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Saylor Innovations Chess Position Evaluator
x402
Saylor Innovations Chess Position Evaluator is a paid API for AI agents from saylorinnovations.com, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-02).
Evaluates a chess position given in FEN notation using Stockfish via the Lichess cloud engine, returning analysis lines and depth
Price / call$0.001
Success—
StatusUnknown
How this service works
Chess Position Evaluation (Stockfish via Lichess cloud). Chess position evaluation from Stockfish via the Lichess cloud: up to 5 best lines with moves, evaluation in pawns or mate-in-N, depth and a plain-language verdict.
Output
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.
Example use cases
Opening theory verification
“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?”
Endgame accuracy check
“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.”
Blunder detection in game review
“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?”
Technical details
Endpoint
GEThttps://saylorinnovations.com/api/chess/eval?utm_source=zero.xyzWhen to prefer
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.
Side effects
- 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
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| inputrequired | object | |
| output | object |
Tags
x402
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