# ContentBlock

> **Interface** in `@langchain/core`

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

## Signature

```javascript
interface ContentBlock
```

## Extends

- `BaseContentBlock`

## Properties

- `id`
- `type`

---

[View source on GitHub](https://github.com/langchain-ai/langchainjs/blob/3fedf7f1934a592b71da866bd16af886b4e0c00d/libs/langchain-core/src/messages/content/index.ts#L13)