Parallel-Safe Implementation

Guidelines for implementing tasks in Ralph parallel mode without causing conflicts.

The Job

1. Implement assigned task completely
2. Stay within declared touches paths
3. Respect mutex boundaries
4. Avoid undeclared hotspots
5. Commit atomically with clear messages

Do NOT: modify DAG, schedule tasks, merge branches, or review other work.

Core Rules

1. Stay in Your Lane

Only modify files within your task's touches declaration:

touches: ["src/auth/**", "tests/auth/**"]

Allowed: src/auth/middleware.ts, tests/auth/login.test.ts Forbidden: src/api/routes.ts, package.json

2. Respect Mutex

If your task has mutex: ["db-migrations"], you have exclusive access to that resource. Other tasks with the same mutex will wait.

3. Avoid Hotspots

Never touch these without explicit mutex:

• package.json / package-lock.json → mutex: lockfile
• Database migrations → mutex: db-migrations
• Route configuration → mutex: router
• Global config files → mutex: global-config

Implementation Checklist

Before starting:

• Read task description and acceptance criteria
• Check touches for allowed paths
• Check mutex for exclusive resources
• Check dependsOn to understand available interfaces

While implementing:

• Make small, focused changes
• Avoid large refactors outside task scope
• Don't rename shared types/interfaces unless task requires it
• Test your changes in isolation

Before committing:

• Verify only allowed files changed
• Run relevant tests
• Write clear commit message referencing task ID

Commit Discipline

Good Commits

AUTH-002: Add auth middleware

- Implement JWT validation
- Add role-based access control
- Add unit tests for middleware

Bad Commits

WIP

various fixes

Conflict Prevention

Do

• Import existing modules, don't copy code
• Use existing patterns from codebase
• Add new files instead of heavily modifying shared ones
• Coordinate interface changes via contracts

Don't

• Refactor unrelated code
• Change file structure outside scope
• Modify global types without contract declaration
• Add dependencies without lockfile mutex

Touched Areas Summary

At task completion, report what you changed:

Task AUTH-002 completed
Files changed: 4
  + src/auth/middleware.ts (new)
  + src/auth/roles.ts (new)
  ~ src/auth/index.ts (export added)
  + tests/auth/middleware.test.ts (new)
  
Within declared touches: ✓
Mutex used: contract:auth-api

Safety Checklist Output

Pre-implementation safety check:
  ✓ touches: ["src/auth/**"] - clear scope
  ✓ mutex: ["contract:auth-api"] - exclusive access
  ✓ dependsOn: ["AUTH-001"] - user table available
  
  Hotspots to avoid:
    ✗ package.json (no lockfile mutex)
    ✗ db/migrations/** (no db-migrations mutex)
    
  Ready to implement safely