---
title: Conversations | Letta Docs
description: Work with one agent across independent message threads
---

A **conversation** is a message thread with an agent. One agent can have many conversations, and every conversation uses the same agent identity and long-term memory.

Use separate conversations to keep tasks independent while preserving what the agent has learned about you and your work.

## Start and resume conversations

When you run `letta` without arguments, the CLI resumes the default conversation with your last-used agent.

Start a new conversation from the CLI:

```
letta --new
```

Or start one during an interactive session:

```
> /new
```

Use `/resume` to browse previous conversations, or pass a conversation ID directly:

```
> /resume
letta --conv conv-abc123
```

## Fork a conversation

Use `/fork` to branch the current conversation, including its in-context history. The new conversation can take a different direction without changing the original thread.

Use `/btw` for a side question. It forks the conversation in the background and returns the answer without interrupting your main task.

## Conversation context and agent memory

A conversation contains the messages needed for its current thread. As it grows, older messages are compacted so the active context remains within the model’s limit.

Long-term knowledge belongs to the agent’s [MemFS memory](/concepts/memfs/index.md), not one conversation. Durable lessons saved there remain available across conversations.