pipecat-didlogic

DIDLogic WebSocket call support for Pipecat.

DidlogicFrameSerializer converts between Pipecat audio frames and the DIDLogic voice-stream protocol, so a Pipecat bot can take a call on a DIDLogic number — or be the agent leg of an outbound call — and speak on it.

Maintained by DIDLogic. We run the platform this talks to.

What it handles

• Audio both ways. PCM16 at 24 kHz in 10 ms frames, base64-encoded inside JSON messages, resampled to and from whatever rate your pipeline runs at.
• Inbound and outbound calls. The serializer reads the start message off the socket, so the call id, the two numbers and the direction do not have to be known before the pipeline is built.
• DTMF, delivered to the pipeline as InputDTMFFrame.
• Interruptions, by sending clear so the platform drops audio it has buffered but not yet played.
• Hanging up, by sending hangup on EndFrame or CancelFrame. No credentials needed — it is one more message on the socket that is already open.
• answered, surfaced as an InputTransportMessageFrame. On an outbound call the platform answers your leg as soon as it has sent start, which is before the person has picked up; answered is what says they are there.

The protocol itself is documented at docs.didlogic.com.

Install

uv add pipecat-didlogic

or:

pip install pipecat-didlogic

Tested with Pipecat 1.12.0.

Use with a Pipecat pipeline

The serializer goes on the WebSocket transport's params. Telephony audio carries no WAV header, so add_wav_header must be False:

from pipecat.transports.websocket.fastapi import (
    FastAPIWebsocketParams,
    FastAPIWebsocketTransport,
)

from pipecat_didlogic import DidlogicFrameSerializer

transport = FastAPIWebsocketTransport(
    websocket=websocket,
    params=FastAPIWebsocketParams(
        audio_in_enabled=True,
        audio_out_enabled=True,
        add_wav_header=False,
        vad_analyzer=SileroVADAnalyzer(),
        serializer=DidlogicFrameSerializer(),
    ),
)

That is the whole integration. Everything else in the pipeline — STT, LLM, TTS — is ordinary Pipecat.

Options

DidlogicFrameSerializer(
    DidlogicFrameSerializer.InputParams(
        didlogic_sample_rate=24000,  # what the platform sends and expects
        sample_rate=None,  # override the pipeline input rate
        auto_hang_up=True,  # send hangup on EndFrame / CancelFrame
    )
)

Pass call_id, from_number, to_number or direction to the constructor if your server reads start before building the serializer. Leave them unset and all four are learned from start.

Waiting for an outbound call to be picked up

On an outbound call the platform answers your leg as soon as it has sent start, which is before the customer's phone has rung. Greeting on connect means talking to an empty line, so wait for answered:

from pipecat.frames.frames import InputTransportMessageFrame, LLMRunFrame
from pipecat.processors.frame_processor import FrameProcessor


class GreetWhenAnswered(FrameProcessor):
    async def process_frame(self, frame, direction):
        await super().process_frame(frame, direction)

        if (
            isinstance(frame, InputTransportMessageFrame)
            and frame.message.get("event") == "answered"
        ):
            await self.push_frame(LLMRunFrame())

        await self.push_frame(frame, direction)

Put it directly after transport.input(). The outbound example below does this.

Examples

examples/ has two complete bots, each self-contained with its own dependencies and setup instructions:

• examples/inbound/ — a bot that answers calls to one of your numbers.
• examples/outbound/ — a bot that places the call through Click2Call and waits for answered before speaking.

Each runs with uv sync && uv run server.py in its own directory. Both need a public wss:// address, because the platform dials your endpoint rather than the other way round.

WebSocket destinations and a_type: stream are enabled per account. If the destination type is absent from the portal, or the API answers 422 a_type_unsupported, ask support to turn on voice streaming for your account.

Development

uv sync --extra dev
uv run pytest
uv run ruff check .
uv run ruff format --check .

License

BSD 2-Clause. See LICENSE.