@mastra/core/dist/docs/references/reference-file-based-agents-memory.md

> Discover all available pages from the documentation index: https://mastra.ai/llms.txt

# Memory

A file-based agent gets [memory](https://mastra.ai/docs/memory/overview) from a `memory.ts` file that default-exports a [`Memory`](https://mastra.ai/reference/memory/memory-class) instance. Use this page for the file-based convention; use the memory docs for message history, semantic recall, storage, and processors.

Without `memory.ts` or `config.memory`, the agent has no memory by default. Each `generate()` or `stream()` call starts without remembered conversation state unless you pass the prior context yourself.

## Quickstart

Create `memory.ts` next to the agent's `config.ts`:

```typescript
import { Memory } from '@mastra/memory'

export default new Memory()
```

The exported instance becomes the agent's `memory`. If your app configures a storage provider on the main Mastra instance, memory data is stored there. See [storage](https://mastra.ai/docs/storage/overview) for more information.

Use the same `resource` and `thread` values when calling the agent to continue a conversation:

```typescript
const response = await weatherAgent.generate('Remember that I prefer Celsius.', {
  memory: {
    resource: 'user-123',
    thread: 'weather-chat',
  },
})
```

## Configure memory

Pass options to `new Memory()` when the default behavior isn't enough.

```typescript
import { Memory } from '@mastra/memory'

export default new Memory({
  options: {
    lastMessages: 20,
    workingMemory: {
      enabled: true,
      scope: 'resource',
    },
  },
})
```

Visit the [`Memory` reference](https://mastra.ai/reference/memory/memory-class) for constructor options. Use these pages for related memory features:

- [Storage](https://mastra.ai/docs/storage/overview): configure persistence for memory data.
- [Semantic recall](https://mastra.ai/docs/memory/semantic-recall): retrieve relevant past messages by semantic meaning.
- [Memory processors](https://mastra.ai/docs/memory/memory-processors): filter, trim, or transform messages before memory adds them to model context.

## Precedence with config

`config.memory` wins over `memory.ts`. If neither is present, the assembled file-based agent has no memory. See [`config.ts` precedence](https://mastra.ai/reference/file-based-agents/config) for the full merge table.