Buyer clients

Buyer clients pay wrapped gateway URLs. They handle HTTP 402 challenges, sign payments with your EVM key, and retry until the gateway proxies the upstream response.

Environment

• AX402_EVM_PRIVATE_KEY — signing key with testnet USDC
• Gateway URL — hostname from your API domain, not the control plane

By language

• TypeScript: @axlabs/ax402-sdk/buyer — SDK guide
• Go: go/buyer — SDK guide
• Python: ax402_sdk.buyer — SDK guide
• CLI: ax402 pay url <gateway-url>

Protocol reference

Low-level signing and facilitator interaction are defined by x402-foundation/x402. Ax402 buyer helpers wrap those primitives for gateway URLs configured in this platform.