> 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/phase03-session03-subagent-lineage-and-mission-graph-runtime/implementation_summary.md).

# Implementation Summary

**Session ID**: `phase03-session03-subagent-lineage-and-mission-graph-runtime` **Package**: Cross-cutting (`packages/protocol`, `apps/hooks`, `apps/server`) **Completed**: 2026-05-29 **Duration**: 1.5 hours

***

## Overview

This session promoted subagent spawn and completion telemetry from opaque mission events into typed, local-only lineage and mission graph runtime state. The implementation adds protocol contracts, bounded hook payload shaping, server-side graph management, parent-child mission links, compact WebSocket frames, export/archive redaction, focused tests, and source-backed docs.

***

## Deliverables

### Files Created

| File                                       | Purpose                                                  |
| ------------------------------------------ | -------------------------------------------------------- |
| `packages/protocol/src/lineage.ts`         | Protocol-owned lineage and mission graph contracts.      |
| `apps/server/src/managers/missionGraph.ts` | Bounded in-memory mission graph manager.                 |
| `packages/protocol/tests/lineage.test.ts`  | Protocol contract coverage for lineage and graph frames. |

### Files Modified

| File                                            | Changes                                                                          |
| ----------------------------------------------- | -------------------------------------------------------------------------------- |
| `packages/protocol/src/ingest.ts`               | Added lineage hook vocabulary and typed spawn/completion payloads.               |
| `packages/protocol/src/missions.ts`             | Added optional parent-child mission and lineage references.                      |
| `packages/protocol/src/events.ts`               | Added `subagent_lineage_update` and `mission_graph_update` frames.               |
| `apps/hooks/src/_lib.js`                        | Added safe lineage ID parsing, sanitization, and degraded reasons.               |
| `apps/hooks/src/factionos-subagent-spawn.js`    | Sends bounded lineage metadata without raw prompts or transcript paths.          |
| `apps/hooks/src/factionos-subagent-complete.js` | Sends bounded completion metadata and missing-ID degraded state.                 |
| `apps/server/src/lib/eventIngest.ts`            | Normalizes typed lineage ingest with server-side ID validation.                  |
| `apps/server/src/routes/event.ts`               | Wires typed lineage route handling and graph WebSocket emissions.                |
| `apps/server/src/managers/missionManager.ts`    | Adds parent-child mission helpers and lineage references.                        |
| `apps/server/src/lib/sessionPrivacy.ts`         | Redacts lineage IDs and transcript path fields recursively.                      |
| `apps/server/src/lib/exportSession.ts`          | Adds deterministic lineage export columns.                                       |
| `apps/server/tests/eventIngest.test.ts`         | Covers spawn, completion, degraded, oversized, duplicate, and fallback behavior. |
| `apps/server/tests/exportSession.test.ts`       | Covers lineage export and archive redaction.                                     |
| `docs/api/README_api.md`                        | Documents typed lineage behavior and boundaries.                                 |
| `docs/api/event-api-hook-contracts.md`          | Updates source-backed ingest, hook, WebSocket, and Phase 03 contracts.           |

***

## Test Results

| Check                               | Result                           |
| ----------------------------------- | -------------------------------- |
| Protocol typecheck                  | Pass                             |
| Server typecheck                    | Pass                             |
| Focused Vitest suite                | 1860 passed, 1 skipped, 0 failed |
| Existing WebSocket tests            | Pass                             |
| Biome check for touched JS/TS files | Pass                             |
| ASCII/LF checks                     | Pass                             |
| `git diff --check`                  | Pass                             |

***

## Boundaries Preserved

* No subagent spawn, stop, resume, fork, or remote-control capability was added.
* No hosted persistence, War Room sync, analytics transfer, database, or credential dependency was added.
* Hook payloads do not send raw prompts or transcript paths for lineage.
* Archive and export redaction covers lineage identifiers and transcript path fields.
* Repo version was bumped from `0.1.36` to `0.1.37` in `package.json` as the session closeout patch increment.

***

## Next Step

Run the `plansession` workflow step if Phase 03 has remaining sessions, or move to `audit` if the phase is fully complete.


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