Session

AgentSession is the conversation state container used across agent runs.

What AgentSession contains

Field	Purpose
StateBag	Arbitrary state container for this session

The C# AgentSession is an abstract base class. Concrete implementations (created via CreateSessionAsync()) may add additional state e.g. an id for remote chat history storage, when service-managed history is used.

Field	Purpose
session_id	Local unique identifier for this session
service_session_id	Remote service conversation identifier (when service-managed history is used)
state	Mutable dictionary shared with context/history providers

Built-in usage pattern

AgentSession session = await agent.CreateSessionAsync();

var first = await agent.RunAsync("My name is Alice.", session);
var second = await agent.RunAsync("What is my name?", session);

session = agent.create_session()

first = await agent.run("My name is Alice.", session=session)
second = await agent.run("What is my name?", session=session)

Creating a session from an existing service conversation ID

Create a new session from an existing conversation id varies by agent type. Here are some examples.

When using ChatClientAgent

AgentSession session = await chatClientAgent.CreateSessionAsync(conversationId);

When using an A2AAgent

AgentSession session = await a2aAgent.CreateSessionAsync(contextId, taskId);

Use this when the backing service already has conversation state.

session = agent.get_session(service_session_id="<service-conversation-id>")
response = await agent.run("Continue this conversation.", session=session)

Serialization and restoration

var serialized = agent.SerializeSession(session);
AgentSession resumed = await agent.DeserializeSessionAsync(serialized);

serialized = session.to_dict()
resumed = AgentSession.from_dict(serialized)

Important

Sessions are agent/service-specific. Reusing a session with a different agent configuration or provider can lead to invalid context.

Next steps

Context Providers