Message History

Message history is the most basic and important form of memory. It gives the LLM a view of recent messages in the context window, enabling your agent to reference earlier exchanges and respond coherently.

You can also retrieve message history to display past conversations in your UI.

info

Each message belongs to a thread (the conversation) and a resource (the user or entity it's associated with). See Threads and resources for more detail.

Getting started

Install the Mastra memory module along with a storage adapter for your database. The examples below use @mastra/libsql, which stores data locally in a mastra.db file.

npm

npm install @mastra/memory@latest @mastra/libsql@latest

pnpm

pnpm add @mastra/memory@latest @mastra/libsql@latest

Yarn

yarn add @mastra/memory@latest @mastra/libsql@latest

Bun

bun add @mastra/memory@latest @mastra/libsql@latest

Message history requires a storage adapter to persist conversations. Configure storage on your Mastra instance if you haven't already:

src/mastra/index.ts

import { Mastra } from "@mastra/core";
import { LibSQLStore } from "@mastra/libsql";

export const mastra = new Mastra({
  storage: new LibSQLStore({
    id: 'mastra-storage',
    url: "file:./mastra.db",
  }),
});

Give your agent a Memory:

src/mastra/agents/your-agent.ts

import { Memory } from "@mastra/memory";
import { Agent } from "@mastra/core/agent";

export const agent = new Agent({
  id: "test-agent",
  memory: new Memory({
    options: {
      lastMessages: 10,
    },
  }),
});

When you call the agent, messages are automatically saved to the database. You can specify a threadId, resourceId, and optional metadata:

Generate

await agent.generate("Hello", {
  memory: {
    thread: {
      id: "thread-123",
      title: "Support conversation",
      metadata: { category: "billing" },
    },
    resource: "user-456",
  },
});

Stream

await agent.stream("Hello", {
  memory: {
    thread: {
      id: "thread-123",
      title: "Support conversation",
      metadata: { category: "billing" },
    },
    resource: "user-456",
  },
});

info

Threads and messages are created automatically when you call agent.generate() or agent.stream(), but you can also create them manually with createThread() and saveMessages().

There are two ways to use this history:

• Automatic inclusion - Mastra automatically fetches and includes recent messages in the context window. By default, it includes the last 10 messages, keeping agents grounded in the conversation. You can adjust this number with lastMessages, but in most cases you don't need to think about it.
• Manual querying - For more control, use the recall() function to query threads and messages directly. This lets you choose exactly which memories are included in the context window, or fetch messages to render conversation history in your UI.

Accessing Memory

To access memory functions for querying, cloning, or deleting threads and messages, call getMemory() on an agent:

const agent = mastra.getAgent("weatherAgent");
const memory = await agent.getMemory();

The Memory instance gives you access to functions for listing threads, recalling messages, cloning conversations, and more.

Querying

Use these methods to fetch threads and messages for displaying conversation history in your UI or for custom memory retrieval logic.

warning

The memory system does not enforce access control. Before running any query, verify in your application logic that the current user is authorized to access the resourceId being queried.

Threads

Use listThreads() to retrieve threads for a resource:

const result = await memory.listThreads({
  filter: { resourceId: "user-123" },
  perPage: false,
});

Paginate through threads:

const result = await memory.listThreads({
  filter: { resourceId: "user-123" },
  page: 0,
  perPage: 10,
});

console.log(result.threads); // thread objects
console.log(result.hasMore); // more pages available?

You can also filter by metadata and control sort order:

const result = await memory.listThreads({
  filter: {
    resourceId: "user-123",
    metadata: { status: "active" },
  },
  orderBy: { field: "createdAt", direction: "DESC" },
});

To fetch a single thread by ID, use getThreadById():

const thread = await memory.getThreadById({ threadId: "thread-123" });

Messages

Once you have a thread, use recall() to retrieve its messages. It supports pagination, date filtering, and semantic search.

Basic recall returns all messages from a thread:

const { messages } = await memory.recall({
  threadId: "thread-123",
  perPage: false,
});

Paginate through messages:

const { messages } = await memory.recall({
  threadId: "thread-123",
  page: 0,
  perPage: 50,
});

Filter by date range:

const { messages } = await memory.recall({
  threadId: "thread-123",
  filter: {
    dateRange: {
      start: new Date("2025-01-01"),
      end: new Date("2025-06-01"),
    },
  },
});

Fetch a single message by ID:

const { messages } = await memory.recall({
  threadId: "thread-123",
  include: [{ id: "msg-123" }],
});

Fetch multiple messages by ID with surrounding context:

const { messages } = await memory.recall({
  threadId: "thread-123",
  include: [
    { id: "msg-123" },
    {
      id: "msg-456",
      withPreviousMessages: 3,
      withNextMessages: 1,
    },
  ],
});

Search by meaning (see Semantic recall for setup):

const { messages } = await memory.recall({
  threadId: "thread-123",
  vectorSearchString: "project deadline discussion",
  threadConfig: {
    semanticRecall: true,
  },
});

UI format

Message queries return MastraDBMessage[] format. To display messages in a frontend, you may need to convert them to a format your UI library expects. For example, toAISdkV5Messages converts messages to AI SDK UI format.

Thread cloning

Thread cloning creates a copy of an existing thread with its messages. This is useful for branching conversations, creating checkpoints before a potentially destructive operation, or testing variations of a conversation.

const { thread, clonedMessages } = await memory.cloneThread({
  sourceThreadId: "thread-123",
  title: "Branched conversation",
});

You can filter which messages get cloned (by count or date range), specify custom thread IDs, and use utility methods to inspect clone relationships.

See cloneThread() and clone utilities for the full API.

Deleting messages

To remove messages from a thread, use deleteMessages(). You can delete by message ID or clear all messages from a thread.