tcpsyn
356bf145b8
- Music crossfade: smooth 3-second blend between tracks instead of hard stop/start - Emotional detection: analyze host mood from recent messages so callers adapt tone - AI caller summaries: generate call summaries with timestamps for show history - Returning callers: persist regular callers across sessions with call history - Session export: generate transcripts with speaker labels and chapter markers - Caller screening: AI pre-screens phone callers to get name and topic while queued Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
2.0 KiB
SignalWire Phone Call-In Design
Goal
Replace browser-based WebSocket call-in with real phone calls via SignalWire. Callers dial 208-439-5853 and enter the show queue.
Architecture
SignalWire handles PSTN connectivity. When a call comes in, SignalWire hits our webhook, we return XML telling it to open a bidirectional WebSocket stream with L16@16kHz audio. The audio flows through our existing pipeline — same queue, channel allocation, transcription, host mic streaming, and TTS streaming.
Call Flow
- Caller dials 208-439-5853
- SignalWire hits
POST /api/signalwire/voice(via Cloudflare tunnel) - We return
<Connect><Stream codec="L16@16000h">XML - SignalWire opens WebSocket to
/api/signalwire/stream - Caller enters queue — host sees phone number on dashboard
- Host takes call — audio flows bidirectionally
- Host hangs up — we call SignalWire REST API to end the phone call
Audio Path
Phone → PSTN → SignalWire → WebSocket (base64 L16 JSON) → Our server
Our server → WebSocket (base64 L16 JSON) → SignalWire → PSTN → Phone
SignalWire WebSocket Protocol
Incoming: {"event": "media", "media": {"payload": "<base64 L16 PCM 16kHz>"}}
Outgoing: {"event": "media", "media": {"payload": "<base64 L16 PCM 16kHz>"}}
Start: {"event": "start", "start": {"streamSid": "...", "callSid": "..."}}
Stop: {"event": "stop"}
What Changes
- Remove: browser call-in page, browser WebSocket handler
- Add: SignalWire webhook + WebSocket handler, hangup via REST API
- Modify: CallerService (name→phone, base64 JSON encoding for send), dashboard (show phone number)
- Unchanged: AudioService, queue logic, transcription, TTS streaming, three-way calls
Config
SIGNALWIRE_PROJECT_ID=8eb54732-ade3-4487-8b40-ecd2cd680df7
SIGNALWIRE_SPACE=macneil-media-group-llc.signalwire.com
SIGNALWIRE_TOKEN=PT9c9b61f44ee49914c614fed32aa5c3d7b9372b5199d81dec
SIGNALWIRE_PHONE=+12084395853
Webhook URL: https://radioshow.macneilmediagroup.com/api/signalwire/voice
No SDK needed — httpx for the one REST call (hangup).