docs/tools/apply-patch.md

---
summary: "Apply multi-file patches with the apply_patch tool"
read_when:
  - You need structured file edits across multiple files
  - You want to document or debug patch-based edits
---

# 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

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