| name | format-json |
| description | Formats an unformatted/minified JSON file into readable, indented JSON. Use when the user asks to format, pretty-print, beautify, or indent a JSON file, or mentions a JSON file that is "unformatted", "minified", "all on one line", or "hard to read". |
Format JSON
Reformat a JSON file into readable, consistently indented JSON, in place (or to a new file if the user asks for one).
Steps
- Identify the target JSON file. If the user didn't name one, look for
.json files in the current project and ask which one if there's more than one candidate.
- Read the file and validate it is parseable JSON. If it fails to parse, report the exact parse error (message + position) instead of guessing at a fix.
- Pretty-print it with 2-space indentation and a trailing newline, preserving key order (do not sort keys unless asked).
- Write the formatted result back to the same file path (unless the user asked for a different output path).
- Show the user a short diff-style summary (e.g. before/after line count) rather than dumping the whole file back at them.
Implementation
Run whichever script matches a runtime already available in the project — do not add a new dependency just to pretty-print JSON:
- Python:
python scripts/format_json.py <path-to-json-file>
- Node:
node scripts/format_json.js <path-to-json-file>
Both scripts validate the JSON, report a parse error and exit non-zero if it's invalid, otherwise rewrite the file in place with 2-space indentation and a trailing newline.
Notes
- Never silently "fix" invalid JSON (e.g. trailing commas, comments) by deleting content — flag it to the user and ask before making structural changes beyond whitespace/formatting.
- Keep number/string formatting as-is; this skill only changes whitespace/indentation, not values.
