Verify x402 payment signatures
The agent confirms whether a payment payload or agent grant is valid, checking signatures, timing, and amounts without on-chain costs.
How it works
Read-onlyFinance and payments
The agent receives a payment payload or agent grant from a user or another agent. It calls the x402_facilitator_verify tool to validate the EIP-712 signature, check the nonce, verify the amount, and ensure the grant has not expired. This step is crucial before proceeding with any service delivery to ensure the payment is legitimate and sufficient.
Prompt
Paste this into an agent that has the servers below connected. Adjust the names and dates to your own.
Prompt for Verify x402 payment signatures
Verify if this payment payload is valid: {"paymentPayload": {"network": "base", "scheme": "exact", "payload": {"from": "0x...", "to": "0x...", "value": "1000", "validAfter": "0", "validBefore": "9999999999", "nonce": "0x...", "signature": "0x..."}, "paymentRequirements": {"maxAmountRequired": "1000", "network": "base"}}}MCP servers it needs
Source
The vendor page this playbook is drawn from, and the passage that supports it.
POST /x402/verify Validate a PaymentPayload or Agent Grant — EIP-712 (EVM). Checks signature, timing, nonce, amount. No on-chain call. Free.AgentPay x402 Facilitator | REST & MCP Payment Tools