Product facts an agent can rely on.

Start here

• API index — GET /api/v1
• Canonical product record — GET /api/v1/product
• Workflow capabilities — GET /api/v1/capabilities
• Canonical resource directory — GET /api/v1/resources
• Service health — GET /api/v1/health
• OpenAPI 3.1 specification
• RFC 9727 API catalog
• Agent instructions and llms.txt

Authentication and privacy

The public product-information endpoints require no authentication and expose no account or user data. They describe what Arcs is, its workflow and the canonical places to learn more. They are deliberately separate from the app’s private on-device intelligence. There is no remote endpoint that accepts a meeting, recording, transcript, document or prompt.

Versioning and deprecation

Stable versions appear in the URL, beginning with /api/v1. Additive fields may appear within a version. Removing or changing the meaning or type of an existing field requires a new major path such as /api/v2. A retiring version will be announced here and in the OpenAPI description at least 180 days before removal. Responses will use the standards-based Deprecation header, a Sunset header with the retirement date and a Link to migration guidance.

Errors

API errors use RFC 9457 application/problem+json. Every problem includes type, title, status, detail, instance, a machine-readable code and a practical resolution hint. Unknown API paths return a real 404 rather than an application shell.

Rate limits

The public information API allows 120 requests per client per minute. Responses advertise the current IETF RateLimit-Policy and RateLimit fields and compatibility fields. A 429 response includes Retry-After and the same typed problem model.

Markdown for agents

Public HTML pages also produce text/markdown when requested through the HTTP Accept header. Negotiated responses include Vary: Accept; unsupported representations receive 406. This keeps browser presentation unchanged while giving agents a smaller, cleaner representation of the same canonical page.