Agent Trust, Verification & Machine-Payable Data Utilities API
Machine-payable verification and trust services for autonomous agents on x402 (USDC on Base). An independent quality-control layer for agents that buy from other agents: submit a third-party output and receive ONE Ed25519-signed, SHA-256-reproducible verdict covering schema, freshness, internal consistency, evidence, and reference-checkable accuracy. Also: conformance-audit any x402 endpoint against a versioned published standard; conformance-check any issuer's signed receipt or payment offer; compute deterministic issuer reputation from signed observation history; govern agent spend with atomic reserved leases, settle and receipts; attest execution readiness and containment; verify C2PA-style content provenance against a content hash; seal caller-supplied data snapshots with honest freshness tiers; store and query a signed evidence vault; prove identity control; threat-model tool permissions; grade model output pairs against a deterministic rubric; and extract invoices, SEC filings, documents and redacted PII. Every paid route answers HTTP 402 with a USDC-on-Base envelope; every signature is verifiable free at a companion route. Deterministic engines only: no LLM inference, no invented scores, and any check that cannot be assessed is named honestly instead of guessed.
1 of 43 routes settlement-verified · $0.02–$2 USDC/request · 43 endpoints · Data · base network · x402 protocol
Verified routes
GET /v1/social/search· $0.02 · 2026-10-17 · receipt
Other routes are unverified.
Networks: Base (settlement-verified)
Discovery is free. Agents search the catalogue here. Payment happens on the listing 402, not on PayAPI.
url https://payapi.market/mcpAbout this API
Agent Trust, Verification & Machine-Payable Data Utilities API is listed in the Data category with pricing at $0.02–$2 USDC/request. One route has been settlement-verified by PayAPI Market on 2026-10-17. View receipt on Basescan.
Payments settle on base in USDC via the x402 protocol. AI agents discover this API through the PayAPI Market MCP server and pay per request without API keys or accounts.
This API exposes 43 endpoints. Only the verified route has been tested by PayAPI Market. Other routes are unverified.
How to call this API
Every protected route returns HTTP 402 with x402 payment requirements. An agent pays the stated USDC amount on Base and retries with the payment header. No API keys, no accounts. Browse the marketplace or list your own API.
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