{"uid":"cap_B8kyUUlaWmbYCPt6Z4sHv","slug":"saylor-innovations-chess-position-evaluator-ddaa4c09","name":"Saylor Innovations Chess Position Evaluator","description":"Chess Position Evaluation (Stockfish via Lichess cloud) — Games","url":"https://saylorinnovations.com/api/chess/eval?utm_source=zero.xyz","method":"GET","headers":{},"bodySchema":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["input"],"properties":{"input":{"type":"object","required":["type","method"],"properties":{"type":{"type":"string","const":"http"},"method":{"enum":["GET","POST","PUT","PATCH","DELETE","HEAD"],"type":"string"},"queryParams":{"type":"object","properties":{"fen":{"type":"string","description":"position in FEN (query)"}}}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string","const":"json"},"example":{"type":"object","required":["found"],"properties":{"depth":{"type":"number"},"found":{"type":"boolean"},"lines":{"type":"array","items":{"type":"object"}}}}}}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.001","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":"$0.001/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.001","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.001","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_2Phv34mmUBz5M7q5rHFDl","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.001","costPer":"request","priority":0,"asset":"EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Evaluates a chess position given in FEN notation using Stockfish via the Lichess cloud engine, returning analysis lines and depth","exampleAgentPrompt":"Can you evaluate this chess position for me: rnbqkbnr/pppppppp/8/8/4P3/8/PPPP1PPP/RNBQKBNR b KQkq e3 0 1 — I want to see the best lines according to Stockfish.","exampleUseCases":[{"title":"Opening theory verification","prompt":"I'm studying the Sicilian Defense and want to know what Stockfish thinks about this position after 1.e4 c5 — can you evaluate the FEN rnbqkbnr/pp1ppppp/8/2p5/4P3/8/PPPP1PPP/RNBQKBNR w KQkq c6 0 2 and show me the top engine lines?"},{"title":"Endgame accuracy check","prompt":"I reached this endgame position in my game and I'm not sure if I'm winning — please analyze the FEN 8/8/4k3/8/8/4K3/4P3/8 w - - 0 1 with Stockfish and tell me the best continuation and how deep the analysis goes."},{"title":"Blunder detection in game review","prompt":"I think I made a mistake on move 23 of my game — can you run a Stockfish evaluation on this position FEN r1bqr1k1/pp3ppp/2n2n2/3pp3/1bP5/2NP1NP1/PP2PPBP/R1BQ1RK1 w - - 0 12 and show me what the engine recommends?"}],"resultDescription":"Returns a JSON object with a 'found' boolean indicating whether the position was in the Lichess cloud cache, an optional 'depth' number indicating how deeply the position was analyzed, and a 'lines' array containing engine analysis lines with candidate moves and evaluations.","failureModes":["Invalid FEN string returns an error or found:false","Position not cached in Lichess cloud returns found:false with no lines","Missing fen query parameter may cause a bad request","Very exotic or illegal positions may not be found in the cloud cache","Rate limiting or payment failure returns a 402 or 429 status"],"whenToPreferThis":"Choose this endpoint when you need fast, cloud-based Stockfish chess analysis without running a local engine. It is ideal for quickly checking well-known or frequently-played positions that are likely cached in the Lichess cloud. Best for agents needing on-demand chess analysis at low cost per query ($0.001 USDC). If you need guaranteed analysis of any arbitrary position including novel ones not yet cached, a dedicated local Stockfish instance may be more reliable.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-02T03:01:18.551Z","isFirstParty":false,"canonicalSlug":"saylor-innovations-chess-position-evaluator-ddaa4c09"}