Backend Standards

Key Principles

• Server is the source of truth - Backend manages all session/worker state
• Structured logging - Use Pino with context objects
• Resource cleanup - Always clean up PTY processes and connections
• Type safety - Define types in shared package, validate at boundaries

Tech Stack

• Bun, Hono, bun-pty, Pino, Valibot

Backend Best Practices

• Resource Cleanup - PTY processes, WebSocket connections, file handles must be cleaned up
• Callback Detachment - Detach callbacks when resources are destroyed (memory leak prevention)
• WebSocket Message Types - Define and validate server→client and client→server types explicitly
• Output Buffering - Buffer rapid PTY output before WebSocket send to reduce message frequency
• Structured Logging - Use Pino with structured data: logger.info({ sessionId }, 'message')

Detailed Documentation

• backend-standards.md - Directory structure, Hono, logging, services, testing, security, best practices
• websocket-patterns.md - Dual WebSocket architecture, message protocol, broadcasting