# SELAT Documentation

- [SELAT Docs](https://selat.ai/docs/index.md): Access any paid API on x402/MPP rails, per call, straight from your agent - no API keys, no per-rail integration. Start here.
- [Agentic payments](https://selat.ai/docs/primers/agentic-payments.md): A primer on how autonomous agents pay for services — the problem SELAT solves.
- [API keys vs pay-per-call](https://selat.ai/docs/primers/api-keys-vs-pay-per-call.md): Two ways an agent can access a paid API — provision a key up front, or pay per call on an HTTP 402 challenge. When each makes sense, and why agents increasingly need the second.
- [Chains](https://selat.ai/docs/chains.md): Where SELAT moves money: the EVM chains you fund on (Circle Gateway), and the rails the router settles merchants on — Circle Gateway nanopayments, Base, Tempo, and Solana.
- [Transactability Index](https://selat.ai/docs/transactability/index.md): SELAT's observability layer for paid endpoints — how to read an endpoint's Transactability Score, its reliability signal on the 402 challenge.
- [First-Party Transactability](https://selat.ai/docs/transactability/first-party.md): Reliability from your agent's own settled payments — the private, authoritative half of SELAT's Transactability signal, read before your agent pays again.
- [Decision trace](https://selat.ai/docs/transactability/decision-trace.md): The machine-readable Transactability reading an agent logs, gates on, and audits — quote.transactabilityTrace, its attribution buckets, and the never-blended network vs first-party readings.
- [HTTP 402 Payment Required](https://selat.ai/docs/primers/http-402.md): A primer on the 402 status code and the payment protocols built on it.
- [x402](https://selat.ai/docs/primers/x402.md): The x402 payment protocol. Inbound USDC on EVM via Circle Gateway.
- [MPP on Tempo](https://selat.ai/docs/primers/mpp-tempo.md): The MPP payment protocol and how SELAT settles it on Tempo.
- [x402 vs MPP](https://selat.ai/docs/primers/x402-vs-mpp.md): Which agent payment protocol should you use — and why the production answer is usually both, behind a rail-neutral layer.
- [Nanopayments powered by Circle Gateway](https://selat.ai/docs/primers/nanopayments-gateway.md): How SELAT uses Circle Gateway to settle batched, very-low-value payments.
- [SELAT Plugins for agent runtimes](https://selat.ai/docs/selat-plugins/index.md): Install SELAT Plugins in Claude Code, Codex, Cursor, Gemini CLI, OpenClaw, or Hermes to discover vetted skills and use the SELAT CLI for approved x402 and MPP payments.
- [SELAT CLI](https://selat.ai/docs/selat-cli/index.md): Set up and run SELAT agent payments from the terminal — discover, rank, and pay x402 services in one command.
- [Catalog MCP](https://selat.ai/docs/selat-mcp/index.md): SELAT's hosted discovery MCP — free ranked search, schemas, and live 402 price quotes over the federated x402/MPP catalog. Discovery is free; paying stays local from your own wallet.
- [SELAT Router](https://selat.ai/docs/router/index.md): Cloud-hosted core that resolves paid execution across x402, MPP, and related flows.
- [SELAT Router SDK](https://selat.ai/docs/selat-sdk/index.md): TypeScript client for routing paid requests through SELAT Router.
- [Quickstart](https://selat.ai/docs/selat-sdk/quickstart.md): Install SELAT Router SDK and send your first paid request.
- [RouterClient: TypeScript API Reference](https://selat.ai/docs/selat-sdk/router-client.md): Use RouterClient in the SELAT Router SDK to send fetch-like paid requests, select x402 or MPP, configure a signer, set timeouts, handle payment challenges, and claim refunds.
- [SELAT Router SDK Signers](https://selat.ai/docs/selat-sdk/signers.md): Choose a SELAT Router SDK signer for TypeScript: private key, Circle Agent Wallet, HTTP remote signer, custom remote signer, or Circle Developer-Controlled Wallet.
- [Examples](https://selat.ai/docs/selat-sdk/examples.md): Practical examples for GET, POST, and runtime payment flows.
- [Troubleshooting](https://selat.ai/docs/selat-sdk/troubleshooting.md): Fix the most common setup and runtime issues.
- [Skills](https://selat.ai/docs/skills/index.md): Find, install, and run agent skills that pay for x402 services through SELAT.
- [Authoring and publishing](https://selat.ai/docs/skills/authoring-and-publishing.md): Scaffold, validate, verify, and submit a skill to the public selat-skills registry.
- [Glossary](https://selat.ai/docs/glossary.md): The vocabulary of agentic payments — x402, MPP, HTTP 402, Circle Gateway, the Transactability Score, self-custody, and the SELAT components — defined in one place.

## Optional

- [selat.ai](https://selat.ai)