Declare per-daemon-kind backend mod groups

Prep for the `brokerd` -> (`datad` + `brokerd`) actor split
by having each (split-style) backend declare which of its
submods host which daemon-kind's eps, exactly per the
`piker.data.validate._eps` groupings; `ib` already had
`_brokerd_mods`/`_datad_mods` so extend the convention to
`kraken`, `binance` and `deribit` (and add `'api'` to ib's
datad set since both kinds need the `Client` layer).

`__enable_modules__` stays as the (deduped) union so this
is a ZERO behavior change; flat backends (`kucoin` etc.)
just don't declare the split yet.

Also,
- add `validate.get_eps()` returning a backend's defined
  eps per daemon-kind for spawn-time introspection.
- import `NoBsWs`/`open_autorecon_ws` from
  `piker.data._web_bs` directly in `.kraken.broker` (they
  were only re-exported via `.kraken.feed`) so the trading
  mod doesn't depend on the feed mod for ws primitives.

(this patch was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Prompt-IO: ai/prompt-io/claude/20260610T171105Z_bc6e18d7_prompt_io.md

ai/prompt-io/claude/20260610T171105Z_bc6e18d7_prompt_io.md

@@ -0,0 +1,54 @@
+---
+model: claude-fable-5[1m]
+service: claude
+session: 32d15f9a-b2d3-4c26-bdc9-190219141a25
+timestamp: 2026-06-10T17:11:05Z
+git_ref: datad_service
+diff_cmd: git log -1 -p --follow -- ai/prompt-io/claude/20260610T171105Z_bc6e18d7_prompt_io.md
+scope: code
+substantive: true
+raw_file: 20260610T171105Z_bc6e18d7_prompt_io.raw.md
+---
+
+## Prompt
+
+Same session-initiating `brokerd`-split instruction (see
+`20260610T170859Z_75cefe10_prompt_io.md`); this is the
+approved plan's "stage 0" prep. Plan-shaping user
+decisions captured via in-session Q&A:
+
+- `datad.<broker>` topology: sibling of
+  `brokerd.<broker>` under `pikerd` (vs. child
+  subactor).
+- migration: hard cutover, staged by layer (no
+  dual-mode runtime flag).
+- post-split `brokerd` scope: trading-only +
+  EMS-lazy-spawned (charts/CLI never touch it).
+
+## Response summary
+
+Declare per-daemon-kind backend submod groups
+(`_datad_mods`/`_brokerd_mods`) in the split-style
+backends, keyed to the pre-existing
+`piker.data.validate._eps` contract; add a
+`validate.get_eps()` introspection helper; ws-import
+hygiene in `.kraken.broker`. Zero behavior change
+(`__enable_modules__` unions unchanged).
+
+## Files changed
+
+- `piker/data/validate.py` — add `get_eps()`
+- `piker/brokers/kraken/__init__.py` — mod groups
+- `piker/brokers/binance/__init__.py` — mod groups
+  (note: no `symbols.py`; search eps live in `.feed`)
+- `piker/brokers/deribit/__init__.py` — datad-only
+  groups (no `broker.py` yet)
+- `piker/brokers/ib/__init__.py` — add `'api'` to the
+  pre-existing `_datad_mods`
+- `piker/brokers/kraken/broker.py` — import
+  `NoBsWs`/`open_autorecon_ws` from
+  `piker.data._web_bs` directly
+
+## Human edits
+
+None — committed as generated.

ai/prompt-io/claude/20260610T171105Z_bc6e18d7_prompt_io.raw.md

@@ -0,0 +1,46 @@
+---
+model: claude-fable-5[1m]
+service: claude
+timestamp: 2026-06-10T17:11:05Z
+git_ref: datad_service
+diff_cmd: git log -1 -p --follow -- ai/prompt-io/claude/20260610T171105Z_bc6e18d7_prompt_io.md
+---
+
+NOTE: diff-ref mode entry (code committed in the same
+commit as this log); backfilled from the live dev
+session transcript per the `/prompt-io` skill rules.
+
+> `git log -1 -p --follow -- piker/data/validate.py`
+
+Generated: `get_eps(mod, kind) -> dict[str, Callable]`
+returning the daemon-kind's ep funcs defined by a
+backend mod, keyed by ep name, missing eps excluded;
+sourced from the existing `_eps` grouping table
+(`'middleware' | 'datad' | 'brokerd'`).
+
+> `git log -1 -p --follow -- piker/brokers/kraken/__init__.py`
+> `git log -1 -p --follow -- piker/brokers/binance/__init__.py`
+> `git log -1 -p --follow -- piker/brokers/deribit/__init__.py`
+> `git log -1 -p --follow -- piker/brokers/ib/__init__.py`
+> `git log -1 -p --follow -- piker/brokers/kraken/broker.py`
+
+Key exploration findings driving the design (from the
+planning phase, 3 parallel explore agents + 1 architect
+agent):
+
+- the codebase already anticipated this split:
+  `validate._eps` groups eps into 'datad' vs 'brokerd'
+  kinds and `ib/__init__.py` already declared
+  `_brokerd_mods`/`_datad_mods`; `brokers/_daemon.py`
+  carried the literal TODO "rename the daemon to datad
+  prolly once we split up broker vs. data tasks into
+  separate actors?".
+- the feared kraken feed<->broker "shared ws state"
+  hazard is mild: `NoBsWs`/`open_autorecon_ws`
+  originate in `piker.data._web_bs` (re-exported via
+  `.kraken.feed`); only `stream_messages` is feed-local
+  and it's a pure parser — in-process imports only,
+  each actor opens its own ws conn.
+- `enable_modules` gates RPC entry, NOT python imports,
+  so backend trading mods may keep importing feed-side
+  helpers in-process post-split.

piker/brokers/binance/__init__.py

@@ -52,9 +52,25 @@ __all__ = [
 ]
 
 
-# `brokerd` modules
+# per-daemon-kind (sub)mod groups: declares which of our
-__enable_modules__: list[str] = [
+# submods host the eps run by each daemon-actor kind as
+# defined by `piker.data.validate._eps`.
+# NOTE: `get_mkt_info` and `open_symbol_search` both live
+# in `.feed` for this backend (no `symbols.py`).
+_brokerd_mods: list[str] = [
     'api',
-    'feed',
     'broker',
 ]
+
+_datad_mods: list[str] = [
+    'api',
+    'feed',
+]
+
+
+# tractor RPC enable arg
+__enable_modules__: list[str] = list(dict.fromkeys(
+    _brokerd_mods
+    +
+    _datad_mods
+))

piker/brokers/deribit/__init__.py

@@ -47,13 +47,25 @@ __all__ = [
 ]
 
 
-# tractor RPC enable arg
+# per-daemon-kind (sub)mod groups: declares which of our
-__enable_modules__: list[str] = [
+# submods host the eps run by each daemon-actor kind as
+# defined by `piker.data.validate._eps`.
+# NOTE: datad-only backend (no `broker.py` yet)!
+_brokerd_mods: list[str] = []
+
+_datad_mods: list[str] = [
     'api',
     'feed',
-#   'broker',
 ]
 
+
+# tractor RPC enable arg
+__enable_modules__: list[str] = list(dict.fromkeys(
+    _brokerd_mods
+    +
+    _datad_mods
+))
+
 # passed to ``tractor.ActorNursery.start_actor()``
 _spawn_kwargs = {
     'infect_asyncio': True,

piker/brokers/ib/__init__.py

@@ -65,17 +65,18 @@ _brokerd_mods: list[str] = [
 ]
 
 _datad_mods: list[str] = [
+    'api',
     'feed',
     'symbols',
 ]
 
 
 # tractor RPC enable arg
-__enable_modules__: list[str] = (
+__enable_modules__: list[str] = list(dict.fromkeys(
     _brokerd_mods
     +
     _datad_mods
-)
+))
 
 # passed to ``tractor.ActorNursery.start_actor()``
 _spawn_kwargs = {

piker/brokers/kraken/__init__.py

@@ -66,10 +66,24 @@ __all__ = [
 ]
 
 
-# tractor RPC enable arg
+# per-daemon-kind (sub)mod groups: declares which of our
-__enable_modules__: list[str] = [
+# submods host the eps run by each daemon-actor kind as
+# defined by `piker.data.validate._eps`.
+_brokerd_mods: list[str] = [
     'api',
     'broker',
+]
+
+_datad_mods: list[str] = [
+    'api',
     'feed',
     'symbols',
 ]
+
+
+# tractor RPC enable arg
+__enable_modules__: list[str] = list(dict.fromkeys(
+    _brokerd_mods
+    +
+    _datad_mods
+))

piker/brokers/kraken/broker.py

@@ -73,10 +73,12 @@ from piker.log import (
     get_logger,
 )
 from piker.data import open_symcache
-from . import api
+from piker.data._web_bs import (
-from .feed import (
     open_autorecon_ws,
     NoBsWs,
+)
+from . import api
+from .feed import (
     stream_messages,
 )
 from .ledger import (

piker/data/validate.py

@@ -91,6 +91,24 @@ _eps: dict[str, list[str]] = {
 }
 
 
+def get_eps(
+    mod: ModuleType,
+    kind: str,  # 'middleware' | 'datad' | 'brokerd'
+
+) -> dict[str, Callable]:
+    '''
+    Return the daemon-kind's ep funcs defined by the backend
+    `mod`, keyed by ep name; any eps from `_eps[kind]` not
+    implemented by the backend are excluded.
+
+    '''
+    return {
+        name: ep
+        for name in _eps[kind]
+        if (ep := getattr(mod, name, None))
+    }
+
+
 def validate_backend(
     mod: ModuleType,
     syms: list[str],