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Riddle with Checkable Answer
x402
Riddle with Checkable Answer is a paid API for AI agents from flat-rate-llm.kikoribera03.workers.dev, paid per call via x402, $0.0025/call, status unknown (last checked 2026-09-15).
Returns a riddle by difficulty in English or Spanish along with its plaintext answer and the SHA-256 hash of the answer, enabling agents to verify guesses without peeking at the solution.
Price / call$0.0025
Success—
StatusUnknown
How this service works
60 paid endpoints with no metering, no API key and no account. Each endpoint has one flat price per call, whatever the size of the request: LLM completions with automatic failover across several large models, read-only EVM tooling over Base, Ethereum, Polygon, Arbitrum and Optimism, and pure crypto utilities that touch no network.
Output
Returns a JSON object with the riddle text, its difficulty level, a unique riddle ID, the plaintext answer, the SHA-256 hash of the answer in lowercase, and a 'howToCheck' field explaining how to verify a guess against the hash — enabling answer validation without spoiling the solution.
Example use cases
Agent self-quizzes on riddles
“Get me a medium-difficulty riddle in English and let me guess the answer — I want to check my guess against the hash without seeing the real answer first.”
Spanish trivia bot for kids
“Fetch me an easy riddle in Spanish for a kids quiz — and give me the answer hash so the bot can check if the child got it right without just showing them the answer.”
Avoid repeats in riddle game
“I need a hard riddle in English that isn't any of these I've already used: riddle-001, riddle-042, riddle-077 — use seed 'game-session-9' so I get a consistent one for this session.”
Technical details
Endpoint
POSThttps://flat-rate-llm.kikoribera03.workers.dev/v1/content/riddleWhen to prefer
Choose this endpoint when you need a riddle that comes with a cryptographic answer hash, allowing an agent or user to verify their guess without reading the solution first — a capability no generic riddle API provides. Also prefer it when you need deterministic riddle retrieval via a seed, multilingual (English/Spanish) support, or deduplication across sessions via the exclude list.
Side effects
- Invalid difficulty value (not easy/medium/hard) may return an error or default behavior
- Invalid language code (not 'en' or 'es') may fall back to English or return an error
- All riddles excluded via the exclude list may result in no riddle returned
- Payment failure (402) if USDC micropayment is not properly handled
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| seed | string | Same seed always returns the same riddle. |
| exclude | array | Ids already seen, comma-separated in a GET. |
| language | string | en | es. Defaults to en. |
| difficulty | string | easy | medium | hard. Omit for any. |
Output
Schema · Response
| Field | Type | Description |
|---|---|---|
| id | string | |
| answer | string | |
| riddle | string | |
| difficulty | string | |
| howToCheck | string | |
| answerSha256 | string |
Tags
x402
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