synthesis-context-lifecycle（综合上下文生命周期）

Context Lifecycle Management

The Problem

AI collaborators start every session with zero context. Their effectiveness depends entirely on the quality of the context they receive. For short-lived projects (2-3 sessions), a single context file works. For long-running projects spanning weeks or months, that file grows unboundedly — combining four types of information with fundamentally different lifecycles:

Combining all four in one file means the file grows linearly with session count, with no mechanism for information to leave. This is the classic hot/warm/cold data problem from database engineering, manifesting in AI context management.

The Architecture

Three Tiers

project/
├── CONTEXT.md      # Working memory (budget: ≤150 lines)
├── REFERENCE.md    # Semantic memory (stable facts, update in place)
├── sessions/       # Episodic memory (archived session logs)
│   └── YYYY-MM.md  # Monthly files
└── [other files]   # Transcripts, artifacts, etc.

This maps to both cognitive science and systems engineering:

These are design principles, not metaphors. Each memory type has different storage, retrieval, and maintenance characteristics.

CONTEXT.md — Working Memory

Purpose: Everything the AI collaborator needs to be effective in THIS session.

Budget: ≤150 lines (hard). For completed projects: ≤80 lines.

Contains ONLY:

• Phase/status header (~5 lines)
• Current state (~15 lines)
• Active tasks with priorities (~50 lines)
• Recent session summaries — last 1-2 only (~30 lines)
• Links to REFERENCE.md and sessions/ (~5 lines)
• Budget footer (~2 lines)

Does NOT contain:

• Completed task checklists (archive to sessions/ first, verify, then remove)
• Session logs older than 1 week (move to sessions/)
• Stable reference facts (live in REFERENCE.md)
• Detailed historical narrative (live in session archive)

Template — new project:

# [Project Name] — Working Context

**Phase:** Initial
**Status:** [description]
**Last session:** YYYY-MM-DD

---

## Current State

[What exists, what doesn't, starting conditions]

## What's Next

1. [ ] [First task]
2. [ ] [Second task]

---

*This file follows the Tiered Context Architecture. Budget: ≤150 lines.*

Template — mature project:

# [Project Name] — Working Context

**Phase:** [Current phase]
**Status:** [Active/Paused]
**Last session:** YYYY-MM-DD

For stable reference facts: see [REFERENCE.md](REFERENCE.md)
For session history: see [sessions/](sessions/)

---

## Current State

- **Production:** [version, deployment status]
- **Blockers:** [if any]

## What's Next — Prioritized

**High:**
1. [ ] [Task with context]

**Medium:**
2. [ ] [Task]

**Deferred:**
3. [ ] [Task — reason for deferral]

## Recent Session: YYYY-MM-DD

[Summary: what was done, decisions made, outcomes]

---

*This file follows the Tiered Context Architecture. Budget: ≤150 lines.*

Template — completed project:

# [Project Name] — Context

**Status:** Completed
**Completed:** YYYY-MM-DD
**Outcome:** [1-2 sentence summary]

---

## Summary

[What was built/accomplished, 5-10 lines]

## Key Decisions

[Notable decisions that might matter if revisited, 5-10 lines]

---

*Completed project. For historical sessions, see [sessions/](sessions/).*

REFERENCE.md — Semantic Memory

Purpose: Stable facts that don't change session-to-session.

Budget: ≤300 lines (soft). Exceeding 300 lines signals the project scope may be too broad.

Contains:

• Project overview and goals (if not obvious from name)
• Team roster with roles
• URLs, repos, remotes, deployment configuration
• Architecture decisions and conventions
• File indexes (transcript logs, artifact locations)
• Setup and cleanup instructions

Key property: Update IN PLACE, not append. When a team member leaves, update the roster — do not add a dated note. When a URL changes, change the URL. This is a living reference document, not a log.

Template:

# [Project Name] — Reference

Stable facts for this project. Updated in place when facts change.

---

## Quick Reference

| Resource | Location |
|----------|----------|
| [Key URL] | [value] |
| [Key command] | [value] |

## Team

| Name | Role | Notes |
|------|------|-------|
| [Name] | [Role] | [Status] |

## Architecture

[Key decisions, conventions, patterns]

## Related Files

[Index of transcripts, artifacts, external documents]

sessions/ — Episodic Archive

Purpose: Historical record of what happened and when. Rarely read, but searchable when historical context is needed.

Organization: Monthly files named YYYY-MM.md.

Template:

# Session Archive — [Month] [Year]

Archived from CONTEXT.md on YYYY-MM-DD. See REFERENCE.md for stable project facts.

---

### YYYY-MM-DD: [Session title — what was accomplished]

[Summary: 5-15 lines per session. What was done, decisions made, outcomes.]

The Archival Protocol

When to Archive

Archive when ANY of these conditions are true:

• CONTEXT.md exceeds 120 lines (approaching 150-line budget)
• Session logs in CONTEXT.md are older than 1 week
• A project phase transition occurs
• The user explicitly requests cleanup

Step by Step

1. Read CONTEXT.md and count lines.
2. Identify cold content:

- Completed task items - Session summaries older than 1 week - Stable facts that belong in REFERENCE.md - Detailed narratives that belong in sessions/

1. Create files if needed:

- REFERENCE.md (if stable facts exist and no REFERENCE.md yet) - sessions/ directory - sessions/YYYY-MM.md for the relevant month

1. Archive FIRST (two-phase commit — write to destination before removing from source):

- Session logs → sessions/YYYY-MM.md (append chronologically) - Stable facts → REFERENCE.md (organize by category) - Completed tasks → sessions/YYYY-MM.md (summarize, then remove from CONTEXT.md)

1. Verify archives exist — Confirm moved content is present in its destination file.
2. Only then rewrite CONTEXT.md with archived content removed.
3. Verify:

- CONTEXT.md ≤150 lines - No information lost (everything archived before removal) - Cross-references updated (CONTEXT.md points to REFERENCE.md and sessions/)

1. Commit AND push with message: "Maintain context: archive sessions, extract reference facts". Stage only the files this invocation modified — do not git add -A. See the Commit Protocol section below for the full rule.

CRITICAL: Archive FIRST, then delete. NEVER delete content from CONTEXT.md before confirming it exists in sessions/ or REFERENCE.md. Two-phase commit: write to destination, verify, then remove from source.

ALSO CRITICAL: Commit-and-push is part of this protocol, not an afterthought. Every non-trivial context modification (archival or otherwise) must be committed and pushed in the same invocation. See the Commit Protocol section for scoping rules.

Decision Tree: Where Does This Content Belong?

Is this information needed for TODAY's work?
├── Yes → CONTEXT.md
└── No
    ├── Is it a stable fact (team, URL, architecture)?
    │   ├── Yes → REFERENCE.md (update in place)
    │   └── No
    │       ├── Is it a record of what happened during a session?
    │       │   ├── Yes → sessions/YYYY-MM.md
    │       │   └── No
    │       │       └── Is it a reusable lesson?
    │       │           ├── Yes → lessons/
    │       │           └── No → delete it
    └── Exception: completed milestones (≤10 lines) stay in CONTEXT.md

Migration Guide

For Projects Over 500 Lines

Full restructuring. Do NOT mechanically split — each project needs judgment about what is working memory vs reference vs archive.

1. Read the entire CONTEXT.md
2. Identify the four content types
3. Create REFERENCE.md with semantic content
4. Create sessions/ with episodic content (grouped by month)
5. Rewrite CONTEXT.md as fresh working memory
6. Verify nothing was lost

For Projects 150-500 Lines

Moderate restructuring:

1. Extract obvious semantic content (team, URLs, architecture) → REFERENCE.md
2. Move session logs → sessions/
3. Tighten CONTEXT.md to ≤150 lines

For Projects Under 150 Lines

Lightweight touch:

1. Add budget footer
2. If >20 lines of reference material exist, consider extracting to REFERENCE.md
3. If completed, simplify to completion summary format

Project Status Transitions

Project Spawning

When a sub-scope exceeds the parent project's boundaries:

1. Create new project directory
2. Seed CONTEXT.md with fresh working memory (not a copy)
3. Add to index.yaml with related: linking to parent
4. Remove spawned scope from parent's CONTEXT.md
5. Cross-reference both projects

The test: Would a new team member reading only the parent's CONTEXT.md be confused by the spawned work? If yes, spawn it.

Measuring Context Quality

Quantitative

Qualitative

After reading CONTEXT.md, the AI collaborator should be able to answer:

1. What is the current state of this project?
2. What should I work on next?
3. What was done in the last session?
4. Where do I find stable reference information?

If any question cannot be answered from CONTEXT.md alone (with a pointer to REFERENCE.md), the working memory is incomplete.

Context as Infrastructure

In traditional engineering, code is managed as infrastructure — version control, CI/CD, testing, deployment. In synthesis engineering (human-AI collaborative development), there is a third infrastructure layer: context infrastructure — the structured information that enables an AI collaborator to be effective across sessions.

The three infrastructure layers:

1. Code infrastructure — git, CI/CD, deployment (solved by traditional engineering)
2. Knowledge infrastructure — lessons, runbooks, compiled knowledge bases (the organizational learning layer)
3. Context infrastructure — working memory, reference facts, session history (the novel contribution — no equivalent in traditional engineering because human engineers carry context in their heads)

Evolution Stages

1. Ad hoc — Re-explain everything each session (most AI users today)
2. Monolithic — Single context file that grows forever (common early approach)
3. Tiered — Working memory + reference + archive with lifecycle management (this skill)
4. Compiled — Context automatically assembled from project state, code, and history (future vision)

Stage 3 is the 80/20 solution that makes long-running AI-assisted projects sustainable. Stage 4 is the long-term vision where context at session start is compiled from live project state rather than manually maintained.

Commit Protocol — Not Optional

Context files are only useful if they reach the remote repository. Every invocation that creates or modifies context files (CONTEXT.md, REFERENCE.md, session archives, daily plans, transcripts) must commit and push those changes before the invocation ends.

This is not deferred to "end of day" or "end of session." Treat it as part of the same action: if you wrote to a context file, you also commit and push it. Interactive sessions span multiple turns and may not have a clean "end" — so the commit must happen at the point of modification, not at some later checkpoint that may never arrive.

Scope Rule: Only Commit Repos Touched in This Invocation

Never run workspace-wide commit or push operations. Only commit repos where this specific invocation created or modified files. If the user has other uncommitted work in unrelated repos (personal projects, other workspaces, unrelated branches), leave those alone — they belong to other sessions.

The pattern:

1. Track which files THIS invocation modified (the agent's own action history is the source of truth).
2. Group those files by containing repo.
3. For each containing repo: git add ONLY those specific files (never git add -A or git add.), commit, push.
4. Never touch repos where you did not create or modify files in this invocation.

Why Point-of-Modification, Not Session-End

Context that exists only on one machine is invisible to the next session on a different machine. The entire point of structured context is cross-session continuity — uncommitted context breaks that guarantee.

Deferring commits to session-end has three failure modes:

1. Session never ends cleanly. Long-running conversations resume across days; a "session-end" hook may never fire.
2. Modified ritual modes skip the day-end checklist. Mid-day syncs, vacation/observer catch-ups, and partial rituals update context without running the full day-end sequence. If commit is only in day-end, these updates never ship.
3. Multiple invocations compound uncommitted work. By the time someone notices, there's a week of context changes stranded on one machine.

Verification

Use synthesis-repo-guard as a detector across the workspace (reports dirty repos) but NEVER as a committer. The commit step must be explicit and per-repo-scoped to this invocation's actual changes. See synthesis-repo-guard for session-end hook integration — that hook should alert and surface dirty repos, not blanket-commit them.