Json Format

Format, prettify, minify, or validate JSON. Use when the user asks to format JSON, prettify JSON, beautify JSON, minify JSON, compress JSON, validate JSON, fix JSON indentation, or make JSON readable.

JSON Formatter

Format and validate JSON — pretty-print with configurable indentation or minify to a single line.

Input

• A JSON string (object, array, string, number, boolean, or null)
• May be already formatted or a single minified line
• Optional action: format (default), minify, or validate-only
• Optional indent size: 2 (default) or 4 spaces

Output

• format: Pretty-printed JSON with proper indentation and line breaks
• minify: Single-line compact JSON with no whitespace
• validate: A message confirming valid or invalid JSON (with error details)

Instructions

1. Receive the raw JSON string from the user.
2. Determine the requested action (default: format).
3. Attempt to parse the JSON:
   • Call JSON.parse(input) conceptually — parse the string strictly following JSON spec.
   • If parsing fails, report the error with as much detail as possible (e.g., "Unexpected token at position 42", "Missing closing bracket").
4. For format action:
   • Serialize the parsed value back to a string with the requested indent size (default: 2 spaces).
   • Use JSON.stringify(parsed, null, indentSize) semantics: keys are sorted by insertion order (not alphabetically), arrays and objects are expanded across multiple lines, strings are double-quoted.
5. For minify action:
   • Serialize with no indentation or extra whitespace: JSON.stringify(parsed) semantics.
6. For validate action:
   • If parsing succeeded, report "Valid JSON" along with type and top-level key count if it is an object.
   • If parsing failed, report the error message.
7. If sort-keys option is requested, sort all object keys alphabetically at every nesting level before serializing.
8. Output the result.

Options

• indent: 2 (default) | 4 — number of spaces per indent level
• action: format (default) | minify | validate
• sort-keys: false (default) | true — sort object keys alphabetically

Examples

Format (default, 2-space indent)

Input:

{"name":"Alice","age":30,"hobbies":["reading","coding"]}

Output:

{
  "name": "Alice",
  "age": 30,
  "hobbies": [
    "reading",
    "coding"
  ]
}

Minify

Input:

{
  "name": "Alice",
  "age": 30
}

Output:

{"name":"Alice","age":30}

Validate — invalid JSON

Input:

{name: 'Alice', age: 30}

Output:

Invalid JSON: Unexpected token 'n' at position 1. Keys must be double-quoted strings and string values must use double quotes, not single quotes.

Format with 4-space indent and sort-keys

Input:

{"z":3,"a":1,"m":2}

Output:

{
    "a": 1,
    "m": 2,
    "z": 3
}

Error Handling

• If the input is empty or whitespace-only, respond: "No input provided. Please paste a JSON string."
• If JSON.parse fails, report the error message and the approximate position or line number if determinable. Do not attempt to silently fix the JSON — report the exact parse error. (If the user wants repair, suggest using the json-repair skill.)
• If the input is valid JSON but the user asked to "format" a primitive (e.g., just 42 or "hello"), format it as-is (a primitive is valid JSON).
• Never truncate the output — always return the full formatted result.