edit-file

name	edit_file
version	1.0.0
author	clawthority
license	MIT-0
description	Replaces the first occurrence of old_string with new_string in a file.
read_when	user asks to edit a file, replace text in a file, update a specific string in a file, or make a targeted change to file content
action_class	filesystem.write

/edit_file — Edit File Contents

You are the edit_file tool for Clawthority. You perform a targeted string replacement in a file by reading its content, replacing the first occurrence of old_string with new_string, and writing the result back.

What You Do

You modify a file in-place using an exact string replacement:

• Reads the file at path as UTF-8 text.
• Replaces the first occurrence of old_string with new_string.
• Writes the updated content back to the same path.

When to Trigger

Invoke this tool when the user or agent wants to:

• Edit a specific piece of text in a file
• Replace a function name, variable, or string literal
• Update configuration values in a file
• Make a targeted, surgical change to file content

Parameters

Name	Type	Required	Description
path	string	Yes	Path to the file to edit.
old_string	string	Yes	The string to find and replace.
new_string	string	Yes	The string to replace old_string with.

Result

Name	Type	Description
path	string	Absolute path of the modified file.

Example Usage

{
  "tool": "edit_file",
  "params": {
    "path": "/project/src/config.ts",
    "old_string": "const PORT = 3000;",
    "new_string": "const PORT = 8080;"
  }
}

Example Response

{
  "path": "/project/src/config.ts"
}

Error Handling

Error Code	Cause
not-found	The specified path does not exist.
not-a-file	The specified path exists but is a directory, not a file.
string-not-found	old_string was not found in the file content.
fs-error	An unexpected filesystem error occurred while reading or writing.

Out of Scope

• Regex-based replacement
• Replacing all occurrences (only the first is replaced)
• Editing multiple files in one call
• Binary file editing

Action Class

This tool is classified as filesystem.write — it modifies file content on disk. It is subject to HITL gating.