Developer tool APIs for AI agents, paid per call
Paid APIs for small computations and utilities agents call while working, that an AI agent can call and pay for on the spot with x402, in USDC. We list 244, from 157 sellers. 213 are live and asking for payment correctly, and 95 delivered when we bought from them with real money. The typical price is $0.005 a call (half ask between $0.002 and $0.01).
The APIs
The first 30, in the same order as our search (GET /v1/discover?category=compute.tools, testnets left out): verified first, then probe score, then price.
Nobody can pay for a place here. Each name opens the full record: every check, every purchase, with dates.
| API | price | status | when we bought |
|---|---|---|---|
| CedarProof HTTP/JSON response classificationfree samplecedarproof-diagnostics.cedarproof-lab.workers.dev | $0 | verified | probes pass; not bought yet |
| Automated /llms.txt & Agent Documentation Context Compiler (llms-generator)free samplellms-generator-72343955726.us-central1.run.app | $0.01 | verified | bought, delivered 2026-10-30 |
| Agent03 OpenAPI structural comparisonfree samplefirstdollar-contract-paid.worker.beacon.host | $1.00 | verified | probes pass; not bought yet |
| PageProof: PDF text with page referencesfree samplepageproof.alert-crab-1890.chatgpt.site | $0.005 | verified | bought, delivered 2026-10-06 |
| FreeTier Agent API: mcp-serversfree samplefreetier-agent-api.pages.dev | $0.001 | verified | bought, delivered 2026-10-30 |
| LAST ONE Original Low-poly GLB Generator — Base USDCfree samplevm5-openapi-x402.onrender.com | $0.05 | verified | probes pass; not bought yet |
| keyronne.com/api/color | $0.001 | verified | bought, did not deliver |
| api.getsly.ai/x402/demo/test | $0.001 | verified | bought, delivered 2026-09-25 |
| twin.unykorn.org/xrpl-drops | $0.001 | verified | probes pass; not bought yet |
| api.solenrich.com/entrypoints/parse-transaction/invoke | $0.001 | verified | probes pass; not bought yet |
| tools.ipintel.ai/json-schema-validator | $0.001 | verified | bought, delivered 2026-10-11 |
| tools.halowerk.com/v1/email/validate | $0.001 | verified | bought, delivered 2026-11-01 |
| api.avedaris.com/v1/paid/url-parse | $0.001 | verified | bought, delivered 2026-11-01 |
| x402.forgemesh.io/metric-imperial-convert | $0.001 | verified | bought, delivered 2026-11-01 |
| api.avedaris.com/v1/paid/uuid-validate | $0.001 | verified | bought, delivered 2026-11-01 |
| api.avedaris.com/v1/paid/querystring-parse | $0.001 | verified | bought, delivered 2026-11-01 |
| nzdata.zakwins.workers.dev/nz/validate/phone | $0.001 | verified | bought, delivered 2026-11-01 |
| api.agent-payload-tools.workers.dev/json-validate | $0.001 | verified | bought, delivered 2026-11-01 |
| digitalworkerapi.com/v1/tools/json-repair | $0.001 | verified | bought, delivered 2026-11-01 |
| toolshed.lemon-agent.dev/convert/json-yaml | $0.002 | verified | bought, delivered 2026-10-20 |
| toolshed.lemon-agent.dev/convert/csv-json | $0.002 | verified | bought, delivered 2026-10-11 |
| toolshed.lemon-agent.dev/convert/yaml-json | $0.002 | verified | bought, delivered 2026-10-11 |
| semver.openverbs.com/v1/parse | $0.002 | verified | probes pass; not bought yet |
| api.aventtech.com/convert/color | $0.002 | verified | probes pass; not bought yet |
| timecode.openverbs.com/v1/convert | $0.002 | verified | probes pass; not bought yet |
| checkdigit.openverbs.com/v1/imei | $0.002 | verified | probes pass; not bought yet |
| geospatial.openverbs.com/v1/utm | $0.002 | verified | probes pass; not bought yet |
| 402.com.tr/api/x402/iban-check | $0.002 | verified | bought, delivered 2026-10-11 |
| Forest Web: /openapi/payload-validatehttp--forest-gas-station-mainnet--lcjl27p8lmjs.code.run | $0.002 | verified | probes pass; not bought yet |
| numeral.openverbs.com/v1/radix | $0.002 | verified | probes pass; not bought yet |
All of them, as data: api.nohumans.directory/v1/discover?category=compute.tools&limit=50. Live figures, as of 2026-11-07 02:39 UTC.
For agents
Search this kind of API from your agent, free, no key. MCP server https://api.nohumans.directory/mcp, tool
find_paid_service with {"category": "compute.tools", "query": "what you need"}, or REST:
GET https://api.nohumans.directory/v1/discover?category=compute.tools&q=<what you need>
Before paying any endpoint, check its record: how, and when not to pay.
Sell one
157 sellers already list Developer tool APIs here, at a typical $0.005 a call. Agents choose on evidence: a free sample, inputs they can read, and a purchase that delivered. Check yours free and list it · what x402 APIs charge and earn · build one with one prompt.
Other kinds of API
- Crypto data APIs
- Web data APIs
- LLM APIs
- Geolocation and maps APIs
- Market data APIs
- Image and media generation APIs
- Weather APIs
- Currency exchange rate APIs
- News APIs
- Stock market data APIs
- Search APIs
- Intelligence and analysis APIs
- DeFi data APIs
- Derivatives and funding rate APIs
- Validation APIs
- Macroeconomic data APIs
- Social media data APIs
- On-chain data APIs
- Verification APIs
- GitHub data APIs
- AI inference APIs
- Web scraping APIs
- Research data APIs
Figures count active listings on mainnet, tunnels and testnets excluded; prices are the live payment requests of verified listings on Base. Records are dated evidence about how an endpoint behaved, not a guarantee. How we check.