feat(#20): persona + authored-history + first-message onto the wt adapter (slice-3)

Slice-3 of the worldtree-sdk cutover: migrate the session persona-state write,
the #347 authored-history write, and get_session_messages onto ratatoskr.wt, and
route the first-message preset seed through the adapter. Retire the last
hand-rolled sessions.py paths the --seed-first-message probe kept alive
(create_session + SessionInfo, set_persona_state, write_authored_history,
get_session_messages, _bifrost_error_from).

- wt.set_persona_state (SDK PadState) — the CLI passes three finite PAD axes; the
  SDK owns the {"pad": {...}} wire (#317). No route-specific error row → the
  SessionApiFailed default.
- wt.write_authored_history (SDK write_history) — v1 author=assistant; 404 →
  AuthoredHistoryUnavailable (hide-existence; the route is the discriminator,
  never the body); every other ApiError → the default. Drops the unused
  author/effects/claimed_original_at params (no caller uses them).
- first_message.seed_preset_first_message now takes a WorldtreeClient and routes
  through wt.write_authored_history; the best-effort invariants (INV-001..004,
  never-raise/never-block/one-write/zero-worldtree-source-import) are unchanged.
  Tests drive a fake WorldtreeClient — the wire is the SDK's to prove.
- CLI --set-persona-pad / --seed-first-message + the _amain and web create-path
  first-message seeds rewired onto the adapter. --set-persona-pad pre-validates
  PAD finiteness (clean usage_error, never a crash on the SDK ConfigurationError).

LIVE-SMOKE on personal :8081 (b128, INV-CUT-5): --seed-first-message → 201
(seq=0, phase=seeded) → read-back verbatim; --set-persona-pad → 204; the --new
create-path preset seed observed routing through the adapter. All slice-3 route
families proven end-to-end through the ratatoskr surface.

docs/coverage-map.md + first_message.contract.md re-anchored onto the adapter;
the slice-2 create/stream/cancel rows re-anchored too (they still named the
deleted sse_client/sessions symbols).

Suite 466 green; mypy no new errors (baseline 22 → 20 in the touched modules);
ruff clean. INV-CUT-1..5 held. Bifrost provider planes untouched.

docs/contracts/first_message.contract.md

@@ -13,11 +13,12 @@ scope: >
   replacement for a system-prompt "startup" instruction. Two entry points:
   `preset_for` (lookup) and `seed_preset_first_message` (best-effort seed).
   Consumed by ratatoskr.cli (the `--new` session path) and ratatoskr.web.server
-  (the POST /api/sessions endpoint). Depends on ratatoskr.sessions
-  (write_authored_history + its exceptions); no core.* / worldtree.* imports.
+  (the POST /api/sessions endpoint). Depends on ratatoskr.wt
+  (`wt.write_authored_history` + AuthoredHistoryUnavailable) over a WorldtreeClient
+  (worldtree-sdk cutover slice-3, #20); no core.* / worldtree.* SOURCE imports.
 depends_on:
-  - "httpx"
-  - "ratatoskr.sessions"
+  - "worldtree_sdk"
+  - "ratatoskr.wt"
 used_by:
   - "ratatoskr.cli"
   - "ratatoskr.web.server"
@@ -26,7 +27,7 @@ complexity: "low"
 estimated_loc: 60
 confidence: 0.9
 assumptions:
-  - "write_authored_history (contract #2 amendment 2026-07-06) is the seed primitive: 200/201 → ack dict, 404 → AuthoredHistoryUnavailable (hide-existence), other non-2xx → SessionApiFailed."
+  - "wt.write_authored_history (the SDK-adapter seed primitive, #20) writes over the worldtree-sdk client: success → ack mapping, 404 → AuthoredHistoryUnavailable (hide-existence), other ApiError → wt.SessionApiFailed. Behavior/semantics unchanged from the retired hand-rolled path — only the transport moved to the SDK."
   - "The preset registry is a static in-module dict keyed by agent_id; editing it is how an operator tunes an agent's opening. Seeded with ratatoskr:sindra only."
   - "Auto-seed is BEST-EFFORT and MUST NOT block session creation: an instance without the session.history.write grant returns the hide-404, which is swallowed (session opens with no seeded greeting)."
 ---
@@ -47,8 +48,8 @@ every new session for a preset agent opens in-character regardless of surface.
 
 ## Data flow
 
-**In:** a live `httpx.AsyncClient` (caller-owned, base_url + bearer set), a fresh
-`session_id`, and the bound `agent_id`.
+**In:** a `WorldtreeClient` (the wt-adapter client, built over ratatoskr's
+caller-owned transport), a fresh `session_id`, and the bound `agent_id`.
 
 **Out:** on a preset agent, one `POST /sessions/{session_id}/history` (author=assistant,
 the preset text, per-content idempotency key). Returns the seeded content on
@@ -104,19 +105,19 @@ TESTS:
   preset_miss [happy]: preset_for("mimir") is None
   empty_agent_id [adversarial]: preset_for("") → AssertionError
 
-FN seed_preset_first_message(client: httpx.AsyncClient, session_id: str, agent_id: str) -> str | None
-BRIEF: Best-effort seed of an agent's preset opening as a #347 authored first-message on session_id. If agent_id has a preset, POST it via write_authored_history (author=assistant, per-content idempotency key, the await bounded by asyncio.wait_for(_SEED_TIMEOUT_S)) and return the seeded content; on no-preset, a malformed input, OR ANY exception except asyncio.CancelledError, return None WITHOUT raising. Never raises (except CancelledError, which propagates) and never blocks session creation — it is wired into three create paths.
+FN seed_preset_first_message(client: WorldtreeClient, session_id: str, agent_id: str) -> str | None
+BRIEF: Best-effort seed of an agent's preset opening as a #347 authored first-message on session_id. If agent_id has a preset, write it via wt.write_authored_history (author=assistant, per-content idempotency key, the await bounded by asyncio.wait_for(_SEED_TIMEOUT_S)) and return the seeded content; on no-preset, a malformed input, OR ANY exception except asyncio.CancelledError, return None WITHOUT raising. Never raises (except CancelledError, which propagates) and never blocks session creation — it is wired into the CLI + web create paths.
 PRE: [PRE-001 hard] client is not None -- soft-guarded: return None (NOT assert) if violated, so a wiring bug can't crash the create path (INV-001)
 PRE: [PRE-002 hard] session_id is a non-empty str -- soft-guarded: return None if violated
 PRE: [PRE-003 hard] agent_id is a non-empty str -- soft-guarded: return None if violated (also guards FIRST_MESSAGE_PRESETS.get against a non-hashable/non-str id)
 POST: [POST-001 return_value] preset agent + successful write → returns the preset text; no-preset, malformed input, OR any swallowed failure → None
-POST: [POST-002 side_effect] a no-preset / malformed-input call issues ZERO HTTP; a preset agent issues exactly one POST /sessions/{session_id}/history with body author="assistant", content=preset, idempotency_key="ratatoskr-preset-"+sha256(preset)[:12], the await bounded by _SEED_TIMEOUT_S so a stalled response cannot block
+POST: [POST-002 side_effect] a no-preset / malformed-input call issues ZERO writes; a preset agent issues exactly one authored-history write (POST /sessions/{session_id}/history via the SDK) with entry author="assistant", content=preset, idempotency_key="ratatoskr-preset-"+sha256(preset)[:12], the await bounded by _SEED_TIMEOUT_S so a stalled response cannot block
 ERROR_ROUTING:
   asyncio.CancelledError:
     local_handling: RE-RAISE (cancellation is not a seed failure; never swallow it — and it is a BaseException, so `except Exception` would miss it anyway)
     flow_control: propagate
     state_recovery: n/a
-  any other Exception (hide-404 AuthoredHistoryUnavailable, SessionApiFailed 409/422/etc., httpx.HTTPError, TimeoutError from wait_for, any unexpected error):
+  any other Exception (hide-404 AuthoredHistoryUnavailable, wt.SessionApiFailed 409/422/etc., SDK ConnectFailed, TimeoutError from wait_for, any unexpected error):
     local_handling: swallow; return None
     flow_control: continue (never blocks session create)
     state_recovery: session opens with no seeded greeting
@@ -125,18 +126,18 @@ STEPS:
   2. [sequential, prescriptive] content = FIRST_MESSAGE_PRESETS.get(agent_id); IF content is None: RETURN None (INV-002 — zero HTTP)
   3. [sequential, prescriptive] Soft-guard: IF client is None OR session_id is not a non-empty str: RETURN None
   4. [sequential, prescriptive] key = "ratatoskr-preset-" + sha256(content utf-8)[:12]
-  5. [sequential, prescriptive] TRY: await asyncio.wait_for(write_authored_history(client, session_id, content=content, idempotency_key=key), timeout=_SEED_TIMEOUT_S)
+  5. [sequential, prescriptive] TRY: await asyncio.wait_for(wt.write_authored_history(client, session_id, content=content, idempotency_key=key), timeout=_SEED_TIMEOUT_S)
      tool: { destructive: false, idempotent: true, read_only: false, open_world: false }
   6. [branch, prescriptive] EXCEPT asyncio.CancelledError: RAISE; EXCEPT Exception: RETURN None
   7. [cleanup, prescriptive] RETURN content
-TESTS:
-  seeds_preset [happy,tracer]: preset agent, mock 201 → returns the preset text; exactly one POST /sessions/{id}/history; body author="assistant" + content=preset + idempotency_key="ratatoskr-preset-"+sha256(preset)[:12]
-  no_preset_zero_http [happy]: agent "mimir" → returns None; NO HTTP issued
-  feature_absent_swallowed [error]: preset agent, mock 404 session_not_found → returns None, no raise
-  session_api_failed_swallowed [error]: preset agent, mock 409 → returns None, no raise
-  transport_error_swallowed [error]: preset agent, mock httpx.ConnectError → returns None, no raise
+TESTS: (driven through a fake WorldtreeClient whose sessions.write_history returns/raises — the wire is the SDK's to prove via its parity corpus)
+  seeds_preset [happy,tracer]: preset agent, fake write_history returns an ack → returns the preset text; exactly one write_history call; entry author="assistant" + content=preset + idempotency_key="ratatoskr-preset-"+sha256(preset)[:12]
+  no_preset_zero_write [happy]: agent "mimir" → returns None; ZERO write_history call
+  feature_absent_swallowed [error]: preset agent, fake raises ApiError(404) → adapter maps to AuthoredHistoryUnavailable → returns None, no raise
+  session_api_failed_swallowed [error]: preset agent, fake raises ApiError(409) → wt.SessionApiFailed → returns None, no raise
+  transport_error_swallowed [error]: preset agent, fake raises SDK ConnectFailed → returns None, no raise
   unexpected_exception_swallowed [error]: preset agent, write raises ValueError → returns None, no raise (INV-001 broad never-raise)
   cancellation_propagates [error]: preset agent, write raises asyncio.CancelledError → RE-RAISED (never swallowed)
-  malformed_agent_id_no_http [adversarial]: agent_id=123 (non-str) OR "" → None; NO HTTP; no raise
-  empty_session_id [adversarial]: session_id="" (preset agent) → None (soft guard); NO HTTP; no raise
+  malformed_agent_id_no_write [adversarial]: agent_id=123 (non-str) OR "" → None; ZERO write; no raise
+  empty_session_id [adversarial]: session_id="" (preset agent) → None (soft guard); ZERO write; no raise
 ```

docs/coverage-map.md

@@ -84,11 +84,11 @@ sub-gap).
 
 | Endpoint | Status | Where consumed | Note |
 |---|---|---|---|
-| `POST /sessions` | ✅ | `sessions.py` `create_session` → `cli.py`,`tui.py`,`web/server.py` | + `end_user_id`, `bifrost` binding; 404→AgentNotFound, 502→BifrostHandshakeFailed. **v0.21.2 (#19): ephemeral-template (Echo) create** — `config` passthrough (`--system-prompt`), `role` not `model` (W-4), `kind`/`config` captured; 422 ephemeral_requires_config now reachable-and-handled. Depth enhancement to an already-covered route — count unchanged |
-| `POST /sessions/{id}/messages` (turn stream, SSE) | ✅ | `sse_client.py:484` `stream_turn` → cli/tui/web | the primary surface; 409→AgentNotAvailable, 503→TurnLaunchUnavailable (b2 #331) |
-| `POST /sessions/{id}/history` (authored-history-write, #347) | ✅ | `sessions.py:583` `write_authored_history` → `cli.py:758` `--seed-first-message` | v1: author=assistant, effects=none, per-session idempotency; 404→AuthoredHistoryUnavailable (hide-existence: feature-absent, never probe); 409/422 mapped. **LIVE-PROVEN 2026-07-06** on personal :8081 (grant applied via a rule-based Heimdall allow, worldtree-dev): create mimir session → seed → **201** (seq=0, phase=seeded, turn_id=1798) → GET /messages reads it back as a plain role=assistant turn (model-invisible provenance confirmed). Hide-404 for ungranted is unit+probe covered |
-| `GET /sessions/{id}/messages` (history) | ✅ | `sessions.py:635` `get_session_messages` → `cli.py:758` `--seed-first-message` read-back | un-deferred as the #347 seed read-back — confirms model-invisible provenance (a seed reads back as a normal `role=assistant` turn) |
-| `POST /sessions/{id}/turns/{turn_id}/cancel` | ✅ | `sse_client.py:581` → cli/tui/web | two-stage Ctrl-C; 404/409 mapped |
+| `POST /sessions` | ✅ | `wt.py` `create_session` (SDK `sessions.create`) → `cli.py`,`web/server.py` | **wt-adapter re-anchored (slice-2, #20)** — + `end_user_id`, `bifrost` binding (consumer-key via SDK per-request auth), `config` passthrough; 404→AgentNotFound, bound-502→BifrostHandshakeFailed. Ephemeral-template (Echo) create (#19) carried through the adapter. Depth enhancement to an already-covered route — count unchanged |
+| `POST /sessions/{id}/messages` (turn stream, SSE) | ✅ | `wt.py` `stream_turn` (SDK resilient `sessions.stream_turn`, auto-resume) → cli/web | **wt-adapter re-anchored (slice-2, #20)** — the primary surface; 409→AgentNotAvailable, 503→TurnLaunchUnavailable, drop→SseConnectionDropped, protocol→same-named; absorbs the old `reconnect_turn` |
+| `POST /sessions/{id}/history` (authored-history-write, #347) | ✅ | `wt.py` `write_authored_history` (SDK `sessions.write_history`) → `cli.py` `--seed-first-message`, `first_message.py` `seed_preset_first_message` (create-path seed) | **wt-adapter re-anchored (slice-3, #20)** — SDK owns the entry shape; v1 author=assistant; 404→AuthoredHistoryUnavailable (hide-existence, route is the discriminator, never probe); 409/422→SessionApiFailed default. **LIVE-SMOKE 2026-07-19** on personal :8081 (b128): `--seed-first-message` on a sindra session → **201** (seq=0, phase=seeded, turn_id=2294) → read-back verbatim; create-path preset seed observed via `--new`. (Prior 2026-07-06 hand-rolled proof superseded.) |
+| `GET /sessions/{id}/messages` (history) | ✅ | `wt.py` `get_session_messages` (SDK `sessions.messages`) → `cli.py` `--seed-first-message` read-back, `web/server.py` messages proxy | **wt-adapter re-anchored (slice-3, #20)** — the #347 seed read-back; open-world passthrough. **LIVE-SMOKE 2026-07-19**: read-back rendered the seeded seq-0 turn as a plain role=assistant message (model-invisible provenance confirmed) |
+| `POST /sessions/{id}/turns/{turn_id}/cancel` | ✅ | `wt.py` `cancel_turn` (SDK `sessions.cancel_turn`) → cli/web | **wt-adapter re-anchored (slice-2, #20)** — two-stage Ctrl-C; 404→CancelTurnNotFound, 409→CancelAlreadyCompleted, late-cancel 200 (`cancelled=False`) is a benign result, not an error |
 | `GET /agents` | ✅ | `sessions.py:341` → `tui.py:1472`,`web/server.py:100` | Tier-1 roster; merged with local index |
 | `GET /agents/{id}/persona_state` | ✅ | `sessions.py:384` → `tui.py:1132`,`web/server.py:386` | persona hydrate; 404/403 mapped |
 | `POST /agents/define` | ✅ | `tier3.py:175` → `_run_define` | Tier-3 create |
@@ -103,7 +103,7 @@ sub-gap).
 | `POST /characters` | ✅ | `sessions.py` `create_character` → `cli.py` `--characters` | create transient character (#161) |
 | `GET /characters/{id}/state` | ✅ | `sessions.py` `get_character_state` → `cli.py` `--characters` | live character PAD/emotions (#161) |
 | `DELETE /characters/{id}` | ✅ | `sessions.py` `delete_character` → `cli.py` `--characters` | remove transient character (#161) |
-| `POST /sessions/{id}/persona_state` | ✅ | `sessions.py` `set_persona_state` → `cli.py` `--set-persona-pad` | persona-state write / affect injection (freeform body — unpinned in the frozen surface) |
+| `POST /sessions/{id}/persona_state` | ✅ | `wt.py` `set_persona_state` (SDK `sessions.set_persona_state`, `PadState`) → `cli.py` `--set-persona-pad` | **wt-adapter re-anchored (slice-3, #20)** — SDK owns the canonical `{"pad": {...}}` wire (#317); CLI passes the 3 PAD axes (finiteness pre-validated); 204→None, else SessionApiFailed default. **LIVE-SMOKE 2026-07-19** on personal :8081: `--set-persona-pad 0.4,0.1,-0.2` → **204** |
 
 **Sub-gaps inside ✅ path groups** (the method we use is live; a sibling method
 on the same path is an unwired frontier item — see frontier Tier 1):

persistent-memory.d/2026-07-19-worldtree-sdk-cutover-slice-1-2-complete.md

@@ -0,0 +1,57 @@
+`[2026-07-19]` **worldtree-sdk cutover — SLICE-1 + SLICE-2 COMPLETE + PUSHED (origin `aba1730`, v0.21.10).**
+
+The consumer client layer's biggest, riskiest slice (sessions/turn) is fully migrated onto
+`worldtree-sdk (Python) 1.0.0` behind the `ratatoskr.wt` adapter, run end-to-end through the House Code
+Discipline. Pushed 2026-07-19 (12-commit arc `b1fbadd`→`aba1730`, tags v0.21.3–.10). Suite **497 green**.
+
+## The arc (all on origin/main)
+
+| Part | Commit | What |
+|---|---|---|
+| Slice-1 foundation | `12cd864` (v0.21.3) | `build_client` + `translate_error` DEFAULT (ApiError→SessionApiFailed) + passthrough; INV-CUT-1 (injected transport, `_owns_client=False`) test-proven |
+| Slice-2 adapter (read/create) | `bb158ae` (v0.21.4) | create/list/messages/tools over `client.sessions.*`, per-route error mapping |
+| Slice-2 adapter (stream/cancel) | `b907a7b` (v0.21.5) | resilient `stream_turn` + `cancel_turn`; SDK stream errors re-wrapped → ratatoskr caller-semantic exceptions (DEC-2) |
+| Slice-2 CLI rewire | `e3a10ad` (v0.21.6) | `_amain`/`_run_turn`/render onto SDK `TurnEvent`s + open dicts |
+| Slice-2 web rewire | `5c595b8` (v0.21.7) | Starlette endpoints + SSE→JSON serialization; browser contract preserved |
+| Slice-2 deletion | `59602fe` (v0.21.8) | sse_client 714→224, sessions 677→608; orphaned turn-stream family + Event model removed; **DEC-4 live-smoke PASSED first** |
+| heid-code-review fixup | `74d41eb` (v0.21.9) | INV-CUT-2 completeness (cancel/stream ApiError default) + contract error-map amendments |
+| heid-bug-hunt fixup | `aba1730` (v0.21.10) | 4 confirmed bugs + open-world render hardening |
+
+## KEY ADAPTER FACTS (foot-guns for slices 3-7)
+
+- **The SDK returns open-world dicts** (`Mapping`, NOT typed objects) for session reads → presenters read
+  mappings (`info["session_id"]`), never attributes. Ratatoskr's typed `SessionInfo`/`SessionPage` retired.
+- **SDK `TurnEvent` shape:** `sse_id: str` (the composite `"{turn}:{seq}"`) + a **body-derived `turn_id`
+  that is ABSENT (None) on text/thinking frames.** The mid-stream cancel target must parse the turn from
+  `sse_id`, NOT read `event.turn_id`. (This was a live bug — sigint-cancel saw "no event".)
+- **The SDK normalizes transport failures to `ConnectFailed(status=0)`** (not raw httpx errors) → presenters
+  catch `wtsdk.ConnectFailed` for network paths; a stream `ConnectFailed` maps → `SseConnectFailed`.
+- **The adapter re-wraps SDK stream errors → ratatoskr's caller-semantic exceptions** (DEC-2 keeps ratatoskr's
+  typed exceptions; SessionRetired→SessionApiFailed, ConnectionDropped→SseConnectionDropped, Malformed*/
+  TurnIdFlip→same-named, ConnectFailed/terminal ResumeError→SseConnectFailed).
+- **`consumer_key` is BOUND-create-only** — the adapter nulls it when `bifrost is None`, else the SDK's
+  credential precedence auths as the consumer instead of the default bearer.
+- **The SDK's error-envelope parser PREFERS the nested `detail`** dict when present, so a top-level
+  `error_code` doesn't surface. That's why create's bound-502 is NOT gated on error_code (unlike list's
+  422+cursor_invalid, whose flat body surfaces the code) — INV-002 also makes the handshake the sole
+  bound-502 cause. This is a genuine cross-frontier triage win: 2/3 heid arms flagged the missing gate; it
+  was correctly REJECTED as category-5 wrong-grounding (the SDK parser wasn't in the arms' file set).
+
+## The two heid gates (the value proof)
+
+- **heid-code-review** (Gróa+Hulda substantive, Regin zero=weak): adopted the cancel/stream ApiError-default
+  completeness + error-map table amendments; correctly rejected the bound-502-gate finding (above).
+- **heid-bug-hunt** (Gróa 8 / Hulda 6 / Regin 6; Heid source-checked, refuted 2 Regin FPs): caught **4 real
+  confirmed bugs the conformance lens structurally could not see** — SessionRetired(410) uncaught by both
+  presenters (crash/dropped-stream), cli consumer_key forwarded on unbound create (auth divergence), sse_id
+  None-crash, cancel never-raise gap — plus open-world render hardening. Rejected 4 as verified FPs (incl.
+  Hulda's "deleted funcs break callers" — grep-verified zero callers pre-deletion). Both surfaces re-smoked
+  live after fixup: create+stream+cancel round-trip clean on :8081 (b128).
+
+## What's still hand-rolled (later slices)
+
+`create_session`/`get_session_messages` (the `--seed-first-message` probe uses them — retire in slice-3);
+`set_persona_state`/`write_authored_history`/`first_message` (slice-3); agents/tier3 incl. `model`→`role`
+(slice-4, deploy live b128); characters/me/capabilities/models (slice-5); `stream_admin_events`/
+`get_session_bifrost` (slice-6). Slice-7 teardown: retire contracts #2/#15, drop `httpx-sse`, minor bump
+(DEC-6, operator approval). Full design → auto-memory `project_worldtree_sdk_cutover`.

persistent-memory.md

@@ -1,6 +1,6 @@
 # Persistent memory — ratatoskr
 
-_Last updated: 2026-07-18_
+_Last updated: 2026-07-19_
 
 > **Always check for `/tmp/ratatoskr-dev-handoff.md`** — if it exists and its
 > `Written:` stamp is under an hour old, read it (it carries the in-flight
@@ -44,34 +44,38 @@ upstream API key stays server-side (INV-003).
 
 ## Current state / in-flight
 
-_As of 2026-07-18 (evening):_
+_As of 2026-07-19:_
 
-**🔨 ACTIVE MIGRATION — worldtree-sdk cutover (issue #20), starting slice-1.** Operator ruled ADOPT
-(2026-07-18): ratatoskr cuts its CONSUMER client layer over to consume **worldtree-sdk (Python) 1.0.0** —
-retire the hand-rolled httpx wrappers (`sessions`/`sse_client`/`tier3`) behind a thin `ratatoskr.wt`
-adapter over the SDK. Both TS + Python SDK 1.0.0 are GA (**Python live + pip-installable on the gitea
-PyPI** — DEC-5 gate cleared). Ratatoskr's own **parity pass shaped the Python spine** (open-world reads,
-caller-injected transport, per-wire role/model). Design locked (6 DECs, vor-cross'd with worldtree-codex,
-heid-panel-reviewed → error-map table added); contract `docs/contracts/worldtree_sdk_cutover.contract.md`
-(committed `e45640c`). **SLICE-1 IN PROGRESS:** ✅ dep integrated + DEC-5 verified + committed (`29c4fda`) — `worldtree-sdk==1.0.0`
-installs from the gitea registry (reuses bifrost's index auth, NO new token; core dep + `[tool.uv.sources]`),
-`WorldtreeClient` constructs with an injected transport (`_owns_client=False`, INV-CUT-1 confirmed live),
-suite 534 green. **NEXT = the adapter** `src/ratatoskr/wt.py` (TDD): `build_client(base_url, *, api_key,
-admin_key, transport)` → `WorldtreeClient(auth=, admin_auth=, transport=)` (DESIGN CARE: SDK does per-request
-auth via the providers; our injected `httpx.AsyncClient` carries base_url/UA/timeout, NOT the Authorization
-header — read the SDK `client.py` @ `~/development/worldtree-sdk` for the split, INV-CUT-1) + `translate_error`
-DEFAULT (SDK `ApiError`→`SessionApiFailed`, discriminated `WorldtreeError` subclasses passthrough; route-specific
-rows come in later slices). Unit-test; NO surface wiring (slice-2). Then slices 2-7 (route-family + deletions,
-live-smoke per slice). Scope: consumer layer ONLY;
-Bifrost provider planes untouched. Multi-session grind. Full design → auto-memory
-`project_worldtree_sdk_cutover`. This SUPERSEDES the #371 "repin rides the later Python milestone" framing
-below (that milestone shipped; we're adopting, not just repinning).
+**🔨 ACTIVE MIGRATION — worldtree-sdk cutover (issue #20): SLICE-1 + SLICE-2 COMPLETE + PUSHED, slice-3 next.**
+Operator ruled ADOPT (2026-07-18): ratatoskr cuts its CONSUMER client layer over to **worldtree-sdk (Python)
+1.0.0**, retiring the hand-rolled httpx wrappers behind a thin `ratatoskr.wt` adapter. Design locked (6 DECs,
+vor-cross'd, heid-panel-reviewed); contract `docs/contracts/worldtree_sdk_cutover.contract.md`. **SLICE-1
+(adapter foundation) ✅ + SLICE-2 (sessions/turn) ✅ DONE + PUSHED** — origin at `aba1730` (12-commit arc
+`b1fbadd`→`aba1730`, tags v0.21.3–.10, pushed 2026-07-19): adapter (`b907a7b`, all 6 route families
+create/list/messages/tools/stream/cancel + the § Error-map mapping) → CLI rewire (`e3a10ad`) → web rewire
+(`5c595b8`) → orphan deletion (`59602fe`, sse_client 714→224 + sessions 677→608; DEC-4 LIVE-SMOKE PASSED on
+:8081 create+stream+cancel FIRST) → heid-code-review fixup (`74d41eb`) → heid-bug-hunt fixup (`aba1730`).
+Suite **497 green**. **KEY ADAPTER FACTS (foot-guns for slices 3-7):** the SDK returns **open-world dicts**
+(not typed objects) for session reads → presenters read mappings, `info["session_id"]`; SDK events
+(`TurnEvent`) carry `sse_id: str` + a **body-derived `turn_id` that's ABSENT on text/thinking frames** → parse
+the cancel target's turn from the composite `sse_id`, NOT `event.turn_id`; the SDK **normalizes transport
+failures to `ConnectFailed(status=0)`** (not raw httpx) → presenters catch it; the adapter re-wraps SDK stream
+errors → ratatoskr caller-semantic exceptions (DEC-2, keep ratatoskr's typed exceptions); `consumer_key` is
+BOUND-create-only (adapter nulls it when unbound, else the SDK auths as the consumer); the SDK's error-envelope
+parser **prefers the nested `detail`** so a top-level `error_code` doesn't surface (why create's bound-502 is
+NOT gated on error_code, unlike list's 422). **NEXT = slice-3** (persona `set_persona_state` + authored-history
+`write_history` + first_message presets — retires the still-hand-rolled `create_session`/`get_session_messages`
+that the `--seed-first-message` probe uses); then slice-4 (agents/tier3, FOLDS the `model`→`role` cutover),
+slice-5 (characters/me/caps), slice-6 (admin — `stream_admin_events`+`get_session_bifrost` still hand-rolled),
+slice-7 (teardown: retire contracts #2/#15, drop `httpx-sse`, minor bump per DEC-6 w/ operator approval).
+Scope: consumer layer ONLY; Bifrost provider planes untouched. Full design → auto-memory
+`project_worldtree_sdk_cutover`.
 
-**⏸️ DEFERRED — tier3 agents `model`→`role` (scope B), on worldtree-dev's deploy flag.** WT renames the
-agents-RESPONSE selector `model`→`role` (spec 1.2, commit `387c67b`, NOT yet deployed). `_parse_tier3_agent_info`
-reads `body["model"]` → KeyErrors post-deploy. Operator chose scope B (full tier3 `model`→`role` incl.
-contract #15 + CLI `--model`→`--role`). Implement ON the deploy flag, not before (breaks the current demo);
-folds into cutover slice-4. Auto-memory `project_tier3_agents_model_to_role_pending`.
+**⏸️ DEFERRED — tier3 agents `model`→`role` (scope B), folds into cutover slice-4.** WT renamed the
+agents-RESPONSE selector `model`→`role` (spec 1.2). **DEPLOY NOW LIVE** on :8080/:8081 (v1.0.0b128,
+worldtree-dev confirmed 2026-07-19 — was the deploy-flag gate; acked). Operator chose scope B (full tier3
+`model`→`role` incl. contract #15 + CLI `--model`→`--role`); lands in cutover slice-4 where tier3.py routes
+through the SDK (doing it standalone now = throwaway). Auto-memory `project_tier3_agents_model_to_role_pending`.
 
 **✅ RESOLVED — the "app product" workstreams leave Rata entirely (operator 2026-07-18).**
 **No arbo fork, no SillyTavern-on-Rata** — a NEW repo (template-dev standing up) takes over BOTH
@@ -115,13 +119,12 @@ Full record → `persistent-memory.d/2026-07-18-368-silo-test-passed.md`. Siblin
 (2) R39 Phase-2 **matched-quartets rebuild** (confirmatory, "whenever"); (3) bifrost **snapshot-cursor
 adoption** (ruled normative, not blocking → `persistent-memory.d/2026-07-16-bifrost-cursor-conformance.md`).
 
-**Substrate / environment:** branch `main` at **v0.21.2**. **origin at `b1fbadd`** (pushed 2026-07-18:
-canonical syncs `5d06a27`/`80c8d58`, ephemeral-Echo `c7016f2` #19, coverage-map→SDK-surface `b1fbadd`).
-**UNPUSHED local commits** (cutover work — operator hasn't pushed): cutover contract `e45640c` #20, the
-`memory:` snapshot, dep-integration `29c4fda` (worldtree-sdk==1.0.0), + this snapshot — **push is the
-operator's call**. origin `git@gitea.phasefinal.com:vh/ratatoskr.git`. **NEW core dep: `worldtree-sdk==1.0.0`**
-(gitea PyPI, `[tool.uv.sources]`). bifrost **`==1.1.4`** / wire v0.7; WT openapi vendored 2.3.0,
-**conversation-api-spec re-synced to v1.1** (`b4a278c`); **suite 534 green**. Personal WT on **b127**
+**Substrate / environment:** branch `main` at **v0.21.10**, **fully PUSHED to origin at `aba1730`** (slice-2
+cutover arc `b1fbadd`→`aba1730` + tags v0.21.3–.10 pushed 2026-07-19). origin
+`git@gitea.phasefinal.com:vh/ratatoskr.git`. **NEW core dep: `worldtree-sdk==1.0.0`** (gitea PyPI,
+`[tool.uv.sources]`; `httpx-sse` retires at slice-7). bifrost **`==1.1.4`** / wire v0.7; WT openapi vendored
+2.3.0, **conversation-api-spec re-synced to v1.1** (`b4a278c`); **suite 497 green** (was 534 pre-cutover; net
+delta = adapter/rewire tests added, ~80 deleted hand-rolled turn-stream tests). Personal WT on **b128**
 (`http://10.250.50.152:8081`; #368 silo + #364 promotion-hygiene live both instances). The combined
 **:8392** provider (memory+affect) + **:8765** web are THE surfaces, dev-box BACKGROUND SHELLS —
 restart via `scratchpad/relaunch_by_pid.py <pid>` (pid via `ss -ltnp | grep <port>`). `env.sh` sets
@@ -271,6 +274,7 @@ decision. Captures rationale that won't be obvious from code alone.
 - `[2026-07-18]` **ephemeral-template (Echo) create SHIPPED (`v0.21.2`, `c7016f2`, #19)** — `config` passthrough + `--system-prompt` + `SessionInfo.kind/config` + `--whoami` roles fix. Diagnosed from the ignored `session_api_failed` startup line; role/model drift resolved w/ worldtree-dev (spec re-synced v1.1). TDD + heid contract-review + bug-hunt.
 - `[2026-07-18]` **Rata = THE reference consumer of the worldtree-sdk Python spine** — parity pass (12 grounded findings) shaped its contract BEFORE build (open-world reads, caller-injected transport, per-wire role/model — adopted); coverage-map re-anchored to the SDK's 41-op ratified surface (`b1fbadd`); 4 ergonomics items parked post-v1 with wtsdk-dev.
 - `[2026-07-18]` **worldtree-sdk cutover DECIDED — adopt the Python SDK for the consumer client layer** (operator, overriding "stay hand-rolled"). Issue #20; contract `docs/contracts/worldtree_sdk_cutover.contract.md` (`e45640c`, vor-cross'd + heid-reviewed); auto-memory `project_worldtree_sdk_cutover`. Consumer layer only, Bifrost provider untouched; slice-1 foundation next. See in-flight.
+- `[2026-07-19]` **worldtree-sdk cutover SLICE-1 + SLICE-2 COMPLETE + PUSHED (origin `aba1730`, v0.21.10, 497 green).** The biggest, riskiest cutover slice done end-to-end through the full House Code Discipline (adapter→cli→web→delete→live-smoke→both heid gates); the bug-hunt caught 4 real confirmed bugs the conformance lens couldn't, and a convergent code-review finding was correctly REJECTED as category-5 (SDK envelope-parser behavior). Slice-3 next. → `persistent-memory.d/2026-07-19-worldtree-sdk-cutover-slice-1-2-complete.md`
 
 _65 older entries (2026-05-* debug-TUI/web era + the 2026-06-14 → 06-18 Bifrost-provider build / #17+#18 / #295-296 era) archived to archival-memory.md._
 

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "hatchling.build"
 
 [project]
 name = "ratatoskr"
-version = "0.21.10"
+version = "0.21.11"
 description = "Worldtree Conversation API debug console (web + headless CLI) — multi-pane observability"
 readme = "README.md"
 requires-python = ">=3.12"

src/ratatoskr/cli.py

@@ -8,6 +8,7 @@ from __future__ import annotations
 import argparse
 import asyncio
 import hashlib
+import math
 import os
 import signal
 import sys
@@ -44,16 +45,12 @@ from ratatoskr.sessions import (
     BifrostHandshakeFailed,
     SessionApiFailed,
     create_character,
-    create_session,
     delete_character,
     endpoint_for_plane,
     get_capabilities,
     get_character_state,
     get_me,
-    get_session_messages,
     list_character_models,
-    set_persona_state,
-    write_authored_history,
 )
 
 # The turn path (create / stream / cancel) is served by the worldtree-sdk adapter
@@ -719,8 +716,8 @@ async def _amain(args: ParsedArgs) -> int:
                 f"agent_id={info['agent_id']}{kind_suffix}\n"
             )
             # #347 authored first-message: seed the agent's preset opening (best-effort).
-            # Uses the transport directly — first_message is a slice-3 hand-rolled path.
-            if await seed_preset_first_message(transport, session_id, args.agent_id):
+            # Routed through the wt adapter (slice-3); the seed never blocks create.
+            if await seed_preset_first_message(client, session_id, args.agent_id):
                 sys.stderr.write(
                     f". first_message: seeded preset opening for {args.agent_id}\n"
                 )
@@ -882,14 +879,27 @@ async def _set_persona_probe(args: ParsedArgs) -> int:
             "(pleasure,arousal,dominance), e.g. '0.4,0.1,-0.2'\n"
         )
         return 10
-    # Canonical POST /sessions/{id}/persona_state body (#317): a named-key dict,
-    # NOT a bare list — {"pad": {"pleasure", "arousal", "dominance"}}.
-    snapshot = {"pad": {"pleasure": pad[0], "arousal": pad[1], "dominance": pad[2]}}
-    async with _probe_client(args) as client:
+    # The SDK rejects a non-finite axis pre-HTTP (a NaN/Infinity would serialize to
+    # null and corrupt the injection). Reject it here as a usage error so the probe
+    # surfaces a clean message instead of crashing on the SDK's ConfigurationError.
+    if not all(math.isfinite(x) for x in pad):
+        sys.stderr.write(
+            "[usage_error] --set-persona-pad values must be finite floats (no nan/inf)\n"
+        )
+        return 10
+    async with _probe_client(args) as transport:
+        client = wt.build_client(args.server_url, api_key=args.api_key, transport=transport)
         try:
-            await set_persona_state(client, args.session_id, snapshot)
-        except SessionApiFailed as exc:
-            sys.stderr.write(f"[session_api_failed] status={exc.status} body={exc.body!r}\n")
+            # The SDK owns the canonical {"pad": {...}} wire body (#317); ratatoskr
+            # passes the three PAD axes and no longer hand-builds the snapshot.
+            await wt.set_persona_state(
+                client, args.session_id, pleasure=pad[0], arousal=pad[1], dominance=pad[2]
+            )
+        except wt.SessionApiFailed as exc:
+            sys.stderr.write(
+                f"[session_api_failed] status={exc.status} "
+                f"error_code={exc.error_code!r} body={exc.body!r}\n"
+            )
             return 20
         except (httpx.ConnectError, httpx.ReadTimeout, httpx.TransportError) as exc:
             sys.stderr.write(f"[network_error] {type(exc).__name__}: {exc}\n")
@@ -914,19 +924,23 @@ async def _seed_first_message_probe(args: ParsedArgs) -> int:
     """
     assert isinstance(args, ParsedArgs)
     assert args.agent_id is not None and args.seed_first_message is not None
-    async with _probe_client(args) as client:
+    async with _probe_client(args) as transport:
+        client = wt.build_client(args.server_url, api_key=args.api_key, transport=transport)
         try:
-            session = await create_session(
+            # wt.create_session returns the SDK's open-world create dict; read as a
+            # mapping (no SessionInfo dataclass — the hand-rolled path is retired).
+            session = await wt.create_session(
                 client, args.agent_id, end_user_id=args.end_user_id
             )
-            sys.stdout.write(f"session: {session.session_id} (agent {session.agent_id})\n")
+            session_id = session["session_id"]
+            sys.stdout.write(f"session: {session_id} (agent {session.get('agent_id')})\n")
             key = "ratatoskr-first-message-" + hashlib.sha256(
                 args.seed_first_message.encode("utf-8")
             ).hexdigest()[:12]
             try:
-                ack = await write_authored_history(
+                ack = await wt.write_authored_history(
                     client,
-                    session.session_id,
+                    session_id,
                     content=args.seed_first_message,
                     idempotency_key=key,
                 )
@@ -941,15 +955,18 @@ async def _seed_first_message_probe(args: ParsedArgs) -> int:
                 f"seeded: seq={ack.get('seq')} phase={ack.get('phase')} "
                 f"turn_id={ack.get('turn_id')} content_chars={ack.get('content_chars')}\n"
             )
-            history = await get_session_messages(client, session.session_id)
+            history = await wt.get_session_messages(client, session_id)
             items = history.get("items", [])
             sys.stdout.write(f"read-back: {len(items)} message(s)\n")
             for m in items:
                 sys.stdout.write(
                     f"  seq={m.get('seq')} role={m.get('role')} content={m.get('content')!r}\n"
                 )
-        except SessionApiFailed as exc:
-            sys.stderr.write(f"[session_api_failed] status={exc.status} body={exc.body!r}\n")
+        except wt.SessionApiFailed as exc:
+            sys.stderr.write(
+                f"[session_api_failed] status={exc.status} "
+                f"error_code={exc.error_code!r} body={exc.body!r}\n"
+            )
             return 20
         except (httpx.ConnectError, httpx.ReadTimeout, httpx.TransportError) as exc:
             sys.stderr.write(f"[network_error] {type(exc).__name__}: {exc}\n")

src/ratatoskr/first_message.py

@@ -14,12 +14,12 @@ blocked (the session simply opens with no seeded greeting). See
 import asyncio
 import hashlib
 
-import httpx
+from worldtree_sdk import WorldtreeClient
 
-from ratatoskr.sessions import write_authored_history
+from ratatoskr import wt
 
-# Cap the best-effort seed write. The CLI/TUI create paths reuse an httpx client
-# with NO read timeout (it streams SSE turns), so an accepted-but-never-answered
+# Cap the best-effort seed write. The CLI create path reuses a transport with NO
+# read timeout (it streams SSE turns), so an accepted-but-never-answered
 # POST /history would otherwise block session creation forever — violating INV-001's
 # "never block". asyncio.wait_for bounds the seed regardless of the client's timeout.
 _SEED_TIMEOUT_S = 10.0
@@ -39,7 +39,7 @@ def preset_for(agent_id: str) -> str | None:
 
 
 async def seed_preset_first_message(
-    client: httpx.AsyncClient, session_id: str, agent_id: str
+    client: WorldtreeClient, session_id: str, agent_id: str
 ) -> str | None:
     """Best-effort: seed ``agent_id``'s preset opening as a #347 authored
     first-message on ``session_id``; return the seeded text, or None.
@@ -64,7 +64,7 @@ async def seed_preset_first_message(
     key = "ratatoskr-preset-" + hashlib.sha256(content.encode("utf-8")).hexdigest()[:12]
     try:
         await asyncio.wait_for(
-            write_authored_history(
+            wt.write_authored_history(
                 client, session_id, content=content, idempotency_key=key
             ),
             timeout=_SEED_TIMEOUT_S,

src/ratatoskr/sessions.py

@@ -5,41 +5,12 @@ Implements docs/contracts/issues/2.contract.md.
 
 from __future__ import annotations
 
-from collections.abc import Mapping
 from dataclasses import dataclass
 from typing import Any
 
 import httpx
 
 
-@dataclass(frozen=True)
-class SessionInfo:
-    """Worldtree session envelope; shared shape for create + list responses.
-
-    INV-001 / INV-002: origin-conditional defaults — `create_session` sets fixed
-    `name=None`, `archived=False`, `tags=[]`; `list_sessions` populates from the
-    response item with the same absent/null defaults but `message_count=None`.
-
-    Amendment 2026-07-18 (issue #161): `kind` ("ephemeral" | "foundational") and
-    `config` (the frozen ephemeral config, create-origin only) captured defensively
-    via `.get()` — both `None` on a pre-cutover server that omits them.
-    """
-
-    session_id: str
-    agent_id: str
-    created_at: str
-    last_active: str
-    metadata: dict[str, Any]
-    message_count: int | None
-    name: str | None
-    archived: bool
-    tags: list[str]
-    kind: str | None = None
-    config: dict[str, Any] | None = None
-
-
-
-
 @dataclass(frozen=True)
 class AgentInfo:
     """Worldtree agent envelope from GET /agents (issue #8).
@@ -198,8 +169,6 @@ class AuthoredHistoryUnavailable(Exception):
         self.session_id = session_id
 
 
-
-
 def endpoint_for_plane(plane: str, base_host: str) -> str:
     """Map a provider plane name to its Worldtree-VISIBLE base URL.
 
@@ -213,113 +182,10 @@ def endpoint_for_plane(plane: str, base_host: str) -> str:
     """
     ports = {"memory": 8391, "affect": 8390, "combined": 8392}
     if plane not in ports:
-        raise ValueError(
-            f"unknown plane: {plane!r} "
-            "(expected 'memory', 'affect', or 'combined')"
-        )
+        raise ValueError(f"unknown plane: {plane!r} (expected 'memory', 'affect', or 'combined')")
     return f"http://{base_host}:{ports[plane]}"
 
 
-def _bifrost_error_from(resp: httpx.Response) -> str | None:
-    """Pull the spec-level `bifrost_error` from a 502 body.
-
-    Tolerates both the FastAPI-nested `{"detail": {"bifrost_error": …}}` shape
-    (the spec's documented form, §"Optional Bifrost binding") and a flat
-    top-level `bifrost_error`, per the both-shape unwrap precedent established for
-    persona_state errors (the real wire returns the detail-nested form).
-    """
-    try:
-        err = resp.json()
-    except ValueError:
-        return None
-    if not isinstance(err, dict):
-        return None
-    bifrost_error = err.get("bifrost_error")
-    if bifrost_error is None and isinstance(err.get("detail"), dict):
-        bifrost_error = err["detail"].get("bifrost_error")
-    return bifrost_error
-
-
-async def create_session(
-    client: httpx.AsyncClient,
-    agent_id: str,
-    *,
-    end_user_id: str | None = None,
-    bifrost: BifrostBinding | None = None,
-    consumer_key: str | None = None,
-    config: Mapping[str, Any] | None = None,
-) -> SessionInfo:
-    """POST /sessions to create a new session. See contract FN create_session.
-
-    Per issue #5: pass `end_user_id` for per-end-user agents (lofn etc.).
-    When None (default), the body shape matches the pre-#5 baseline
-    `{"agent_id": agent_id}` so existing callers (mimir smoke) are unaffected.
-    Empty-string `end_user_id` is rejected before HTTP (PRE-003).
-
-    Per issue #17: when `bifrost` is set the request carries the binding and
-    authenticates with `consumer_key` (NOT the client's default canary bearer);
-    Worldtree handshakes synchronously to our provider before 201.
-    """
-    assert client is not None
-    assert agent_id and isinstance(agent_id, str)
-    assert end_user_id is None or (isinstance(end_user_id, str) and end_user_id)
-    # PRE-004 (issue #161): config is None or a Mapping.
-    assert config is None or isinstance(config, Mapping)
-    # PRE-005 (issue #161): ephemeral config + Bifrost binding are mutually
-    # exclusive (server would 422 ephemeral_does_not_accept_bifrost). The CLI
-    # guards this at arg-parse; this assert is defense-in-depth.
-    assert not (config is not None and bifrost is not None)
-
-    # PRE-001 (INV-001): a bifrost binding REQUIRES a non-empty consumer key,
-    # enforced before any HTTP so a bound create never falls back to the canary.
-    if bifrost is not None and not (isinstance(consumer_key, str) and consumer_key):
-        raise BifrostConsumerKeyMissing()
-
-    body: dict[str, Any] = {"agent_id": agent_id}
-    if end_user_id is not None:
-        body["end_user_id"] = end_user_id
-    # Issue #161: ephemeral-template config passthrough — verbatim, role/model-
-    # agnostic. The caller (CLI) builds {"system_prompt": ...}; the wrapper never
-    # injects a selector. Absent when None (foundational baseline unchanged).
-    if config is not None:
-        body["config"] = dict(config)
-    headers: dict[str, str] = {}
-    if bifrost is not None:
-        body["bifrost"] = {
-            "endpoint_url": bifrost.endpoint_url,
-            "scope": bifrost.scope,
-        }
-        # INV-001: the bound create authenticates with the consumer key,
-        # overriding the httpx client's default canary bearer per-request.
-        headers["Authorization"] = f"Bearer {consumer_key}"
-    resp = await client.post("/sessions", json=body, headers=headers)
-    if resp.status_code == 404:
-        raise AgentNotFound(agent_id=agent_id)
-    # POST-002 (INV-002): a 502 on a BOUND create is the synchronous Bifrost
-    # handshake failing. Gated on `bifrost is not None` — an unbound create's
-    # 502 is a generic upstream fault and stays SessionApiFailed.
-    if bifrost is not None and resp.status_code == 502:
-        raise BifrostHandshakeFailed(
-            bifrost_error=_bifrost_error_from(resp), body=resp.content
-        )
-    if resp.status_code != 201:
-        raise SessionApiFailed(status=resp.status_code, body=resp.content)
-    body = resp.json()
-    return SessionInfo(
-        session_id=body["session_id"],
-        agent_id=body["agent_id"],
-        created_at=body["created_at"],
-        last_active=body["last_active"],
-        metadata=body.get("metadata", {}),
-        message_count=body["message_count"],
-        name=None,
-        archived=False,
-        tags=[],
-        kind=body.get("kind"),      # INV-001 amendment (#161): "ephemeral"|"foundational"|None
-        config=body.get("config"),  # frozen ephemeral config; None for foundational
-    )
-
-
 async def list_agents(client: httpx.AsyncClient) -> list[AgentInfo]:
     """GET /agents — list available agents. See contract FN list_agents (issue #8).
 
@@ -347,9 +213,7 @@ async def list_agents(client: httpx.AsyncClient) -> list[AgentInfo]:
     ]
 
 
-async def get_persona_state(
-    client: httpx.AsyncClient, agent_id: str
-) -> dict[str, Any]:
+async def get_persona_state(client: httpx.AsyncClient, agent_id: str) -> dict[str, Any]:
     """GET /agents/{agent_id}/persona_state — fetch current persona snapshot.
 
     Worldtree #204 / v0.28.0. Returns the same `snapshot` dict shape as the
@@ -473,27 +337,6 @@ async def delete_character(client: httpx.AsyncClient, character_id: str) -> None
     raise SessionApiFailed(status=resp.status_code, body=resp.content)
 
 
-async def set_persona_state(
-    client: httpx.AsyncClient, session_id: str, snapshot: dict[str, Any]
-) -> None:
-    """POST /sessions/{session_id}/persona_state — set a session's persona state (affect injection).
-
-    The request body is FREEFORM on the wire (the OpenAPI declares no request
-    schema), but worldtree-dev's prose now pins the canonical shape (#317):
-    `{"pad": {"pleasure": p, "arousal": a, "dominance": d}}` — a named-key dict
-    (each in [-1, 1]), NOT a bare list; PAD-only, session-scoped, pull-over-push
-    (#289). The caller supplies the snapshot. 204 No Content → None; any other
-    status → SessionApiFailed.
-    """
-    assert client is not None
-    assert session_id and isinstance(session_id, str)
-    assert isinstance(snapshot, dict)
-    resp = await client.post(f"/sessions/{session_id}/persona_state", json=snapshot)
-    if resp.status_code == 204:
-        return None
-    raise SessionApiFailed(status=resp.status_code, body=resp.content)
-
-
 async def get_session_bifrost(
     client: httpx.AsyncClient, session_id: str, *, admin_key: str
 ) -> dict[str, Any]:
@@ -519,8 +362,6 @@ async def get_session_bifrost(
     raise SessionApiFailed(status=resp.status_code, body=resp.content)
 
 
-
-
 async def get_capabilities(client: httpx.AsyncClient) -> dict[str, Any]:
     """GET /capabilities — server capability discovery (spec §Ephemeral Templates).
 
@@ -534,75 +375,3 @@ async def get_capabilities(client: httpx.AsyncClient) -> dict[str, Any]:
     if resp.status_code == 200:
         return resp.json()
     raise SessionApiFailed(status=resp.status_code, body=resp.content)
-
-
-async def write_authored_history(
-    client: httpx.AsyncClient,
-    session_id: str,
-    *,
-    content: str,
-    idempotency_key: str,
-    author: str = "assistant",
-    effects: str | None = None,
-    claimed_original_at: str | None = None,
-) -> dict[str, Any]:
-    """POST /sessions/{session_id}/history — the #347 authored-history-write primitive.
-
-    Write one model-visible turn into the session's ledger AS the bound agent,
-    WITHOUT a generation and WITHOUT lived-turn side effects (the SillyTavern
-    "first message"). v1: `author="assistant"`, `effects` omitted (== "none"),
-    `idempotency_key` REQUIRED (per-session dedup). The server pins the body
-    (`AuthoredWriteRequest`, `extra="forbid"`), so `effects` /
-    `claimed_original_at` are sent only when non-None — never as null keys.
-
-    Success is 201 (fresh) or 200 (idempotent replay, byte-identical body); both
-    return the `AuthoredTurnResponse` dict verbatim (`{author, content_chars,
-    injected_at, phase, seq, session_id, turn_id}` — provenance is audit-only,
-    never on this body).
-
-    404 → `AuthoredHistoryUnavailable` (hide-existence: feature-absent /
-    ungranted / session-absent are indistinguishable by design; the caller falls
-    back and NEVER capability-probes — server INV-347-1). Any other non-2xx →
-    `SessionApiFailed` (notably 409 `generation_active`, 422 `content_too_long` /
-    `validation_failed`).
-    """
-    assert client is not None
-    assert session_id and isinstance(session_id, str)
-    assert content and isinstance(content, str)
-    assert idempotency_key and isinstance(idempotency_key, str)
-    assert author and isinstance(author, str)
-    body: dict[str, Any] = {
-        "author": author,
-        "content": content,
-        "idempotency_key": idempotency_key,
-    }
-    if effects is not None:
-        body["effects"] = effects
-    if claimed_original_at is not None:
-        body["claimed_original_at"] = claimed_original_at
-    resp = await client.post(f"/sessions/{session_id}/history", json=body)
-    if resp.status_code in (200, 201):
-        return resp.json()
-    if resp.status_code == 404:
-        raise AuthoredHistoryUnavailable(session_id=session_id)
-    raise SessionApiFailed(status=resp.status_code, body=resp.content)
-
-
-async def get_session_messages(
-    client: httpx.AsyncClient, session_id: str
-) -> dict[str, Any]:
-    """GET /sessions/{session_id}/messages — the session's message history.
-
-    Un-deferred as the #347 seed read-back: a seeded turn renders as a normal
-    `role=assistant` message (model-invisible provenance — indistinguishable
-    from a lived turn on read). Returns `{session_id, items: [{seq, role,
-    content, ...}], next_cursor}` verbatim; owner-scoped; any non-200 →
-    `SessionApiFailed`. v1 reads the server default page (no pagination params —
-    add limit/cursor when a caller needs scrollback).
-    """
-    assert client is not None
-    assert session_id and isinstance(session_id, str)
-    resp = await client.get(f"/sessions/{session_id}/messages")
-    if resp.status_code == 200:
-        return resp.json()
-    raise SessionApiFailed(status=resp.status_code, body=resp.content)

src/ratatoskr/tier3.py

@@ -9,7 +9,7 @@ posture (same as ratatoskr.sessions). Exposes three lifecycle operations:
 
 Plus a frozen ``Tier3AgentInfo`` dataclass for the response shape. The picker
 already handles colon-containing agent_ids generically (issue #8); session
-creation works unchanged via ``ratatoskr.sessions.create_session``.
+creation works unchanged via ``ratatoskr.wt.create_session`` (worldtree-sdk cutover).
 
 Spec reference: ``docs/conversation-api-spec.md`` §2576-2750 (Phase 2.0).
 """

src/ratatoskr/web/server.py

@@ -179,17 +179,17 @@ async def _create_session_endpoint(request: Request) -> JSONResponse:
 
     try:
         async with client_factory() as client:
+            wt_client = _wt_client(client)
             info = await wt.create_session(
-                _wt_client(client),
+                wt_client,
                 agent_id,
                 end_user_id=end_user_id,
                 bifrost=bifrost,
                 consumer_key=consumer_key if bifrost else None,
             )
             # #347 authored first-message: seed the agent's preset opening (best-effort;
-            # never blocks create). first_message is a slice-3 hand-rolled path — it
-            # reuses the raw transport (its default bearer), not the adapter client.
-            await seed_preset_first_message(client, info["session_id"], agent_id)
+            # never blocks create). Routed through the wt adapter (slice-3).
+            await seed_preset_first_message(wt_client, info["session_id"], agent_id)
     except AgentNotFound:
         return JSONResponse({"error_code": "agent_not_found"}, status_code=404)
     except BifrostConsumerKeyMissing:

src/ratatoskr/wt.py

@@ -33,14 +33,15 @@ from typing import Any
 
 import httpx
 import worldtree_sdk as wtsdk
-from worldtree_sdk import ApiError, AuthProvider, CancelResult, WorldtreeClient
+from worldtree_sdk import ApiError, AuthProvider, CancelResult, PadState, WorldtreeClient
 
-# Transitional (slice-2): the caller-semantic exceptions + the BifrostBinding input
+# Transitional (slice-2/3): the caller-semantic exceptions + the BifrostBinding input
 # type still live in the retiring `sessions` / `sse_client` modules; they relocate
-# into this adapter as their call-sites are rewired in later slice-2 commits. wt →
+# into this adapter as their call-sites are rewired in later slices. wt →
 # sessions / sse_client is one-way (neither imports wt), so there is no cycle.
 from .sessions import (
     AgentNotFound,
+    AuthoredHistoryUnavailable,
     BifrostBinding,
     BifrostConsumerKeyMissing,
     BifrostHandshakeFailed,
@@ -342,3 +343,71 @@ async def cancel_turn(
     except ApiError as exc:
         # INV-CUT-2 default: an undiscriminated ApiError on this route → SessionApiFailed.
         raise translate_error(exc) from exc
+
+
+# ── slice-3: persona + authored-history adapter routes ───────────────────────
+# The session-scoped affect write (set_persona_state) and the #347 authored-history
+# write (write_authored_history). The SDK owns the wire shapes — the canonical
+# `{"pad": {...}}` persona body via `PadState`, and the authored-write entry — so
+# ratatoskr no longer hand-builds either. Error map (INV-CUT-2): persona has no row
+# beyond the default; authored-history's 404 is the sole hide-existence route
+# (AuthoredHistoryUnavailable), everything else the SessionApiFailed default.
+
+
+async def set_persona_state(
+    client: WorldtreeClient,
+    session_id: str,
+    *,
+    pleasure: float,
+    arousal: float,
+    dominance: float,
+) -> None:
+    """Set a session's PAD persona state (POST /sessions/{id}/persona_state, W-7).
+
+    The adapter builds the canonical `PadState`; the SDK owns the wire wrapper
+    (`{"pad": {pleasure, arousal, dominance}}`, prose-pinned #317) — ratatoskr no
+    longer hand-assembles it. Resolves on 204 (→ None). Error map (INV-CUT-2): no
+    route-specific row → the `SessionApiFailed` default. (A non-finite axis is the
+    caller's to reject; the SDK raises `ConfigurationError` pre-HTTP and the CLI
+    surface pre-validates finiteness before calling.)
+    """
+    assert session_id and isinstance(session_id, str)
+    try:
+        await client.sessions.set_persona_state(
+            session_id, PadState(pleasure=pleasure, arousal=arousal, dominance=dominance)
+        )
+    except ApiError as exc:
+        raise translate_error(exc) from exc
+
+
+async def write_authored_history(
+    client: WorldtreeClient,
+    session_id: str,
+    *,
+    content: str,
+    idempotency_key: str,
+) -> Mapping[str, Any]:
+    """Write one authored assistant turn into the session ledger (POST
+    /sessions/{id}/history, #347) — the durable first-message primitive.
+
+    v1 accepts only `author="assistant"` (INV-347-4), so the adapter fixes it; the
+    caller supplies `content` + the per-content `idempotency_key` (REQUIRED, never
+    SDK-generated — a replay with the same (session, key) is an idempotent 200).
+    Returns the open-world `AuthoredTurn` ack verbatim. Error map (INV-CUT-2): a 404
+    → `AuthoredHistoryUnavailable` (the ROUTE is the discriminator — hide-existence,
+    never body-sniffed: feature-absent / ungranted / session-absent are one 404 by
+    design, server INV-347-1); every other `ApiError` (notably 409 generation_active,
+    422 validation) → the `SessionApiFailed` default.
+    """
+    assert session_id and isinstance(session_id, str)
+    assert content and isinstance(content, str)
+    assert idempotency_key and isinstance(idempotency_key, str)
+    try:
+        return await client.sessions.write_history(
+            session_id,
+            {"author": "assistant", "content": content, "idempotency_key": idempotency_key},
+        )
+    except ApiError as exc:
+        if exc.status == 404:
+            raise AuthoredHistoryUnavailable(session_id=session_id) from exc
+        raise translate_error(exc) from exc

tests/test_first_message.py

@@ -1,12 +1,21 @@
-"""Tests for ratatoskr.first_message per docs/contracts/first_message.contract.md."""
+"""Tests for ratatoskr.first_message per docs/contracts/first_message.contract.md.
+
+Slice-3 (worldtree-sdk cutover): `seed_preset_first_message` routes through the
+`ratatoskr.wt` adapter over a `WorldtreeClient`, no longer the hand-rolled httpx
+wrapper. These tests drive it through a fake client whose `sessions.write_history`
+returns or raises the SDK's real types — exercising the adapter's error mapping AND
+first_message's best-effort swallow in one pass. The wire format itself is the SDK's
+to prove (the parity corpus); first_message's contract is behavioral: never block,
+never raise (except CancelledError), and exactly one write on a preset hit.
+"""
 
 import asyncio
 import hashlib
-import json
+from typing import Any, cast
 
-import httpx
 import pytest
-import respx
+import worldtree_sdk as wtsdk
+from worldtree_sdk import ApiError, WorldtreeClient
 
 from ratatoskr.first_message import (
     FIRST_MESSAGE_PRESETS,
@@ -15,6 +24,33 @@ from ratatoskr.first_message import (
 )
 
 
+class _FakeSessions:
+    """Stand-in for `WorldtreeClient.sessions` — records each `write_history` call
+    and returns a canned ack or raises a canned error (the SDK's real exceptions)."""
+
+    def __init__(self, *, result: Any = None, error: BaseException | None = None) -> None:
+        self._result = result if result is not None else {}
+        self._error = error
+        self.calls: list[tuple[str, Any]] = []
+
+    async def write_history(self, session_id: str, entry: Any) -> Any:
+        self.calls.append((session_id, entry))
+        if self._error is not None:
+            raise self._error
+        return self._result
+
+
+class _FakeClient:
+    def __init__(self, sessions: _FakeSessions) -> None:
+        self.sessions = sessions
+
+
+def _wt(sessions: _FakeSessions) -> WorldtreeClient:
+    """Cast the structural fake to the nominal client type (no network; the seed
+    path only touches `client.sessions.write_history`, which the fake provides)."""
+    return cast(WorldtreeClient, _FakeClient(sessions))
+
+
 class TestPresetFor:
     """first_message contract — preset_for (dict lookup)."""
 
@@ -36,120 +72,70 @@ class TestPresetFor:
 class TestSeedPresetFirstMessage:
     """first_message contract — seed_preset_first_message (best-effort #347 seed)."""
 
-    @respx.mock
     async def test_seeds_preset(self) -> None:
-        """seeds_preset [happy,tracer]: preset agent → one history POST, correct body."""
+        """seeds_preset [happy,tracer]: preset agent → one write_history, correct entry."""
         content = FIRST_MESSAGE_PRESETS["ratatoskr:sindra"]
         key = "ratatoskr-preset-" + hashlib.sha256(content.encode("utf-8")).hexdigest()[:12]
-        route = respx.post("https://w.example/sessions/s1/history").mock(
-            return_value=httpx.Response(
-                201,
-                json={
-                    "author": "assistant",
-                    "seq": 0,
-                    "phase": "seeded",
-                    "turn_id": "t1",
-                    "session_id": "s1",
-                    "content_chars": len(content),
-                    "injected_at": "2026-07-06T00:00:00+00:00",
-                },
-            )
-        )
-        async with httpx.AsyncClient(base_url="https://w.example") as client:
-            result = await seed_preset_first_message(client, "s1", "ratatoskr:sindra")
+        fake = _FakeSessions(result={"seq": 0, "phase": "seeded"})
+        result = await seed_preset_first_message(_wt(fake), "s1", "ratatoskr:sindra")
         assert result == content
-        assert route.call_count == 1  # POST-002: exactly one history POST
-        assert json.loads(route.calls[0].request.content) == {
+        assert len(fake.calls) == 1  # POST-002: exactly one history write
+        session_id, entry = fake.calls[0]
+        assert session_id == "s1"
+        assert entry == {
             "author": "assistant",
             "content": content,
             "idempotency_key": key,
         }
 
-    @respx.mock
-    async def test_no_preset_zero_http(self) -> None:
-        """no_preset_zero_http [happy]: no-preset agent → None, ZERO HTTP (INV-002)."""
-        route = respx.post("https://w.example/sessions/s1/history").mock(
-            return_value=httpx.Response(201, json={})
-        )
-        async with httpx.AsyncClient(base_url="https://w.example") as client:
-            result = await seed_preset_first_message(client, "s1", "mimir")
+    async def test_no_preset_zero_write(self) -> None:
+        """no_preset_zero_write [happy]: no-preset agent → None, ZERO write (INV-002)."""
+        fake = _FakeSessions()
+        result = await seed_preset_first_message(_wt(fake), "s1", "mimir")
         assert result is None
-        assert not route.called
+        assert fake.calls == []
 
-    @respx.mock
     async def test_feature_absent_swallowed(self) -> None:
-        """feature_absent_swallowed [error]: 404 hide-existence → None, no raise (INV-001)."""
-        respx.post("https://w.example/sessions/s1/history").mock(
-            return_value=httpx.Response(404, json={"error_code": "session_not_found"})
-        )
-        async with httpx.AsyncClient(base_url="https://w.example") as client:
-            result = await seed_preset_first_message(client, "s1", "ratatoskr:sindra")
+        """feature_absent_swallowed [error]: 404 → AuthoredHistoryUnavailable → None (INV-001)."""
+        fake = _FakeSessions(error=ApiError("session_not_found", "no", status=404))
+        result = await seed_preset_first_message(_wt(fake), "s1", "ratatoskr:sindra")
         assert result is None
+        assert len(fake.calls) == 1  # the write was attempted, then swallowed
 
-    @respx.mock
     async def test_session_api_failed_swallowed(self) -> None:
-        """session_api_failed_swallowed [error]: 409 → None, no raise (INV-001)."""
-        respx.post("https://w.example/sessions/s1/history").mock(
-            return_value=httpx.Response(409, json={"error_code": "generation_active"})
-        )
-        async with httpx.AsyncClient(base_url="https://w.example") as client:
-            result = await seed_preset_first_message(client, "s1", "ratatoskr:sindra")
+        """session_api_failed_swallowed [error]: 409 → SessionApiFailed → None (INV-001)."""
+        fake = _FakeSessions(error=ApiError("generation_active", "busy", status=409))
+        result = await seed_preset_first_message(_wt(fake), "s1", "ratatoskr:sindra")
         assert result is None
 
-    @respx.mock
     async def test_transport_error_swallowed(self) -> None:
-        """transport_error_swallowed [error]: httpx.ConnectError → None, no raise (INV-001)."""
-        respx.post("https://w.example/sessions/s1/history").mock(
-            side_effect=httpx.ConnectError("boom")
-        )
-        async with httpx.AsyncClient(base_url="https://w.example") as client:
-            result = await seed_preset_first_message(client, "s1", "ratatoskr:sindra")
+        """transport_error_swallowed [error]: SDK ConnectFailed → None, no raise (INV-001)."""
+        fake = _FakeSessions(error=wtsdk.ConnectFailed("connect_failed", "boom", status=0))
+        result = await seed_preset_first_message(_wt(fake), "s1", "ratatoskr:sindra")
         assert result is None
 
-    @respx.mock
     async def test_unexpected_exception_swallowed(self) -> None:
         """unexpected_exception [error]: write raises ValueError → None (broad never-raise)."""
-        respx.post("https://w.example/sessions/s1/history").mock(
-            side_effect=ValueError("unexpected")
-        )
-        async with httpx.AsyncClient(base_url="https://w.example") as client:
-            result = await seed_preset_first_message(client, "s1", "ratatoskr:sindra")
+        fake = _FakeSessions(error=ValueError("unexpected"))
+        result = await seed_preset_first_message(_wt(fake), "s1", "ratatoskr:sindra")
         assert result is None
 
     async def test_cancellation_propagates(self) -> None:
         """cancellation_propagates [error]: CancelledError from the write is RE-RAISED."""
-        import ratatoskr.first_message as fm
+        fake = _FakeSessions(error=asyncio.CancelledError())
+        with pytest.raises(asyncio.CancelledError):
+            await seed_preset_first_message(_wt(fake), "s1", "ratatoskr:sindra")
 
-        async def _cancel(*_a: object, **_k: object) -> None:
-            raise asyncio.CancelledError
+    async def test_malformed_agent_id_no_write(self) -> None:
+        """malformed_agent_id [adversarial]: non-str or empty agent_id → None; no write; no raise."""
+        fake = _FakeSessions()
+        assert await seed_preset_first_message(_wt(fake), "s1", 123) is None  # type: ignore[arg-type]
+        assert await seed_preset_first_message(_wt(fake), "s1", "") is None
+        assert fake.calls == []
 
-        orig = fm.write_authored_history
-        fm.write_authored_history = _cancel  # type: ignore[assignment]
-        try:
-            async with httpx.AsyncClient(base_url="https://w.example") as client:
-                with pytest.raises(asyncio.CancelledError):
-                    await seed_preset_first_message(client, "s1", "ratatoskr:sindra")
-        finally:
-            fm.write_authored_history = orig  # type: ignore[assignment]
-
-    @respx.mock
-    async def test_malformed_agent_id_no_http(self) -> None:
-        """malformed_agent_id [adversarial]: non-str or empty agent_id → None; no HTTP; no raise."""
-        route = respx.post(url__regex=r".*/history$").mock(
-            return_value=httpx.Response(201, json={})
-        )
-        async with httpx.AsyncClient(base_url="https://w.example") as client:
-            assert await seed_preset_first_message(client, "s1", 123) is None  # type: ignore[arg-type]
-            assert await seed_preset_first_message(client, "s1", "") is None
-        assert not route.called
-
-    @respx.mock
     async def test_empty_session_id(self) -> None:
-        """empty_session_id [adversarial]: "" → None (soft guard); no HTTP; no raise."""
-        route = respx.post("https://w.example/sessions/s1/history").mock(
-            return_value=httpx.Response(201, json={})
-        )
-        async with httpx.AsyncClient(base_url="https://w.example") as client:
-            result = await seed_preset_first_message(client, "", "ratatoskr:sindra")
+        """empty_session_id [adversarial]: "" → None (soft guard); no write; no raise."""
+        fake = _FakeSessions()
+        result = await seed_preset_first_message(_wt(fake), "", "ratatoskr:sindra")
         assert result is None
-        assert not route.called
+        assert fake.calls == []

tests/test_sessions.py

@@ -7,16 +7,10 @@ import respx
 from ratatoskr.sessions import (
     AgentInfo,
     AgentNotAvailable,
-    AgentNotFound,
-    AuthoredHistoryUnavailable,
     AuthScopeDenied,
-    BifrostBinding,
-    BifrostConsumerKeyMissing,
-    BifrostHandshakeFailed,
     PersonaNotConfigured,
     SessionApiFailed,
     create_character,
-    create_session,
     delete_character,
     endpoint_for_plane,
     get_capabilities,
@@ -24,522 +18,25 @@ from ratatoskr.sessions import (
     get_me,
     get_persona_state,
     get_session_bifrost,
-    get_session_messages,
     list_agents,
     list_character_models,
-    set_persona_state,
-    write_authored_history,
 )
 
 
-class TestCreateSession:
-    @respx.mock
-    async def test_happy_create(self) -> None:
-        """happy_create [happy,tracer]: full 201 body -> SessionInfo with create-origin defaults."""
-        respx.post("https://w.example/sessions").mock(
-            return_value=httpx.Response(
-                201,
-                json={
-                    "session_id": "550e8400-e29b-41d4-a716-446655440000",
-                    "agent_id": "mimir",
-                    "message_count": 0,
-                    "created_at": "2026-04-15T12:00:00+00:00",
-                    "last_active": "2026-04-15T12:00:00+00:00",
-                    "metadata": {},
-                },
-            )
-        )
-        async with httpx.AsyncClient(base_url="https://w.example") as client:
-            info = await create_session(client, "mimir")
-        assert info.session_id == "550e8400-e29b-41d4-a716-446655440000"
-        assert info.agent_id == "mimir"
-        assert info.created_at == "2026-04-15T12:00:00+00:00"
-        assert info.last_active == "2026-04-15T12:00:00+00:00"
-        assert info.metadata == {}
-        assert info.message_count == 0
-        # INV-001 create-origin fixed defaults
-        assert info.name is None
-        assert info.archived is False
-        assert info.tags == []
-
-    @respx.mock
-    async def test_happy_create_with_metadata(self) -> None:
-        """happy_create_with_metadata: response carries metadata -> SessionInfo.metadata matches."""
-        respx.post("https://w.example/sessions").mock(
-            return_value=httpx.Response(
-                201,
-                json={
-                    "session_id": "s1",
-                    "agent_id": "mimir",
-                    "message_count": 0,
-                    "created_at": "2026-04-15T12:00:00+00:00",
-                    "last_active": "2026-04-15T12:00:00+00:00",
-                    "metadata": {"model": "glm5-turbo"},
-                },
-            )
-        )
-        async with httpx.AsyncClient(base_url="https://w.example") as client:
-            info = await create_session(client, "mimir")
-        assert info.metadata == {"model": "glm5-turbo"}
-
-    @respx.mock
-    async def test_request_body_shape(self) -> None:
-        """request_body_shape [trace]: outbound JSON is exactly {"agent_id": <arg>}."""
-        import json as _json
-
-        route = respx.post("https://w.example/sessions").mock(
-            return_value=httpx.Response(
-                201,
-                json={
-                    "session_id": "s1",
-                    "agent_id": "mimir",
-                    "message_count": 0,
-                    "created_at": "2026-04-15T12:00:00+00:00",
-                    "last_active": "2026-04-15T12:00:00+00:00",
-                    "metadata": {},
-                },
-            )
-        )
-        async with httpx.AsyncClient(base_url="https://w.example") as client:
-            await create_session(client, "mimir")
-        body = _json.loads(route.calls[0].request.content)
-        assert body == {"agent_id": "mimir"}
-
-    @respx.mock
-    async def test_unknown_agent_id(self) -> None:
-        """unknown_agent_id: 404 -> AgentNotFound(agent_id=<arg>)."""
-        respx.post("https://w.example/sessions").mock(
-            return_value=httpx.Response(404, json={"error": "unknown_agent_id"})
-        )
-        async with httpx.AsyncClient(base_url="https://w.example") as client:
-            with pytest.raises(AgentNotFound) as exc_info:
-                await create_session(client, "mimir")
-        assert exc_info.value.agent_id == "mimir"
-
-    @respx.mock
-    async def test_validation_failed(self) -> None:
-        """validation_failed: 422 -> SessionApiFailed(status=422); body truncated."""
-        respx.post("https://w.example/sessions").mock(
-            return_value=httpx.Response(
-                422,
-                json={"error_code": "validation_failed", "message": "missing agent_id"},
-            )
-        )
-        async with httpx.AsyncClient(base_url="https://w.example") as client:
-            with pytest.raises(SessionApiFailed) as exc_info:
-                await create_session(client, "mimir")
-        assert exc_info.value.status == 422
-        assert len(exc_info.value.body) <= 1024
-
-    @respx.mock
-    async def test_unexpected_status_truncates(self) -> None:
-        """unexpected_status_truncates: 500 + 5000-byte body -> SessionApiFailed; body == 1024."""
-        big = b"x" * 5000
-        respx.post("https://w.example/sessions").mock(
-            return_value=httpx.Response(500, content=big)
-        )
-        async with httpx.AsyncClient(base_url="https://w.example") as client:
-            with pytest.raises(SessionApiFailed) as exc_info:
-                await create_session(client, "mimir")
-        assert exc_info.value.status == 500
-        assert exc_info.value.body == big[:1024]
-
-    @respx.mock
-    async def test_empty_agent_id(self) -> None:
-        """empty_agent_id [adversarial]: '' -> AssertionError; no HTTP issued."""
-        route = respx.post("https://w.example/sessions").mock(
-            return_value=httpx.Response(201, content=b"{}")
-        )
-        async with httpx.AsyncClient(base_url="https://w.example") as client:
-            with pytest.raises(AssertionError):
-                await create_session(client, "")
-        assert route.call_count == 0
-
-    @respx.mock
-    async def test_happy_create_with_end_user_id(self) -> None:
-        """happy_create_with_end_user_id [happy]: body carries both keys (issue #5)."""
-        import json as _json
-
-        route = respx.post("https://w.example/sessions").mock(
-            return_value=httpx.Response(
-                201,
-                json={
-                    "session_id": "s-new",
-                    "agent_id": "lofn",
-                    "message_count": 0,
-                    "created_at": "2026-05-22T12:00:00+00:00",
-                    "last_active": "2026-05-22T12:00:00+00:00",
-                    "metadata": {},
-                },
-            )
-        )
-        async with httpx.AsyncClient(base_url="https://w.example") as client:
-            info = await create_session(client, "lofn", end_user_id="alice")
-        body = _json.loads(route.calls[0].request.content)
-        # INV: body MUST be exactly {"agent_id": ..., "end_user_id": ...} — byte-for-byte
-        assert body == {"agent_id": "lofn", "end_user_id": "alice"}
-        assert info.session_id == "s-new"
-        assert info.agent_id == "lofn"
-
-    @respx.mock
-    async def test_default_omits_end_user_id(self) -> None:
-        """default_omits_end_user_id [trace]: omit kwarg → body has no end_user_id (INV-002)."""
-        import json as _json
-
-        route = respx.post("https://w.example/sessions").mock(
-            return_value=httpx.Response(
-                201,
-                json={
-                    "session_id": "s-new",
-                    "agent_id": "mimir",
-                    "message_count": 0,
-                    "created_at": "2026-05-22T12:00:00+00:00",
-                    "last_active": "2026-05-22T12:00:00+00:00",
-                    "metadata": {},
-                },
-            )
-        )
-        async with httpx.AsyncClient(base_url="https://w.example") as client:
-            await create_session(client, "mimir")
-        body = _json.loads(route.calls[0].request.content)
-        # Exact equality — no end_user_id key in the body when the kwarg is omitted
-        assert body == {"agent_id": "mimir"}
-        assert "end_user_id" not in body
-
-    @respx.mock
-    async def test_empty_end_user_id(self) -> None:
-        """empty_end_user_id [adversarial]: '' → AssertionError before HTTP (PRE-003)."""
-        route = respx.post("https://w.example/sessions").mock(
-            return_value=httpx.Response(201, content=b"{}")
-        )
-        async with httpx.AsyncClient(base_url="https://w.example") as client:
-            with pytest.raises(AssertionError):
-                await create_session(client, "mimir", end_user_id="")
-        assert route.call_count == 0
-
-
-class TestCreateSessionEphemeral:
-    """Amendment 2026-07-18 — ephemeral-template (Echo) session creation."""
-
-    @respx.mock
-    async def test_happy_ephemeral_create(self) -> None:
-        """happy_ephemeral_create [happy,tracer]: config threaded; kind/config captured."""
-        import json as _json
-
-        route = respx.post("https://w.example/sessions").mock(
-            return_value=httpx.Response(
-                201,
-                json={
-                    "session_id": "eph-1",
-                    "agent_id": "echo",
-                    "kind": "ephemeral",
-                    "message_count": 0,
-                    "created_at": "2026-07-18T09:30:13+00:00",
-                    "last_active": "2026-07-18T09:30:13+00:00",
-                    "metadata": {},
-                    "config": {"system_prompt": "You are X.", "role": "echo"},
-                },
-            )
-        )
-        async with httpx.AsyncClient(base_url="https://w.example") as client:
-            info = await create_session(
-                client, "echo", config={"system_prompt": "You are X."}
-            )
-        body = _json.loads(route.calls[0].request.content)
-        assert body == {"agent_id": "echo", "config": {"system_prompt": "You are X."}}
-        assert info.kind == "ephemeral"
-        assert info.config == {"system_prompt": "You are X.", "role": "echo"}
-
-    @respx.mock
-    async def test_foundational_omits_config(self) -> None:
-        """foundational_omits_config [trace]: no config key; kind/config None when absent."""
-        import json as _json
-
-        route = respx.post("https://w.example/sessions").mock(
-            return_value=httpx.Response(
-                201,
-                json={
-                    "session_id": "s1",
-                    "agent_id": "mimir",
-                    "message_count": 0,
-                    "created_at": "2026-04-15T12:00:00+00:00",
-                    "last_active": "2026-04-15T12:00:00+00:00",
-                    "metadata": {},
-                },
-            )
-        )
-        async with httpx.AsyncClient(base_url="https://w.example") as client:
-            info = await create_session(client, "mimir")
-        body = _json.loads(route.calls[0].request.content)
-        assert body == {"agent_id": "mimir"}
-        assert info.kind is None
-        assert info.config is None
-
-    @respx.mock
-    async def test_foundational_captures_kind(self) -> None:
-        """foundational_captures_kind [happy]: kind='foundational' captured; config None."""
-        respx.post("https://w.example/sessions").mock(
-            return_value=httpx.Response(
-                201,
-                json={
-                    "session_id": "s1",
-                    "agent_id": "mimir",
-                    "kind": "foundational",
-                    "message_count": 0,
-                    "created_at": "2026-04-15T12:00:00+00:00",
-                    "last_active": "2026-04-15T12:00:00+00:00",
-                    "metadata": {},
-                },
-            )
-        )
-        async with httpx.AsyncClient(base_url="https://w.example") as client:
-            info = await create_session(client, "mimir")
-        assert info.kind == "foundational"
-        assert info.config is None
-
-    @respx.mock
-    async def test_ephemeral_requires_config_422(self) -> None:
-        """ephemeral_requires_config_422 [error]: 422 → SessionApiFailed carrying the code."""
-        respx.post("https://w.example/sessions").mock(
-            return_value=httpx.Response(
-                422,
-                json={"detail": {"error_code": "ephemeral_requires_config"}},
-            )
-        )
-        async with httpx.AsyncClient(base_url="https://w.example") as client:
-            with pytest.raises(SessionApiFailed) as exc:
-                await create_session(client, "echo")
-        assert exc.value.status == 422
-        assert b"ephemeral_requires_config" in exc.value.body
-
-    @respx.mock
-    async def test_model_not_allowed_422(self) -> None:
-        """model_not_allowed_422 [error]: config.model → 422 (wrapper passes config verbatim)."""
-        import json as _json
-
-        route = respx.post("https://w.example/sessions").mock(
-            return_value=httpx.Response(
-                422, json={"detail": {"error_code": "model_not_allowed"}}
-            )
-        )
-        async with httpx.AsyncClient(base_url="https://w.example") as client:
-            with pytest.raises(SessionApiFailed) as exc:
-                await create_session(
-                    client, "echo", config={"system_prompt": "x", "model": "glm5-turbo"}
-                )
-        body = _json.loads(route.calls[0].request.content)
-        assert body["config"] == {"system_prompt": "x", "model": "glm5-turbo"}
-        assert exc.value.status == 422
-
-    @respx.mock
-    async def test_config_and_bifrost_conflict(self) -> None:
-        """config_and_bifrost_conflict [adversarial]: both → AssertionError (PRE-005); no HTTP."""
-        route = respx.post("https://w.example/sessions").mock(
-            return_value=httpx.Response(201, content=b"{}")
-        )
-        async with httpx.AsyncClient(base_url="https://w.example") as client:
-            with pytest.raises(AssertionError):
-                await create_session(
-                    client,
-                    "echo",
-                    config={"system_prompt": "x"},
-                    bifrost=BifrostBinding(endpoint_url="https://p.example"),
-                    consumer_key="ck",
-                )
-        assert route.call_count == 0
-
-    @respx.mock
-    async def test_config_not_a_mapping(self) -> None:
-        """config_not_a_mapping [adversarial]: non-Mapping → AssertionError (PRE-004); no HTTP."""
-        route = respx.post("https://w.example/sessions").mock(
-            return_value=httpx.Response(201, content=b"{}")
-        )
-        async with httpx.AsyncClient(base_url="https://w.example") as client:
-            with pytest.raises(AssertionError):
-                await create_session(client, "echo", config="not-a-dict")  # type: ignore[arg-type]
-        assert route.call_count == 0
-
-
-class TestCreateSessionBifrostBind:
-    """Issue #17 slice 1 — the create_session Bifrost-bind primitive."""
-
-    @respx.mock
-    async def test_bind_happy_consumer_key_and_body(self) -> None:
-        """bind_happy [tracer]: a bifrost binding makes the body carry the
-        `bifrost` field AND overrides the bearer to the consumer key (NOT the
-        client's canary default), 201 → SessionInfo. Proves the bind path
-        end-to-end (FN create_session STEPS 1-2, POST-001, INV-001)."""
-        import json as _json
-
-        route = respx.post("https://w.example/sessions").mock(
-            return_value=httpx.Response(
-                201,
-                json={
-                    "session_id": "s-bound",
-                    "agent_id": "ratatoskr:sindra",
-                    "message_count": 0,
-                    "created_at": "2026-06-18T12:00:00+00:00",
-                    "last_active": "2026-06-18T12:00:00+00:00",
-                    "metadata": {},
-                },
-            )
-        )
-        binding = BifrostBinding(endpoint_url="http://10.100.10.50:8391")
-        async with httpx.AsyncClient(
-            base_url="https://w.example",
-            headers={"Authorization": "Bearer canary-key"},
-        ) as client:
-            info = await create_session(
-                client,
-                "ratatoskr:sindra",
-                end_user_id="smoke-user",
-                bifrost=binding,
-                consumer_key="consumer-key",
-            )
-        req = route.calls[0].request
-        body = _json.loads(req.content)
-        # body carries the bifrost field alongside agent_id/end_user_id
-        assert body == {
-            "agent_id": "ratatoskr:sindra",
-            "end_user_id": "smoke-user",
-            "bifrost": {
-                "endpoint_url": "http://10.100.10.50:8391",
-                "scope": None,
-            },
-        }
-        # bearer overridden to the consumer key (INV-001: never the canary default)
-        assert req.headers["Authorization"] == "Bearer consumer-key"
-        assert info.session_id == "s-bound"
-        assert info.agent_id == "ratatoskr:sindra"
-
-    @respx.mock
-    async def test_bind_without_consumer_key_raises_before_http(self) -> None:
-        """missing_key [adversarial]: bifrost set but consumer_key None →
-        BifrostConsumerKeyMissing BEFORE any HTTP (PRE-001, INV-001: never fall
-        back to the canary key)."""
-        route = respx.post("https://w.example/sessions").mock(
-            return_value=httpx.Response(201, content=b"{}")
-        )
-        binding = BifrostBinding(endpoint_url="http://10.100.10.50:8391")
-        async with httpx.AsyncClient(base_url="https://w.example") as client:
-            with pytest.raises(BifrostConsumerKeyMissing):
-                await create_session(client, "ratatoskr:sindra", bifrost=binding)
-        assert route.call_count == 0
-
-    @respx.mock
-    async def test_bind_with_empty_consumer_key_raises_before_http(self) -> None:
-        """empty_key [adversarial]: empty-string consumer_key is also rejected
-        before HTTP (PRE-001 requires a NON-EMPTY str)."""
-        route = respx.post("https://w.example/sessions").mock(
-            return_value=httpx.Response(201, content=b"{}")
-        )
-        binding = BifrostBinding(endpoint_url="http://10.100.10.50:8391")
-        async with httpx.AsyncClient(base_url="https://w.example") as client:
-            with pytest.raises(BifrostConsumerKeyMissing):
-                await create_session(
-                    client, "ratatoskr:sindra", bifrost=binding, consumer_key=""
-                )
-        assert route.call_count == 0
-
-    @respx.mock
-    async def test_bind_handshake_failure_maps_to_502(self) -> None:
-        """handshake_502 [adversarial]: a bound create that 502s with
-        detail.bifrost_error → BifrostHandshakeFailed carrying the bifrost_error
-        + raw body (POST-002, INV-002 bind-time failure). 'bifrost.auth_rejected'
-        is the canary-key-instead-of-consumer-key tell."""
-        respx.post("https://w.example/sessions").mock(
-            return_value=httpx.Response(
-                502,
-                json={
-                    "error_code": "bifrost_handshake_failed",
-                    "detail": {"bifrost_error": "bifrost.auth_rejected"},
-                },
-            )
-        )
-        binding = BifrostBinding(endpoint_url="http://10.100.10.50:8391")
-        async with httpx.AsyncClient(base_url="https://w.example") as client:
-            with pytest.raises(BifrostHandshakeFailed) as exc_info:
-                await create_session(
-                    client, "ratatoskr:sindra", bifrost=binding, consumer_key="ck"
-                )
-        assert exc_info.value.bifrost_error == "bifrost.auth_rejected"
-        # the raw 502 body is carried for debugging
-        assert exc_info.value.body
-
-    @respx.mock
-    async def test_bind_ephemeral_rejection_is_session_api_failed(self) -> None:
-        """ephemeral_422 [boundary]: 422 ephemeral_does_not_accept_bifrost is a
-        generic create failure → SessionApiFailed, NOT a distinct exception
-        (POST-003 — deliberate, an operator config error)."""
-        respx.post("https://w.example/sessions").mock(
-            return_value=httpx.Response(
-                422, json={"error_code": "ephemeral_does_not_accept_bifrost"}
-            )
-        )
-        binding = BifrostBinding(endpoint_url="http://10.100.10.50:8391")
-        async with httpx.AsyncClient(base_url="https://w.example") as client:
-            with pytest.raises(SessionApiFailed) as exc_info:
-                await create_session(
-                    client, "echo", bifrost=binding, consumer_key="ck"
-                )
-        assert exc_info.value.status == 422
-
-    @respx.mock
-    async def test_unbound_create_unchanged_no_auth_override(self) -> None:
-        """unbound_unchanged [regression]: with no bifrost, the body is the
-        pre-#17 shape AND create_session sends NO per-request Authorization
-        override — the client's default canary bearer governs (INV-001: the two
-        call sites never cross)."""
-        import json as _json
-
-        route = respx.post("https://w.example/sessions").mock(
-            return_value=httpx.Response(
-                201,
-                json={
-                    "session_id": "s1",
-                    "agent_id": "mimir",
-                    "message_count": 0,
-                    "created_at": "2026-04-15T12:00:00+00:00",
-                    "last_active": "2026-04-15T12:00:00+00:00",
-                    "metadata": {},
-                },
-            )
-        )
-        async with httpx.AsyncClient(
-            base_url="https://w.example",
-            headers={"Authorization": "Bearer canary-key"},
-        ) as client:
-            await create_session(client, "mimir")
-        req = route.calls[0].request
-        body = _json.loads(req.content)
-        assert body == {"agent_id": "mimir"}
-        # the client default bearer is used unchanged — no consumer-key override
-        assert req.headers["Authorization"] == "Bearer canary-key"
-
-
 class TestEndpointForPlane:
     """Issue #17 — endpoint_for_plane: plane name → Worldtree-visible base URL."""
 
     def test_memory_plane_maps_to_8391(self) -> None:
         """memory [tracer]: 'memory' → http://<host>:8391 (POST-001)."""
-        assert (
-            endpoint_for_plane("memory", "10.100.10.50")
-            == "http://10.100.10.50:8391"
-        )
+        assert endpoint_for_plane("memory", "10.100.10.50") == "http://10.100.10.50:8391"
 
     def test_affect_plane_maps_to_8390(self) -> None:
         """affect: 'affect' → http://<host>:8390 (POST-001)."""
-        assert (
-            endpoint_for_plane("affect", "10.100.10.50")
-            == "http://10.100.10.50:8390"
-        )
+        assert endpoint_for_plane("affect", "10.100.10.50") == "http://10.100.10.50:8390"
 
     def test_combined_plane_maps_to_8392(self) -> None:
         """combined [#18 composite]: 'combined' → http://<host>:8392 (POST-001)."""
-        assert (
-            endpoint_for_plane("combined", "10.100.10.50")
-            == "http://10.100.10.50:8392"
-        )
+        assert endpoint_for_plane("combined", "10.100.10.50") == "http://10.100.10.50:8392"
 
     def test_unknown_plane_raises_value_error(self) -> None:
         """unknown_plane [adversarial]: any other plane → ValueError (PRE-001)."""
@@ -636,9 +133,7 @@ class TestListAgents:
     @respx.mock
     async def test_happy_empty(self) -> None:
         """happy_empty: 200 with [] returns empty list (no error)."""
-        respx.get("https://w.example/agents").mock(
-            return_value=httpx.Response(200, json=[])
-        )
+        respx.get("https://w.example/agents").mock(return_value=httpx.Response(200, json=[]))
         async with httpx.AsyncClient(base_url="https://w.example") as client:
             agents = await list_agents(client)
         assert agents == []
@@ -1026,9 +521,7 @@ class TestTransientCharacters:
     @respx.mock
     async def test_delete_204(self) -> None:
         """delete [happy]: 204 → None."""
-        respx.delete("https://w.example/characters/char_x").mock(
-            return_value=httpx.Response(204)
-        )
+        respx.delete("https://w.example/characters/char_x").mock(return_value=httpx.Response(204))
         async with httpx.AsyncClient(base_url="https://w.example") as client:
             assert await delete_character(client, "char_x") is None
 
@@ -1042,213 +535,3 @@ class TestTransientCharacters:
             with pytest.raises(SessionApiFailed) as exc:
                 await create_character(client, {"name": "H"})
         assert exc.value.status == 403
-
-
-class TestSetPersonaState:
-    """#2 contract — set_persona_state (POST /sessions/{id}/persona_state)."""
-
-    @respx.mock
-    async def test_happy_204(self) -> None:
-        """happy [happy,tracer]: freeform snapshot body; 204 → None."""
-        import json as _json
-
-        route = respx.post("https://w.example/sessions/s1/persona_state").mock(
-            return_value=httpx.Response(204)
-        )
-        async with httpx.AsyncClient(base_url="https://w.example") as client:
-            result = await set_persona_state(
-                client, "s1", {"pad": {"pleasure": 0.4, "arousal": 0.1, "dominance": -0.2}}
-            )
-        assert result is None
-        assert _json.loads(route.calls[0].request.content) == {
-            "pad": {"pleasure": 0.4, "arousal": 0.1, "dominance": -0.2}
-        }
-
-    @respx.mock
-    async def test_non_204_raises(self) -> None:
-        """non_204 [error]: 422 (bad snapshot shape) → SessionApiFailed(422)."""
-        respx.post("https://w.example/sessions/s1/persona_state").mock(
-            return_value=httpx.Response(422, json={"error_code": "validation_failed"})
-        )
-        async with httpx.AsyncClient(base_url="https://w.example") as client:
-            with pytest.raises(SessionApiFailed) as exc:
-                await set_persona_state(client, "s1", {"pad": [1, 2, 3]})
-        assert exc.value.status == 422
-
-
-_AUTHORED_ACK = {
-    "author": "assistant",
-    "content_chars": 5,
-    "injected_at": "2026-07-06T12:00:00+00:00",
-    "phase": "seeded",
-    "seq": 0,
-    "session_id": "s1",
-    "turn_id": "t1",
-}
-
-
-class TestWriteAuthoredHistory:
-    """write_authored_history — #347 POST /sessions/{id}/history (contract #2 amendment)."""
-
-    @respx.mock
-    async def test_happy_fresh_201(self) -> None:
-        """happy_fresh_201 [happy,tracer]: 201 → ack verbatim; minimal body."""
-        import json as _json
-
-        route = respx.post("https://w.example/sessions/s1/history").mock(
-            return_value=httpx.Response(201, json=_AUTHORED_ACK)
-        )
-        async with httpx.AsyncClient(base_url="https://w.example") as client:
-            result = await write_authored_history(
-                client, "s1", content="hello", idempotency_key="k1"
-            )
-        assert result == _AUTHORED_ACK
-        assert _json.loads(route.calls[0].request.content) == {
-            "author": "assistant",
-            "content": "hello",
-            "idempotency_key": "k1",
-        }
-
-    @respx.mock
-    async def test_happy_replay_200(self) -> None:
-        """happy_replay_200 [happy]: 200 replay (byte-identical body) → dict verbatim."""
-        respx.post("https://w.example/sessions/s1/history").mock(
-            return_value=httpx.Response(200, json=_AUTHORED_ACK)
-        )
-        async with httpx.AsyncClient(base_url="https://w.example") as client:
-            result = await write_authored_history(
-                client, "s1", content="hello", idempotency_key="k1"
-            )
-        assert result == _AUTHORED_ACK
-
-    @respx.mock
-    async def test_body_includes_effects(self) -> None:
-        """body_includes_effects [trace]: effects + claimed_original_at appear iff non-None."""
-        import json as _json
-
-        route = respx.post("https://w.example/sessions/s1/history").mock(
-            return_value=httpx.Response(201, json=_AUTHORED_ACK)
-        )
-        async with httpx.AsyncClient(base_url="https://w.example") as client:
-            await write_authored_history(
-                client,
-                "s1",
-                content="hi",
-                idempotency_key="k1",
-                effects="none",
-                claimed_original_at="2020-01-01T00:00:00Z",
-            )
-        assert _json.loads(route.calls[0].request.content) == {
-            "author": "assistant",
-            "content": "hi",
-            "idempotency_key": "k1",
-            "effects": "none",
-            "claimed_original_at": "2020-01-01T00:00:00Z",
-        }
-
-    @respx.mock
-    async def test_hide_existence_404(self) -> None:
-        """hide_existence_404 [error]: 404 → AuthoredHistoryUnavailable (NOT SessionApiFailed)."""
-        respx.post("https://w.example/sessions/s1/history").mock(
-            return_value=httpx.Response(404, json={"error_code": "session_not_found"})
-        )
-        async with httpx.AsyncClient(base_url="https://w.example") as client:
-            with pytest.raises(AuthoredHistoryUnavailable) as exc:
-                await write_authored_history(client, "s1", content="hi", idempotency_key="k1")
-        assert exc.value.session_id == "s1"
-
-    @respx.mock
-    async def test_generation_active_409(self) -> None:
-        """generation_active_409 [error]: 409 → SessionApiFailed(409)."""
-        respx.post("https://w.example/sessions/s1/history").mock(
-            return_value=httpx.Response(409, json={"error_code": "generation_active"})
-        )
-        async with httpx.AsyncClient(base_url="https://w.example") as client:
-            with pytest.raises(SessionApiFailed) as exc:
-                await write_authored_history(client, "s1", content="hi", idempotency_key="k1")
-        assert exc.value.status == 409
-
-    @respx.mock
-    async def test_content_too_long_422(self) -> None:
-        """content_too_long_422 [error]: 422 → SessionApiFailed(422)."""
-        respx.post("https://w.example/sessions/s1/history").mock(
-            return_value=httpx.Response(422, json={"error_code": "content_too_long"})
-        )
-        async with httpx.AsyncClient(base_url="https://w.example") as client:
-            with pytest.raises(SessionApiFailed) as exc:
-                await write_authored_history(client, "s1", content="x", idempotency_key="k1")
-        assert exc.value.status == 422
-
-    @respx.mock
-    async def test_empty_content(self) -> None:
-        """empty_content [adversarial]: content="" → AssertionError; no HTTP issued."""
-        route = respx.post("https://w.example/sessions/s1/history").mock(
-            return_value=httpx.Response(201, json=_AUTHORED_ACK)
-        )
-        async with httpx.AsyncClient(base_url="https://w.example") as client:
-            with pytest.raises(AssertionError):
-                await write_authored_history(client, "s1", content="", idempotency_key="k1")
-        assert not route.called
-
-    @respx.mock
-    async def test_empty_idempotency_key(self) -> None:
-        """empty_idempotency_key [adversarial]: key="" → AssertionError; no HTTP issued."""
-        route = respx.post("https://w.example/sessions/s1/history").mock(
-            return_value=httpx.Response(201, json=_AUTHORED_ACK)
-        )
-        async with httpx.AsyncClient(base_url="https://w.example") as client:
-            with pytest.raises(AssertionError):
-                await write_authored_history(client, "s1", content="hi", idempotency_key="")
-        assert not route.called
-
-    @respx.mock
-    async def test_empty_session_id(self) -> None:
-        """empty_session_id [adversarial]: session_id="" → AssertionError; no HTTP issued."""
-        route = respx.post("https://w.example/sessions/s1/history").mock(
-            return_value=httpx.Response(201, json=_AUTHORED_ACK)
-        )
-        async with httpx.AsyncClient(base_url="https://w.example") as client:
-            with pytest.raises(AssertionError):
-                await write_authored_history(client, "", content="hi", idempotency_key="k1")
-        assert not route.called
-
-
-class TestGetSessionMessages:
-    """#2 contract (amendment 2026-07-06) — get_session_messages (GET /sessions/{id}/messages)."""
-
-    @respx.mock
-    async def test_happy(self) -> None:
-        """happy [happy,tracer]: 200 {session_id, items, next_cursor} → dict verbatim."""
-        payload = {
-            "session_id": "s1",
-            "items": [{"seq": 0, "role": "assistant", "content": "hello there"}],
-            "next_cursor": None,
-        }
-        respx.get("https://w.example/sessions/s1/messages").mock(
-            return_value=httpx.Response(200, json=payload)
-        )
-        async with httpx.AsyncClient(base_url="https://w.example") as client:
-            result = await get_session_messages(client, "s1")
-        assert result == payload
-
-    @respx.mock
-    async def test_not_found_404(self) -> None:
-        """not_found_404 [error]: 404 → SessionApiFailed(404)."""
-        respx.get("https://w.example/sessions/s1/messages").mock(
-            return_value=httpx.Response(404, json={"error_code": "session_not_found"})
-        )
-        async with httpx.AsyncClient(base_url="https://w.example") as client:
-            with pytest.raises(SessionApiFailed) as exc:
-                await get_session_messages(client, "s1")
-        assert exc.value.status == 404
-
-    @respx.mock
-    async def test_empty_session_id(self) -> None:
-        """empty_session_id [adversarial]: "" → AssertionError; no HTTP issued."""
-        route = respx.get("https://w.example/sessions/s1/messages").mock(
-            return_value=httpx.Response(200, json={})
-        )
-        async with httpx.AsyncClient(base_url="https://w.example") as client:
-            with pytest.raises(AssertionError):
-                await get_session_messages(client, "")
-        assert not route.called

tests/test_wt.py

@@ -17,10 +17,11 @@ from typing import Any, cast
 import httpx
 import pytest
 import worldtree_sdk as wtsdk
-from worldtree_sdk import ApiError, CancelResult, WorldtreeClient
+from worldtree_sdk import ApiError, CancelResult, PadState, WorldtreeClient
 
 from ratatoskr.sessions import (
     AgentNotFound,
+    AuthoredHistoryUnavailable,
     BifrostBinding,
     BifrostConsumerKeyMissing,
     BifrostHandshakeFailed,
@@ -46,8 +47,10 @@ from ratatoskr.wt import (
     get_session_messages,
     get_session_tools,
     list_sessions,
+    set_persona_state,
     stream_turn,
     translate_error,
+    write_authored_history,
 )
 
 
@@ -101,6 +104,12 @@ class _FakeSessions:
     async def cancel_turn(self, *args: Any, **kwargs: Any) -> Any:
         return await self._dispatch("cancel_turn", *args, **kwargs)
 
+    async def set_persona_state(self, *args: Any, **kwargs: Any) -> Any:
+        return await self._dispatch("set_persona_state", *args, **kwargs)
+
+    async def write_history(self, *args: Any, **kwargs: Any) -> Any:
+        return await self._dispatch("write_history", *args, **kwargs)
+
 
 class _FakeClient:
     def __init__(self, sessions: _FakeSessions) -> None:
@@ -440,3 +449,72 @@ class TestCancelTurn:
         with pytest.raises(SessionApiFailed) as ei:
             await cancel_turn(_wt(fake), "s", 42)
         assert ei.value.status == 500
+
+
+class TestSetPersonaState:
+    """slice-3: set_persona_state → SDK sessions.set_persona_state(PadState). The
+    adapter builds the canonical PadState (the SDK owns the {"pad": {...}} wire
+    shape); no error row beyond the § Error map default (SessionApiFailed)."""
+
+    async def test_happy_builds_padstate_and_returns_none(self) -> None:
+        fake = _FakeSessions(result=None)  # SDK resolves the 204 to None
+        out = await set_persona_state(
+            _wt(fake), "s-1", pleasure=0.4, arousal=0.1, dominance=-0.2
+        )
+        assert out is None
+        name, args, _kwargs = fake.calls[-1]
+        assert name == "set_persona_state"
+        assert args[0] == "s-1"
+        pad = args[1]
+        assert isinstance(pad, PadState)
+        assert (pad.pleasure, pad.arousal, pad.dominance) == (0.4, 0.1, -0.2)
+
+    async def test_falsy_zero_pad_preserved(self) -> None:
+        # A 0.0 axis must survive verbatim (not be dropped as falsy).
+        fake = _FakeSessions(result=None)
+        await set_persona_state(_wt(fake), "s", pleasure=0.0, arousal=0.0, dominance=0.0)
+        pad = fake.calls[-1][1][1]
+        assert (pad.pleasure, pad.arousal, pad.dominance) == (0.0, 0.0, 0.0)
+
+    async def test_error_maps_to_session_api_failed(self) -> None:
+        fake = _FakeSessions(error=ApiError("upstream", "boom", status=500, body="x"))
+        with pytest.raises(SessionApiFailed) as ei:
+            await set_persona_state(_wt(fake), "s", pleasure=0.0, arousal=0.0, dominance=0.0)
+        assert ei.value.status == 500
+
+
+class TestWriteAuthoredHistory:
+    """slice-3: write_authored_history → SDK sessions.write_history. Builds the
+    v1 authored-write entry (author="assistant", the only accepted author);
+    404 → AuthoredHistoryUnavailable (hide-existence); else the default."""
+
+    async def test_happy_builds_entry_and_returns_dict(self) -> None:
+        ack = {"seq": 0, "phase": "seeded", "turn_id": "t1", "content_chars": 3}
+        fake = _FakeSessions(result=ack)
+        out = await write_authored_history(
+            _wt(fake), "s-1", content="hi!", idempotency_key="k1"
+        )
+        assert out is ack  # open-world passthrough
+        name, args, _kwargs = fake.calls[-1]
+        assert name == "write_history"
+        assert args[0] == "s-1"
+        assert args[1] == {
+            "author": "assistant",
+            "content": "hi!",
+            "idempotency_key": "k1",
+        }
+
+    async def test_404_maps_to_authored_history_unavailable(self) -> None:
+        # Hide-existence: the ROUTE is the discriminator (never the body) — any 404
+        # on write_history → AuthoredHistoryUnavailable, no capability-probe.
+        fake = _FakeSessions(error=ApiError("session_not_found", "no", status=404))
+        with pytest.raises(AuthoredHistoryUnavailable) as ei:
+            await write_authored_history(_wt(fake), "s-1", content="hi", idempotency_key="k")
+        assert ei.value.session_id == "s-1"
+
+    async def test_other_error_maps_to_session_api_failed(self) -> None:
+        # 409 generation_active (retryable) is NOT a hide-existence 404 → default.
+        fake = _FakeSessions(error=ApiError("generation_active", "busy", status=409))
+        with pytest.raises(SessionApiFailed) as ei:
+            await write_authored_history(_wt(fake), "s", content="hi", idempotency_key="k")
+        assert ei.value.status == 409

uv.lock

@@ -472,7 +472,7 @@ wheels = [
 
 [[package]]
 name = "ratatoskr"
-version = "0.21.10"
+version = "0.21.11"
 source = { editable = "." }
 dependencies = [
     { name = "httpx" },