# SDK
> Gate HTTP services and pay HTTP 402 challenges from TypeScript, Rust, Go, and Python.

- [SDK overview](/docs/sdk/index.md): Choose the pay CLI or an in-process SDK for gating and consuming HTTP services.
- [TypeScript SDK](/docs/sdk/typescript/index.md): Gate HTTP routes with @solana/pay-kit and web-standard Request and Response types.
- [TypeScript: payment schemes](/docs/sdk/typescript/schemes/index.md): Use fixed, metered, subscription, and session gates across MPP and x402.
- [TypeScript: pricing and gates](/docs/sdk/typescript/pricing-and-gates/index.md): Declare inline prices, named gates, fees, splits, and dynamic per-request pricing.
- [TypeScript: client](/docs/sdk/typescript/client/index.md): Consume HTTP 402 APIs with a payment-aware fetch that pays and retries automatically.
- [TypeScript: signers](/docs/sdk/typescript/signers/index.md): Load local keypairs or remote signing backends through the Signer factory.
- [TypeScript: errors](/docs/sdk/typescript/errors/index.md): Handle pay-kit errors and boot-time configuration safety checks.
- [Rust SDK](/docs/sdk/rust/index.md): Gate HTTP routes with solana-pay-kit and a dual-protocol Axum gate.
- [Rust: payment schemes](/docs/sdk/rust/schemes/index.md): Use fixed, metered, and batch-settlement gate functions.
- [Rust: pricing](/docs/sdk/rust/pricing/index.md): Price a route with a fixed dollar string or per-request closure.
- [Rust: client](/docs/sdk/rust/client/index.md): Read an MPP challenge, sign a credential, and retry the request.
- [Rust: signers](/docs/sdk/rust/signers/index.md): Load local keypairs or remote signing backends through Solana Keychain.
- [Rust: errors](/docs/sdk/rust/errors/index.md): Handle solana-pay-kit errors and boot-time configuration safety checks.
- [Go SDK](/docs/sdk/go/index.md): Gate net/http routes with the pay-kit Go module and dual-protocol middleware.
- [Go: payment schemes](/docs/sdk/go/schemes/index.md): Use fixed and metered gates and understand where MPP sessions fit.
- [Go: pricing](/docs/sdk/go/pricing/index.md): Price a gate with typed USD amounts, settlement assets, and fee splits.
- [Go: client](/docs/sdk/go/client/index.md): Settle HTTP 402 challenges through a standard http.Client wrapper.
- [Go: signers](/docs/sdk/go/signers/index.md): Load local operator keys or implement the KMS-ready signer interface.
- [Go: errors](/docs/sdk/go/errors/index.md): Handle pay-kit initialization and per-request payment errors.
- [Python SDK](/docs/sdk/python/index.md): Gate Flask, FastAPI, and Django routes with solana-pay-kit.
- [Python: payment schemes](/docs/sdk/python/schemes/index.md): Use fixed, metered, and session gates through decorators or dependencies.
- [Python: frameworks](/docs/sdk/python/frameworks/index.md): Integrate the framework-agnostic core with Flask, FastAPI, and Django.
- [Python: pricing](/docs/sdk/python/pricing/index.md): Declare typed USD amounts, named pricing, fee splits, and dynamic prices.
- [Python: client](/docs/sdk/python/client/index.md): Settle x402 challenges through a payment-aware httpx.AsyncClient.
- [Python: signers](/docs/sdk/python/signers/index.md): Load local keypairs or configure the operator signer from the environment.
- [Python: errors](/docs/sdk/python/errors/index.md): Handle configuration exceptions and per-request payment failures.