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This guide covers the provider="daily" SIP mode, where Daily directly connects its SIP leg to your telephony carrier (Twilio, Telnyx, Five9, Genseys, Cisco, …). This SIP mode with provider="daily" gives you:
  • Static egress IPs you can allow-list on the carrier side for tighter ACLs.
  • One SIP configuration that works across carriers — the bot code doesn’t change when you swap providers.
The reference implementation lives in the Twilio SIP examples because Twilio is the most common carrier, but the same bot code works with any SIP-capable provider — only the carrier-side webhook / SIP URI changes.

SIP Dial-in Example

Inbound calls routed from a carrier into a Daily room via provider="daily" SIP

SIP Dial-out Example

Outbound calls initiated from Daily and routed out through the carrier

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Things you’ll need

  • A Daily API key.
  • An account with a SIP-capable carrier (Twilio, Telnyx, Plivo, Exotel, …) with at least one provisioned number.

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Environment Setup

.env
DAILY_API_KEY=...
DAILY_API_URL=https://api.daily.co/v1
OPENAI_API_KEY=...
CARTESIA_API_KEY=...

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Creating a Daily room with provider="daily"

The key difference from the carrier-default SIP flow is a single field on the room SIP config:
server_utils.py
sip_config = await configure(
    session,
    sip_caller_phone=call_data.from_phone,
    sip_provider="daily",   # <-- routes SIP through Daily's own infrastructure
    enable_dialout=True,
    room_geo="us-east-1",   # <-- optional, this anchors the Daily Room to a location
)
This returns a sip_endpoint you hand to your carrier for call forwarding, and (for dial-out) a room configured to accept start_dialout with {"provider": "daily", ...}. Daily’s SIP address are of the format: sip:$roomName.$index@$domainName.sip-us.daily.co.

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Dial-in

Dial-in lets a caller reach your bot by calling a carrier-owned phone number. The carrier forwards the audio into Daily over SIP.

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Flow

  1. Carrier receives the incoming call and hits your webhook server.
  2. Your server creates a Daily room with sip_provider="daily" and spawns the bot.
  3. Your server responds to the carrier with hold music. So the caller isn’t in silence while the bot boots.
  4. The bot fires on_dialin_ready with a Daily SIP endpoint URI.
  5. The bot calls the carrier’s API to update the in-progress call, forwarding its audio to that SIP endpoint.
  6. Caller and bot are connected; Daily carries the media over WebRTC.

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Bot configuration

bot.py
from pipecat.transports.daily import DailyTransport, DailyParams

async def run_bot(room_url: str, token: str, call_sid: str, sip_endpoint: str):
    transport = DailyTransport(
        room_url,
        token,
        "Voice Bot",
        DailyParams(
            audio_in_enabled=True,
            audio_out_enabled=True,
            video_out_enabled=False,
            transcription_enabled=True,
        ),
    )

    call_already_forwarded = False

    @transport.event_handler("on_dialin_ready")
    async def on_dialin_ready(transport, cdata):
        nonlocal call_already_forwarded
        if call_already_forwarded:
            return
        # Forward the carrier's in-progress call to Daily's SIP endpoint.
        # This example uses Twilio; swap for your carrier's call-update API.
        twilio_client.calls(call_sid).update(
            twiml=f"<Response><Dial><Sip>{sip_endpoint}</Sip></Dial></Response>"
        )
        call_already_forwarded = True

Complete dial-in server + bot

Full FastAPI server, bot, and README with setup instructions

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Dial-out

Dial-out initiates an outbound call from Daily, routed out through the carrier.

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Flow

  1. Your app triggers a dial-out (API call, agent decision, scheduled task).
  2. Server creates a Daily room with sip_provider="daily" and enable_dialout=True.
  3. Bot joins the Daily room and sets up the WebRTC transport.
  4. Bot calls transport.start_dialout(...) with provider="daily" and a SIP URI pointing at the carrier.
  5. Carrier places the PSTN call to the destination number.
  6. Recipient answers; media flows through Daily’s WebRTC transport to the bot.

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Bot configuration

bot.py
from pipecat.transports.daily import DailyTransport, DailyParams

async def run_bot(room_url: str, token: str, target_number: str, sip_uri: str):
    transport = DailyTransport(
        room_url,
        token,
        "Voice Bot",
        DailyParams(
            audio_in_enabled=True,
            audio_out_enabled=True,
            video_out_enabled=False,
            transcription_enabled=True,
        ),
    )

    @transport.event_handler("on_joined")
    async def on_joined(transport, data):
        await transport.start_dialout(
            {
                "sipUri": sip_uri,
                "displayName": "Pipecat Bot",
                "provider": "daily",
            }
        )

    @transport.event_handler("on_dialout_connected")
    async def on_dialout_connected(transport, data):
        logger.info(f"Dial-out connected: {data}")

    @transport.event_handler("on_dialout_stopped")
    async def on_dialout_stopped(transport, data):
        logger.info(f"Dial-out stopped: {data}")
        await task.cancel()

    @transport.event_handler("on_dialout_warning")
    async def on_dialout_warning(transport, data):
        logger.warning(f"Dial-out warning: {data}")

Complete dial-out server + bot

Full FastAPI server, bot, and README with setup instructions

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DTMF

When provider="daily" is in use, Daily surfaces DTMF tones from the connected carrier leg and lets you send tones back out over the same session.

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Receiving DTMF

Register on_dtmf_event on the transport. The event fires once per keypress and the payload contains the sessionId of the calling leg and the pressed tone:
bot.py
@transport.event_handler("on_dtmf_event")
async def on_dtmf_event(transport, data):
    logger.info(f"DTMF event: {data}")
    # data = {"sessionId": "...", "tone": "1", ...}
Internally, Pipecat also pushes each inbound digit as an InputDTMFFrame into the pipeline, so processors like DTMFAggregator can collect a sequence and feed it to an LLM as context; use that path if you want the bot to “hear” DTMF alongside speech.

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Sending DTMF

To send DTMF tones back to the caller, send them through Daily’s native DTMF channel. Use the session id from the inbound event (or the dial-out session id captured in on_dialout_connected) as the target. The default methodto send the DTMF tones is auto, determined in the SIP offer/answer negotiation. However, if you already know what the remote party supports, then pick the appropriate option: telephone-events which are in-band RTP packets (RFC2833/4733) or as a sip-info message.
bot.py
@transport.event_handler(“on_dialout_answered”)
async def on_dialout_answered(transport, data):
    logger.info(f”Dial-out answered: {data}”)
    # Wait briefly for the IVR prompt before sending the PIN
    await asyncio.sleep(1)

    err = await transport.send_dtmf({
        “sessionId”: data[“sessionId”],  # the dialed-out participant
        “tones”: “1234#”,                # full sequence in one call
        “digitDurationMs”: 100,
        # “method”: “sip-info” | “telephone-event” | “auto”
    })
    if err:
        logger.error(f”send_dtmf failed: {err}”)
You can also push OutputDTMFFrame / OutputDTMFUrgentFrame through the pipeline for cases where the tones are part of your bot’s conversational logic (IVR navigation, confirming a menu choice) rather than a direct invocation: 
# Single key (backward compatible)
await transport.queue_frame(OutputDTMFUrgentFrame(button=KeypadEntry.ONE))

# Multi-key dial string
await transport.queue_frame(OutputDTMFFrame.from_string("1234#"))

# Daily with explicit session + method
await transport.queue_frame(
    DailyOutputDTMFFrame.from_string(
        "1234#",
        session_id="abc",
        digit_duration_ms=80,
        method="sip-info",
    )
)

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Best Practices

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Guard against duplicate forwarding

on_dialin_ready can fire more than once when you have multiple sip endpoints defined on a room, for example for supervisory actions (silent monitoring, barge-in). In this case, you will need to keep track of which sip endpoint is assigned to which incoming call. Daily’s SIP address are of the format: sip:$roomName.$index@$domainName.sip-us.daily.co.

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Allow-list Daily’s static IPs

One of the main reasons to pick provider="daily" is that Daily publishes static IPs that you can allow-list on the carrier side, tightening SIP ACLs. Fetch the current list from Daily’s Networking Guide and configure your SIP trunk / IP access control list accordingly. There are different Static IP addresses for SIP signaling and media traffic.

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Next Steps