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x402index Verdict — API Listing Vetting & Demand Scoring
x402
x402index Verdict — API Listing Vetting & Demand Scoring is a paid API for AI agents from api.firstmention.uk, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-29).
Vets one or more x402-indexed API listings for demand, reliability, and seller credibility, returning a confidence-scored verdict and price-tier standing among peers.
Price / call$0.01
Success—
StatusUnknown
How this service works
Pay-per-call HTTP APIs, paid with x402 in USDC on Base (eip155:8453): agentkit, api-change-check, basedue, basewatch, chainread, check-sanctions, chgwatch, company-facts, composite, edgar, feednews, pageaudit, solcheck, token-dd, txpreflight, walletcheck, webmd, webread, websearch, x402index. Each operation describes its service.
Output
Returns a JSON object containing: a 'verdict' label (e.g. 'proven seller'), a 'demand' object with tier classification and 30-day distinct payer count, a 'confidence' rating (e.g. 'high'), and 'price_standing' showing how many tag peers exist and the listing's price percentile among them.
Example use cases
Pre-integration trust check on a single API
“I found this x402 API listing at https://api.firstmention.uk/s/webread/fetch — can you check its verdict, demand tier, and confidence score before I start paying for calls?”
Ranking a shortlist of candidate APIs
“I have three x402 API URLs I'm considering for my agent's search capability — can you rank them by demand and tell me which one is the proven seller with the best price standing among its peers?”
Discovering top-demand APIs by tag
“Find me up to 10 x402 APIs tagged 'edgar' that have had at least 20 distinct payers in the last 30 days, ranked by demand tier.”
Technical details
Endpoint
GEThttps://api.firstmention.uk/s/x402index/verdict?utm_source=zero.xyzWhen to prefer
Use this endpoint when an AI agent needs to programmatically vet or compare x402 pay-per-call API listings before committing to integration — especially when choosing between multiple candidates or verifying that a listing has real, sustained demand. Prefer this over manual inspection or generic API directories when operating within the x402/Base USDC payment ecosystem.
Side effects
- Unknown or uncrawled listing URL returns low-confidence or null verdict
- Tag with no matching listings returns empty candidates
- limit out of range (must be 1–25) causes validation error
- resources array exceeding 25 items rejected
- Missing both resource and tag fields returns schema validation error
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| inputrequired | object | |
| output | object |
Output
Schema · Response
{
"type": "json",
"example": {
"demand": {
"tier": "high demand",
"payers_30d": 2402
},
"verdict": "proven seller",
"confidence": "high",
"price_standing": {
"tag_peers": 873,
"percentile": 62
}
}
}Tags
x402
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