chess402.vercel.app
Pay-per-call chess API. x402 + MPP wrappers around popular Lichess endpoints.
DataLiveeip155:8453Exactvia cdp
Calls · 30d
1
This endpoint's own trailing-30-day call count, as published by the upstream catalog and snapshotted daily. 7 snapshots so far.
$40.48
Verified settled volume
113 settlements proven x402 by their on-chain EIP-3009 marker.
$0.0030
Listed price
As published in the catalog. Always read the live 402 before paying.
1
Calls · 30d
Upstream's own call count for this endpoint, not ours.
1
Unique payers · 30d
Last called 2026-09-17 03:59Z
—
Upstream on-chain volume
Reported by the source catalog.
Paid to
0xfbd46201267609ad3c66bd1b99b7f1cc80b1852fThe wallet the 402 directs payment to. Its whole payment record — every payer, every chain — is on the merchant page.
Asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913
Provider
The payTo wallet does not resolve to a registered ERC-8004 agent. That is not a verdict on the service — most of the catalog is unregistered.
Accepts
The payment requirements as published to the catalog. Read the live 402 before paying — a price here is a claim, not a quote.
0.003USDC≈ $0.003 USD
on Base · exact scheme
Pay 0.003 USDC on Base to 0xfbd4…1852f. The signed payment is good for 5 minutes.
- Paid to
- 0xfbd4…1852f
- USD Coin contract
- 0x8335…02913
- Payment window
- 5 minutes
- As published
- 3000 smallest units
The catalog’s raw entry
[
{
"asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
"extra": {
"name": "USD Coin",
"version": "2"
},
"payTo": "0xfbd46201267609ad3c66bd1b99b7f1cc80b1852f",
"amount": "3000",
"scheme": "exact",
"network": "eip155:8453",
"maxTimeoutSeconds": 300
}
]Extensions
{
"bazaar": {
"info": {
"input": {
"body": {
"fen": "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1",
"play": "e2e4,e7e5",
"moves": 12,
"topGames": 4
},
"type": "http",
"method": "POST",
"bodyType": "json"
},
"output": {
"type": "json",
"example": {
"black": 198217,
"draws": 311203,
"moves": [
{
"san": "Nf3",
"uci": "g1f3",
"game": null,
"black": 64210,
"draws": 98421,
"white": 152340,
"opening": {
"eco": "C42",
"name": "Russian Game"
},
"averageRating": 2434
}
],
"white": 482141,
"opening": {
"eco": "C20",
"name": "King's Pawn Game"
},
"topGames": [
{
"id": "Sxov6E94",
"uci": "g1f3",
"year": 2019,
"black": {
"name": "Carlsen, M.",
"rating": 2882
},
"month": "2019-08",
"white": {
"name": "Caruana, F.",
"rating": 2818
},
"winner": "white"
}
]
}
}
},
"schema": {
"type": "object",
"$schema": "https://json-schema.org/draft/2020-12/schema",
"required": [
"input"
],
"properties": {
"input": {
"type": "object",
"required": [
"type",
"method",
"bodyType",
"body"
],
"properties": {
"body": {
"type": "object",
"$schema": "https://json-schema.org/draft/2020-12/schema",
"required": [
"fen"
],
"properties": {
"fen": {
"type": "string",
"maxLength": 100,
"minLength": 15,
"description": "Standard FEN position string, e.g. 'rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1'"
},
"play": {
"type": "string",
"maxLength": 500,
"description": "Comma-separated UCI move sequence to apply to the FEN before lookup (e.g. 'e2e4,e7e5')."
},
"moves": {
"type": "integer",
"maximum": 50,
"minimum": 1,
"description": "Max number of top moves to return. Default 12."
},
"since": {
"type": "integer",
"maximum": 2100,
"minimum": 1500,
"description": "Include games from this year onward."
},
"until": {
"type": "integer",
"maximum": 2100,
"minimum": 1500,
"description": "Include games up to this year."
},
"topGames": {
"type": "integer",
"maximum": 15,
"minimum": 0,
"description": "Number of recent top games to include. Default 4."
}
},
"description": "Masters opening explorer request: FEN plus optional filters and play sequence.",
"additionalProperties": false
},
"type": {
"type": "string",
"const": "http"
},
"method": {
"enum": [
"POST",
"PUT",
"PATCH"
],
"type": "string"
},
"bodyType": {
"enum": [
"json",
"form-data",
"text"
],
"type": "string"
}
},
"additionalProperties": false
},
"output": {
"type": "object",
"required": [
"type"
],
"properties": {
"type": {
"type": "string"
},
"example": {
"type": "object",
"$schema": "https://json-schema.org/draft/2020-12/schema",
"required": [
"white",
"draws",
"black",
"moves"
],
"properties": {
"black": {
"type": "integer",
"maximum": 9007199254740991,
"minimum": -9007199254740991,
"description": "Total black wins at this position."
},
"draws": {
"type": "integer",
"maximum": 9007199254740991,
"minimum": -9007199254740991,
"description": "Total draws at this position."
},
"moves": {
"type": "array",
"items": {
"type": "object",
"required": [
"uci",
"san",
"white",
"draws",
"black"
],
"properties": {
"san": {
"type": "string",
"description": "SAN move string."
},
"uci": {
"type": "string",
"description": "UCI move string."
},
"game": {
"anyOf": [
{
"type": "object",
"required": [
"uci",
"id",
"winner",
"white",
"black",
"year"
],
"properties": {
"id": {
"type": "string",
"description": "Lichess game id."
},
"uci": {
"type": "string",
"description": "UCI move played in this game."
},
"year": {
"type": "integer",
"maximum": 9007199254740991,
"minimum": -9007199254740991,
"description": "Year the game was played."
},
"black": {
"type": "object",
"required": [
"name",
"rating"
],
"properties": {
"name": {
"type": "string",
"description": "Player name."
},
"rating": {
"type": "integer",
"maximum": 9007199254740991,
"minimum": -9007199254740991,
"description": "Player rating."
}
},
"description": "Black player.",
"additionalProperties": false
},
"month": {
"type": "string",
"description": "Month string (YYYY-MM)."
},
"white": {
"type": "object",
"required": [
"name",
"rating"
],
"properties": {
"name": {
"type": "string",
"description": "Player name."
},
"rating": {
"type": "integer",
"maximum": 9007199254740991,
"minimum": -9007199254740991,
"description": "Player rating."
}
},
"description": "White player.",
"additionalProperties": false
},
"winner": {
"anyOf": [
{
"enum": [
"white",
"black"
],
"type": "string"
},
{
"type": "null"
}
],
"description": "Winner, or null for a draw."
}
},
"additionalProperties": {}
},
{
"type": "null"
}
],
"description": "Representative game for this move, if available."
},
"black": {
"type": "integer",
"maximum": 9007199254740991,
"minimum": -9007199254740991,
"description": "Games won by black from this move."
},
"draws": {
"type": "integer",
"maximum": 9007199254740991,
"minimum": -9007199254740991,
"description": "Drawn games from this move."
},
"white": {
"type": "integer",
"maximum": 9007199254740991,
"minimum": -9007199254740991,
"description": "Games won by white from this move."
},
"opening": {
"anyOf": [
{
"type": "object",
"required": [
"eco",
"name"
],
"properties": {
"eco": {
"type": "string",
"description": "ECO opening code."
},
"name": {
"type": "string",
"description": "Opening name."
}
},
"additionalProperties": {}
},
{
"type": "null"
}
],
"description": "ECO opening classification for this move, when recognized."
},
"averageRating": {
"type": "integer",
"maximum": 9007199254740991,
"minimum": -9007199254740991,
"description": "Average rating of players who played this move."
}
},
"additionalProperties": {}
},
"description": "Top moves ordered by frequency."
},
"white": {
"type": "integer",
"maximum": 9007199254740991,
"minimum": -9007199254740991,
"description": "Total white wins at this position."
},
"opening": {
"anyOf": [
{
"type": "object",
"required": [
"eco",
"name"
],
"properties": {
"eco": {
"type": "string",
"description": "ECO opening code."
},
"name": {
"type": "string",
"description": "Opening name."
}
},
"additionalProperties": {}
},
{
"type": "null"
}
],
"description": "ECO opening classification for the position, when recognized."
},
"topGames": {
"type": "array",
"items": {
"type": "object",
"required": [
"uci",
"id",
"winner",
"white",
"black",
"year"
],
"properties": {
"id": {
"type": "string",
"description": "Lichess game id."
},
"uci": {
"type": "string",
"description": "UCI move played in this game."
},
"year": {
"type": "integer",
"maximum": 9007199254740991,
"minimum": -9007199254740991,
"description": "Year the game was played."
},
"black": {
"type": "object",
"required": [
"name",
"rating"
],
"properties": {
"name": {
"type": "string",
"description": "Player name."
},
"rating": {
"type": "integer",
"maximum": 9007199254740991,
"minimum": -9007199254740991,
"description": "Player rating."
}
},
"description": "Black player.",
"additionalProperties": false
},
"month": {
"type": "string",
"description": "Month string (YYYY-MM)."
},
"white": {
"type": "object",
"required": [
"name",
"rating"
],
"properties": {
"name": {
"type": "string",
"description": "Player name."
},
"rating": {
"type": "integer",
"maximum": 9007199254740991,
"minimum": -9007199254740991,
"description": "Player rating."
}
},
"description": "White player.",
"additionalProperties": false
},
"winner": {
"anyOf": [
{
"enum": [
"white",
"black"
],
"type": "string"
},
{
"type": "null"
}
],
"description": "Winner, or null for a draw."
}
},
"additionalProperties": {}
},
"description": "Recent top master games at this position."
}
},
"description": "Masters database aggregate stats for the position.",
"additionalProperties": {}
}
}
}
}
}
}
}Provenance
- Seen in the source catalog
- 2026-09-17 03:59Z
- Last indexed by Roundhouse
- 2026-09-24 20:00Z
- Last enriched (probe, favicon, geo)
- 2026-09-12 20:45Z
- x402 version
- 2
- Max timeout
- 300s
- Liveness probe
- HTTP 405
Hand this page to an agent
Copy the prompt and paste it into Claude, an MCP client or your own agent — it will vet this service and call it over the free read API. No key, no account.
GET api.roundhouseai.io/v0/endpoints
This endpoint's own trailing-30-day call count, as published by the upstream catalog and snapshotted daily. 7 snapshots so far. Verified volume counts only settlements with an on-chain EIP-3009 marker.
Show the promptHide the prompt
Using Roundhouse, look up the x402 service chess402.vercel.app and tell me whether it is worth paying: what a call costs, whether the endpoint answered when last probed, and what its payment record actually shows. curl -s 'https://api.roundhouseai.io/v0/endpoints?q=chess402.vercel.app' curl -s 'https://api.roundhouseai.io/v0/merchants/<the payTo wallet returned above>' Then call it: read the price from the live 402 at https://chess402.vercel.app/api/masters, never from a cached figure, and pay with an x402 client. The /v0 API needs an API key (`authorization: Bearer rh_live_…`) on everything except /v0/unified* and /v0/endpoints. Mint a personal key for $0.01 at GET https://api.roundhouseai.io/v0/test/x402, or use an organization key from https://roundhouseai.io/dashboard/team. If you do not have Roundhouse tools or skills installed, read https://roundhouseai.io/skill.md first — it is the whole procedure.