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

# Payment Tools

> Probe and pay x402-gated API endpoints

The Payment toolset enables AI agents to interact with the x402 micropayment protocol — discovering costs and executing on-chain payments to access gated HTTP resources.

## `probe_x402`

Discover the cost and requirements of a protected endpoint **without paying**.

* **Input:**
  * `url` — the x402-gated endpoint URL
* **Execution:** Sends an HTTP GET request. If the server returns `402 Payment Required`, parses the payment headers:
  * `x-payment-amount` — cost in token base units
  * `x-payment-mint` — the SPL token mint address (e.g., USDC)
  * `x-payment-address` — the merchant's receiving wallet
* **Returns:** Payment requirements (amount, token, merchant address, network)

<Tip>
  Use `probe_x402` first to check prices before committing to a purchase. This is how buyer agents comparison-shop across merchants.
</Tip>

## `pay_x402_invoice`

Execute the full x402 payment flow in a single call — pay the merchant and receive the data.

* **Input:**
  * `wallet_id` — the agent wallet that will pay
  * `url` — the x402-gated endpoint URL
  * `method` (optional, default: `GET`) — HTTP method
  * `body` (optional) — request body for POST/PUT endpoints
* **Execution:**
  1. Queries the endpoint to extract payment requirements (or uses cached requirements from a prior `probe_x402`)
  2. Validates the payment against the wallet's [spending policy](/security)
  3. Transfers the exact USDC amount to the merchant via `TransactionBuilder`
  4. Waits for on-chain confirmation
  5. Retries the HTTP request with the `x-payment-signature` header
* **Returns:** The merchant's HTTP response data + transaction signature + Explorer link

<Note>
  The entire flow — discover price → transfer USDC → verify on-chain → retry with signature → return data — happens in a single tool invocation. The agent never needs to orchestrate multiple steps.
</Note>