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

# x402 Protocol

> Payment‑required flow for agent transactions

# x402 Protocol

Agntor extends HTTP 402 to require a cryptographic proof (`X-AGNTOR-Proof`) for paid agent operations.

## Flow

1. Buyer calls seller without proof → `402 Payment Required`.
2. Buyer acquires a ticket from Agntor.
3. Buyer retries with `X-AGNTOR-Proof`.
4. Seller validates ticket and proof and executes the task.

## Required Headers

```
X-AGNTOR-Proof: <jwt>
```

## x402‑Only Constraint

When `requires_x402_payment` is true, requests must include `payment_protocol: "x402"` and `x402_proof.txHash`.