> ## Documentation Index
> Fetch the complete documentation index at: https://docs.mcp-use.com/llms.txt
> Use this file to discover all available pages before exploring further.

# In-Memory Storage

> Using in-memory session storage for development and single-instance deployments

`InMemorySessionStore` stores session metadata in the server's memory. This is the default storage provider when no custom `sessionStore` is provided.

## Usage

```typescript theme={null}
import { MCPServer, InMemorySessionStore } from 'mcp-use/server';

const server = new MCPServer({
  name: 'my-server',
  version: '1.0.0',
  sessionStore: new InMemorySessionStore()  // Default, can be omitted
});
```

## Characteristics

### Advantages

* ✅ **Fast** - No I/O overhead, all operations are in-memory
* ✅ **No dependencies** - Works out of the box, no Redis or database needed
* ✅ **Simple** - Zero configuration required
* ✅ **All features work** - Notifications, sampling, subscriptions all work on a single server

### Limitations

* ❌ **Sessions lost on restart** - All session data is cleared when the server restarts
* ❌ **Not distributed** - Cannot share sessions across multiple server instances
* ❌ **Memory bound** - All sessions must fit in server memory

## When to Upgrade

Upgrade to [Redis Storage](/typescript/server/session-management/redis-storage) when you need:

* Sessions to persist across server restarts
* Multiple server instances behind a load balancer
* Distributed notifications/sampling across servers

## Related Documentation

* [Session Management Overview](/typescript/server/session-management)
* [File System Storage](/typescript/server/session-management/filesystem-storage)
* [Redis Storage](/typescript/server/session-management/redis-storage)