← The evidence ledger
Evidence row 72316
Observed , by baseline/1.
- Kind
- listing
- About
- source_record x402_bazaar:https://chess402.vercel.app/api/masters
- Recorded
- Previous row
- None: the first of its kind about this subject
- Body SHA-256
- 745e69a48a1d356d269c5b6eafefa9d1a16fdb23628489b8ecec82a352e87a20
- Leaf
- 0x42a0867e8538d97e4f933450fba5a06dbe55ed1f15bf9b06631222eef2080408
What was observed
{
"endpoints": [
[
"x402",
"https://chess402.vercel.app/api/masters"
]
],
"name": "chess402.vercel.app/api/masters",
"owner_address": "0xfbd46201267609ad3c66bd1b99b7f1cc80b1852f",
"raw": {
"accepts": [
{
"amount": "3000",
"asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
"extra": {
"name": "USD Coin",
"version": "2"
},
"maxTimeoutSeconds": 300,
"network": "eip155:8453",
"payTo": "0xfbd46201267609ad3c66bd1b99b7f1cc80b1852f",
"scheme": "exact"
}
],
"description": "Masters opening explorer for a position. Returns top moves, win/draw/loss rates, and recent top master games from the Lichess masters database.",
"extensions": {
"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"
}
}
},
"lastUpdated": "2026-10-25T14:40:35.793Z",
"quality": {
"l30DaysTotalCalls": 4,
"l30DaysUniquePayers": 4,
"lastCalledAt": "2026-10-25T14:40:35.563Z"
},
"resource": "https://chess402.vercel.app/api/masters",
"type": "http",
"x402Version": 2
},
"source": "x402_bazaar",
"summary": "Masters opening explorer for a position. Returns top moves, win/draw/loss rates, and recent top master games from the Lichess masters database."
}What the leaf hashes
{"body":"745e69a48a1d356d269c5b6eafefa9d1a16fdb23628489b8ecec82a352e87a20","id":72316,"kind":"listing","method":"baseline/1","observed_us":1793025485628270,"prev":null,"subject":"x402_bazaar:https://chess402.vercel.app/api/masters","subject_kind":"source_record"}Proof
Fold these into the leaf in order, hashing each sorted pair with keccak256, to reach the root of (296695 rows).
- 0x42a0026bc8c9aa8df9a3475470fff2642bac866394fafc177f95226d4f42203f
- 0xaf39fa86007fee7ab1b7e692f6fdfb072a8f3a893c354189b4e180c4098b0d83
- 0xb8b8482d1e41798bd8314a81ffe32f00a52bb5c112d4144aedb9e169502ba45b
- 0xa8abf9098e427b662cd72b1ae83fec5a0bef85d8bbc2930d48cb86a73e1d5582
- 0x652d98cd83d4b3231dbe2edcb38284c41681c32d9e7f4d0810859e18c8371c10
- 0xeb4b357c0c3e87a19f05ec5efb1e01452802405206d573caba94778a364a5cca
- 0x9aaea7af7d1e30c567a05426272456c1069715de9bf729b5292283c26431f55c
- 0x1ee22cdc3e290330116b3fe60a44c742a4eab07b5650009fafeb024e7e2cafc9
- 0x75cc7f5a9e041e691a712d48afcdb3411bc10d2105c8f6d3612b5f722af18590
- 0xc268ff3f1dd69d7c668cdb05ded405db6f682a95f21c57e98e683c14e6e2ff89
- 0x5209b44231d259fd8508722a1ae64f1b73c7b7f19b456b1ecd950d5b281c35b6
- 0x58f4330f9ac32da273a2a76d85bc0768d037638cddbd3d1f09d9b64094bfd942
- 0xd406739acce2ba016f8d49081b15f266a4ea4a0b0fc5ef171c89c8fd2dda4d80
- 0x8b27a4c21bf4ba962fd008c8f4300bc6953764a5032b9ab0cfe696b318c45326
- 0x4b52a97f7a80ff7778a702b85267b8d2e5c93ce160942656435c29ae7be68bf4
- 0x2e6a32eb32761c210560e852405e2f865f958ddbe01027894f8b9c1b3433b9f0
- 0x9a83be955a206deb65b995adfd92c58fa31c95fbbf926bd199d300e70b08b26d
- 0x20704208aa6923d6b2450ef74ede87a6e0265d46447926038fe9506e9e154b2d
- 0x9b9ce5b74b9bab5121612ef6b64920a8d453cbf311096a423eef9702747e868a
- Day root
- 0xf43e8dcc3d451a4788b26be904c55e8c4c0fa75c9666796c51db38d37e2c0df8
- Chained
- 0x702d5ac508f08b0d1accf36af25822d8e5660367494edd17a642fb61e158a57a
- Published
- On Arc Testnet, block 69251483: 0x495162f8936e19f0039918feebe6c307f327cd6bf8c37219620b1970041fa9ae