registrar
+
+            bound = actor.accept_addrs
+            assert len(bound) == len(bind_addrs)
+
+            # bindspaces must match
+            bound_bs = _bound_bindspaces(actor)
+            for ba in bind_addrs:
+                assert wrap_address(ba).bindspace in bound_bs
+
+            # TCP port=0 should resolve to a real port
+            for uw_addr in bound:
+                w = wrap_address(uw_addr)
+                if w.proto_key == 'tcp':
+                    _host, port = uw_addr
+                    assert port > 0
+
+    trio.run(_main)
+
+
+# ------------------------------------------------------------------
+# 3) Non-registrar, default random bind (baseline)
+# ------------------------------------------------------------------
+def test_non_registrar_default_random_bind(
+    daemon,
+    reg_addr: tuple,
+    debug_mode: bool,
+):
+    '''
+    Baseline: no `tpt_bind_addrs`, daemon running.
+    Bound bindspace matches registry bindspace,
+    but bound addr differs from reg_addr (random).
+
+    '''
+    reg_wrapped = wrap_address(reg_addr)
+
+    async def _main():
+        async with tractor.open_root_actor(
+            registry_addrs=[reg_addr],
+            debug_mode=debug_mode,
+        ):
+            actor = tractor.current_actor()
+            assert not actor.is_registrar
+
+            bound_bs = _bound_bindspaces(actor)
+            assert reg_wrapped.bindspace in bound_bs
+
+            # bound addr should differ from the registry addr
+            # (the runtime picks a random port/path)
+            bound_w = _bound_wrapped(actor)
+            assert reg_wrapped not in bound_w
+
+    trio.run(_main)
+
+
+# ------------------------------------------------------------------
+# 4) Multiaddr string input
+# ------------------------------------------------------------------
+def test_tpt_bind_addrs_as_maddr_str(
+    reg_addr: tuple,
+    debug_mode: bool,
+):
+    '''
+    Pass multiaddr strings as `tpt_bind_addrs`.
+    Runtime should parse and bind successfully.
+
+    '''
+    reg_wrapped = wrap_address(reg_addr)
+    # build a port-0 / random maddr string for binding
+    rando = reg_wrapped.get_random(
+        bindspace=reg_wrapped.bindspace,
+    )
+    maddr_str: str = str(mk_maddr(rando))
+
+    async def _main():
+        async with tractor.open_root_actor(
+            registry_addrs=[reg_addr],
+            tpt_bind_addrs=[maddr_str],
+            debug_mode=debug_mode,
+        ):
+            actor = tractor.current_actor()
+            assert actor.is_registrar
+
+            for uw_addr in actor.accept_addrs:
+                w = wrap_address(uw_addr)
+                if w.proto_key == 'tcp':
+                    _host, port = uw_addr
+                    assert port > 0
+
+    trio.run(_main)
+
+
+# ------------------------------------------------------------------
+# 5) Registrar merge produces union of binds
+# ------------------------------------------------------------------
+def test_registrar_merge_binds_union(
+    tpt_proto: str,
+    debug_mode: bool,
+):
+    '''
+    Registrar + disjoint bind addr: bound set must include
+    both registry and explicit bind addresses.
+
+    '''
+    reg_addr = get_rando_addr(tpt_proto)
+    reg_wrapped = wrap_address(reg_addr)
+
+    rando = reg_wrapped.get_random(
+        bindspace=reg_wrapped.bindspace,
+    )
+    bind_addrs = [rando.unwrap()]
+
+    async def _main():
+        async with tractor.open_root_actor(
+            registry_addrs=[reg_addr],
+            tpt_bind_addrs=bind_addrs,
+            debug_mode=debug_mode,
+        ):
+            actor = tractor.current_actor()
+            assert actor.is_registrar
+
+            bound = actor.accept_addrs
+            bound_w = _bound_wrapped(actor)
+
+            # must have at least 2 (registry + bind)
+            assert len(bound) >= 2
+
+            # registry addr must appear in bound set
+            assert reg_wrapped in bound_w
+
+    trio.run(_main)
+
+
+# ------------------------------------------------------------------
+# 6) open_nursery forwards tpt_bind_addrs
+# ------------------------------------------------------------------
+def test_open_nursery_forwards_tpt_bind_addrs(
+    reg_addr: tuple,
+    debug_mode: bool,
+):
+    '''
+    `open_nursery(tpt_bind_addrs=...)` forwards through
+    `**kwargs` to `open_root_actor()`.
+
+    '''
+    reg_wrapped = wrap_address(reg_addr)
+    rando = reg_wrapped.get_random(
+        bindspace=reg_wrapped.bindspace,
+    )
+    bind_addrs = [rando.unwrap()]
+
+    async def _main():
+        async with tractor.open_nursery(
+            registry_addrs=[reg_addr],
+            tpt_bind_addrs=bind_addrs,
+            debug_mode=debug_mode,
+        ):
+            actor = tractor.current_actor()
+            bound_bs = _bound_bindspaces(actor)
+
+            for ba in bind_addrs:
+                assert wrap_address(ba).bindspace in bound_bs
+
+    trio.run(_main)
diff --git a/tractor/_root.py b/tractor/_root.py
index 97bf7062..02757c32 100644
--- a/tractor/_root.py
+++ b/tractor/_root.py
@@ -446,7 +446,7 @@ async def open_root_actor(
             tpt_bind_addrs = list(set(
                 tpt_bind_addrs
                 +
-                uw_reg_addrs
+                [wrap_address(a) for a in uw_reg_addrs]
             ))
 
             # - it is normally desirable for any registrar to stay up