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Agent Buyer Identity Preflight | x402 Purchase Governance
x402
Agent Buyer Identity Preflight | x402 Purchase Governance is a paid API for AI agents from base-agent-preflight.bytoken2023.workers.dev, paid per call via x402, $0.25/call, status unknown (last checked 2026-09-14).
Pre-purchase risk assessment that verifies whether an AI agent's buyer identity, role, and context are appropriate for a given x402 API, dataset, or tool purchase before the transaction is executed.
Price / call$0.25
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 a risk assessment with a risk_level (e.g. 'low', 'medium', 'high'), a numeric risk_score, any risk flags triggered, plus contextual data about the network, product, buyer identity, and provenance — helping the agent decide whether to proceed with the purchase.
Example use cases
Screening agent before API purchase
“Before my agent pays 0.25 USDC to buy that analytics API on Base, check whether the wallet 0xABCDEF1234567890ABCDEF1234567890ABCDEF12 is authorized to purchase from 0x9876543210ABCDEF9876543210ABCDEF98765432 for action 'api.analytics'.”
Compliance gate for sensitive dataset purchase
“My agent wants to buy a sensitive financial dataset on Base chain — run a risk preflight to see if buyer wallet 0xAABBCCDDEEFF00112233445566778899AABBCCDD is cleared to transact with seller 0x1122334455667788990011223344556677889900 for 'dataset.financial' at 5.00 USDC before we proceed.”
Low-risk tool purchase approval
“Check if it's safe for my agent at 0xDEADBEEFDEADBEEFDEADBEEFDEADBEEFDEADBEEF to buy a code generation tool from 0xCAFEBABECAFEBABECAFEBABECAFEBABECAFEBABE on Base for action 'tool.codegen' at 0.10 USDC — I need the risk score before we approve the payment.”
Technical details
Endpoint
GEThttps://base-agent-preflight.bytoken2023.workers.dev/v1/x402/agent-risk/safe-transaction-reviewWhen to prefer
Use this endpoint when an AI agent is about to execute an x402 micropayment purchase and you need a pre-transaction governance check — specifically to validate buyer identity fitness, product category compatibility, and spending policy compliance before committing USDC. Prefer this over post-hoc auditing when the cost of an unauthorized or policy-violating purchase is high, or when operating in a multi-agent environment where individual agents have restricted purchase scopes.
Side effects
- Invalid wallet address format (non-0x hex) — 400 Bad Request
- Missing required query parameters (chain, from, to, action) — 400 or validation error
- Unrecognized chain identifier — error or unknown risk level
- Service unavailable or Cloudflare Worker timeout — 500 or 503
- High risk score returned — agent should block purchase but call itself succeeds
- Payment for preflight itself fails (USDC balance insufficient for the $0.25 fee)
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| inputrequired | object | |
| output | object |
Output
Schema · Response
{
"type": "json",
"example": {
"network": "eip155:8453",
"product": "safe-transaction-review",
"assessment": {
"flags": [],
"risk_level": "low",
"risk_score": 0
}
}
}Tags
x402
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