# Agent402.Tools for agents

500+ tools an agent calls and pays for per request. Base URL: https://agent402.tools

## Start here

- **First call:** web.search: `GET https://agent402.tools/api/search?q=your+query`, $0.01 per call: ranked live web results as JSON (title, URL, snippet, age). For a cited answer, web.answer (`GET /api/answer`, $0.08, model-backed).
- **Access:** No account, no API key. 170 pure-CPU tools run free with proof-of-work and no wallet (listed at `GET /api/pow`); the rest are paid per call in stablecoins (USDC, and USDG on Robinhood Chain) over x402 or MPP (Tempo settles in its own stablecoins), quoted in the 402 before you pay.
- **Use when:** You need live web data newer than your training, or a capability your sandbox lacks (a headless browser, OCR, PDF and media processing, market data); not when you already hold the URL (read it with `POST /api/extract`, or browser.render for JavaScript pages) or the work is a local computation you can run yourself. When a call fails: [/agents.md](#when-a-call-fails).

## When a call fails

- **If a call fails:** On x402 a call the tool fails is not charged: settlement runs after the tool and only for a response under 400, and no `PAYMENT-RESPONSE` header means nothing settled. One exception: a transfer that lands after a timed-out settle, or a disconnect during settle, is booked as a refund owed and repaid after on-chain proof. On MPP a Tempo push payment is sent before the call, so a failure there is booked as a refund owed.
- **If an answer is lost:** On an EVM x402 payment, re-send the same request with the same signed payment inside the replay window for the first answer (`X-Replayed-Answer: 1`) with no second settlement; not on identity-bound routes, routes with a lasting effect or streamed calls.
- **To retry:** Send an `Idempotency-Key`: the same key with the same credential (an x402 payment, a proof-of-work token or a credits key), route and body returns the first 200 answer (up to 1 MB) without a second charge.
- **If a call is slow:** On a slow route, send the paid call with `Prefer: respond-async` for a 202 and a job link, then poll `GET /api/jobs/{id}` (free); payment settles only on the delivered answer.

## Connect

- **Plain HTTP:** call any route. An unpaid call answers HTTP 402 with the price and both offers (x402 `PAYMENT-REQUIRED` and MPP `WWW-Authenticate: Payment`); pay from your wallet and send the call again with the payment.
- **MCP, hosted (streamable HTTP, nothing to install):** `https://agent402.tools/mcp`. The proof-of-work tools run free there with no wallet.
- **MCP over stdio, with a wallet for paid tools:** `npx -y agent402-mcp@0.13.27` with `AGENT_KEY` set to a new wallet holding a few dollars of USDC, never your main wallet.
- **Buyer SDK:** `npm install agent402-client` resolves a task to a tool and calls it: proof-of-work is solved for you on the free tools, and paid tools use the payment-aware fetch you pass in.

## Pay

- **x402:** USDC on Base, Solana, Polygon, Arbitrum, Monad, Celo, Avalanche, Sei, Optimism, Arc, Stellar, or Algorand - or USDG on Robinhood Chain. Gas is sponsored on the EVM chains, so a wallet needs only the stablecoin.
- **MPP:** USDC.e or PathUSD natively on Tempo, USDC on Base or Celo, or a card on routes priced $0.50 or more, on the same 402.
- **Proof-of-work:** 170 pure-CPU tools take a sha256 puzzle instead of payment. Get one at `GET https://agent402.tools/api/pow/challenge?slug=hash` and send the solution as `X-Pow-Solution`.
- **Prices:** most tools $0.001 to $0.02 per call; every price is in `https://agent402.tools/api/pricing` and quoted in the 402 before you pay.

## Find more

- `GET https://agent402.tools/api/find?q=<task>`: the best-matching tools for a task, with route, price, input schema and a ready example.
- [/llms.txt](https://agent402.tools/llms.txt) and [/llms-full.txt](https://agent402.tools/llms-full.txt): the full index, every route with its price.
- [/openapi.json](https://agent402.tools/openapi.json): every input and output schema.
- [/.well-known/x402](https://agent402.tools/.well-known/x402): the x402 discovery document.
- [/status](https://agent402.tools/status): live health, measured from outside production.

Maintained by Havok Holdings LLC.