Sessions

The Agents SDK provides built-in session memory to automatically maintain conversation history across multiple agent runs, eliminating the need to manually handle .to_input_list() between turns.

Sessions stores conversation history for a specific session, allowing agents to maintain context without requiring explicit manual memory management. This is particularly useful for building chat applications or multi-turn conversations where you want the agent to remember previous interactions.

Quick start

from agents import Agent, Runner, SQLiteSession

# Create agent
agent = Agent(
    name="Assistant",
    instructions="Reply very concisely.",
)

# Create a session instance with a session ID
session = SQLiteSession("conversation_123")

# First turn
result = await Runner.run(
    agent,
    "What city is the Golden Gate Bridge in?",
    session=session
)
print(result.final_output)  # "San Francisco"

# Second turn - agent automatically remembers previous context
result = await Runner.run(
    agent,
    "What state is it in?",
    session=session
)
print(result.final_output)  # "California"

# Also works with synchronous runner
result = Runner.run_sync(
    agent,
    "What's the population?",
    session=session
)
print(result.final_output)  # "Approximately 39 million"

How it works

When session memory is enabled:

1. Before each run: The runner automatically retrieves the conversation history for the session and prepends it to the input items.
2. After each run: All new items generated during the run (user input, assistant responses, tool calls, etc.) are automatically stored in the session.
3. Context preservation: Each subsequent run with the same session includes the full conversation history, allowing the agent to maintain context.

This eliminates the need to manually call .to_input_list() and manage conversation state between runs.

Memory operations

Basic operations

Sessions supports several operations for managing conversation history:

from agents import SQLiteSession

session = SQLiteSession("user_123", "conversations.db")

# Get all items in a session
items = await session.get_items()

# Add new items to a session
new_items = [
    {"role": "user", "content": "Hello"},
    {"role": "assistant", "content": "Hi there!"}
]
await session.add_items(new_items)

# Remove and return the most recent item
last_item = await session.pop_item()
print(last_item)  # {"role": "assistant", "content": "Hi there!"}

# Clear all items from a session
await session.clear_session()

Using pop_item for corrections

The pop_item method is particularly useful when you want to undo or modify the last item in a conversation:

from agents import Agent, Runner, SQLiteSession

agent = Agent(name="Assistant")
session = SQLiteSession("correction_example")

# Initial conversation
result = await Runner.run(
    agent,
    "What's 2 + 2?",
    session=session
)
print(f"Agent: {result.final_output}")

# User wants to correct their question
assistant_item = await session.pop_item()  # Remove agent's response
user_item = await session.pop_item()  # Remove user's question

# Ask a corrected question
result = await Runner.run(
    agent,
    "What's 2 + 3?",
    session=session
)
print(f"Agent: {result.final_output}")

Memory options

No memory (default)

# Default behavior - no session memory
result = await Runner.run(agent, "Hello")

OpenAI Conversations API memory

Use the OpenAI Conversations API to persist conversation state without managing your own database. This is helpful when you already rely on OpenAI-hosted infrastructure for storing conversation history.

from agents import OpenAIConversationsSession

session = OpenAIConversationsSession()

# Optionally resume a previous conversation by passing a conversation ID
# session = OpenAIConversationsSession(conversation_id="conv_123")

result = await Runner.run(
    agent,
    "Hello",
    session=session,
)

SQLite memory

from agents import SQLiteSession

# In-memory database (lost when process ends)
session = SQLiteSession("user_123")

# Persistent file-based database
session = SQLiteSession("user_123", "conversations.db")

# Use the session
result = await Runner.run(
    agent,
    "Hello",
    session=session
)

Multiple sessions

from agents import Agent, Runner, SQLiteSession

agent = Agent(name="Assistant")

# Different sessions maintain separate conversation histories
session_1 = SQLiteSession("user_123", "conversations.db")
session_2 = SQLiteSession("user_456", "conversations.db")

result1 = await Runner.run(
    agent,
    "Hello",
    session=session_1
)
result2 = await Runner.run(
    agent,
    "Hello",
    session=session_2
)

SQLAlchemy-powered sessions

For more advanced use cases, you can use a SQLAlchemy-powered session backend. This allows you to use any database supported by SQLAlchemy (PostgreSQL, MySQL, SQLite, etc.) for session storage.

Example 1: Using from_url with in-memory SQLite

This is the simplest way to get started, ideal for development and testing.

import asyncio
from agents import Agent, Runner
from agents.extensions.memory.sqlalchemy_session import SQLAlchemySession

async def main():
    agent = Agent("Assistant")
    session = SQLAlchemySession.from_url(
        "user-123",
        url="sqlite+aiosqlite:///:memory:",
        create_tables=True,  # Auto-create tables for the demo
    )

    result = await Runner.run(agent, "Hello", session=session)

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

Example 2: Using an existing SQLAlchemy engine

In a production application, you likely already have a SQLAlchemy AsyncEngine instance. You can pass it directly to the session.

import asyncio
from agents import Agent, Runner
from agents.extensions.memory.sqlalchemy_session import SQLAlchemySession
from sqlalchemy.ext.asyncio import create_async_engine

async def main():
    # In your application, you would use your existing engine
    engine = create_async_engine("sqlite+aiosqlite:///conversations.db")

    agent = Agent("Assistant")
    session = SQLAlchemySession(
        "user-456",
        engine=engine,
        create_tables=True,  # Auto-create tables for the demo
    )

    result = await Runner.run(agent, "Hello", session=session)
    print(result.final_output)

    await engine.dispose()

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

Custom memory implementations

You can implement your own session memory by creating a class that follows the Session protocol:

from agents.memory.session import SessionABC
from agents.items import TResponseInputItem
from typing import List

class MyCustomSession(SessionABC):
    """Custom session implementation following the Session protocol."""

    def __init__(self, session_id: str):
        self.session_id = session_id
        # Your initialization here

    async def get_items(self, limit: int | None = None) -> List[TResponseInputItem]:
        """Retrieve conversation history for this session."""
        # Your implementation here
        pass

    async def add_items(self, items: List[TResponseInputItem]) -> None:
        """Store new items for this session."""
        # Your implementation here
        pass

    async def pop_item(self) -> TResponseInputItem | None:
        """Remove and return the most recent item from this session."""
        # Your implementation here
        pass

    async def clear_session(self) -> None:
        """Clear all items for this session."""
        # Your implementation here
        pass

# Use your custom session
agent = Agent(name="Assistant")
result = await Runner.run(
    agent,
    "Hello",
    session=MyCustomSession("my_session")
)

Session management

Session ID naming

Use meaningful session IDs that help you organize conversations:

• User-based: "user_12345"
• Thread-based: "thread_abc123"
• Context-based: "support_ticket_456"

Memory persistence

• Use in-memory SQLite (SQLiteSession("session_id")) for temporary conversations
• Use file-based SQLite (SQLiteSession("session_id", "path/to/db.sqlite")) for persistent conversations
• Use SQLAlchemy-powered sessions (SQLAlchemySession("session_id", engine=engine, create_tables=True)) for production systems with existing databases supported by SQLAlchemy
• Use OpenAI-hosted storage (OpenAIConversationsSession()) when you prefer to store history in the OpenAI Conversations API
• Consider implementing custom session backends for other production systems (Redis, Django, etc.) for more advanced use cases

Session management

# Clear a session when conversation should start fresh
await session.clear_session()

# Different agents can share the same session
support_agent = Agent(name="Support")
billing_agent = Agent(name="Billing")
session = SQLiteSession("user_123")

# Both agents will see the same conversation history
result1 = await Runner.run(
    support_agent,
    "Help me with my account",
    session=session
)
result2 = await Runner.run(
    billing_agent,
    "What are my charges?",
    session=session
)

Complete example

Here's a complete example showing session memory in action:

import asyncio
from agents import Agent, Runner, SQLiteSession


async def main():
    # Create an agent
    agent = Agent(
        name="Assistant",
        instructions="Reply very concisely.",
    )

    # Create a session instance that will persist across runs
    session = SQLiteSession("conversation_123", "conversation_history.db")

    print("=== Sessions Example ===")
    print("The agent will remember previous messages automatically.\n")

    # First turn
    print("First turn:")
    print("User: What city is the Golden Gate Bridge in?")
    result = await Runner.run(
        agent,
        "What city is the Golden Gate Bridge in?",
        session=session
    )
    print(f"Assistant: {result.final_output}")
    print()

    # Second turn - the agent will remember the previous conversation
    print("Second turn:")
    print("User: What state is it in?")
    result = await Runner.run(
        agent,
        "What state is it in?",
        session=session
    )
    print(f"Assistant: {result.final_output}")
    print()

    # Third turn - continuing the conversation
    print("Third turn:")
    print("User: What's the population of that state?")
    result = await Runner.run(
        agent,
        "What's the population of that state?",
        session=session
    )
    print(f"Assistant: {result.final_output}")
    print()

    print("=== Conversation Complete ===")
    print("Notice how the agent remembered the context from previous turns!")
    print("Sessions automatically handles conversation history.")


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

API Reference

For detailed API documentation, see:

• Session - Protocol interface
• SQLiteSession - SQLite implementation
• OpenAIConversationsSession - OpenAI Conversations API implementation
• SQLAlchemySession - SQLAlchemy-powered implementation