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Nomos Payment Preflight Decision API
x402
Nomos Payment Preflight Decision API is a paid API for AI agents from base-agent-preflight.bytoken2023.workers.dev, paid per call via x402, $0.2/call, status unknown (last checked 2026-09-14).
Evaluates an autonomous agent's proposed USDC payment before execution, returning a risk score, risk level, and any compliance flags.
Price / call$0.2
Success—
StatusUnknown
How this service works
Machine-payable service intelligence for discovering, verifying, and monitoring identity, risk, authorization, execution-preflight, and evidence APIs before autonomous agents spend.
Output
Returns a JSON object containing the Base network identifier (eip155:8453), product name, and an assessment object with risk_score (numeric), risk_level (e.g. 'low', 'medium', 'high'), and a flags array listing any detected compliance or risk issues. May also include identity, activity, and provenance sub-objects for deeper analysis.
Example use cases
Agent payment safety gate
“My trading agent wants to send 100 USDC to a new counterparty — run a preflight risk check for agent ID 'trader-agent-007', amount 100 USDC, purpose 'market-maker-settlement', and let me know if the risk score is too high to proceed.”
Compliance screening for payroll agent
“Before my payroll agent disburses 500 USDC to a contractor, screen the payment using agent ID 'payroll-bot-003' with purpose 'contractor-payment' and recipient risk level MEDIUM so I know if there are any compliance flags.”
Low-value micropayment preflight
“My content agent is about to pay 0.50 USDC for an API call — do a quick Nomos preflight check for agent ID 'content-agent-12', amount 0.50, purpose 'data-api-access', so we can confirm risk is low before it executes.”
Technical details
Endpoint
POSThttps://base-agent-preflight.bytoken2023.workers.dev/x402/v1/decision/payment-preflightWhen to prefer
Use this endpoint when an autonomous agent needs a decision gate before executing a USDC payment on Base — especially when the payment is to an unknown or variable-risk recipient, or when compliance evidence is required before disbursement. Prefer this over generic on-chain analytics when you need a structured risk_score + flags output specifically designed for agent-to-agent or agent-to-vendor payment flows, and when you want an auditable preflight record tied to a specific agent_id.
Side effects
- Missing required query params (agent_id, amount_usdc, purpose) returns 400 validation error
- Invalid amount_usdc format (non-numeric or >6 decimal places) causes schema rejection
- Unknown or unsupported recipient_risk_level enum value returns validation error
- Payment of $0.20 USDC not completed triggers 402 Payment Required before assessment is returned
- Downstream risk engine unavailable may return 503 or empty assessment
- idempotency_key collision with different parameters may return cached or conflicting response
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| inputrequired | object | |
| output | object |
Output
Schema · Response
{
"type": "json",
"example": {
"network": "eip155:8453",
"product": "nomos-payment-preflight",
"assessment": {
"flags": [],
"risk_level": "low",
"risk_score": 0
}
}
}Tags
x402
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