Agent discovery

An agent that lands on editor.pascal.app from a search result, a link or a person’s request can find everything it needs from the site itself. This page lists what Pascal publishes and how to check each piece with curl.

Read pages as Markdown

The homepage and the contact page have Markdown twins. Pascal serves them when the request asks for Markdown, when a user-initiated assistant fetches the page (ChatGPT-User, Claude-User, Perplexity-User), or on /?mode=agent. Browsers keep getting HTML, and both answers carry Vary: Accept, User-Agent.

curl -sS -i -H 'Accept: text/markdown' https://editor.pascal.app/
curl -sS https://editor.pascal.app/index.md
curl -sS https://editor.pascal.app/contact.md

Each HTML page advertises its twin with <link rel="alternate" type="text/markdown"> and the same Link response header. A Markdown request for a path that doesn’t exist answers 404 with a Markdown body that links the docs, /llms.txt and the sitemap.

Document	What it holds
`/llms.txt`	Routing index: when to use Pascal, instructions for agents, every guide and interface
`/agents.md`	When to use Pascal and how an agent should call it
`/auth.md`	How an agent authenticates: OAuth, API keys, agent accounts and claims
`/pricing.md`	Plans, credit packs and what each hosted service costs
`/docs/llms.txt`	The documentation index
`/changelog/llms.txt`	Every changelog entry, newest first

Catalogs and well-known documents

Path	Standard	What it lists
`/.well-known/api-catalog`	RFC 9727 linkset	Every interface with its description and documentation
`/.well-known/ard.json`	Agentic Resource Discovery	The MCP server, the Scene API, the public skills and the API catalog, with sample queries. The same document is served at `/.well-known/ai-catalog.json` and linked from every page with `rel="ai-catalog"`.
`/.well-known/mcp`	MCP discovery	The hosted server, its transport, how to authorize, and every tool it lists with the scope that tool needs
`/.well-known/mcp/server-card.json`	MCP server card	The server’s identity, transport, authentication, tools, resources and prompts
`/.well-known/agent-skills/index.json`	Agent Skills Discovery 0.2.0	The public `pascal-3d` and `furniture-fit` skills, each with the SHA-256 digest of the `SKILL.md` it serves
`/.well-known/oauth-protected-resource`	RFC 9728	The MCP resource, its authorization server and scopes
`/api/openapi.json`	OpenAPI 3.1	The Scene API and the Pascal API

None of these needs a credential. Listing the MCP server’s tools, scopes and annotations is public; calling a tool is not. Discovery describes what Pascal offers, never an account’s entitlements.

curl -sS https://editor.pascal.app/.well-known/mcp | jq '.servers[0].authorization'
curl -sS https://editor.pascal.app/.well-known/agent-skills/index.json | jq '.skills[].name'

Structured data

Every page carries schema.org JSON-LD for Pascal (the Organization, with its contact points and address), the site and the application. The homepage adds its FAQ (FAQPage) and the open-source editor (SoftwareSourceCode); /contact is a ContactPage.

WebMCP in the browser

Pascal’s pages register WebMCP tools on document.modelContext (falling back to navigator.modelContext) for agents that work in the person’s browser:

Homepage: get_pascal_agent_access (the MCP URL and how to authorize), search_community_projects and open_pascal_page.
Editor: the shared scene tools list_levels, get_level_summary, get_walls, get_zones, get_node, find_by_type, create_room, add_wall, add_door, add_window and delete_node. They run in the open project through the same executor as Pascal’s assistant, so every edit lands in the person’s undo history and is attributed to the agent.

A browser without WebMCP registers nothing.

Errors and limits

API errors are JSON with a machine-readable code, every counted response carries RateLimit headers, and deprecated endpoints announce themselves with Deprecation and Sunset. See Errors, rate limits and versioning.

Integrate

Extend Pascal

Agent discovery

Read pages as Markdown

Catalogs and well-known documents

Structured data

WebMCP in the browser

Errors and limits

​Read pages as Markdown

​Catalogs and well-known documents

​Structured data

​WebMCP in the browser

​Errors and limits

Read pages as Markdown

Catalogs and well-known documents

Structured data

WebMCP in the browser

Errors and limits