File Modify Tool
Write new files or edit existing files with exact string replacement. Uses the workspace-contained native filesystem backend.
Path sandbox: all paths resolve inside the per-workflow workspace root. Use workspace-relative paths (e.g. reports/summary.md); .. and ~ segments are rejected, and absolute paths are remapped into the workspace.
file_modify Tool
Schema Fields
| Field | Type | Required | Description |
|---|---|---|---|
| operation | string | Yes | write (create or wholesale-replace the file) or edit (surgical find-and-replace inside an existing file) |
| file_path | string | Yes | Path to the file |
| content | string | If write | Full file content to write — overwrites any existing file at this path |
| old_string | string | If edit | Exact text to find and replace |
| new_string | string | If edit | Replacement text |
| replace_all | boolean | No | Replace all occurrences (default: false, old_string must be unique) |
Examples
Write a new file:
json{ "operation": "write", "file_path": "/path/to/new_file.py", "content": "print('hello world')" }
Edit an existing file:
json{ "operation": "edit", "file_path": "/path/to/file.py", "old_string": "def old_name():", "new_string": "def new_name():" }
Replace all occurrences:
json{ "operation": "edit", "file_path": "/path/to/file.py", "old_string": "TODO", "new_string": "DONE", "replace_all": true }
Response Format
Write:
json{"operation": "write", "file_path": "/path/to/file.py"}
Edit:
json{"operation": "edit", "file_path": "/path/to/file.py", "occurrences": 1}
Guidelines
- Use
writeto create a new file or replace an existing file's contents wholesale. Provide the full new contents incontent; any existing file atfile_pathis replaced. - Use
editfor surgical string replacement inside an existing file — it is the right choice when you want to change a small portion of a file rather than rewrite the whole thing. - For edit:
old_stringmust be unique in the file unlessreplace_allis true. - Prefer
editoverwritewhen changing only part of an existing file — it produces a smaller diff and is less destructive. - Read the file first before editing to ensure correct context.
