# Chess Notation Tools – Square Info

> Chess Notation Tools – Square Info is a paid API for AI agents from chess-notation.x402tookit.com, paid per call via x402, $0.02/call, status unknown (last checked 2026-10-29).

Returns file, rank, color, index, diagonals, mirror squares, and positional flags for a given chess square like e4.

## Facts

- Endpoint: GET https://chess-notation.x402tookit.com/square-info?utm_source=zero.xyz
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-29
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/chess-notation-tools-square-info-8e24ed9e
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_e9VHY_229omLaHtCy7eZ6

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability chess-notation-tools-square-info-8e24ed9e
```

Example prompt: What are all the properties of the chess square e4 — its file, rank, color, 0-63 index, diagonal lengths, mirror squares, and whether it's an edge, corner, or centre square?

## When to prefer this

Use this endpoint when you need low-level geometric and positional metadata about a single chess square — its color, index, diagonals, mirror squares, or edge/corner/centre classification — especially in chess tool-building, engine integration, or educational applications. Prefer over manual calculation or full board analysis endpoints when only square-specific properties are needed.

## Known failure modes

- Invalid square input (e.g. 'z9') returns an error or null fields
- Missing required 'square' query parameter returns a validation error
- Non-standard square notation (e.g. 'E4' uppercase) may not be recognized
- Service temporarily unavailable returns a 5xx error
- Payment failure via x402 protocol returns a 402 response

## How this service works

File, rank, light or dark colour, 0-63 index, diagonals and mirror squares for a chess square like e4.

## Output

A JSON object containing the square's file letter, rank number, file number (1–8), color (light/dark), 0-to-63 index, long diagonal length, anti-diagonal length, mirror-left-right square, mirror-top-bottom square, rotated-180 square, boolean flags for isEdge/isCorner/isCentre, a correspondence notation string, and summary/verdict/reason fields.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "square"
     ],
     "properties": {
      "square": {
       "type": "string",
       "description": "A square such as e4 (file a-h, rank 1-8)"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "properties": {
      "asOf": {
       "type": [
        "null",
        "string"
       ]
      },
      "file": {
       "type": [
        "null",
        "string"
       ]
      },
      "rank": {
       "type": [
        "null",
        "number"
       ]
      },
      "color": {
       "type": [
        "null",
        "string"
       ]
      },
      "isEdge": {
       "type": [
        "boolean",
        "null"
       ]
      },
      "source": {
       "type": [
        "null",
        "string"
       ]
      },
      "square": {
       "type": [
        "null",
        "string"
       ]
      },
      "reasons": {
       "type": [
        "array",
        "null"
       ],
       "items": {
        "type": "string"
       }
      },
      "summary": {
       "type": [
        "null",
        "string"
       ]
      },
      "verdict": {
       "type": [
        "null",
        "string"
       ]
      },
      "degraded": {
       "type": [
        "boolean",
        "null"
       ]
      },
      "isCentre": {
       "type": [
        "boolean",
        "null"
       ]
      },
      "isCorner": {
       "type": [
        "boolean",
        "null"
       ]
      },
      "disclaimer": {
       "type": [
        "null",
        "string"
       ]
      },
      "fileNumber": {
       "type": [
        "null",
        "number"
       ]
      },
      "index0to63": {
       "type": [
        "null",
        "number"
       ]
      },
      "notChecked": {
       "type": [
        "array",
        "null"
       ],
       "items": {
        "type": "string"
       }
      },
      "rotated180": {
       "type": [
        "null",
        "str
… (truncated)
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/chess-notation-tools-square-info-8e24ed9e/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from chess-notation.x402tookit.com](https://www.zero.xyz/host/chess-notation.x402tookit.com/llms.txt)