edit_file
Make line-based edits to text files by specifying original lines and their replacements. Returns a git-style diff showing changes made to files on your PC.
Instructions
Make line-based edits to a text file. Provide original lines and their replacements. Returns a git-style diff showing the changes made. Each edit replaces exact line sequences with new content.
Input Schema
TableJSON Schema
| Name | Required | Description | Default |
|---|---|---|---|
| path | Yes | The path to the file to edit | |
| edits | Yes | Array of edit operations to apply |
Implementation Reference
- src/index.ts:307-340 (handler)The handler for the 'edit_file' tool. Reads the target file, applies each specified edit by replacing 'oldText' with 'newText' (ensuring 'oldText' exists first), overwrites the file with the modified content, generates a simple unified diff using the helper function, and returns the diff.case "edit_file": { const filePath = args.path as string; const edits = args.edits as Array<{ oldText: string; newText: string; }>; let content = await fs.readFile(filePath, "utf-8"); const originalContent = content; // Apply each edit for (const edit of edits) { if (!content.includes(edit.oldText)) { throw new Error( `Could not find text to replace: ${edit.oldText.substring(0, 100)}...` ); } content = content.replace(edit.oldText, edit.newText); } await fs.writeFile(filePath, content, "utf-8"); // Generate diff const diff = generateDiff(originalContent, content, filePath); return { content: [ { type: "text", text: `Successfully edited ${filePath}\n\n${diff}`, }, ], }; }
- src/index.ts:55-82 (schema)Input schema for the 'edit_file' tool, defining required parameters: 'path' (string) and 'edits' (array of objects with 'oldText' and 'newText').inputSchema: { type: "object", properties: { path: { type: "string", description: "The path to the file to edit", }, edits: { type: "array", description: "Array of edit operations to apply", items: { type: "object", properties: { oldText: { type: "string", description: "The exact text to search for (can be multiple lines)", }, newText: { type: "string", description: "The text to replace it with", }, }, required: ["oldText", "newText"], }, }, }, required: ["path", "edits"], },
- src/index.ts:52-83 (registration)Registration of the 'edit_file' tool in the TOOLS array, which is returned by the listTools handler. Includes name, description, and input schema.{ name: "edit_file", description: "Make line-based edits to a text file. Provide original lines and their replacements. Returns a git-style diff showing the changes made. Each edit replaces exact line sequences with new content.", inputSchema: { type: "object", properties: { path: { type: "string", description: "The path to the file to edit", }, edits: { type: "array", description: "Array of edit operations to apply", items: { type: "object", properties: { oldText: { type: "string", description: "The exact text to search for (can be multiple lines)", }, newText: { type: "string", description: "The text to replace it with", }, }, required: ["oldText", "newText"], }, }, }, required: ["path", "edits"], }, },
- src/index.ts:523-552 (helper)Helper function 'generateDiff' that creates a simple git-style unified diff between original and modified file contents. Called by the edit_file handler to include the diff in the response.function generateDiff( original: string, modified: string, filepath: string ): string { const originalLines = original.split("\n"); const modifiedLines = modified.split("\n"); let diff = `--- ${filepath}\n+++ ${filepath}\n`; let lineNum = 0; while ( lineNum < originalLines.length || lineNum < modifiedLines.length ) { if (originalLines[lineNum] !== modifiedLines[lineNum]) { diff += `@@ -${lineNum + 1} +${lineNum + 1} @@\n`; if (lineNum < originalLines.length) { diff += `- ${originalLines[lineNum]}\n`; } if (lineNum < modifiedLines.length) { diff += `+ ${modifiedLines[lineNum]}\n`; } } lineNum++; } return diff; }