chess402.vercel.app
Masters opening explorer for a position. Returns top moves, win/draw/loss rates, and recent top master games from the Lichess masters database.
Offering
- Provider
- chess402.vercel.app
- Method
- POST
- Offering type
- Api Endpoint
- Transport type
- http
- Category
- General Utilities
- Delivery
- Not provided
- Pricing model
- Not provided
- x402 version
- 2
Endpoint context
- URL
https://chess402.vercel.app/api/masters- MIME type
- Not provided
- First seen
- 2026-10-16T01:54:06.400Z
- Last seen
- Tags
- None supplied
Payment pricing
x402 payment terms are the authoritative price for calling this endpoint.
- Payment option 1
- 0.003 USDC
Atomic price: 3000 · Network: eip155:8453 · Asset: USDC · Scheme: exact
Raw x402 terms
[
{
"scheme": "exact",
"network": "eip155:8453",
"asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
"amount": "3000",
"payTo": "0xfbd46201267609ad3c66bd1b99b7f1cc80b1852f"
}
]Observed health
- Status
- Healthy
- Latest latency
- 70 ms
- Average latency
- 564 ms
- HTTP status
- 204
- Last checked
- Reachability
- 100% over 14 checks
Latency is measured to the first response headers. A reachable result does not verify response accuracy or merchant identity.
Input schema
{
"additionalProperties": false,
"properties": {
"body": {
"$schema": "https://json-schema.org/draft/2020-12/schema",
"additionalProperties": false,
"description": "Masters opening explorer request: FEN plus optional filters and play sequence.",
"properties": {
"fen": {
"description": "Standard FEN position string, e.g. 'rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1'",
"maxLength": 100,
"minLength": 15,
"type": "string"
},
"moves": {
"description": "Max number of top moves to return. Default 12.",
"maximum": 50,
"minimum": 1,
"type": "integer"
},
"play": {
"description": "Comma-separated UCI move sequence to apply to the FEN before lookup (e.g. 'e2e4,e7e5').",
"maxLength": 500,
"type": "string"
},
"since": {
"description": "Include games from this year onward.",
"maximum": 2100,
"minimum": 1500,
"type": "integer"
},
"topGames": {
"description": "Number of recent top games to include. Default 4.",
"maximum": 15,
"minimum": 0,
"type": "integer"
},
"until": {
"description": "Include games up to this year.",
"maximum": 2100,
"minimum": 1500,
"type": "integer"
}
},
"required": [
"fen"
],
"type": "object"
},
"bodyType": {
"enum": [
"json",
"form-data",
"text"
],
"type": "string"
},
"method": {
"enum": [
"POST",
"PUT",
"PATCH"
],
"type": "string"
},
"type": {
"const": "http",
"type": "string"
}
},
"required": [
"type",
"method",
"bodyType",
"body"
],
"type": "object"
}Output schema
{
"properties": {
"example": {
"$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"
}