x4PayAPI Market

New verified APIs on PayAPI Market: week of 26 Oct 2026

Since 2026-10-24 we paid to verify 20 new APIs on PayAPI Market. Here are five of them, and what each verification actually proved.

What "verified" means here

We do not take a provider's word for it. For every API on this list we sent a real payment in USDC on Base, from our own wallet, and checked that the response contained genuine data.

Each check uses an input the provider did not advertise, so a canned example response cannot pass. Where the underlying data is public, we compare the paid response against the original source field by field.

The APIs

Calibration Court from SML

Calibration scoring and recalibration for decision models and label sets. POST /api/v1/recalibrate costs $0.01 and POST /api/v1/calibrate-labels costs $0.05, USDC on Base via x402.

  • Provider: ScriptMasterLabs
  • Price: $0.01 per request
  • Verified route: POST /api/v1/recalibrate {"model":"jev-1.13.0","prob":0.72}
  • Settlement: 0x6514e9b027fb… on Base

Money Reactor Unit Converter (Length Weight Temp)

Unit converter across length, weight and temperature (mm..mi, mg..st, C/F/K) - deterministic physical math for logistics and IoT agents. Settles in USDC via x402 (Base).

  • Provider: Money Reactor
  • Price: $0.10 per request
  • Verified route: GET /api/unit-convert?value=100&from=cm&to=in
  • Settlement: 0xdab203763109… on Base

Money Reactor Request Headers Echo

Request headers echo: exact JSON of what your HTTP client actually sends - debug auth, signatures and x402 payments in seconds. Settles in USDC via x402 (Base).

  • Provider: Money Reactor
  • Price: $0.10 per request
  • Verified route: GET /api/headers-echo
  • Settlement: 0xc7d192a3a609… on Base

Money Reactor Roman Numerals Converter

Roman numerals bidirectional converter (1..3999) with strict validation - document numbering, stylized content and legal citations. Settles in USDC via x402 (Base).

  • Provider: Money Reactor
  • Price: $0.10 per request
  • Verified route: GET /api/roman?value=2026
  • Settlement: 0x9b3725436817… on Base

Money Reactor Geo Distance Calculator

Great-circle distance between two coordinates (haversine): km, miles, nautical miles plus initial bearing - logistics and geo-fencing math. Settles in USDC via x402 (Base).

  • Provider: Money Reactor
  • Price: $0.10 per request
  • Verified route: GET /api/geo-distance?lat1=51.5&lon1=-0.12&lat2=48.85&lon2=2.35
  • Settlement: 0x7eaf1a7961d3… on Base

How an agent finds these

Every verified API is queryable as JSON. An agent does not need to read this post, or the website, to find them.

curl "https://payapi.market/agent/list"
curl "https://payapi.market/agent/search?q=property"

Those endpoints return only live listings, and by default only ones we have paid to verify.

The current catalogue

PayAPI Market lists 943 live APIs, of which 932 are settlement-verified, across 5 categories: Data, Finance, Intelligence, Tools, Verification.

By · Published 2026-10-25 · Last updated October 25, 2026 · 2 min read