--- title: "PubFi for Developers" description: "Start with PubFi Runtime OpenAPI, the complete capability catalog, hosted MCP, and explicit API-key, OAuth, or accountless x402 access lanes." canonical_url: "https://pubfi.ai/developers" --- # Build against one live data contract > PubFi publishes public catalog reads and exact capability detail before authentication. Use the selected route's current schema, readiness, and billing mode for execution. Canonical HTML: https://pubfi.ai/developers ## The minimum reliable integration loop ### Enumerate the full catalog Follow every opaque next_cursor until it is absent. Do not combine partial or conflicting generations. [Open the catalog](https://api.pubfi.ai/v1/capabilities) ### Read exact capability detail Confirm raw path, method, request, response, readiness, and per-method billing before execution. ### Select in the client The client agent evaluates the returned contracts. PubFi does not infer intent or rank providers. ### Execute in one lane Send the exact path and method with the selected account credential or x402 payment proof. Never mix lanes. ## Public developer entry points ### Runtime OpenAPI The Rust-generated OpenAPI 3.1 document for current PubFi HTTP routes. [Open OpenAPI](https://pubfi.ai/openapi.json) ### Hosted MCP The public discovery manifest for catalog reads and protected execution tools. [Open MCP manifest](https://pubfi.ai/.well-known/mcp.json) ### Agent guide The current machine-readable boundary and execution guide. [Read agents.md](https://pubfi.ai/agents.md) ### Authentication guide A concise Markdown guide to public, account, OAuth, and x402 lanes. [Read auth.md](https://pubfi.ai/auth.md) ## Stable within the public REST major PubFi publishes lifecycle changes before they affect an integration. ### /v1 is the stable public REST major PubFi does not silently remove routes or introduce breaking contract changes within the /v1 major. ### Deprecations stay explicit Future deprecations are documented and marked in Runtime OpenAPI. An affected response uses the Deprecation header when deprecation is scheduled. It uses the RFC 8594 Sunset header only after a removal date is committed. ### No current removal is scheduled No current /v1 route is scheduled for removal. ## Access paths ### Public discovery and contracts - Cost: No account. - Authentication: No authentication is required for these read-only public resources. - Purpose: Read Discovery, the complete Registry capability catalog, exact capability detail, Runtime OpenAPI, and public MCP catalog tools. - Use this lane to find sources and inspect current executable contracts. - Public catalog access does not authorize route execution. - The live Registry, not checked-in marketing content, owns readiness. - Next: [Open Developers](https://pubfi.ai/developers). ### Registered account - Cost: Credits or account-bound :free. - Authentication: The selected credential must resolve to an admitted billing account. Exact :free variants remain account-bound and charge no Credit. - Purpose: Use a PubFi API key for HTTP execution or a PubFi API key or Supabase OAuth access token for protected hosted MCP tools. - Eligible billing accounts receive one lifetime starter grant of 1,000 Credits. Each starter allocation is valid for 365 days. - The current checked-in catalog defines 1,000 Credits for USD 1.00, valid for 365 days. - A purchase is available only when the authenticated billing response returns the exact current offer. Per-operation Credit cost comes from the live Registry. - Next: [Open app](https://pubfi.ai/login). ### Accountless x402 - Cost: Exact live route quote. - Authentication: Do not send a Bearer credential. The unsigned request receives an exact payment challenge, and the signed retry uses the environment-matched x402 lane. - Purpose: Use the explicit HTTP or MCP x402 endpoint for a route that the live Registry currently enables for accountless payment. - The live Registry, signed offer, pay-to address, asset, network, and payment challenge are authoritative. - x402 consumes no account Credits and creates no PubFi account, invoice, API key, or anonymous dashboard. - A published route can be unavailable, free, account-priced, or x402-priced. Do not infer a payment path from Discovery content. - Next: [Read the x402 guide](https://docs.pubfi.ai/getting-started/x402). ### Custom delivery - Cost: Custom terms. - Authentication: Access, commercial terms, and delivery boundaries are confirmed in writing for the selected program. - Purpose: Use a separately scoped delivery when a production program needs custom source integration, data packaging, service levels, or support. - Custom delivery does not make every indexed provider executable. - Source rights, credentials, route contracts, and acceptance stay explicit. - Contact PubFi with the workflow, data scope, and expected delivery requirements. - Next: [Discuss custom delivery](mailto:hello@pubfi.ai?subject=PubFi%20custom%20delivery). ## When to use PubFi - **An agent must inspect before it calls:** Use PubFi when the client can enumerate the live catalog, read exact capability detail, and select a route from current evidence. - **A product needs one execution boundary:** Use PubFi when a team wants server-side provider credentials, typed route validation, bounded delivery, and account or x402 admission behind one Registry-backed gateway. - **Source discovery and execution must stay distinct:** Use PubFi when public source research is useful but runtime availability must remain fail-closed and independently verified. ## When not to use PubFi - **You need PubFi to choose the provider:** PubFi does not infer intent, rank capabilities, or select a route. The client agent owns that decision. - **You need one universal request or response schema:** Each capability keeps its exact route-specific request and response contract. PubFi does not flatten all providers into one schema. - **You need automatic supplier purchase or settlement:** PubFi accountless x402 is a seller-side payment lane for approved PubFi routes. It is not supplier procurement, wallet custody, or automatic provider payment. ## Continue - [Read the quickstart](https://docs.pubfi.ai/getting-started/quickstart) - [Inspect Runtime OpenAPI](https://pubfi.ai/openapi.json)