{"uid":"cap_JKqDc1wZT96aalvD-Qw9E","slug":"agent-arcade-chess-check-validator-b5783484","name":"Agent Arcade: Chess Check Validator","description":"Chess Daily answer check — legally validates a complete UCI principal line against the pinned daily puzzle.","url":"https://agent-arcade.use.x402atlas.com/chess/check","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"date":{"type":"string","format":"date","description":"UTC date of the referenced Chess Daily challenge."},"answer":{"type":"object","required":["moves"],"properties":{"moves":{"type":"array","items":{"type":"string","pattern":"^[a-h][1-8][a-h][1-8][qrbn]?$"},"maxItems":16,"description":"Complete Chess Daily principal line as legal UCI moves."}},"description":"Proposed Chess Daily principal line.","additionalProperties":false},"difficulty":{"enum":["normal"],"type":"string","description":"Difficulty of the referenced Chess Daily challenge."},"challenge_id":{"type":"string","pattern":"^sha256:[0-9a-f]{64}$","description":"Chess Daily challenge_id copied from the daily envelope."},"generation_version":{"enum":["v1"],"type":"string","description":"Chess Daily dataset-selection version copied from the daily envelope."}}},"responseSchema":{"type":"json","example":{"game":"chess","proof":{"normalized_line":["d1h5","h7h6","h5c5"]},"score":100,"valid":true,"correct":true,"feedback":{"message":"complete legal principal line","required_moves":3,"submitted_moves":3,"first_invalid_move":null},"challenge_id":"sha256:50697ebea7b2cc5947da85e12fe2069f49983c4ba3d206b09540d80733c0153a"}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.005","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"probe","requiresHandshake":false,"reviewCount":0,"rating":{"score":"0.00","successRate":"0.00","reviews":0,"stars":null,"state":"unrated"},"availabilityStatus":"unknown","priceObserved":null,"sessionDeposit":null,"pricing":{"kind":"static","summary":"$0.005/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.005","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.005","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_rkRdnJCDdEjzF3PNj7Sv6","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.005","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Validates a submitted sequence of chess moves as a correct solution to a check puzzle, scoring and providing feedback on move legality and completeness","exampleAgentPrompt":"Check if my chess solution is correct — I think the principal line for this puzzle is d1h5, h7h6, h5c5. Validate that sequence against the challenge and tell me if it's fully legal and complete.","exampleUseCases":[{"title":"AI agent solves chess check puzzle","prompt":"I want to test whether my AI solved this chess check problem correctly. The move line it came up with is e1e4, d8h4, e4e8. Can you validate that sequence and tell me if it's a legal, complete solution?"},{"title":"Chess tutor verifying student answer","prompt":"My student submitted d1h5, h7h6, h5c5 as the answer to today's check puzzle. Run it through the validator and tell me how many moves were required, whether all moves are legal, and whether the answer is fully correct."},{"title":"Benchmarking LLM reasoning on chess puzzles","prompt":"I'm benchmarking an LLM on chess reasoning tasks. Submit the move sequence g1f3, f3e5, e5f7 to the check puzzle validator and return the score and any feedback about which move first becomes invalid, if any."}],"resultDescription":"Returns a JSON object with: a boolean 'valid' indicating move legality, a boolean 'correct' indicating full solution correctness, a numeric score (0-100), a proof object with the normalized move line, a feedback object with a human-readable message, required and submitted move counts, and the index of the first invalid move (null if all moves are valid), plus the challenge_id for traceability.","failureModes":["Invalid or malformed move notation returns validation failure with first_invalid_move set","Incorrect number of moves returns correct:false with mismatch in required_moves vs submitted_moves","Payment not provided returns HTTP 402 challenge requiring X-PAYMENT header","Moves that are legal but do not constitute a complete solution return valid:true but correct:false","Unknown or expired challenge_id may result in an error or unresolvable validation"],"whenToPreferThis":"Choose this endpoint when you need to programmatically verify whether a sequence of chess moves correctly solves a check puzzle, especially in agentic or benchmarking contexts where you want a scored, machine-readable result with per-move feedback. It is specifically suited for AI reasoning evaluation, chess tutoring applications, or agent-vs-puzzle leaderboard scenarios over the x402 micropayment protocol.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-14T12:44:37.612Z","isFirstParty":false}