Context Sync

Keeps .context/ files in sync with the actual codebase. Prevents context drift — the #1 failure mode of spec-driven development.

When to Use This Skill

• After installing or removing a dependency
• After creating new files or directories
• After completing a feature spec
• When starting a new session (validation mode)

Sync Rules

Dependency Changes → stack.md

When a dependency is added, removed, or upgraded:

1. Read .context/stack.md
2. Check if the change is already reflected
3. If not, propose an update with: package name, purpose, version, and constraints

Trigger signals:

• npm install, pip install, dotnet add, go get commands
• Changes to package.json, requirements.txt, *.csproj, go.mod

New Files/Directories → architecture.md

When new files or directories are created outside the existing structure:

1. Read .context/architecture.md
2. Check if the new path fits an existing module
3. If not, propose adding it to the directory structure section

Trigger signals:

• mkdir commands
• Creating files in previously empty directories
• Adding new top-level directories

Feature Completion → project.md

When a spec status changes to [x] Completed:

1. Read .context/project.md
2. Update the "Current Status" section to reflect the new capability
3. Suggest moving the spec to .context/specs/.archive/

Conventions Changes → conventions.md

When the team agrees on a new pattern during development:

1. Read .context/conventions.md
2. Propose adding the new convention with rationale
3. Ensure it doesn't conflict with existing conventions

Validation Mode

When activated at session start, perform a quick audit:

SYNC CHECK:
✅ stack.md     — matches package.json (last verified: {timestamp})
✅ architecture — all src/ modules documented
⚠️ project.md  — 2 completed specs not yet reflected
❌ conventions  — new pattern "useQuery hooks" found but not documented

Output Format

Always present sync suggestions as a clear diff:

### Suggested Update: stack.md

**Trigger:** `npm install @tanstack/react-query`

| Package | Purpose | Constraints |
|---|---|---|
| `@tanstack/react-query` | Server state management & caching | v5.x — do not downgrade, peer dep on React 18+ |

**Apply this update?** [Y/N]

Integration

This skill is designed to fire automatically after other skills complete. Skills that should trigger a sync check:

• spec-lifecycle (on status change)
• architecture-guard (on new file creation)
• commit-conventions (on commit — optional)