Chat history is not getting retrieved on the chat resume

[ashish6ai]

Hi
I'm saving the chat history to the postgresdb through data layer but when I'm doing the chat resume the history is not getting loaded but the chat title is coming up in the side bar and chat is also getting stored into the threads tables.
I have provided the code snippet which I'm using, please let me know if there are any issues in the approach or any changes needs to be done.

Code Snippet -
"""
connection_string = os.getenv('DB_CONNECTION_STRING')
cl_data._data_layer = SQLAlchemyDataLayer(conninfo=connection_string)

@cl.on_chat_start
async def start():
settings = await cl.ChatSettings(
[
Select(
id="model",
label="Large Language Model",
values=[
"gemini-1.5-flash",
"gpt-4o",
"llama3.2:3b"
],
initial_index=0,
),
]
).send()
setup_llm(settings)

welcome_message = await cl.Message(author="Codegen",content=prompts.WELCOME_CONTENT).send()

# Save welcome message to database
await cl_data._data_layer.create_step({
    "id": welcome_message.id,
    "threadId": cl.user_session.get("thread_id"),
    "type": "ai",
    "name": "welcome",
    "output": prompts.WELCOME_CONTENT
})

cl.user_session.set("message_history_openai", [{"role": "system", "content": prompts.WELCOME_CONTENT}])
cl.user_session.set("message_history_gemini", [{"role": "model", "parts": prompts.WELCOME_CONTENT}])
cl.user_session.set("message_history_ollama", [{"role": "system", "content": prompts.SYSTEM_PROMPT}])

@cl.on_chat_resume
async def on_chat_resume(thread: ThreadDict):
settings = await cl.ChatSettings(
[
Select(
id="model",
label="Large Language Model",
values=[
"gemini-1.5-flash",
"gpt-4o",
"llama3.2:3b"
],
initial_index=0,
),
]).send()
setup_llm(settings)

thread_data = await cl_data._data_layer.get_thread(thread['id'])
print(thread_data)
# Reconstruct message history for each model
if thread_data:
    messages = thread_data['steps']

    message_history_openai = [{"role": "system", "content": prompts.WELCOME_CONTENT}]
    message_history_gemini = [{"role": "model", "parts": prompts.WELCOME_CONTENT}]
    message_history_ollama = [{"role": "system", "content": prompts.SYSTEM_PROMPT}]

    for step in messages:
        if step['type'] == 'human':
            message_history_openai.append({"role": "user", "content": step['output']})
            message_history_gemini.append({"role": "user", "parts": step['output']})
            message_history_ollama.append({"role": "user", "content": step['output']})
        else:
            message_history_openai.append({"role": "assistant", "content": step['output']})
            message_history_gemini.append({"role": "model", "parts": step['output']})
            message_history_ollama.append({"role": "assistant", "content": step['output']})

cl.user_session.set("message_history_openai", message_history_openai)
cl.user_session.set("message_history_gemini", message_history_gemini)
cl.user_session.set("message_history_ollama", message_history_ollama)

await cl.Message(content="Welcome back! How can I assist you?").send()

@cl.on_message
async def on_message(msg: cl.Message):
model_name = cl.user_session.get("model_name")
model = cl.user_session.get("model")

# Save user message to database
await cl_data._data_layer.create_step({
    "id": msg.id,
    "threadId": cl.user_session.get("thread_id"),
    "type": "human",
    "name": "user_message",
    "output": msg.content
})

if not msg.elements:
    if "gemini" in model_name:
        message_history_gemini = cl.user_session.get("message_history_gemini")
        message_history_gemini.append({"role": "user", "parts": msg.content})
        res = gemini_tool_chat(msg.content, model, message_history_gemini)
        message_history_gemini.append({"role": "model", "parts": res})
        cl.user_session.set("message_history_gemini", message_history_gemini)
    elif "gpt" in model_name:
        message_history_openai = cl.user_session.get("message_history_openai")
        message_history_openai.append({"role": "user", "content": msg.content})
        res = openai_tool(prompts.SYSTEM_PROMPT, str(message_history_openai), model, model_name)
        message_history_openai.append({"role": "assistant", "content": res})
        cl.user_session.set("message_history_openai", message_history_openai)
    elif "llama" in model_name:
        message_history_ollama = cl.user_session.get("message_history_ollama")
        message_history_ollama.append({"role": "user", "content": msg.content})
        res = ollama_chat_tool(OLLAMA_API_URL, model_name, message_history_ollama)
        message_history_ollama.append({"role": "assistant", "content": res})

    response_message = await cl.Message(author="Codegen", content=res).send()

    # Save assistant's response to database
    await cl_data._data_layer.create_step({
        "id": response_message.id,
        "threadId": cl.user_session.get("thread_id"),
        "type": "ai",
        "name": "assistant_response",
        "output": res
    })

"""

[daviddwlee84]

Same issue using Literal AI

I was able to recover chat history and continue chatting, but the history of messages won't show after resuming

1. Select a history session
   
2. Click resume
   
3. Missing history messages
   
4. Create a new chat and the history session will refresh
   

Followed the cookbook with little modification
cookbook/resume-chat at main · Chainlit/cookbook

With Python 3.11 and dependencies

chainlit==1.3.1
langchain==0.3.7
langchain-community==0.3.5
langchain-core==0.3.15
langchain-openai==0.2.3