Stockfish cloud evaluation for a FEN position
Stockfish cloud evaluation for a FEN position. Returns depth, evaluation, and principal variation(s) when Lichess has the position cached.
Answeringour last check, 2026-09-24
1 of 1checks answered this week
559 msmedian answer time
$0.005listed price per call
$0.005price it asked us
Paid test badge: not yet. The checks above are free: we call the tool without paying and read the payment request it sends back. The Verified badge needs paid calls whose answers match the promised output, and nobody can buy a badge.
Endpoint
POST https://chess402.vercel.app/api/cloud-eval
| Category | Everything else |
|---|---|
| Provider host | chess402.vercel.app |
| Networks | eip155:8453 |
| Payment schemes | exact |
| Self-reported calls, 30 days | 5 from 5 payers (the provider's figure, not ours) |
Our checks, last 30 days
| Day | Result | HTTP | Asked | Time |
|---|---|---|---|---|
| 2026-09-24 | valid payment request | 402 | $0.005 | 559 ms |
Example input (from the provider)
{
"body": {
"fen": "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1",
"multiPv": 1
},
"bodyType": "json",
"method": "POST",
"type": "http"
}
Promised output schema (from the provider)
{
"$schema": "https://json-schema.org/draft/2020-12/schema",
"properties": {
"input": {
"additionalProperties": false,
"properties": {
"body": {
"$schema": "https://json-schema.org/draft/2020-12/schema",
"additionalProperties": false,
"description": "Cloud-eval request: FEN position to analyze plus options.",
"properties": {
"fen": {
"description": "Standard FEN position string, e.g. 'rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1'",
"maxLength": 100,
"minLength": 15,
"type": "string"
},
"multiPv": {
"description": "Number of principal variations to return (1-5). Default 1.",
"maximum": 5,
"minimum": 1,
"type": "integer"
},
"variant": {
"description": "Chess variant. Default 'standard'.",
"enum": [
"standard",
"chess960",
"crazyhouse",
"antichess",
"atomic",
"horde",
"kingOfTheHill",
"racingKings",
"threeCheck"
],
"type": "string"
}
},
"required": [
"fen"
],
"type": "object"
},
"bodyType": {
"enum": [
"json",
"form-data",
"text"
],
"type": "string"
},
"method": {
"enum": [
"POST",
"PUT",
"PATCH"
],
"type": "string"
},
"type": {
"const": "http",
"type": "string"
}
},
"required": [
"type",
"method",
"bodyType",
"body"
],
"type": "object"
},
"output": {
"properties": {
"example": {
"$schema": "https://json-schema.org/draft/2020-12/schema",
"additionalProperties": {},
"description": "Cloud-eval response: depth, knodes, and principal variations.",
"properties": {
"depth": {
"description": "Search depth in plies.",
"maximum": 9007199254740991,
"minimum": -9007199254740991,
"type": "integer"
},
"fen": {
"description": "Echoed FEN that was evaluated.",
"type": "string"
},
"knodes": {
"description": "Kilonodes searched.",
"maximum": 9007199254740991,
"minimum": -9007199254740991,
"type": "integer"
},
"pvs": {
"description": "Principal variations (one per multiPv).",
"items": {
"additionalProperties": {},
"properties": {
"cp": {
"description": "Evaluation in centipawns from the side-to-move POV.",
"maximum": 9007199254740991,
"minimum": -9007199254740991,
"type": "integer"
},
"mate": {
"description": "Mate-in-N from the side-to-move POV, when applicable.",
"maximum": 9007199254740991,
"minimum": -9007199254740991,
"type": "integer"
},
"moves": {
"description": "Space-separated UCI moves of the principal variation.",
"type": "string"
}
},
"required": [
"moves"
],
"type": "object"
},
"type": "array"
}
},
"required": [
"fen",
"pvs"
],
"type": "object"
},
"type": {
"type": "string"
}
},
"required": [
"type"
],
"type": "object"
}
},
"required": [
"input"
],
"type": "object"
}