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IntentFence x402 Quote Verifier
x402
IntentFence x402 Quote Verifier is a paid API for AI agents from agentpass-protocol.rmalka06.chatgpt.site, paid per call via x402, $0.005/call, status unknown (last checked 2026-09-15).
Verifies an x402 payment quote before an AI agent pays, checking the asset, price, payee, and resource binding for safety.
Price / call$0.005
Success—
StatusUnknown
How this service works
Fail-closed, action-bound authorization for AI agents with five-minute ES256 receipts, MCP risk scanning, and x402 payment safety.
Output
A JSON object with a safety status (e.g. 'safe_to_proceed'), an IntentFence score, a verification tier, a SHA-256 hash of the observed payment requirements, a signed receipt with assurance label, and a unique request ID. This lets the agent confirm whether the quote is safe to pay before committing funds.
Example use cases
Agent pre-flight payment safety check
“Before my agent pays any x402 invoice, I want it to verify the quote through IntentFence first — confirm the asset is Base USDC, the price matches what was advertised, and the payee is correctly bound to the resource.”
Detecting tampered x402 payment quotes
“I'm worried a middleware service might be rewriting x402 quotes to swap the payee address — can you check this quote against IntentFence to see if the payment requirements SHA-256 and payee look legitimate before we authorize anything?”
Automated x402 compliance gate for agent fleet
“Set up a rule so that every time one of my agents receives an x402 payment challenge, it first submits the quote to IntentFence for a caller-observed assessment and only proceeds if the verification tier comes back as x402-quote-assessment+x402-settled and the status is safe_to_proceed.”
Technical details
Endpoint
POSThttps://agentpass-protocol.rmalka06.chatgpt.site/api/x402-assessmentsWhen to prefer
Use this endpoint when an AI agent is about to authorize an x402 micropayment and needs a caller-observed safety check before funds are sent. It is specifically designed for the x402 protocol on Base USDC, and is the right choice when you want a signed receipt and a structured IntentFence score rather than a simple format validation. Prefer it over no-op checks or generic schema validators when financial risk from a tampered payee or mispriced quote is a concern.
Side effects
- Quote fails validation — payee or resource binding mismatch returns a non-safe status
- Asset is not Base USDC — quote is flagged as unsafe
- Price deviation detected — quote price does not match expected amount
- Malformed or missing x402 payment requirements in the request body
- Network or service errors returning non-200 responses
- Stale or replayed quote with mismatched SHA-256 hash
Output
Schema · Response
{
"type": "json",
"example": {
"status": "safe_to_proceed",
"receipt": {
"signed": true,
"assurance": "caller-observed-x402-quote-assessment"
},
"observed": {
"x402_version": 2,
"payment_requirements_sha256": "6902df25de3f5724ff75332b01efab618f7082e69cb3b541a99b6cd4cbf3a2a6"
},
"request_id": "7d7fbf44-3c39-4eca-89d6-b44d756c8df1",
"intentfence": "0.6",
"verification_tier": "x402-quote-assessment+x402-settled"
}
}Tags
x402
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