Access a session context from a custom API endpoints

[rachidbch]

My application makes use of custom API endpoints to create webhooks that are triggered by external applications.
When a webhook is trigered the application is able to identify:

• The user that should be informed of the event.
• Its session id

Unfortunately I haven't found a document way to send a message to that user from the API endpoint handler so that the user can see the message on Chainlit web ui.

Inside the API endpoint handler, there's no Context defined and Chainlit doesn't offer a documented way the context of a session even if the session_id is known.

For the time beeing, I use an horrible hack to work around this problem.

What is the recommended way to summon a the context of a specific session so that we can use the standard Chainlit API to send and receive messages from a user.

Of course the webhook could be triggered while the target user is not connected to the Web UI, but that should be trivial to deal with at the application level.

[willydouhard]

The problem is how to link a session id to a custom http request.

The following code works but you would have to pass the session_id somehow to your custom endpoint call, and not use a global variable:

import chainlit as cl
from chainlit.server import app
from chainlit.session import Session
from chainlit.context import init_context
from fastapi import Request
from fastapi.responses import (
    HTMLResponse,
)

session_id = None


@cl.on_chat_start
async def start():
    global session_id
    session_id = cl.user_session.get("id")


@app.get("/hello")
async def hello(request: Request):
    if not session_id:
        return HTMLResponse("No session id found")

    session = Session.get_by_id(session_id)
    init_context(session)

    await cl.Message(content="Hello from custom endpoint").send()

[rachidbch]

Really nice! That’s exactly what I need. Looking (too rapidly) in the source code of Chainlit, I couldn’t find a hint on how to achieve that.

As for linking to the pertinent session_id, I do it right now by maintaining a mapping between emails and session ids as a global map.

This custom API endpoint always receives the email of the user that is then converted to the corresponding session_id.

It’s ok for a POC.

Of course, if things would go further than a POC, the app would benefit from a standard way to find session_ids based on the key/values set with user_session.set(key, value).

That way, the app could generate tokens to users that could be used by external apps to interact with the Chainlit app.

Thank you for your helpful answer! And keep up the good work!

[maddyonline]

Is there an updated version of this working example for version 1? Would really appreciate it. Thanks!