ToolAssay

Chess Daily answer check — legally validates a complete UCI principal line again

Chess Daily answer check — legally validates a complete UCI principal line against the pinned daily puzzle.

Answeringour last check, 2026-09-24
1 of 1checks answered this week
628 msmedian answer time
$0.005listed price per call
$0.005price it asked us

Paid test badge: not yet. The checks above are free: we call the tool without paying and read the payment request it sends back. The Verified badge needs paid calls whose answers match the promised output, and nobody can buy a badge.

Endpoint

POST https://agent-arcade.use.x402atlas.com/chess/check

CategoryEverything else
Provider hostagent-arcade.use.x402atlas.com
Networkseip155:137, eip155:42161, eip155:8453
Payment schemesexact
Self-reported calls, 30 days4 from 1 payers (the provider's figure, not ours)

Our checks, last 30 days

DayResultHTTPAskedTime
2026-09-24 valid payment request 402$0.005 628 ms

Example input (from the provider)

{
  "body": {
    "answer": {
      "moves": [
        "d1h5",
        "h7h6",
        "h5c5"
      ]
    },
    "challenge_id": "sha256:50697ebea7b2cc5947da85e12fe2069f49983c4ba3d206b09540d80733c0153a",
    "date": "2026-07-01",
    "difficulty": "normal",
    "generation_version": "v1"
  },
  "bodyType": "json",
  "method": "POST",
  "type": "http"
}

Promised output schema (from the provider)

{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "properties": {
    "input": {
      "additionalProperties": false,
      "properties": {
        "body": {
          "additionalProperties": false,
          "description": "Chess Daily answer-check request using the identity and complete UCI line for a daily puzzle.",
          "properties": {
            "answer": {
              "additionalProperties": false,
              "description": "Proposed Chess Daily principal line.",
              "properties": {
                "moves": {
                  "description": "Complete Chess Daily principal line as legal UCI moves.",
                  "items": {
                    "pattern": "^[a-h][1-8][a-h][1-8][qrbn]?$",
                    "type": "string"
                  },
                  "maxItems": 16,
                  "type": "array"
                }
              },
              "required": [
                "moves"
              ],
              "type": "object"
            },
            "challenge_id": {
              "description": "Chess Daily challenge_id copied from the daily envelope.",
              "pattern": "^sha256:[0-9a-f]{64}$",
              "type": "string"
            },
            "date": {
              "description": "UTC date of the referenced Chess Daily challenge.",
              "format": "date",
              "type": "string"
            },
            "difficulty": {
              "description": "Difficulty of the referenced Chess Daily challenge.",
              "enum": [
                "normal"
              ],
              "type": "string"
            },
            "generation_version": {
              "description": "Chess Daily dataset-selection version copied from the daily envelope.",
              "enum": [
                "v1"
              ],
              "type": "string"
            }
          },
          "required": [
            "challenge_id",
            "generation_version",
            "date",
            "difficulty",
            "answer"
          ],
          "type": "object"
        },
        "bodyType": {
          "enum": [
            "json",
            "form-data",
            "text"
          ],
          "type": "string"
        },
        "method": {
          "enum": [
            "POST"
          ],
          "type": "string"
        },
        "type": {
          "const": "http",
          "type": "string"
        }
      },
      "required": [
        "type",
        "method",
        "bodyType",
        "body"
      ],
      "type": "object"
    },
    "output": {
      "properties": {
        "example": {
          "additionalProperties": false,
          "description": "Chess Daily answer-check legality and principal-line verdict.",
          "properties": {
            "challenge_id": {
              "description": "Checked Chess Daily challenge identity.",
              "type": "string"
            },
            "correct": {
              "description": "Whether the complete Chess Daily principal line matches.",
              "type": "boolean"
            },
            "feedback": {
              "additionalProperties": false,
              "description": "Chess Daily move legality and line-length feedback.",
              "properties": {
                "first_invalid_move": {
                  "type": [
                    "integer",
                    "null"
                  ]
                },
                "message": {
                  "type": "string"
                },
                "required_moves": {
                  "type": "integer"
                },
                "submitted_moves": {
                  "type": "integer"
                }
              },
              "required": [
                "message",
                "first_invalid_move",
                "submitted_moves",
                "required_moves"
              ],
              "type": "object"
            },
            "game": {
              "description": "Chess Daily game identity.",
              "enum": [
                "chess"
              ],
              "type": "string"
            },
            "proof": {
              "additionalProperties": false,
              "description": "Present only after a correct Chess Daily answer.",
              "properties": {
                "normalized_line": {
                  "items": {
                    "type": "string"
                  },
                  "type": "array"
                }
              },
              "required": [
                "normalized_line"
              ],
              "type": "object"
            },
            "score": {
              "description": "Informational Chess Daily score: 100 when correct, otherwise 0.",
              "type": "integer"
            },
            "valid": {
              "description": "Whether every submitted Chess Daily move is legal.",
              "type": "boolean"
            }
          },
          "required": [
            "challenge_id",
            "game",
            "valid",
            "correct",
            "score",
            "feedback"
          ],
          "type": "object"
        },
        "type": {
          "type": "string"
        }
      },
      "required": [
        "type"
      ],
      "type": "object"
    }
  },
  "required": [
    "input"
  ],
  "type": "object"
}

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