Get ChatMessages from Workflow session

[Toni Wenzel (twenzel)]

I've a workflow as agent with a custom agent session store (sql).

I want to retrieve all chat messages from this agent/store in order to show these in a UI.

Is there a possibility to extract ChatMessages from a AgentSession (or in particular a WorkflowSession)?

[Michael Volz (VolzM)]

Toni Wenzel (@twenzel) Have you found a solution?

[Toni Wenzel (twenzel)]

This is what I currently use:

/// <summary>
	/// Gets the ChatMessages from the session.
	/// </summary>
	/// <param name="session">The session to get the internal messages from.</param>
	/// <param name="agent">The agent of the session.</param>
	/// <returns></returns>
	public static async Task<List<ChatMessage>> ToChatMessages(this AgentSession session, AIAgent agent)
	{
		if (session.TryGetInMemoryChatHistory(out var chatHistory))
			return chatHistory;

		var messages = session.GetService<IList<ChatMessage>>();
		if (messages != null)
			return messages.ToList();

		messages = agent.GetService<IList<ChatMessage>>();
		if (messages != null)
			return messages.ToList();

		var historyProvider = agent.GetService<ChatHistoryProvider>();
		if (historyProvider is InMemoryChatHistoryProvider memoryChatHistoryProvider)
			return memoryChatHistoryProvider.GetMessages(session);

		var root = await agent.SerializeSessionAsync(session, JsonSerializerOptions.Web);

		var customSession = JsonSerializer.Deserialize<SerializedSession>(root, JsonSerializerOptions.Web);

		return customSession?.ChatHistoryProviderState?.Messages ?? [];
	}

[Michael Volz (VolzM)]

Hmm doesn't work for the WorkflowSession. I will take a closer look thank you :)

[Denis Samatov (denis-samatov)]

Correction: InMemoryChatHistoryProvider.GetMessages(session) is not a supported transcript path for a WorkflowSession. A workflow-as-agent session installs its own internal workflow history provider, so resolving an InMemoryChatHistoryProvider does not expose that history. This limitation is tracked in #6946.

I would also avoid deserializing SerializedSession or reading ChatHistoryProviderState.Messages; those are persistence internals, not a public transcript contract.

For a UI or audit transcript, maintain an application-owned projection instead:

1. Assign an application conversation ID at the API/UI boundary.
2. Persist each user message before calling the agent.
3. Persist the outer AgentResponse messages (or aggregated streaming response) after the run.
4. If executor-level workflow events are also needed, store them in a separate event log rather than mixing them into the user-visible transcript.
5. Store the workflow session/checkpoint identifier alongside that conversation ID so execution can resume independently of transcript rendering.

This keeps two different concerns separate: the workflow checkpoint/session is resume state, while the SQL projection is the queryable conversation shown by the UI. If a future package exposes a public workflow-history API, use that API after verifying the exact version; on affected versions there is no comfortable supported extraction from WorkflowSession.