> ## Documentation Index
> Fetch the complete documentation index at: https://darwin.so/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# x402 payments

> Handle an HTTP-native payment challenge without exposing wallet authority to an AI.

x402 uses HTTP `402 Payment Required` to describe what a client must pay before retrying a resource request. Darwin Pay can adapt that exchange when the selected capability and payment interaction explicitly support x402.

## Follow the challenge

```text theme={null}
request resource -> 402 payment requirements -> review bound interaction
                 -> satisfy compatible payment -> retry request
                 -> verify settlement -> return resource
```

Darwin binds the resource, network, asset, amount, recipient, scheme, expiry, and Action revision before asking for authority. The client cannot replace those fields through the generic Pay operation.

## Protect wallet authority

Wallet keys and signing authority stay in the user's chosen wallet or payment provider. Darwin receives only the scoped proof required for the challenged request. It never places a private key, seed phrase, reusable signature, or raw payment credential in a prompt.

An HTTP success response alone is not durable payment evidence. Darwin verifies the protocol result and then updates the same Action.