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@@ 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"}

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