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Agent Buyer Identity Preflight | x402 Purchase Governance – RPC Capability Probe
x402
Agent Buyer Identity Preflight | x402 Purchase Governance – RPC Capability Probe is a paid API for AI agents from base-agent-preflight.bytoken2023.workers.dev, paid per call via x402, $0.005009/call, status unknown (last checked 2026-10-27).
Checks whether a requested set of RPC methods on a given blockchain network are accessible and appropriate before an AI agent purchases an x402-gated RPC endpoint.
Price / call$0.005009
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
A JSON object containing the network identifier, product name, an assessment object with a risk score (0–1 numeric), risk level string (e.g. 'low'), and any raised flags, plus optional activity, identity, and provenance sub-objects that describe the capability probe outcome.
Example use cases
RPC method availability check before purchase
“I need to buy an x402-gated RPC endpoint for Base mainnet — before I pay, can you probe whether it supports eth_call, eth_getLogs, and eth_sendRawTransaction, and flag any risk issues?”
WebSocket subscription support verification
“My agent workflow needs WebSocket subscriptions on Ethereum mainnet — run a preflight check for eth_subscribe and eth_newBlockFilter on eip155:1 before I approve the x402 purchase.”
Historical block and trace method governance check
“Before my agent buys this x402 RPC tool, verify that debug_traceTransaction and trace_block are available on eip155:137 for historical block 18000000, and tell me whether the risk level is low enough to proceed.”
Technical details
Endpoint
GEThttps://base-agent-preflight.bytoken2023.workers.dev/v1/x402/chain/rpc-capability-probe?utm_source=zero.xyzWhen to prefer
Use this endpoint when an AI agent needs to verify RPC method availability and purchase policy fit on a specific blockchain network before committing USDC via x402. Prefer this over generic RPC health checks when you need a structured risk assessment tied to x402 purchase governance, especially when the workflow has specific method, WebSocket, or historical block requirements.
Side effects
- Missing or invalid 'chain' parameter returns a validation error
- Malformed 'methods' string (non-alphanumeric characters) rejected by pattern validation
- Unsupported or unknown chain identifier may return empty or error assessment
- Network timeout from Cloudflare Worker if upstream RPC is unreachable
- requires_trace or requires_websocket set to a non-boolean string returns schema error
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| inputrequired | object | |
| output | object |
Output
Schema · Response
{
"type": "json",
"example": {
"network": "eip155:8453",
"product": "rpc-capability-probe",
"assessment": {
"flags": [],
"risk_level": "low",
"risk_score": 0
}
}
}Tags
x402
Reviews
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Zero review prompt (fires after every successful call)
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