chess-eval.x402supply.com
Evaluate a chess position with Stockfish: best move, centipawn/mate score, principal variation, and optional multipv. No mocks — a real single-threaded Stockfish 10 (asm.js) runs in-isolate per call.; Play out Stockfish's predicted principal variation as SAN moves with a per-ply eval, re-searching a
OtherLiveeip155:8453Exactvia facilitator:thirdweb
Calls · 30d
2→ 0%
This endpoint's own trailing-30-day call count, as published by the upstream catalog and snapshotted daily. 19 snapshots so far.
$0.55
Verified settled volume
29 settlements proven x402 by their on-chain EIP-3009 marker.
$0.010
Listed price
As published in the catalog. Always read the live 402 before paying.
—
Calls · 30d
Upstream's own call count for this endpoint, not ours.
—
Unique payers · 30d
Never called
—
Upstream on-chain volume
Reported by the source catalog.
Paid to
0x07fFB5044cF2Cd4352Be4655f578D0ba8cb754EBThe 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.
Live 402 challenge
Captured by the enrichment pass, not read just now. Prices can change — always read the 402 the endpoint answers with.
{
"error": "Payment required",
"accepts": [
{
"asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
"extra": {
"name": "USD Coin",
"version": "2",
"outputSchema": {
"input": {
"type": "object",
"required": [
"fen"
],
"properties": {
"fen": {
"type": "string"
},
"depth": {
"type": "integer",
"maximum": 18,
"minimum": 1
},
"multipv": {
"type": "integer",
"maximum": 5,
"minimum": 1
}
},
"additionalProperties": false
},
"output": {
"type": "object",
"required": [
"status",
"bestMove",
"pv",
"depthReached",
"timedOut",
"multipv",
"engine",
"fenEchoed"
],
"properties": {
"pv": {
"type": "array",
"items": {
"type": "string"
},
"description": "Principal variation in SAN"
},
"pvUci": {
"type": "array",
"items": {
"type": "string"
}
},
"engine": {
"type": "string"
},
"evalCp": {
"type": "number",
"description": "Centipawn score from the side-to-move's perspective, omitted if mateIn is set"
},
"mateIn": {
"type": "integer",
"description": "Moves to mate from the side-to-move's perspective (negative = getting mated), omitted if evalCp is set"
},
"status": {
"enum": [
"ok",
"checkmate",
"stalemate",
"draw"
],
"type": "string"
},
"multipv": {
"type": "array",
"items": {
"type": "object",
"required": [
"move",
"moveSan",
"pv",
"pvUci"
],
"properties": {
"pv": {
"type": "array",
"items": {
"type": "string"
}
},
"move": {
"type": "string"
},
"evalCp": {
"type": "number",
"description": "Centipawn score from the side-to-move's perspective, omitted if mateIn is set"
},
"mateIn": {
"type": "integer",
"description": "Moves to mate from the side-to-move's perspective (negative = getting mated), omitted if evalCp is set"
},
"moveSan": {
"type": "string"
}
}
}
},
"bestMove": {
"type": [
"string",
"null"
]
},
"timedOut": {
"type": "boolean"
},
"fenEchoed": {
"type": "string"
},
"bestMoveSan": {
"type": [
"string",
"null"
]
},
"depthReached": {
"type": "integer"
}
}
}
}
},
"payTo": "0x07fFB5044cF2Cd4352Be4655f578D0ba8cb754EB",
"amount": "10000",
"scheme": "exact",
"network": "eip155:8453",
"maxTimeoutSeconds": 60
}
],
"resource": {
"url": "https://chess-eval.x402supply.com/tools/evaluate_position",
"mimeType": "application/json",
"description": "Evaluate a chess position with Stockfish: best move, centipawn/mate score, principal variation, and optional multipv. No mocks — a real single-threaded Stockfish 10 (asm.js) runs in-isolate per call."
},
"extensions": {
"bazaar": {
"info": {
"input": {
"body": {
"fen": "rnbqkbnr/pppppppp/8/8/4P3/8/PPPP1PPP/RNBQKBNR b KQkq e3 0 1",
"depth": 10
},
"type": "http",
"method": "POST",
"bodyType": "json"
},
"output": {
"type": "json",
"example": {
"pv": [
"d5",
"e5",
"d4",
"c3",
"Nc6",
"Nf3",
"dxc3"
],
"pvUci": [
"d7d5",
"e4e5",
"d5d4",
"c2c3",
"b8c6",
"g1f3",
"d4c3"
],
"engine": "stockfish 10 asm.js",
"evalCp": -29,
"status": "ok",
"multipv": [
{
"pv": [
"d5",
"e5",
"d4",
"c3",
"Nc6",
"Nf3",
"dxc3"
],
"move": "d7d5",
"pvUci": [
"d7d5",
"e4e5",
"d5d4",
"c2c3",
"b8c6",
"g1f3",
"d4c3"
],
"evalCp": -29,
"moveSan": "d5"
}
],
"bestMove": "d7d5",
"timedOut": false,
"fenEchoed": "rnbqkbnr/pppppppp/8/8/4P3/8/PPPP1PPP/RNBQKBNR b KQkq e3 0 1",
"bestMoveSan": "d5",
"perspective": "side-to-move",
"depthReached": 10
}
}
},
"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",
"required": [
"fen"
],
"properties": {
"fen": {
"type": "string"
},
"depth": {
"type": "integer",
"maximum": 18,
"minimum": 1
},
"multipv": {
"type": "integer",
"maximum": 5,
"minimum": 1
}
},
"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"
}
}
}
}
}
}
},
"x402Version": 2
}Accepts
The payment requirements as published to the catalog. Read the live 402 before paying — a price here is a claim, not a quote.
0.01USDC≈ $0.01 USD
on Base · exact scheme
Pay 0.01 USDC on Base to 0x07fF…754EB. The signed payment is good for 1 minute.
- Paid to
- 0x07fF…754EB
- USD Coin contract
- 0x8335…02913
- Payment window
- 1 minute
- As published
- 10000 smallest units
- Returns
- application/json
The catalog’s raw entry
[
{
"asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
"payTo": "0x07fFB5044cF2Cd4352Be4655f578D0ba8cb754EB",
"scheme": "exact",
"network": "eip155:8453",
"mimeType": "application/json",
"resource": "https://chess-eval.x402supply.com/tools/evaluate_position",
"description": "",
"maxAmountRequired": "10000",
"maxTimeoutSeconds": 60
}
]Provenance
- Seen in the source catalog
- 2026-10-12 19:30Z
- Last indexed by Roundhouse
- 2026-10-25 20:46Z
- Last enriched (probe, favicon, geo)
- 2026-10-15 13:45Z
- x402 version
- 1
- Max timeout
- 60s
- Liveness probe
- HTTP 402
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. 19 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 chess-eval.x402supply.com 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=chess-eval.x402supply.com' 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://chess-eval.x402supply.com/tools/evaluate_position, 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. Either pay over x402 (mint a personal key for $0.01 at GET https://api.roundhouseai.io/v0/test/x402), or ask me for an organization key, which I create at https://roundhouseai.io/dashboard/connections. If you have neither, ask before going further. If you do not have Roundhouse tools or skills installed, read https://roundhouseai.io/skill.md first — it is the whole procedure.