# CompositeBackend

> **Class** in `deepagents`

📖 [View in docs](https://reference.langchain.com/javascript/deepagents/backends/CompositeBackend)

Backend that routes file operations to different backends based on path prefix.

This enables hybrid storage strategies like:
- `/memories/` → StoreBackend (persistent, cross-thread)
- Everything else → StateBackend (ephemeral, per-thread)

The CompositeBackend handles path prefix stripping/re-adding transparently.

## Signature

```javascript
class CompositeBackend
```

## Implements

- `BackendProtocolV2`

## Constructors

- [`constructor()`](https://reference.langchain.com/javascript/deepagents/backends/CompositeBackend/constructor)

## Properties

- `id`
- `routePrefixes`

## Methods

- [`delete()`](https://reference.langchain.com/javascript/deepagents/backends/CompositeBackend/delete)
- [`downloadFiles()`](https://reference.langchain.com/javascript/deepagents/backends/CompositeBackend/downloadFiles)
- [`edit()`](https://reference.langchain.com/javascript/deepagents/backends/CompositeBackend/edit)
- [`execute()`](https://reference.langchain.com/javascript/deepagents/backends/CompositeBackend/execute)
- [`glob()`](https://reference.langchain.com/javascript/deepagents/backends/CompositeBackend/glob)
- [`grep()`](https://reference.langchain.com/javascript/deepagents/backends/CompositeBackend/grep)
- [`ls()`](https://reference.langchain.com/javascript/deepagents/backends/CompositeBackend/ls)
- [`read()`](https://reference.langchain.com/javascript/deepagents/backends/CompositeBackend/read)
- [`readRaw()`](https://reference.langchain.com/javascript/deepagents/backends/CompositeBackend/readRaw)
- [`uploadFiles()`](https://reference.langchain.com/javascript/deepagents/backends/CompositeBackend/uploadFiles)
- [`write()`](https://reference.langchain.com/javascript/deepagents/backends/CompositeBackend/write)
- [`isInstance()`](https://reference.langchain.com/javascript/deepagents/backends/CompositeBackend/isInstance)

---

[View source on GitHub](https://github.com/langchain-ai/deepagentsjs/blob/60e32118b0ba24ea7ef636476a9a96add9d1a99b/libs/deepagents/src/backends/composite.ts#L34)