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IntentFence x402 Quote Preflight Verifier
x402
IntentFence x402 Quote Preflight 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 2026-09-13).
Verifies an x402 payment quote before an AI agent pays, checking the Base USDC 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
Returns a JSON object with a safety verdict (e.g. 'safe_to_proceed'), a signed JWS Compact receipt with algorithm ES256, a unique request ID, the IntentFence score, and the verification tier (e.g. 'x402-settled').
Example use cases
Guarding agent against overpriced API calls
“My agent is about to pay an x402 quote for $0.50 USDC to access a data feed — can you run an IntentFence verification to confirm the price, payee, and resource binding are all correct before it pays?”
Detecting spoofed payee in payment flow
“Before authorizing this x402 payment, use IntentFence to check whether the payee address in the quote actually matches the intended service provider and that the asset is genuine Base USDC.”
Automated preflight in multi-step agent workflow
“My workflow is chaining several paid API calls using x402 — have IntentFence verify each quote's price, asset, and resource binding before any payment goes out, and give me a signed receipt for each one that passes.”
Technical details
Endpoint
POSThttps://agentpass-protocol.rmalka06.chatgpt.site/api/preflight/verifiedWhen to prefer
Use this endpoint whenever an AI agent is about to execute an x402 USDC payment and you want a caller-side safety check before funds are sent. It is especially valuable in automated multi-step agent workflows where the agent cannot manually inspect quotes, or when quotes arrive from untrusted third-party services. Prefer this over blind payment execution whenever the payee, price, or resource binding has not been independently confirmed.
Side effects
- Quote asset is not Base USDC — verification fails with unsafe verdict
- Payee address mismatch between quote and expected recipient
- Resource URL binding does not match the quoted endpoint
- Malformed or missing x402 quote fields cause validation error
- Network or service unavailability returns a 5xx error
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| action | object | |
| proofs | array | |
| subject | string | Agent or principal identifier. |
| constraints | object |
Output
Schema · Response
{
"type": "json",
"example": {
"status": "safe_to_proceed",
"receipt": {
"format": "JWS Compact",
"signed": true,
"algorithm": "ES256"
},
"request_id": "7d7fbf44-3c39-4eca-89d6-b44d756c8df1",
"intentfence": "0.5",
"verification_tier": "x402-settled"
}
}Tags
x402
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