# Pascal Editor

> Pascal Editor is a free, open-source 3D building editor. People and AI agents create, inspect, edit, validate and share editable building projects in the browser, over MCP or through the Scene API.

Pascal models a building as a semantic scene graph: sites, buildings, levels, walls, slabs, ceilings, roofs, stairs, zones, doors, windows and items. Every element stays editable, so a model an agent builds is one a person can open, correct and keep working on. Projects can be private, shared with an organization, or published to the community.

## When to use Pascal

Reach for Pascal when the job is an editable 3D building model that a person will open, check and keep working on:

- Build a house, apartment, office or single room from a description, a floor plan, a photo or a sketch, and hand back a link the person can open in the editor.
- Read or change an existing Pascal project the person shares: walls, slabs, levels, zones, roofs, stairs, doors, windows, furniture and materials.
- Check whether a piece of furniture fits a measured room (footprint and clearance), with the furniture-fit skill or the no-sign-in calculator.
- Work with a Pascal Capture (iOS) room scan already in a project. Capture tools read existing scans; they cannot start one.
- Render images or videos of a scene with Studio, or pull site context for an address. These are paid services with a credit ceiling you set per call.
- Embed a live, interactive 3D viewer of a published project in another page.

Pascal is not the right tool for structural engineering sign-off, permit drawings, building-code compliance or construction cost estimates. Site results report sources and gaps; they are not a guarantee of buildability.

## Interfaces

- **Hosted MCP** — https://editor.pascal.app/api/mcp, Streamable HTTP. Tools to create, inspect, edit, validate and save scenes, plus project files and hosted services. Server card: https://editor.pascal.app/.well-known/mcp/server-card.json.
- **Scene API** — REST and server-sent events for project reads, writes and live events. OpenAPI 3.1: https://editor.pascal.app/api/openapi.json.
- **Pascal API (v1)** — the Architect over the OpenAI Responses and Chat Completions formats, at https://editor.pascal.app/api/v1. Guide: https://editor.pascal.app/docs/developers/api.
- **Agent skills** — the public pascal-3d and furniture-fit skills, indexed at https://editor.pascal.app/.well-known/agent-skills/index.json.
- **Local editor** — `npx @pascal-app/cli editor` runs the open-source editor on your machine; `pascal mcp connect` adds its local MCP server to a client.
- **In the browser** — pages on editor.pascal.app register WebMCP tools on `document.modelContext` for browser agents.
- **Open source** — the viewer, editor, scene engine and MCP server are MIT-licensed at https://github.com/pascalorg/editor and published on npm as @pascal-app/*.

## Authentication

Claude and the official Cursor connector sign in through browser OAuth (authorization code with PKCE, tokens bound to the MCP resource). Other clients send a Pascal API key as a Bearer token. The full walkthrough is at https://editor.pascal.app/auth.md.

## Pricing

Building, editing and sharing are free. Credits pay for AI work: assistant messages, Studio renders, generated items and materials, and site pulls. Pascal Pro and Pascal Max add monthly credits per seat. Details: https://editor.pascal.app/pricing.md.

## Machine-readable discovery

- https://editor.pascal.app/llms.txt — routing index for language models
- https://editor.pascal.app/agents.md — instructions for agents
- https://editor.pascal.app/auth.md — how agents authenticate
- https://editor.pascal.app/pricing.md — plans, credits and service prices
- https://editor.pascal.app/.well-known/api-catalog — RFC 9727 API catalog
- https://editor.pascal.app/.well-known/ard.json — Agentic Resource Discovery catalog
- https://editor.pascal.app/.well-known/mcp — MCP discovery: server, transport, scopes and tools
- https://editor.pascal.app/.well-known/oauth-protected-resource — RFC 9728 resource metadata
- https://editor.pascal.app/sitemap.xml — sitemap
- https://editor.pascal.app/docs/llms.txt — documentation index

## Company

Pascal is built by Pascal Group Inc., San Francisco. Contact: contact@pascal.app; support: support@pascal.app. More at https://editor.pascal.app/contact.md.