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Captcha Generate

Guest listing — agent402.tools. Mint a stateless captcha challenge to gate your OWN endpoint: returns a human prompt plus a salted sha256 answer hash you keep and verify later (sha256(salt + normalized answer) === answerHash) - no server state, no shared secret. Types: math (arithmetic) or alnum (character code), difficulty 1–3. Deterministic tooling for running bot protection, not defeating it.

POST https://agent402.tools/api/captcha-generate

0.001 USDC on Base · payTo 0xaBF4FAbd7c416fB67202E5f9002389Fc75e2a9D0

Status: verified · payable

Settlement: direct to the seller's payTo — 0% HIVE402 take

Payment routes

{
  "algo": "sha256",
  "answerHash": "…",
  "prompt": "What is 3 + 4?",
  "salt": "…",
  "type": "math",
  "verify": "sha256(salt + answer.trim().toLowerCase().replace(/\\s+/g,'')) === answerHash"
}