API Reference

ARCP exposes three groups of endpoints: Registry (discovery + publisher metadata), Router (query routing + receipts), and Publisher (content delivery).

Authentication

Authenticated endpoints require a Bearer API key:

Authorization: Bearer arcp_your_key_here
Content-Type: application/json
User-Agent: your-app/1.0

Registry Endpoints

Base URL: https://registry.arcp-protocol.com

GET/.well-known/arcp-rootNo auth

Root discovery metadata for the ARCP protocol.

GET/v1/publishersNo auth

List all active publishers. Returns publisher ID, display name, query URL, and verification status.

GET/v1/publishers/:publisherIdNo auth

Get metadata for a single publisher.

GET/v1/revocationsNo auth

List revoked publisher keys and suspended publishers.

GET/v1/jwksNo auth

Registry public keys in JWKS format.

Router Endpoints

Base URL: https://router.arcp-protocol.com

POST/v1/router/queryBearer API key

Query across selected publishers in parallel. Returns structured content envelopes, claims, render tokens, and receipts.

Field	Type	Required	Description
`query`	string	Yes	The search query (max 1000 chars)
`publishers`	string[]	Yes	Publisher IDs to query (max 10)
`client_id`	string	Yes	Your client ID
`user_id`	string	No	End-user identifier for receipts
`profile`	string	No	Content profile (default: "MVP")

POST/v1/router/render/openedBearer API key

Track a render link open. Issues a signed render-open receipt for the publisher.

Field	Type	Required	Description
`publisher_id`	string	Yes	Publisher whose content was opened
`content_id`	string	Yes	The content item that was viewed
`render_url`	string	No	The render URL that was clicked
`user_id`	string	No	End-user identifier

GET/v1/router/receipts/exportBearer API key

Export receipts for a publisher and day.

Query params: publisher_id (required), date (YYYY-MM-DD, optional — defaults to today)

GET/v1/router/metricsAdmin key

Usage metrics for the router (events, receipts, active clients). Query param: days (default: 7).

GET/.well-known/arcp-routerNo auth

Router discovery metadata including supported protocol versions and endpoint URLs.

GET/v1/jwksNo auth

Router public keys for receipt and render token verification.

MCP Endpoint

GET/mcpNo auth

MCP server metadata and available tools list.

POST/mcpBearer API key

JSON-RPC 2.0 endpoint for MCP clients. Supports: initialize, tools/list, tools/call.

Available MCP tools: arcp_discover, arcp_query, arcp_render_opened, arcp_receipts_export

Managed Auth Endpoints

These endpoints require an admin API key (scoped to managed:read or managed:write).

POST/v1/router/managed/users/linkmanaged:write

Link a user identity for managed subscription tracking.

POST/v1/router/managed/subscriptions/upsertmanaged:write

Create or update a managed subscription.

POST/v1/router/managed/subscriptions/cancelmanaged:write

Cancel a managed subscription.

GET/v1/router/managed/entitlementsmanaged:read

Query entitlements for a user and publisher.

Rate Limits

Endpoint	Default limit
`/v1/router/query`	60 req/min, 5000 req/day
`/v1/router/render/opened`	120 req/min
`/v1/router/receipts/export`	30 req/min

Rate limit headers: X-RateLimit-Limit-Minute, X-RateLimit-Usage-Minute, X-RateLimit-Limit-Daily, X-RateLimit-Usage-Daily

Error Responses

Status	Error code	Description
400	`INVALID_INPUT`	Missing or invalid request field
401	`UNAUTHORIZED_CLIENT`	Missing or invalid API key
401	`INVALID_API_KEY`	API key not found
401	`API_KEY_REVOKED`	API key has been revoked
401	`API_KEY_EXPIRED`	API key has expired
403	`CLIENT_SUSPENDED`	Client account suspended
413	`PAYLOAD_TOO_LARGE`	Request body exceeds 32KB
429	`RATE_LIMIT_EXCEEDED`	Minute rate limit hit
429	`DAILY_QUOTA_EXCEEDED`	Daily quota exhausted
503	`CLIENT_AUTH_SCHEMA_NOT_READY`	Migration not applied