SIDECAR.md — Project instructions

Create a SIDECAR.md file in your project root to give SideCar project-specific instructions that persist across sessions. This is analogous to CLAUDE.md for Claude Code.

How it works

SideCar reads SIDECAR.md on every message and includes it in the system prompt. The file is cached in memory and automatically invalidated when you save changes (via a file watcher).

Where to put it

Place it in the root of your workspace:

my-project/
  SIDECAR.md    <-- here
  src/
  package.json
  ...

Example

# Project: My App

## Build
- Run `npm run build` to compile
- Run `npm test` to run tests (Vitest)
- Run `npm run lint` to check code style

## Conventions
- Use TypeScript strict mode
- Prefer async/await over callbacks
- Components go in src/components/
- Tests go in src/__tests__/
- Use conventional commit messages

## Architecture
- Express API in src/server/
- React frontend in src/client/
- Shared types in src/shared/types.ts

## Important
- Never modify migration files after they've been applied
- Environment variables are in .env.example (don't commit .env)

Tips

• Keep it concise — the content counts against your context window. Focus on what the AI needs to know, not what it can read from the code.
• Include build/test commands — the agent uses these when running tests and fixing errors.
• List conventions — coding style, directory structure, naming patterns.
• Note gotchas — things the AI might get wrong without guidance (e.g., “use the v2 API, not v1”).
• Update it as you go — add instructions when the agent makes a mistake you don’t want repeated.