# Chess Notation Tools – FEN to ASCII Board

> Chess Notation Tools – FEN to ASCII Board is a paid API for AI agents from chess-notation.x402tookit.com, paid per call via x402, $0.02/call, status unknown (last checked 2026-10-30).

Renders a FEN position string as an 8x8 ASCII chess board (White at bottom) plus a piece-by-square inventory list.

## Facts

- Endpoint: GET https://chess-notation.x402tookit.com/fen-board?utm_source=zero.xyz
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-30
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/chess-notation-tools-fen-to-ascii-board-a35c6a33
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Q6CqjdsgPVkIogQUxWJBI

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-fen-to-ascii-board-a35c6a33
```

Example prompt: Can you render the FEN 'rnbqkbnr/pppppppp/8/8/4P3/8/PPPP1PPP/RNBQKBNR b KQkq e3 0 1' as an ASCII chessboard with a list of all pieces and their squares?

## When to prefer this

Choose this endpoint when you need a human-readable or agent-readable visual representation of a chess position from a FEN string, especially for display, debugging, or explaining board state. It is the right choice when you want both an ASCII diagram and a structured piece-by-square list in one call, rather than writing your own FEN parser.

## Known failure modes

- Missing or malformed FEN query parameter returns an error
- Invalid FEN piece placement characters cause a parse failure
- Completely empty FEN string is rejected
- Payment not included or insufficient USDC results in 402 response

## How this service works

Render a FEN position as an 8x8 ASCII board (White at the bottom) plus a piece-by-square list.

## Output

Returns an ASCII 8x8 board string with White at the bottom, an array of row strings, a list of pieces each with color, piece type, and square identifier, and a piece count. Also includes metadata fields like source and timestamp.

## 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": [
      "fen"
     ],
     "properties": {
      "fen": {
       "type": "string",
       "description": "A FEN string; only the first field (piece placement) is required"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "properties": {
      "asOf": {
       "type": [
        "null",
        "string"
       ]
      },
      "rows": {
       "type": [
        "array",
        "null"
       ],
       "items": {
        "type": "string"
       }
      },
      "ascii": {
       "type": [
        "null",
        "string"
       ]
      },
      "pieces": {
       "type": [
        "array",
        "null"
       ],
       "items": {
        "type": "object",
        "properties": {
         "color": {
          "type": [
           "null",
           "string"
          ]
         },
         "piece": {
          "type": [
           "null",
           "string"
          ]
         },
         "square": {
          "type": [
           "null",
           "string"
          ]
         }
        }
       }
      },
      "source": {
       "type": [
        "null",
        "string"
       ]
      },
      "reasons": {
       "type": [
        "array",
        "null"
       ]
      },
      "summary": {
       "type": [
        "null",
        "string"
       ]
      },
      "verdict": {
       "type": [
        "null",
        "string"
       ]
      },
      "degraded": {
       "type": [
        "boolean",
        "null"
       ]
      },
      "disclaimer": {
       "type": [
        "null",
        "string"
       ]
      },
      "notChecked": {
       "type": [
        "array",
        "null"
       ],
       "items": {
        "type": "string"
       }
      },
      "pieceCount": {
       "type": [
        "null",
        "number"
       ]
      }
     }
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/chess-notation-tools-fen-to-ascii-board-a35c6a33/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)