Transport should provide call data, if available

[julian-hecker]

Problem Statement

Inside a bot, it's useful to have access to call data from a telephony provider. For example, Twilio call_sid. This is not currently easy or clean to access.

When using create_transport, the websocket already has to be parsed in order to find out which provider is used and information like the call_sid. However, the twilio example shows you have to manually parse the websocket and create a serializer to get the call_sid. If you try to parse the websocket twice, by manually doing so and using create_transport, you get an error.

I was able to obtain call info as such by accessing "private" members on the transport. However, this does not feel right.

from operator import attrgetter

def get_call_sid(transport: BaseTransport) -> str | None:
    try:
        return str(attrgetter("_params.serializer._call_sid")(transport))
    except AttributeError:
        return None

I wish there was a simple way to get call data like the call_sid from the transport.

Proposed Solution

Add a parameter to BaseTransport, maybe called transport_details which is populated at runtime depending on which provider is used. Twilio gets call_sid. Other telephony get their respective fields. WebRTC has its own additional details.

[jpagh]

I'm using this code which I'm very sure is based on code in the examples. Does this do what you want? It works well for me.

from fastapi import FastAPI, WebSocket
from pipecat.runner.types import WebSocketRunnerArguments

@app.websocket("/ws")
async def websocket_endpoint(websocket: WebSocket):
    """
    Handle WebSocket connections for inbound calls.
    """
    await websocket.accept()

    runner_args = WebSocketRunnerArguments(websocket=websocket)
    runner_args.handle_sigint = True

    await bot(runner_args)

async def bot(runner_args: WebSocketRunnerArguments):
    """
    Main bot entry point.
    """
    transport_type, call_data = await parse_telephony_websocket(runner_args.websocket)

    call_id = call_data["call_id"]
    custom_twilio_parameter = call_data["body"].get("custom_twilio_parameter")

    ...(rest of function)...