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Universal Content Access Protocol

The open standard for AI agents to access publisher content. Built on UCP.

UCAP extends the Universal Commerce Protocol (UCP) with capabilities purpose-built for content access — discovery, catalog search, entitlement-based reading, and subscription management. Where UCP handles commerce, UCAP handles content.

Learn

Protocol overview, core concepts, and design principles.

Read the docs

Implement

Technical spec, HTTP API, MCP integration, and reference implementations.

View the spec

HTTP-Native

Built on standard HTTP. Any client that speaks HTTP can access content — no proprietary SDKs required.

Agent-First

Designed for automated access by AI agents, not human browsers. Structured data in, structured data out.

Human-in-Loop Payments

Agents facilitate content access. Humans authorize payments. Trust stays where it belongs.

Transport Agnostic

Works via REST, MCP, or other protocols. Choose the transport that fits your stack.

Platform Agnostic

Supports any content platform — Patreon, Ghost, WordPress, Substack, and more.

Secure by Default

RFC 9421 HTTP Message Signatures on every request. OAuth 2.0 for user delegation. Rate limiting built in.

See it in action

An agent requests paywalled content. UCAP returns the full article if entitled, or subscription offers if not.

{
  "content": {
    "html": "<article>Full post content...</article>",
    "text": "Plain text version...",
    "format": "html"
  },
  "metadata": {
    "id": "post-123",
    "title": "Premium Article Title",
    "author": "Creator Name",
    "published_at": "2026-02-01T10:00:00Z",
    "tier": "premium",
    "word_count": 2500
  },
  "attribution": {
    "required": true,
    "format": "Source: [My Newsletter](https://example.com/post-123)"
  }
}

Agents discover content across publishers with structured search — filter by category, price, language, and freshness.

{
  "query": "AI newsletters",
  "filters": {
    "categories": ["technology", "artificial-intelligence"],
    "price": { "max": 1500, "currency": "USD" },
    "recency": "30d"
  },
  "context": {
    "intent": "weekly digest of AI news for research"
  }
}

When content requires payment, UCAP returns a checkout URL for the human to complete — keeping agents out of the payment loop.

{
  "status": "pending_payment",
  "checkout": {
    "session_id": "session_abc123",
    "url": "https://example.com/checkout/session_abc123",
    "expires_at": "2026-02-04T13:00:00Z"
  },
  "message": "Complete payment to activate subscription"
}

Protocol Stack

UCAP works alongside UCP for payment handling and RFC 9421 HTTP Message Signatures for agent identity verification.

┌─────────────────────────────────────────────────────────────┐
│                      Protocol Stack                         │
├─────────────────────────────────────────────────────────────┤
│                                                             │
│   ┌──────────┐    ┌──────────┐    ┌─────────────────┐      │
│   │   UCAP   │    │   UCP    │    │   RFC 9421      │      │
│   │(Content) │    │(Payments)│    │ (HTTP Signatures)│      │
│   └──────────┘    └──────────┘    └─────────────────┘      │
│        │               │                  │                 │
│        └───────────────┴──────────────────┘                 │
│                         │                                   │
│                  ┌──────┴──────┐                            │
│                  │    HTTP     │                            │
│                  └─────────────┘                            │
│                                                             │
└─────────────────────────────────────────────────────────────┘

Get Started

Read

Understand the core concepts and protocol design.

Implement

Follow the specification to build a conformant server or agent.

Contribute

Join the community and help shape the future of agentic content access.