> For the complete documentation index, see [llms.txt](https://faction-os.gitbook.io/faction-os-docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://faction-os.gitbook.io/faction-os-docs/.spec_system/archive/sessions/phase05-session02-worker-api-hardening-and-client-contract/implementation-notes.md).

# Implementation Notes

**Session ID**: `phase05-session02-worker-api-hardening-and-client-contract` **Package**: Cross-cutting (`apps/warroom`, `packages/protocol`) **Started**: 2026-05-29 23:36 **Last Updated**: 2026-05-29 23:52

***

## Session Progress

| Metric              | Value   |
| ------------------- | ------- |
| Tasks Completed     | 22 / 22 |
| Estimated Remaining | 0 hours |
| Blockers            | 0       |

***

## Task Log

### 2026-05-29 - Session Start

**Environment verified**:

* [x] Prerequisites confirmed
* [x] Workspace-local TypeScript available
* [x] Workspace-local Vitest available
* [x] Directory structure ready

***

### Task T001 - Verify current protocol and Worker test baseline

**Started**: 2026-05-29 23:35 **Completed**: 2026-05-29 23:36 **Duration**: 1 minute

**Notes**:

* Ran spec system analysis and environment prereq checks.
* Confirmed global `tsc` and `vitest` are not installed, but workspace-local binaries are available through `node_modules/.bin` and npm scripts.
* Ran focused protocol and War Room baseline checks before behavior changes.

**Commands / Results**:

* `npm --workspace packages/protocol run typecheck` - passed.
* `npm --workspace apps/warroom run typecheck` - passed.
* `npm test -- packages/protocol/tests apps/warroom/tests/warroom.test.ts apps/warroom/tests/worker.test.ts` - passed, 12 files / 88 tests.

**Files Changed**:

* `.spec_system/specs/phase05-session02-worker-api-hardening-and-client-contract/implementation-notes.md` - recorded environment and baseline evidence.

***

### Task T002 - Add explicit protocol workspace dependency

**Started**: 2026-05-29 23:36 **Completed**: 2026-05-29 23:37 **Duration**: 1 minute

**Notes**:

* Added `@factionos/protocol` to the War Room package dependencies so Worker boundary imports are declared explicitly.

**Files Changed**:

* `apps/warroom/package.json` - added the workspace protocol dependency.

***

### Task T003 - Sync workspace lockfile

**Started**: 2026-05-29 23:37 **Completed**: 2026-05-29 23:38 **Duration**: 1 minute

**Notes**:

* Ran `npm install --package-lock-only` to refresh workspace dependency metadata.
* The lockfile now records the `apps/warroom` dependency on `@factionos/protocol`.
* The lockfile also synchronized existing root package metadata changes already present in the worktree.

**Files Changed**:

* `package-lock.json` - synced workspace package metadata.

***

### Task T004 - Expand War Room constants and vocabularies

**Started**: 2026-05-29 23:38 **Completed**: 2026-05-29 23:40 **Duration**: 2 minutes

**Notes**:

* Added protocol-owned room code, participant cap, recent-event cap, lifecycle, role, join decision, safe-frame, rate-limit, and error-code constants.
* Kept code and role values aligned with the existing Worker behavior.

**Files Changed**:

* `packages/protocol/src/warroom.ts` - added shared constants and union types.

***

### Task T005 - Define War Room REST and socket contracts

**Started**: 2026-05-29 23:38 **Completed**: 2026-05-29 23:40 **Duration**: 2 minutes

**Notes**:

* Added typed room snapshot, create, join, decision, rate-limit, socket catch-up, remote event, and socket error contracts.
* Preserved the existing `Participant` export for current consumers while adding `WarRoomParticipant` aliasing.

**Files Changed**:

* `packages/protocol/src/warroom.ts` - added shared REST and WebSocket contract shapes.

***

### Task T006 - Add runtime validators and error builders

**Started**: 2026-05-29 23:38 **Completed**: 2026-05-29 23:40 **Duration**: 2 minutes

**Notes**:

* Added stable War Room error envelopes and status mapping.
* Added validators for room codes, room creation, join, approval/rejection decisions, socket participants, and safe socket frames.
* Added blocked-frame-key detection so sensitive payload categories are rejected before Worker persistence.
* Ran `npm --workspace packages/protocol run typecheck` after the protocol changes; it passed.

**Files Changed**:

* `packages/protocol/src/warroom.ts` - added validation helpers and error envelope builders.

**BQC Fixes**:

* Trust boundary enforcement: request and socket payloads now have explicit protocol validators before Worker consumption (`packages/protocol/src/warroom.ts`).
* Error information boundaries: validators return stable codes and field-level metadata without raw request bodies (`packages/protocol/src/warroom.ts`).

***

### Task T007 - Align War Room event and catch-up types

**Started**: 2026-05-29 23:40 **Completed**: 2026-05-29 23:41 **Duration**: 1 minute

**Notes**:

* Updated War Room join decision events to use explicit approved/rejected frame types.
* Updated catch-up events to carry protocol-owned safe recent event frames.
* Kept pending-withdrawn as a separate typed event rather than overloading the catch-up shape.
* Ran `npm --workspace packages/protocol run typecheck`; it passed.

**Files Changed**:

* `packages/protocol/src/events.ts` - aligned War Room events with shared War Room protocol contracts.

**BQC Fixes**:

* Contract alignment: event union catch-up payloads now match the protocol-owned safe recent event shape (`packages/protocol/src/events.ts`).

***

### Task T008 - Create War Room protocol contract tests

**Started**: 2026-05-29 23:41 **Completed**: 2026-05-29 23:42 **Duration**: 1 minute

**Notes**:

* Added focused contract tests for constants, typed request/response shapes, room code validation, create/join/decision payload validation, deterministic error envelopes, safe frame allowlists, blocked sensitive fields, and participant ordering.
* Ran `npm test -- packages/protocol/tests/warroom.test.ts packages/protocol/tests/events.test.ts`; it passed, 2 files / 22 tests.

**Files Changed**:

* `packages/protocol/tests/warroom.test.ts` - added War Room protocol contract coverage.

**BQC Fixes**:

* Trust boundary enforcement: tests now prove unknown request fields and blocked safe-frame fields are rejected (`packages/protocol/tests/warroom.test.ts`).
* Contract alignment: tests assert catch-up frames typecheck through the shared server event union (`packages/protocol/tests/warroom.test.ts`).

***

### Task T009 - Document protocol ownership

**Started**: 2026-05-29 23:42 **Completed**: 2026-05-29 23:43 **Duration**: 1 minute

**Notes**:

* Documented `src/warroom.ts` as the source of truth for Worker client contracts.
* Recorded the intentionally narrow safe socket frame scope for Session 02.
* Reiterated the blocked payload categories that must not cross the Worker boundary.

**Files Changed**:

* `packages/protocol/README_protocol.md` - added hardened Worker client contract notes.

***

### Task T010 - Import shared protocol contracts into Worker boundary

**Started**: 2026-05-29 23:43 **Completed**: 2026-05-29 23:46 **Duration**: 3 minutes

**Notes**:

* Refactored the Worker entry to import protocol-owned constants, types, validators, error envelopes, limits, and safe-frame contracts from `@factionos/protocol`.
* Typed create, init, join, decision, room snapshot, catch-up, remote event, and socket error serialization against protocol exports.

**Files Changed**:

* `apps/warroom/src/index.ts` - imported and consumed shared protocol contracts.

***

### Task T011 - Harden top-level room create and room-code routing

**Started**: 2026-05-29 23:43 **Completed**: 2026-05-29 23:46 **Duration**: 3 minutes

**Notes**:

* Added top-level `POST /rooms` JSON parsing and create-body validation before Durable Object delegation.
* Replaced regex-only room-code matching with protocol `validateWarRoomCode` failures for malformed room paths.
* Rate-limit responses now use stable protocol error envelopes.

**Files Changed**:

* `apps/warroom/src/index.ts` - hardened router boundary validation and error mapping.

**BQC Fixes**:

* Trust boundary enforcement: top-level room creation validates request bodies before mutation (`apps/warroom/src/index.ts`).
* Failure path completeness: malformed room codes and rate limits now return deterministic envelopes (`apps/warroom/src/index.ts`).

***

### Task T012 - Harden init/info snapshot serialization

**Started**: 2026-05-29 23:43 **Completed**: 2026-05-29 23:46 **Duration**: 3 minutes

**Notes**:

* Validated `/init` payloads through protocol contracts.
* Added `WarRoomRoomSnapshot` serialization with deterministic participant ordering and pending-join summaries.
* Kept persisted room state bounded to participant snapshots and recent safe events.

**Files Changed**:

* `apps/warroom/src/index.ts` - hardened room initialization, persistence, and snapshot serialization.

**BQC Fixes**:

* State freshness on re-entry: snapshots are rebuilt from current persisted state with sorted participants (`apps/warroom/src/index.ts`).
* Contract alignment: `/info` now returns the protocol-owned snapshot shape (`apps/warroom/src/index.ts`).

***

### Task T013 - Harden join validation and duplicate handling

**Started**: 2026-05-29 23:43 **Completed**: 2026-05-29 23:46 **Duration**: 3 minutes

**Notes**:

* Added protocol validation for join bodies.
* Made duplicate join ids idempotent before room-cap checks so duplicate triggers do not consume capacity or fail spuriously.
* Preserved the 16-participant cap with stable error details.

**Files Changed**:

* `apps/warroom/src/index.ts` - hardened `/join` behavior.

**BQC Fixes**:

* Duplicate action prevention: duplicate joins return the existing participant instead of mutating state again (`apps/warroom/src/index.ts`).

***

### Task T014 - Harden approve authority and stale decision handling

**Started**: 2026-05-29 23:43 **Completed**: 2026-05-29 23:46 **Duration**: 3 minutes

**Notes**:

* Added protocol validation for approval bodies.
* Enforced leader authority before applying decisions.
* Mapped non-pending or missing requester decisions to `stale_join_decision`.

**Files Changed**:

* `apps/warroom/src/index.ts` - hardened approval handling.

**BQC Fixes**:

* Trust boundary enforcement: approval authority is checked at the Durable Object boundary before mutation (`apps/warroom/src/index.ts`).
* Failure path completeness: stale approvals now have an explicit error path (`apps/warroom/src/index.ts`).

***

### Task T015 - Implement reject join decision contract

**Started**: 2026-05-29 23:43 **Completed**: 2026-05-29 23:46 **Duration**: 3 minutes

**Notes**:

* Added `POST /reject` handling through the same validated join decision path as approve.
* Rejections remove pending participants, broadcast a rejected decision frame, and return a stable decision response.

**Files Changed**:

* `apps/warroom/src/index.ts` - added reject route behavior.

**BQC Fixes**:

* Contract alignment: approve and reject now share one validated decision contract (`apps/warroom/src/index.ts`).

***

### Task T016 - Harden socket handshake validation

**Started**: 2026-05-29 23:43 **Completed**: 2026-05-29 23:46 **Duration**: 3 minutes

**Notes**:

* Validated upgrade headers and participant query parameters with stable error codes.
* Revalidated participants before socket acceptance and rejected pending or forbidden participants deterministically.
* Replaced stale same-participant sockets before accepting a new socket.

**Files Changed**:

* `apps/warroom/src/index.ts` - hardened socket handshake and re-entry behavior.

**BQC Fixes**:

* Resource cleanup: existing participant sockets are closed or removed before replacement (`apps/warroom/src/index.ts`).
* State freshness on re-entry: participant online state and initial frames are rebuilt during each accepted socket lifecycle (`apps/warroom/src/index.ts`).

***

### Task T017 - Allowlist safe socket frame persistence

**Started**: 2026-05-29 23:43 **Completed**: 2026-05-29 23:46 **Duration**: 3 minutes

**Notes**:

* Replaced opaque client event persistence with protocol `parseWarRoomSocketFrame`.
* `ping` remains non-persistent.
* Unknown, malformed, or blocked-field frames return a socket error frame to the sender and are not persisted or broadcast.

**Files Changed**:

* `apps/warroom/src/index.ts` - hardened client message handling and persistence.

**BQC Fixes**:

* Trust boundary enforcement: only allowlisted safe management frames can enter recent-event storage (`apps/warroom/src/index.ts`).
* Error information boundaries: socket errors expose stable codes and field metadata only (`apps/warroom/src/index.ts`).

***

### Task T018 - Preserve recent-event bounds, sender exclusion, and cleanup

**Started**: 2026-05-29 23:43 **Completed**: 2026-05-29 23:46 **Duration**: 3 minutes

**Notes**:

* Kept recent-event storage capped at the protocol limit.
* Preserved sender-excluded fan-out for accepted safe frames.
* Improved send-failure cleanup by disconnecting failed peers and broadcasting updated participant state.
* Ran `npm --workspace apps/warroom run typecheck`; it passed.

**Files Changed**:

* `apps/warroom/src/index.ts` - preserved and hardened socket broadcast and cleanup behavior.

**BQC Fixes**:

* Resource cleanup: failed socket sends now trigger participant disconnect cleanup (`apps/warroom/src/index.ts`).
* Contract alignment: catch-up and remote events now carry safe protocol frame shapes (`apps/warroom/src/index.ts`).

***

### Task T019 - Update Worker README contract notes

**Started**: 2026-05-29 23:47 **Completed**: 2026-05-29 23:48 **Duration**: 1 minute

**Notes**:

* Documented the new reject endpoint.
* Added deterministic error envelope, stable error code, and rate-limit header notes.
* Replaced the old opaque-event hardening gap with the current safe management frame scope.

**Files Changed**:

* `apps/warroom/README_warroom.md` - updated Worker endpoint and contract documentation.

***

### Task T020 - Expand Durable Object tests

**Started**: 2026-05-29 23:48 **Completed**: 2026-05-29 23:51 **Duration**: 3 minutes

**Notes**:

* Replaced loose-shape Worker tests with hardened contract assertions.
* Added coverage for invalid init/join payloads, duplicate join idempotency, full-room behavior, approval authority, stale approvals, reject success, stale rejection, socket handshake errors, invalid socket frame drops, blocked field rejection, safe catch-up, sender exclusion, ring caps, periodic persistence, and cleanup on send failure.
* Ran `npm test -- apps/warroom/tests/warroom.test.ts apps/warroom/tests/worker.test.ts`; it passed, 2 files / 32 tests.

**Files Changed**:

* `apps/warroom/tests/warroom.test.ts` - expanded Durable Object behavior coverage.

**BQC Fixes**:

* Duplicate action prevention: tests prove duplicate joins are idempotent (`apps/warroom/tests/warroom.test.ts`).
* Resource cleanup: tests prove failed socket sends mark peers offline and announce participant changes (`apps/warroom/tests/warroom.test.ts`).
* Trust boundary enforcement: tests prove malformed, unknown, and sensitive socket frames do not persist (`apps/warroom/tests/warroom.test.ts`).

***

### Task T021 - Expand Worker router tests

**Started**: 2026-05-29 23:48 **Completed**: 2026-05-29 23:51 **Duration**: 3 minutes

**Notes**:

* Added router coverage for typed 429 envelopes, rate-limit headers, CORS headers, create-body validation, malformed room code errors, isolated Durable Object routing, and delegated pending/reject error behavior.
* Ran `npm test -- apps/warroom/tests/warroom.test.ts apps/warroom/tests/worker.test.ts`; it passed, 2 files / 32 tests.

**Files Changed**:

* `apps/warroom/tests/worker.test.ts` - expanded Worker router coverage.

**BQC Fixes**:

* Failure path completeness: tests prove router-level malformed room code, invalid create body, pending socket, and rate-limit errors are visible and deterministic (`apps/warroom/tests/worker.test.ts`).

***

### Task T022 - Run focused final verification

**Started**: 2026-05-29 23:51 **Completed**: 2026-05-29 23:52 **Duration**: 1 minute

**Notes**:

* Formatted touched TypeScript and JSON files with Biome.
* Ran focused protocol and War Room typechecks.
* Ran focused protocol and War Room Vitest coverage.
* Ran Biome lint over touched TypeScript files.
* Ran ASCII and LF checks over touched code, docs, package, lockfile, task, and notes files.
* Ran `git diff --check` over touched files.

**Commands / Results**:

* `npm exec -- biome format --write apps/warroom/src/index.ts apps/warroom/tests/warroom.test.ts apps/warroom/tests/worker.test.ts apps/warroom/package.json packages/protocol/src/warroom.ts packages/protocol/src/events.ts packages/protocol/tests/warroom.test.ts package-lock.json` - passed.
* `npm --workspace packages/protocol run typecheck` - passed.
* `npm --workspace apps/warroom run typecheck` - passed.
* `npm exec -- biome lint apps/warroom/src/index.ts apps/warroom/tests/warroom.test.ts apps/warroom/tests/worker.test.ts packages/protocol/src/warroom.ts packages/protocol/src/events.ts packages/protocol/tests/warroom.test.ts` - passed.
* `npm test -- packages/protocol/tests apps/warroom/tests/warroom.test.ts apps/warroom/tests/worker.test.ts` - passed, 13 files / 96 tests.
* ASCII validation over touched session files - passed.
* LF validation over touched session files - passed.
* `git diff --check -- [touched files]` - passed.

**Files Changed**:

* `.spec_system/specs/phase05-session02-worker-api-hardening-and-client-contract/tasks.md` - marked all tasks and completion checklist complete.
* `.spec_system/specs/phase05-session02-worker-api-hardening-and-client-contract/implementation-notes.md` - recorded final verification evidence.


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