> 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/phase17-session01-protocol-notice-contract-parity/implementation_summary.md).

# Implementation Summary

**Session ID**: `phase17-session01-protocol-notice-contract-parity` **Package**: `packages/protocol` **Completed**: 2026-06-05 **Duration**: 3-4 hours

***

## Overview

Expanded the shared Notice Board protocol surface in `packages/protocol` to cover the recovered canonical notice contract, compatibility aliases, route shapes, WebSocket payloads, and pure normalization helpers. The session keeps existing `body`, `targets`, `postedAt`, and `severity` consumers compiling while introducing the recovered `type`, `priority`, `authorType`, `targetSessionIds`, `relatedFiles`, and event compatibility keys needed by the later Phase 17 server, web, CLI, hook, and War Room sessions.

***

## Deliverables

### Files Created

| File                                                                                             | Purpose                                                   | Lines |
| ------------------------------------------------------------------------------------------------ | --------------------------------------------------------- | ----- |
| `.spec_system/specs/phase17-session01-protocol-notice-contract-parity/IMPLEMENTATION_SUMMARY.md` | Session handoff summary                                   | \~70  |
| `packages/protocol/tests/notices.test.ts`                                                        | Notice Board contract, helper, and compatibility coverage | \~319 |

### Files Modified

| File                                        | Changes                                                                                                        |
| ------------------------------------------- | -------------------------------------------------------------------------------------------------------------- |
| `packages/protocol/src/notices.ts`          | Added canonical notice vocabularies, expanded notice types, route contracts, guards, and normalization helpers |
| `packages/protocol/src/events.ts`           | Added Notice Board hydrate/message/resolution compatibility payload keys and expanded `ClientPostNotice`       |
| `packages/protocol/src/rest.ts`             | Re-exported canonical Notice Board REST contracts and compatibility `/notice` shapes                           |
| `packages/protocol/tests/events.test.ts`    | Added Notice Board event and client-message coverage                                                           |
| `packages/protocol/tests/rest.test.ts`      | Added canonical and compatibility REST contract type coverage                                                  |
| `packages/protocol/README_protocol.md`      | Documented Notice Board ownership and privacy boundaries                                                       |
| `.spec_system/state.json`                   | Marked the session complete and advanced phase tracking                                                        |
| `.spec_system/PRD/phase_17/PRD_phase_17.md` | Marked Session 01 complete and updated phase progress                                                          |
| `.spec_system/PRD/PRD.md`                   | Updated the global phase summary to reflect Phase 17 progress                                                  |
| `package.json`                              | Bumped the repository patch version from `0.1.118` to `0.1.119`                                                |

***

## Technical Decisions

1. **Keep protocol contracts canonical and compatibility-aware**: the shared model now exposes recovered Notice Board vocabulary while preserving the older `body`, `targets`, `postedAt`, and `severity` fields so downstream packages can migrate without a hard cutover.
2. **Fail closed in protocol helpers**: notice parsing and normalization reject invalid values instead of guessing, which keeps the later runtime sessions from depending on unsafe or ambiguous payloads.

***

## Test Results

| Metric   | Value        |
| -------- | ------------ |
| Tests    | 29           |
| Passed   | 29           |
| Coverage | Not measured |

***

## Lessons Learned

1. The Notice Board protocol needs explicit compatibility aliases at the contract layer before server or UI code can move to the canonical shape.
2. Shared route and event types are easier to validate when the normalization helpers stay pure and bounded inside the protocol package.

***

## Future Considerations

Items for future sessions:

1. Consume the new contracts from the server persistence and routing sessions.
2. Carry the canonical notice vocabulary through the web cockpit, CLI, hook, and War Room relay sessions without reintroducing local shape drift.

***

## Session Statistics

* **Tasks**: 22 completed
* **Files Created**: 2
* **Files Modified**: 10
* **Tests Added**: 1
* **Blockers**: 0 resolved


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