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

# Creating a Chat

> How to initialize and configure a Chat session

## Basic Creation

A Chat requires an Agent and session/user identifiers:

```python theme={null}
import asyncio
from upsonic import Agent, Chat


async def main():
    agent = Agent("anthropic/claude-sonnet-4-5")

    chat = Chat(
        session_id="session1",
        user_id="user1",
        agent=agent
    )

    response = await chat.invoke("Hello!")
    print(response)


if __name__ == "__main__":
    asyncio.run(main())
```

## With Memory Configuration

Enable conversation memory features:

```python theme={null}
import asyncio
from upsonic import Agent, Chat


async def main():
    agent = Agent("anthropic/claude-sonnet-4-5")

    chat = Chat(
        session_id="session1",
        user_id="user1",
        agent=agent,
        full_session_memory=True,
        summary_memory=True,
        user_analysis_memory=True,
        num_last_messages=50
    )

    await chat.invoke("My name is Alice")
    response = await chat.invoke("What is my name?")
    print(response)


if __name__ == "__main__":
    asyncio.run(main())
```

## With Custom Storage

Use persistent storage for session data:

```python theme={null}
import asyncio
from upsonic import Agent, Chat
from upsonic.storage import SqliteStorage


async def main():
    storage = SqliteStorage(db_file="chat.db")
    agent = Agent("anthropic/claude-sonnet-4-5")

    chat = Chat(
        session_id="session1",
        user_id="user1",
        agent=agent,
        storage=storage
    )

    response = await chat.invoke("Hello!")
    print(response)


if __name__ == "__main__":
    asyncio.run(main())
```

## With Retry Configuration

Configure retry behavior for transient failures:

```python theme={null}
import asyncio
from upsonic import Agent, Chat


async def main():
    agent = Agent("anthropic/claude-sonnet-4-5")

    chat = Chat(
        session_id="session1",
        user_id="user1",
        agent=agent,
        retry_attempts=5,
        retry_delay=2.0,
        max_concurrent_invocations=2
    )

    response = await chat.invoke("Hello!")
    print(response)


if __name__ == "__main__":
    asyncio.run(main())
```

## Session and User IDs

* `session_id`: Unique per conversation (e.g., `"user123_session1"`)
* `user_id`: Unique per user, can have multiple sessions

Use consistent IDs to maintain context across application restarts.