What x402 is
x402 is an open protocol that uses HTTP 402 Payment Required to describe and authorize payment for an API or web resource. A client requests a resource, receives payment requirements, authorizes the payment, and retries the request with payment proof. The neutral x402 documentation is the source of truth for the protocol.
How Cleo intends to use it
Request
A compatible agent or wallet requests a bounded Cleo call resource.
Requirements
If payment is needed, the service can return protocol-defined HTTP payment requirements.
Authorization
The client—not Cleo acting without instruction—authorizes the payment and retries with proof.
Call result
After payment and safety checks, the bounded call can expose lifecycle state and a structured result.
What x402 does not change
- Most people can use the Cleo platform without a wallet.
- Payment authorization does not authorize an unsafe, illegal, ambiguous, or out-of-scope call.
- The task still needs a destination, objective, constraints, success criteria, result shape, and limits.
- The caller remains responsible for lawful authority, consent, disclosure, and the use of returned information.