# ContentBlock

> **Type Alias** in `langchain_core`

📖 [View in docs](https://reference.langchain.com/python/langchain-core/messages/content/ContentBlock)

A union of all defined `ContentBlock` types and aliases.

## Signature

```python
ContentBlock = TextContentBlock | InvalidToolCall | ReasoningContentBlock | NonStandardContentBlock | DataContentBlock | ToolContentBlock
```

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[View source on GitHub](https://github.com/langchain-ai/langchain/blob/8fec4e7ceee2c368b068c49f9fed453276e210e7/libs/core/langchain_core/messages/content.py#L845)