apply_patch tool

Apply file changes using a structured patch format. This is ideal for multi-file or multi-hunk edits where a single edit call would be brittle.The tool accepts a single input string that wraps one or more file operations:


*** Begin Patch
*** Add File: path/to/file.txt
+line 1
+line 2
*** Update File: src/app.ts
@@
-old line
+new line
*** Delete File: obsolete.txt
*** End Patch

Parameters

input (required): Full patch contents including *** Begin Patch and *** End Patch.

Notes

Paths are resolved relative to the workspace root.
Use *** Move to: within an *** Update File: hunk to rename files.
*** End of File marks an EOF-only insert when needed.
Experimental and disabled by default. Enable with tools.exec.applyPatch.enabled.
OpenAI-only (including OpenAI Codex). Optionally gate by model via tools.exec.applyPatch.allowModels.
Config is only under tools.exec.

Example


{
  "tool": "apply_patch",
  "input": "*** Begin Patch\n*** Update File: src/index.ts\n@@\n-const foo = 1\n+const foo = 2\n*** End Patch"
}