Overview

There are two ways to add stablecoin payment gating to an HTTP service:

• the pay CLI — declare your endpoints and pricing in a YAML spec and run a gateway, no code; or
• a language SDK — gate routes inside your own server process, when you need deeper integration.

Both speak the same 402 Payment Required handshake (MPP and x402) and the same gate model — an amount, the protocols you accept, and optional fees — so you can move from one to the other (or run both) without changing the payment model.

Start with the CLI

For most APIs the CLI is the fastest path and needs no code. Point it at a provider YAML and it runs a gateway that issues 402 challenges, verifies and settles payments, and (optionally) proxies paid requests to your upstream:

pay server start provider.yml

The YAML declares routing, pricing and metering, subscriptions, and payment splits — see Building with pay. Reach for the CLI when you're gating an existing or upstream API, want the pay-skills catalog and discovery, or simply don't want payment logic in your application code.

Reach for an SDK when you need deeper integration

An SDK gates routes inside your application process, so you can:

• price or meter a request from your own app state — tokens generated, bytes served, rows returned;
• run logic in the paid handler and read the verified payment;
• embed gating in your existing framework's middleware;
• act as a paying client, not just a server.

The SDKs

Every SDK ships a paying client of some form; TypeScript is the reference surface and the most complete.

Scheme support

Which payment schemes each SDK exposes as a one-line gate today. Where a cell is —, the protocol is often still reachable through that SDK's lower-level protocol layer — see the per-language guide.

Next

• Building with pay — the CLI + YAML path, end to end.
• Toolchain — the full pay CLI reference.
• Per-language guides: TypeScript, Rust, Go, Python.