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.
3000 (raw units)
price
1
calls / 30d
1
unique payers
2026-09-17
updated
Provider
chess402.vercel.app · discovered, not yet claimed by its owner
Payment (x402 accepts[])
[
{
"scheme": "exact",
"network": "eip155:8453",
"payTo": "0xfbd46201267609ad3c66bd1b99b7f1cc80b1852f",
"asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
"amount": "3000",
"maxTimeoutSeconds": 300
}
]Output schema
{
"bazaar": {
"info": {
"input": {
"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"
},
"output": {
"example": {
"black": 198217,
"draws": 311203,
"moves": [
{
"averageRating": 2434,
"black": 64210,
"draws": 98421,
"game": null,
"opening": {
"eco": "C42",
"name": "Russian Game"
},
"san": "Nf3",
"uci": "g1f3",
"white": 152340
}
],
"opening": {
"eco": "C20",
"name": "King's Pawn Game"
},
"topGames": [
{
"black": {
"name": "Carlsen, M.",
"rating": 2882
},
"id": "Sxov6E94",
"month": "2019-08",
"uci": "g1f3",
"white": {
"name": "Caruana, F.",
"rating": 2818
},
"winner": "white",
"year": 2019
}
],
"white": 482141
},
"type": "json"
}
},
"schema": {
"$schema": "https://json-schema.org/draft/2020-12/schema",
"properties": {
"input": {
"additionalProperties": false,
"properties": {
"body": {
"$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.",
"type": "string"
},
"rating": {
"description": "Player rating.",
"maximum": 9007199254740991,
"minimum": -9007199254740991,
"type": "integer"
}
},
"required": [
"name",
"rating"
],
"type": "object"
},
"winner": {
"anyOf": [
{
"enum": [
"white",
"black"
],
"type": "string"
},
{
"type": "null"
}
],
"description": "Winner, or null for a draw."
},
"year": {
"description": "Year the game was played.",
"maximum": 9007199254740991,
"minimum": -9007199254740991,
"type": "integer"
}
},
"required": [
"uci",
"id",
"winner",
"white",
"black",
"year"
],
"type": "object"
},
{
"type": "null"
}
],
"description": "Representative game for this move, if available."
},
"opening": {
"anyOf": [
{
"additionalProperties": {},
"properties": {
"eco": {
"description": "ECO opening code.",
"type": "string"
},
"name": {
"description": "Opening name.",
"type": "string"
}
},
"required": [
"eco",
"name"
],
"type": "object"
},
{
"type": "null"
}
],
"description": "ECO opening classification for this move, when recognized."
},
"san": {
"description": "SAN move string.",
"type": "string"
},
"uci": {
"description": "UCI move string.",
"type": "string"
},
"white": {
"description": "Games won by white from this move.",
"maximum": 9007199254740991,
"minimum": -9007199254740991,
"type": "integer"
}
},
"required": [
"uci",
"san",
"white",
"draws",
"black"
],
"type": "object"
},
"type": "array"
},
"opening": {
"anyOf": [
{
"additionalProperties": {},
"properties": {
"eco": {
"description": "ECO opening code.",
"type": "string"
},
"name": {
"description": "Opening name.",
"type": "string"
}
},
"required": [
"eco",
"name"
],
"type": "object"
},
{
"type": "null"
}
],
"description": "ECO opening classification for the position, when recognized."
},
"topGames": {
"description": "Recent top master games at this position.",
"items": {
"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.",
"type": "string"
},
"rating": {
"description": "Player rating.",
"maximum": 9007199254740991,
"minimum": -9007199254740991,
"type": "integer"
}
},
"required": [
"name",
"rating"
],
"type": "object"
},
"winner": {
"anyOf": [
{
"enum": [
"white",
"black"
],
"type": "string"
},
{
"type": "null"
}
],
"description": "Winner, or null for a draw."
},
"year": {
"description": "Year the game was played.",
"maximum": 9007199254740991,
"minimum": -9007199254740991,
"type": "integer"
}
},
"required": [
"uci",
"id",
"winner",
"white",
"black",
"year"
],
"type": "object"
},
"type": "array"
},
"white": {
"description": "Total white wins at this position.",
"maximum": 9007199254740991,
"minimum": -9007199254740991,
"type": "integer"
}
},
"required": [
"white",
"draws",
"black",
"moves"
],
"type": "object"
},
"type": {
"type": "string"
}
},
"required": [
"type"
],
"type": "object"
}
},
"required": [
"input"
],
"type": "object"
}
}
}Use it
curl
curl "https://chess402.vercel.app/api/masters" # -> 402 Payment Required, accepts[] lists how to pay # retry with a PAYMENT-SIGNATURE (or PAYMENT header) once paid
JavaScript
const res = await fetch("https://chess402.vercel.app/api/masters");
if (res.status === 402) {
const { accepts } = await res.json();
// pay one of accepts[] via an x402 client, then retry with the payment header
}Python
import httpx
res = httpx.get("https://chess402.vercel.app/api/masters")
if res.status_code == 402:
accepts = res.json()["accepts"]
# pay one of accepts[] via an x402 client, then retry with the payment headerMachine-readable
Everything on this page is also available as clean JSON at /resources/13034.json, and this resource appears in /discovery/resources and /discovery/search.