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Pay-per-call APIs for AI agents

Best x402 APIs for AI agents (2027 list)

x402 API directory · x402 Bazaar alternatives · Pay-per-call MCP tools

1,137 settlement-verified APIs, 2,335 listed. 29702 endpoints in total. AI agents discover via MCP and pay per request in USDC on Base, Solana or Algorand. Like the browsable grid, the rows below show settlement-verified listings only.

Verification

  • $0.05 /v1/au/climate-disclosure-check · Australia Climate Disclosure Coverage Check (AASB S2) · Checks if an Australian entity is in Group 1, 2 or 3 for mandatory climate reporting (AASB S2). Returns JSON with… · 1 route verified
  • $0.01 /v1/token/verdict · DevX Token Check · Token safety verdict before an agent buys or accepts a token: honeypot / sell simulation, owner privileges… · 1 route verified
  • $0.005 /imo · IMO ship number · IMO ship identification checksum. Does not confirm the ship or a name. · 1 route verified

See all Verification

Finance

  • $0.005 /api/board/name · Coil stock read · Coil's score and setup for one US stock or ETF, from a board of 650+ names re-scored about every 5 minutes in market… · 1 route verified
  • $0.005 /kelly · Trade Math Kelly EV · Kelly / EV / fee-adjusted edge calculator for trading agents. Pure compute — you supply p_yes and venue ask/bid; no… · 1 route verified
  • $0.05 /api/lending-rates · Money Reactor Lending Rates Compare · Supply/borrow rates right now across Aave, Compound and more (DeFiLlama): market, chain, asset, supply APY, borrow APY… · 1 route verified

See all Finance

Data

  • $0.002 /base32 · Base32 length check · RFC 4648 or Crockford base32 alphabet and length check. Decoded bytes are not returned. Unknown input returns 404 and… · 1 route verified
  • $0.01 /v1/nsw-da/applications · NSW Planning Data · NSW (Australia) development applications, CDCs and property planning reports: zoning, height, FSR and nearby building… · 1 of 11 routes verified
  • $0.05 /m2m/intelligence · Syntalium Market Intelligence · Closed-candle crypto market scans for AI agents, with market states, reason codes, freshness and SNAP proof pointers… · 1 route verified

See all Data

Tools

  • $0.09 /v1/quick · DevX API Health Audit - Quick · Quick API health check for agents: POST one public API endpoint URL, get a verdict, latency/reliability over 3 samples… · 1 route verified
  • $0.01 /v1/netintel · Beggar Bot x402 Agent Utilities · 10 pay-per-call agent utilities, $0.01 USDC each on Base via x402: /v1/verify (USDC payment landed?), /v1/risk… · 1 route verified
  • $0.01 /v1/audit · AgentSiteAudit · Website audit API for AI agents: 69 checks across security, SEO, TLS, performance, accessibility, DNS and agent… · 1 route verified

See all Tools

Intelligence

  • $0.05 /sentiment · Indonesia News Sentiment Index · Indonesia news sentiment index: one auditable 0-100 number per beat instead of 25 headlines. Returns label… · 1 route verified
  • $0.05 /api/v1/web/intelligence · VALUNARIA Web Intelligence · Source-bound structured intelligence for AI agents. Analyze a public URL to extract key facts, entities and insights… · 1 route verified
  • $0.09 /tiebreaker (provider example body) · Tiebreaker · Tiebreaker provides Autonomous Agents with Human Level Reasoning and Decision Making through a proven decision… · 1 route verified

See all Intelligence

Live listings that we have not paid for yet are not hidden, only unselected by default: browse every live listing, verified and not.

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Frequently asked questions

How does an agent pay for an API here?

Call the provider's endpoint unpaid. It replies HTTP 402 with the price, wallet and network. Your agent signs a USDC payment authorisation, retries the request with the signed payment attached, and gets the response. No API key or account is needed. Discovery is free; payment only happens when your agent calls a provider directly.

What does settlement-verified mean?

It means PayAPI Market paid a real call on one specific route from its own wallet, got real product back, and there is an on-chain USDC receipt that anyone can check, on Base for most routes. It is not a health ping. Verification covers the route we paid, not the whole listing: a listing with 10 routes and one paid route reads 1 of 10 routes settlement-verified.

Do I need an API key?

No. The payment is the authentication. Your agent signs a per-call USDC payment, and the provider's endpoint validates it. There is no account, API key, OAuth flow or signup. The agent needs a wallet holding USDC on Base, but no keys from any individual provider.

How much does it cost to use an API?

Each provider sets its own price per call, shown on the listing. Prices start at fractions of a cent, and the exact USDC amount arrives in the 402 challenge before any money moves. There are no subscriptions, minimums or monthly fees. Your agent pays only for the calls it makes, in USDC on Base, and you can cap spend by funding a dedicated wallet with a bounded balance.