Masters opening explorer for a position
Masters opening explorer for a position. Returns top moves, win/draw/loss rates, and recent top master games from the Lichess masters database.
Answeringour last check, 2026-09-24
1 of 1checks answered this week
248 msmedian answer time
$0.003listed price per call
$0.003price 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/masters
| Category | Everything else |
|---|---|
| Provider host | chess402.vercel.app |
| Networks | eip155:8453 |
| Payment schemes | exact |
| Self-reported calls, 30 days | 1 from 1 payers (the provider's figure, not ours) |
Our checks, last 30 days
| Day | Result | HTTP | Asked | Time |
|---|---|---|---|---|
| 2026-09-24 | valid payment request | 402 | $0.003 | 248 ms |
Example input (from the provider)
{
"body": {
"fen": "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1",
"moves": 12,
"play": "e2e4,e7e5",
"topGames": 4
},
"bodyType": "json",
"method": "POST",
"type": "http"
}
Promised output schema (from the provider)
{
"$schema": "https://json-schema.org/draft/2020-12/schema",
"properties": {
"input": {
"additionalProperties": false,
"properties": {
"body": {
"$schema": "https://json-schema.org/draft/2020-12/schema",
"additionalProperties": false,
"description": "Masters opening explorer request: FEN plus optional filters and play sequence.",
"properties": {
"fen": {
"description": "Standard FEN position string, e.g. 'rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1'",
"maxLength": 100,
"minLength": 15,
"type": "string"
},
"moves": {
"description": "Max number of top moves to return. Default 12.",
"maximum": 50,
"minimum": 1,
"type": "integer"
},
"play": {
"description": "Comma-separated UCI move sequence to apply to the FEN before lookup (e.g. 'e2e4,e7e5').",
"maxLength": 500,
"type": "string"
},
"since": {
"description": "Include games from this year onward.",
"maximum": 2100,
"minimum": 1500,
"type": "integer"
},
"topGames": {
"description": "Number of recent top games to include. Default 4.",
"maximum": 15,
"minimum": 0,
"type": "integer"
},
"until": {
"description": "Include games up to this year.",
"maximum": 2100,
"minimum": 1500,
"type": "integer"
}
},
"required": [
"fen"
],
"type": "object"
},
"bodyType": {
"enum": [
"json",
"form-data",
"text"
],
"type": "string"
},
"method": {
"enum": [
"POST",
"PUT",
"PATCH"
],
"type": "string"
},
"type": {
"const": "http",
"type": "string"
}
},
"required": [
"type",
"method",
"bodyType",
"body"
],
"type": "object"
},
"output": {
"properties": {
"example": {
"$schema": "https://json-schema.org/draft/2020-12/schema",
"additionalProperties": {},
"description": "Masters database aggregate stats for the position.",
"properties": {
"black": {
"description": "Total black wins at this position.",
"maximum": 9007199254740991,
"minimum": -9007199254740991,
"type": "integer"
},
"draws": {
"description": "Total draws at this position.",
"maximum": 9007199254740991,
"minimum": -9007199254740991,
"type": "integer"
},
"moves": {
"description": "Top moves ordered by frequency.",
"items": {
"additionalProperties": {},
"properties": {
"averageRating": {
"description": "Average rating of players who played this move.",
"maximum": 9007199254740991,
"minimum": -9007199254740991,
"type": "integer"
},
"black": {
"description": "Games won by black from this move.",
"maximum": 9007199254740991,
"minimum": -9007199254740991,
"type": "integer"
},
"draws": {
"description": "Drawn games from this move.",
"maximum": 9007199254740991,
"minimum": -9007199254740991,
"type": "integer"
},
"game": {
"anyOf": [
{
"additionalProperties": {},
"properties": {
"black": {
"additionalProperties": false,
"description": "Black player.",
"properties": {
"name": {
"description": "Player name.",
"type": "string"
},
"rating": {
"description": "Player rating.",
"maximum": 9007199254740991,
"minimum": -9007199254740991,
"type": "integer"
}
},
"required": [
"name",
"rating"
],
"type": "object"
},
"id": {
"description": "Lichess game id.",
"type": "string"
},
"month": {
"description": "Month string (YYYY-MM).",
"type": "string"
},
"uci": {
"description": "UCI move played in this game.",
"type": "string"
},
"white": {
"additionalProperties": false,
"description": "White player.",
"properties": {
"name": {
"description": "Player name.",