x402 Demand Provenance Check
$0.05/callPer-analysisSeparate candidate demand from owner-funded and duplicate x402 activity.
POST /api/agent-services/x402-provenance/checkAnswer-engine brief
Canonical answer for x402 Demand Provenance Check
- Direct answer
- x402 Demand Provenance Check is a deterministic x402 API for AI agents. Separate candidate demand from owner-funded and duplicate x402 activity.
- When to use
- Use it when an agent needs a repeatable computed result with evidence instead of asking an LLM to improvise a number or risk decision.
- Inputs
- resourceUrl, payTo, ownerWallets, payments
- Outputs
- status, service, signal, confidence, scope
- Pricing
- $0.05 per call, paid over x402 in USDC on Base. No API key is required.
- Citation target
- https://hermesplant.com/agent-services/x402-provenance
What it does
Deterministic provenance analysis for caller-supplied x402 payment records. Excludes duplicate transaction hashes, separates declared owner wallets from candidate external payers, measures concentration and evidence coverage, and states limitations explicitly. It does not fetch the chain or claim wallet independence.
- Excludes duplicate transaction hashes and declared owner wallets
- Measures payer independence, concentration, coverage, and freshness
- Caller-supplied evidence stays explicitly unverified
Example request
POST /api/agent-services/x402-provenance/check
{
"resourceUrl": "https://hermesplant.com/api/agent-services/action-safety/quick",
"ownerWallets": [
"0x1111111111111111111111111111111111111111"
],
"payments": [
{
"payer": "0x2222222222222222222222222222222222222222",
"txHash": "0xaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa",
"occurredAt": "2026-07-16T12:00:00Z"
}
]
}Example response (HTTP 200)
Deterministic — the same inputs always return the same audited output.
{
"status": "analyzed",
"service": "x402-demand-provenance",
"signal": "credible_candidate_pattern",
"confidence": "moderate",
"scope": {
"recordSource": "caller_supplied"
},
"metrics": {
"analyzedPayments": 2,
"ownerFundedCalls": 0,
"uniqueCandidateExternalPayers": 2,
"topPayerShare": 0.5
},
"limitations": [
"Caller-supplied records are not independently verified onchain."
]
}Input schema
Top-level request fields. Nested shapes are shown in the example above and the OpenAPI spec.
| Field | Type | Required | Description |
|---|---|---|---|
| resourceUrl | string | — | |
| payTo | string | — | Optional expected Base/EVM recipient address. |
| ownerWallets | array | Yes | Known operator wallets to exclude from external-demand candidates. |
| payments | array | Yes |
How to call it over x402
- 1. Send the request. The first unpaid call returns HTTP 402 with an x402 payment challenge — $0.05, USDC on Base, and the recipient.
- 2. Pay per call. Your x402 client signs the USDC payment and retries automatically — no API key, no account, no subscription. New to x402?
- 3. Read the result. HTTP 200 returns the computed values plus evidence-backed findings.
With the x402 fetch client (Node / TypeScript)
import { wrapFetchWithPayment } from "@x402/fetch";
import { privateKeyToAccount } from "viem/accounts";
const account = privateKeyToAccount(process.env.AGENT_WALLET_KEY);
const pay = wrapFetchWithPayment(fetch, account); // USDC on Base
const res = await pay("https://hermesplant.com/api/agent-services/x402-provenance/check", {
method: "POST",
headers: { "content-type": "application/json" },
body: JSON.stringify({
"resourceUrl": "https://hermesplant.com/api/agent-services/action-safety/quick",
"ownerWallets": [
"0x1111111111111111111111111111111111111111"
],
"payments": [
{
"payer": "0x2222222222222222222222222222222222222222",
"txHash": "0xaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa",
"occurredAt": "2026-07-16T12:00:00Z"
}
]
}),
});
const result = await res.json();Inspect the 402 with curl
curl -i -X POST https://hermesplant.com/api/agent-services/x402-provenance/check \
-H "content-type: application/json" \
-d '{"resourceUrl":"https://hermesplant.com/api/agent-services/action-safety/quick","ownerWallets":["0x1111111111111111111111111111111111111111"],"payments":[{"payer":"0x2222222222222222222222222222222222222222","txHash":"0xaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa","occurredAt":"2026-07-16T12:00:00Z"}]}'
# → HTTP/1.1 402 Payment Required (x402 challenge: price, USDC asset, Base network, recipient)
# → sign the USDC-on-Base payment and retry to receive HTTP 200Prefer no wallet? Get a free API key (250 calls/mo) and send it as X-API-Key instead of signing an x402 payment — the same call, no crypto, ideal for looping over many records.
Prefer zero code? This endpoint is also exposed as a tool on the Hermes Plant MCP server, so an MCP-capable agent can call it with its own x402 wallet.
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One signed preflight for an autonomous x402 payment: WalletGuard counterparty screening, Payment Policy challenge validation, and structured evidence verification.
CashflowLens return and DCF analytics plus PortfolioGuard concentration and risk scoring in one paid call, with structured internal evidence and a tamper-evident signed receipt.
Need a calculator that isn’t here yet? contact@hermesplant.com