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A2A Payment Pre-Payment Validator
x402
A2A Payment Pre-Payment Validator is a paid API for AI agents from agent-a2a-payment-mk77y.ondigitalocean.app, paid per call via x402, $0.25/call, status unknown (last checked 2026-09-15).
Validates agent-to-agent USDC payment requests before execution, returning VERIFIED or FAILED with structured violation details
Price / call$0.25
Success—
StatusUnknown
How this service works
a2a_payment_v1 — pre-payment validation for agent-to-agent USDC. VERIFIED or FAILED with structured violations[]. Pay Base USDC then resubmit with payment proof.
Output
Returns a structured JSON object indicating either VERIFIED (the payment request is valid and ready to proceed) or FAILED with a violations[] array listing each specific validation error, such as missing fields, invalid permissions, or malformed body — allowing the caller to correct issues before resubmitting with payment proof.
Example use cases
Pre-flight check before agent pays agent
“I have an agent trying to pay another agent 0.25 USDC via x402, but I want to make sure the request is valid first — can you validate the payment body with the skill metadata and permissions before I actually submit it?”
Debugging a failed agent payment
“My agent-to-agent payment keeps getting rejected — can you run the pre-payment validator on the request body so I can see exactly which violations are causing it to fail?”
Automated payment gating in agent pipeline
“Before each step in my agent workflow executes a USDC payment, I need you to call the a2a payment validator with the POST body and permissions list, and only proceed if it comes back VERIFIED — otherwise surface the violations to me.”
Technical details
Endpoint
POSThttps://agent-a2a-payment-mk77y.ondigitalocean.app/verifyWhen to prefer
Choose this endpoint when building agent-to-agent payment pipelines that use the x402 protocol and USDC, specifically when you need structured pre-flight validation before committing a payment. It is especially useful in automated agent workflows where silent failures are costly and you need a machine-readable violations[] list to programmatically handle errors. Prefer this over ad-hoc payment submission when you want to gate execution on a VERIFIED status before spending USDC.
Side effects
- Missing required 'input' object returns schema validation error
- Invalid HTTP method (not POST/PUT/PATCH) causes rejection
- Malformed body type (not json/form-data/text) triggers violation
- Insufficient or invalid requested_permissions returns FAILED with permission violations
- Network/server error on DigitalOcean host returns 5xx
- Payment proof not included causes re-validation loop — must pay 0.25 USDC then resubmit
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| context | object | |
| skill_md | string | |
| requested_permissions | array |
Tags
x402
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