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
@@ optional change context
-old line
+new line
*** Delete File: obsolete.txt
*** End Patch

Parameters

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

Notes

• Patch paths support relative paths (from the workspace directory) and absolute paths.
• tools.exec.applyPatch.workspaceOnly defaults to true (workspace-contained). Set it to false only if you intentionally want apply_patch to write/delete outside the workspace directory.
• Use *** Move to: within an *** Update File: hunk to rename files.
• *** End of File marks an EOF-only insert when needed.
• Enabled by default for every model. Set tools.exec.applyPatch.enabled: false to disable it, or restrict it to specific models with tools.exec.applyPatch.allowModels (accepts raw ids like gpt-5.4 or full ids like openai/gpt-5.4).
• Config lives under tools.exec.applyPatch.*.

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"
}

Related

Source: docs/tools/apply-patch.md