# Pascal Editor — Setup

## Prerequisites

- [Bun](https://bun.sh/) 1.3+ (recommended), or Node.js 22+

## Quick Start

```bash
bun install
bun dev
```

The editor will be running at **http://localhost:3000**.

## Environment Variables (optional)

Copy `.env.example` to `.env` if you need:

```bash
cp .env.example .env
```

| Variable | Required | Description |
|----------|----------|-------------|
| `NEXT_PUBLIC_GOOGLE_MAPS_API_KEY` | No | Enables address search in the editor |
| `PORT` | No | Dev server port (default: 3000) |

## AI Design Agent

Saved scenes expose an `AI Designer` sidebar. Configure an OpenAI-compatible
model endpoint before using it:

```env
PASCAL_AGENT_API_KEY=your_api_key
PASCAL_AGENT_BASE_URL=https://api.openai.com/v1
PASCAL_AGENT_MODEL=gpt-4.1-mini
PASCAL_DATA_DIR=/absolute/path/to/pascal-data
PASCAL_AGENT_PROXY_SECRET=replace_with_a_long_random_value
```

The editor and Agent MCP processes must use the same `PASCAL_DATA_DIR` or
`PASCAL_DB_PATH`. Each chat request launches an isolated `pascal-mcp` stdio
process, binds it to the current scene, and closes it when streaming finishes.
This prevents concurrent users from sharing the MCP bridge's in-memory scene.

The default safety limits are 18 tool steps, 90 seconds per tool, and 5 minutes
per turn. Override them with `PASCAL_AGENT_MAX_STEPS`,
`PASCAL_AGENT_STEP_TIMEOUT_MS`, and `PASCAL_AGENT_TOTAL_TIMEOUT_MS`.

When the application runs under Node rather than Bun, make Bun available on
`PATH` or set `PASCAL_MCP_COMMAND` to its absolute path. Set
`PASCAL_MCP_ENTRY` when the built MCP executable is outside the monorepo.

Production requests must pass through a trusted reverse proxy that authenticates
the user, strips any incoming `X-Pascal-Agent-Proxy-Secret` header, and injects
the configured value before forwarding to Pascal. Bind the Pascal service to a
private interface so users cannot bypass the proxy.

For a same-domain hosted deployment, set
`NEXT_PUBLIC_PASCAL_BASE_PATH=/pascal-service` before building and
`PASCAL_REQUIRE_HOST_USER=true` at build and runtime. The reverse proxy must
also strip and inject `X-Pascal-User-Id`. New scenes persist that value as
`ownerId`; list, read, mutation, event-stream, and Agent routes reject scenes
owned by another user.

The standalone app scripts force Next.js to run under Bun because scene
persistence uses built-in SQLite. Starting the app with Node 20 or earlier will
fail when a scene is first loaded or saved.

The core editor works without environment variables; the AI agent remains disabled until configured.

## Monorepo Structure

```
├── apps/
│   └── editor/          # Next.js editor application
├── packages/
│   ├── core/            # @pascal-app/core — Scene schema, state, systems
│   ├── viewer/          # @pascal-app/viewer — 3D rendering
│   └── ui/              # Shared UI components
└── tooling/             # Build & release tooling
```

## Scripts

| Command | Description |
|---------|-------------|
| `bun dev` | Start the development server |
| `bun build` | Build all packages |
| `bun check` | Lint and format check (Biome) |
| `bun check:fix` | Auto-fix lint and format issues |
| `bun check-types` | TypeScript type checking |

## Contributing

See [CONTRIBUTING.md](./CONTRIBUTING.md) for guidelines on submitting PRs and reporting issues.