# build_approval_preview

> **Function** in `deepagents_cli`

📖 [View in docs](https://reference.langchain.com/python/deepagents-cli/file_ops/build_approval_preview)

Collect summary info and diff for HITL approvals.

## Signature

```python
build_approval_preview(
    tool_name: str,
    args: dict[str, Any],
    assistant_id: str | None,
) -> ApprovalPreview | None
```

## Returns

`ApprovalPreview | None`

ApprovalPreview with diff and details, or None if tool not supported.

---

[View source on GitHub](https://github.com/langchain-ai/deepagents/blob/3bcc51a95da80094cfc8bc4bcaf25dc1e2ad8f44/libs/cli/deepagents_cli/file_ops.py#L169)