Reading this as an agent? Start at llms.txt, or resolve a task in one free call: GET /api/find?q=
openapi.json .well-known/x402 /api/pricing /mcpWatch an agent pay its way.
402 → signed auth → verified → receiptOne round trip. The agent asks, the paywall quotes, the wallet signs, the response comes back with a receipt that settles on chain. No checkout, no key, no human in the loop.
❯ pull the latest 10-K risk factors for TSLA and summarise ⏺ agent402_find(q: "sec 10-K filing text") ⎿ edgar-filing-text · $0.004 · POST /api/edgar-filing-text ⏺ agent402_call(edgar-filing-text, { cik: "TSLA", form: "10-K" }) ⎿ HTTP/1.1 402 PAYMENT REQUIRED WWW-Authenticate: Payment realm="agent402" ⎿ signed EIP-3009 USDC authorization → facilitator ⎿ verified · settled · Payment-Receipt: 0x8f2a…c41d ✓ $0.004 settled on Base · 41 risk factors extracted ⏺ agent402_call(answer, { q: "summarise these risk factors" }) ✓ $0.010 settled · 6 themes, 12 citations total spend $0.014 · 2 calls · 0 API keys · 0 signups
Same URL, either dialect
The paywall answers x402 and MPP on the same route. An mppx client gets a WWW-Authenticate: Payment challenge; an @x402/fetch client gets the x402 challenge. Same price, same facilitator, same receipt. The buyer's client picks.
Add it in one line
claude mcp add --transport http agent402 https://agent402.tools/mcp
No wallet? Still works
Pure-CPU tools are payable in compute: a single-use, slug-scoped sha256 proof-of-work the MCP server solves for you in under a second.
Or pay with CPU instead.
no wallet · no signup · runs in this tabThe pure-CPU tools are payable in compute: the server issues a signed sha256 puzzle, you burn a fraction of a second solving it, and the call is served free. This is not a diagram - press the button and your browser will fetch a real challenge from the live server, solve it here, and make a real paid call.
- ·Request a challenge
signed, single-use, scoped to one tool - ·Solve it in your browser
~65k hashes at 16 bits - ·Call the tool, free
hash the challenge, submit the token
# the same three steps, from a shell:
curl -s '/api/pow/challenge?slug=hash'
# solve: sha256("<challenge>:" + nonce) with N leading zero bits
curl -X POST /api/hash -H 'content-type: application/json' -H 'X-Pow-Solution: <token>:<nonce>' -d '{"text":"hello","algo":"sha256"}'
Sell into the agent economy.
free listing · nothing deducted · non-custodialAgents are already buying, and they cannot fill in a signup form. If you run an API - or a site AI crawlers keep scraping for free - the same rails that let them buy let you charge. Money moves buyer wallet → your wallet. Nothing sits in between.
Get routed by the Smart Order Router
Serve x402 challenges, register your origin, and the index crawler picks you up hourly. You get ranked next to 531 of our own tools by match score, then health, then price - and a public leaderboard row once your on-chain volume shows up.
# or paste your origin below - same call, no terminal needed
curl -X POST https://agent402.tools/api/index/register -H 'content-type: application/json' -d '{"origin":"https://api.you.com"}'
Charge AI crawlers per page
Humans browse free; known bots get 402 Payment Required and either pay in USDC or solve a proof-of-work. The open, crypto-native answer to closed pay-per-crawl: no CDN lock-in, no merchant-of-record, no signup.
# express · next.js · cloudflare · proxy · wordpress
npm i agent402-tollbooth
GATE YOUR CRAWLERS →
| Listing fee | $0 |
|---|---|
| Commission | 0% |
| Routing | health-aware |
| Discovery | 4 surfaces |
| How Agent402 earns | buyer-side |
| Cross-chain buyers | Base · Algorand |
6 of 28,876 paid calls (under 0.1%) came through the router, which is the only path Agent402 earns on. Every other paid call went buyer wallet to seller wallet.
The index, not just a seller.
hourly on-chain snapshot · Bazaar → eth_getLogs → aggregate by payToEvery x402 seller we can crawl, ranked by real Base USDC settled volume - not self-reported traffic. include=external excludes us from our own ranking, because a neutral index has to be checkable.
| # | seller | usdc settled | calls | buyers |
|---|---|---|---|---|
| 01 | BlockRun.AI | $27,958.07 | 2,572,489 | 167 |
| 02 | api.botpay.network | $1,155.47 | 14,868 | 2,319 |
| 03 | StableEnrich | $664.42 | 23,881 | 179 |
| 04 | api.m2mcent.com | $188.25 | 1,034 | 2 |
| 05 | x402.twit.sh | $182.28 | 30,230 | 47 |
| 06 | AgentUtility.ai | $128.44 | 4,790 | 22 |
Settled on every rail, not just Base.
calls settled per rail · live from /api/statsAll twelve rails carry real settled traffic, not just the headline one. Buyers pay on the chain they already hold stablecoins on, gas is sponsored on EVM, and the router pays external sellers on that same chain.
What agents actually pay for.
lanes shown · figures are a paid readSettlements are on chain, but which tool an agent bought is not - so this is the one demand signal no block explorer can reconstruct. Here are the lanes agents spend most in. The full per-tool ranking is itself a paid tool.
Questions people and agents ask.
How do I sell my API for USDC per call?
+
Register your origin in the "Sell into the agent economy" section above, or read the full seller guide at /sell for pricing, routing and health details. If your site is not x402-native yet, agent402-tollbooth is an open pay-per-crawl gate you can install instead.
Do I need a wallet to try it?
+
No. The pure-CPU tools are payable in compute: your own machine solves a single-use, slug-scoped sha256 proof-of-work instead of paying, which costs about a second of CPU. A wallet only matters for tools that cost real money to run, and those quote their price in the 402 challenge before anything is charged.
Is it open source, and can I run my own?
+
Yes. The server is AGPL-3.0 and self-hostable; the client SDK, MCP connector and tollbooth packages are MIT. Clone it and run FREE_MODE=true npm start for all tools as an HTTP API plus MCP, with no payments and no keys.
More, including data handling and the OpenAI-compatible gateway: /faq