Json Modifier

Safely apply structured JSON patches (RFC 6902) to files. Use this skill when you need to update configuration files, package.json, or memory JSONs without r...

A utility for modifying JSON files using RFC 6902 JSON Patch format. Supports precise additions, removals, replacements, moves, copies, and tests.

Usage

# Modify a file in place
node skills/json-modifier/index.js --file path/to/config.json --patch '[{"op": "replace", "path": "/key", "value": "new_value"}]'

# Modify and save to a new file
node skills/json-modifier/index.js --file input.json --patch '[...]' --out output.json

# Use a patch file
node skills/json-modifier/index.js --file input.json --patch-file patches/update.json

Patch Format (RFC 6902)

The patch must be a JSON array of operation objects.

Examples

Replace a value:

[
  { "op": "replace", "path": "/version", "value": "2.0.0" }
]

Add a new key:

[
  { "op": "add", "path": "/features/new_feature", "value": true }
]

Remove a key:

[
  { "op": "remove", "path": "/deprecated_key" }
]

Append to an array:

[
  { "op": "add", "path": "/list/-", "value": "item" }
]

Safety

• Validates patch against document before applying.
• Atomic write (writes to temporary file, then renames).
• Preserves indentation (default: 2 spaces).