---
title: Contributing
description: Local development workflow for contributors working on the Multica codebase.
---

## Development Model

Local development uses one shared PostgreSQL container and one database per checkout.

- The main checkout usually uses `.env` and `POSTGRES_DB=multica`
- Each Git worktree uses its own `.env.worktree`
- Every checkout connects to the same PostgreSQL host: `localhost:5432`
- Isolation happens at the database level, not by starting a separate Docker Compose project
- Backend and frontend ports are still unique per worktree

## Prerequisites

- Node.js `v20+`
- `pnpm` `v10.28+`
- Go `v1.26+`
- Docker

## First-Time Setup

### Main Checkout

```bash
cp .env.example .env
make setup-main
```

What `make setup-main` does:

- Installs JavaScript dependencies with `pnpm install`
- Ensures the shared PostgreSQL container is running
- Creates the application database if it does not exist
- Runs all migrations against that database

Start the app:

```bash
make start-main
```

### Worktree

From the worktree directory:

```bash
make worktree-env
make setup-worktree
```

Start the worktree app:

```bash
make start-worktree
```

## Daily Workflow

### Main Checkout

```bash
make start-main
make stop-main
make check-main
```

### Feature Worktree

```bash
git worktree add ../multica-feature -b feat/my-change main
cd ../multica-feature
make worktree-env
make setup-worktree
make start-worktree
```

Day-to-day:

```bash
make start-worktree
make stop-worktree
make check-worktree
```

## Running Main and Worktree Simultaneously

This is a first-class workflow. Both checkouts use the same PostgreSQL container but different databases and ports:

| | Main | Worktree |
|---|---|---|
| Database | `multica` | `multica_my_feature_702` |
| Backend port | `8080` | generated (e.g. `18782`) |
| Frontend port | `3000` | generated (e.g. `13702`) |

## Commands

```bash
# Frontend (all commands go through Turborepo)
pnpm install
pnpm dev:web          # Next.js dev server (port 3000)
pnpm dev:desktop      # Electron dev (electron-vite, HMR)
pnpm build            # Build all frontend apps
pnpm typecheck        # TypeScript check
pnpm lint             # ESLint
pnpm test             # TS tests (Vitest)

# Backend (Go)
make dev              # Run Go server (port 8080)
make daemon           # Run local daemon
make build            # Build server + CLI binaries
make test             # Go tests
make sqlc             # Regenerate sqlc code
make migrate-up       # Run database migrations
make migrate-down     # Rollback migrations
```

## Testing

Run all local checks:

```bash
make check
```

This runs:

1. TypeScript typecheck
2. TypeScript unit tests
3. Go tests
4. Playwright E2E tests

## Troubleshooting

### Missing Env File

Create the expected env file:

```bash
# Main checkout
cp .env.example .env

# Worktree
make worktree-env
```

### Check Which Database a Checkout Uses

```bash
cat .env           # or .env.worktree
```

Look for `POSTGRES_DB`, `DATABASE_URL`, `PORT`, `FRONTEND_PORT`.

### List All Local Databases

```bash
docker compose exec -T postgres psql -U multica -d postgres \
  -At -c "select datname from pg_database order by datname;"
```

### Destructive Reset

Stop PostgreSQL and keep local databases:

```bash
make db-down
```

Wipe all local PostgreSQL data:

```bash
docker compose down -v
```

> **Warning:** This deletes the shared Docker volume and all databases. After that you must run `make setup-main` or `make setup-worktree` again.
