413 lines
21 KiB
Markdown
413 lines
21 KiB
Markdown
# Hold Slayer 🔥
|
|
|
|
**An AI-powered telephony gateway that calls companies, navigates IVR menus, waits on hold, and transfers you when a human picks up.**
|
|
|
|
You give it a phone number and an intent ("dispute a charge on my December statement"). It dials the number through your SIP trunk, navigates the phone tree, sits through the hold music, and rings your desk phone the instant a live person answers. You never hear Vivaldi again.
|
|
|
|
> [!CAUTION]
|
|
> **Emergency calling — 911**
|
|
> Hold Slayer passes `911` and `9911` directly to the PSTN trunk.
|
|
> **Your SIP trunk provider must support E911 on your DID and have your
|
|
> correct registered location on file before this system is put into
|
|
> service.** VoIP emergency calls are location-dependent — verify
|
|
> with your provider. Do not rely on this system as your only means
|
|
> of reaching emergency services.
|
|
|
|
## Architecture
|
|
|
|
```
|
|
┌─────────────────────────────────────────────────────────────────┐
|
|
│ FastAPI Server │
|
|
│ │
|
|
│ ┌──────────┐ ┌──────────┐ ┌───────────┐ ┌──────────────┐ │
|
|
│ │ REST API │ │WebSocket │ │MCP Server │ │ Dashboard │ │
|
|
│ │ /api/* │ │ /ws/* │ │ (SSE) │ │ /dashboard │ │
|
|
│ └────┬─────┘ └────┬─────┘ └─────┬─────┘ └──────────────┘ │
|
|
│ │ │ │ │
|
|
│ ┌────┴──────────────┴──────────────┴────┐ │
|
|
│ │ Event Bus │ │
|
|
│ │ (asyncio Queue pub/sub per client) │ │
|
|
│ └────┬──────────────┬──────────────┬────┘ │
|
|
│ │ │ │ │
|
|
│ ┌────┴─────┐ ┌─────┴─────┐ ┌────┴──────────┐ │
|
|
│ │ Call │ │ Hold │ │ Services │ │
|
|
│ │ Manager │ │ Slayer │ │ (LLM, STT, │ │
|
|
│ │ │ │ │ │ Recording, │ │
|
|
│ │ │ │ │ │ Analytics, │ │
|
|
│ │ │ │ │ │ Notify) │ │
|
|
│ └────┬─────┘ └─────┬─────┘ └──────────────┘ │
|
|
│ │ │ │
|
|
│ ┌────┴──────────────┴───────────────────┐ │
|
|
│ │ Sippy B2BUA Engine │ │
|
|
│ │ (SIP calls, DTMF, conference bridge) │ │
|
|
│ └────┬──────────────────────────────────┘ │
|
|
│ │ │
|
|
└───────┼─────────────────────────────────────────────────────────┘
|
|
│
|
|
┌────┴────┐
|
|
│SIP Trunk│ ──→ PSTN
|
|
└─────────┘
|
|
```
|
|
|
|
## What's Implemented
|
|
|
|
### Core Engine
|
|
- **Sippy B2BUA Engine** (`core/sippy_engine.py`) — SIP call control, DTMF, bridging, conference, trunk registration
|
|
- **PJSUA2 Media Pipeline** (`core/media_pipeline.py`) — Audio routing, recording ports, conference bridge, WAV playback
|
|
- **Call Manager** (`core/call_manager.py`) — Active call state tracking, lifecycle management
|
|
- **Event Bus** (`core/event_bus.py`) — Async pub/sub with per-subscriber queues, type filtering, history
|
|
|
|
### Hold Slayer
|
|
- **IVR Navigation** (`services/hold_slayer.py`) — Follows stored call flows step-by-step through phone menus, including SPEAK steps that synthesize speech via TTS
|
|
- **Audio Classifier** (`services/audio_classifier.py`) — Real-time waveform analysis: silence, tones, DTMF, music, speech detection
|
|
- **Call Flow Learner** (`services/call_flow_learner.py`) — Builds reusable call flows from exploration data, merges new discoveries
|
|
- **LLM Fallback** — When a LISTEN step has no hardcoded DTMF, the LLM analyzes the transcript and picks the right menu option
|
|
|
|
### AI Receptionist & Smart Routing
|
|
- **AI Receptionist** (`services/receptionist.py`) — Answers inbound calls, greets via TTS, captures the caller's intent with STT + LLM, then routes to a device or takes a voicemail
|
|
- **Smart Routing** (`services/routing.py`) — Caller-pattern (glob), DNIS, time-of-day (with tz + midnight wrap), per-device DND, and ring-chain priority. Rules win over the LLM on conflict.
|
|
- **TTS** (`services/tts.py`) — [Rhema](https://github.com/heluca/rhema) (OpenAI-compatible `/v1/audio/speech`) — synthesizes Kokoro voices for the SPEAK step and receptionist prompts
|
|
|
|
### Intelligence Layer
|
|
- **LLM Client** (`services/llm_client.py`) — OpenAI-compatible API client (Ollama, vLLM, LM Studio, OpenAI) with JSON parsing, retry, stats
|
|
- **Transcription** (`services/transcription.py`) — Speaches/Whisper STT integration for live call transcription
|
|
- **Recording** (`services/recording.py`) — WAV recording with date-organized storage, dual-channel support, persisted to the `recordings` table
|
|
- **Call Persistence** (`services/call_persistence.py`) — Writes completed calls + transcript chunks to the database on hangup
|
|
- **Call Analytics** (`services/call_analytics.py`) — Hold time stats, success rates, per-company patterns, time-of-day trends
|
|
- **Notifications** (`services/notification.py`) — WebSocket + SMS alerts for human detection, call failures, hold status
|
|
|
|
### API Surface
|
|
- **REST API** — Call management, call history, transcripts, recordings, routing rules, device DND, call flow CRUD
|
|
- **WebSocket** — Real-time call events, transcripts, classification updates, receptionist state transitions
|
|
- **MCP Server** — 10 tools for AI assistant integration (make calls, send DTMF, get transcripts, manage flows)
|
|
- **Dashboard** — SvelteKit UI served at `/dashboard` with live monitor, call history with transcript playback, and a routing-rules editor
|
|
|
|
### Data Models
|
|
- **Call** — Active call state with classification history, transcript chunks, hold time tracking
|
|
- **Call Flow** — Stored IVR trees with steps (DTMF, LISTEN, HOLD, TRANSFER, SPEAK)
|
|
- **Routing Rule** — Match (caller pattern, DNIS, time range) + action (ring_device, ring_chain, take_message, reject, dnd)
|
|
- **Transcript Chunk** — Per-call STT segments with speaker tag and timestamp offset (for click-to-seek playback)
|
|
- **Recording** — WAV file metadata (path, duration, size) per call
|
|
- **Events** — 30+ typed events (call lifecycle, hold slayer, audio, device, system, receptionist, routing)
|
|
- **Device** — SIP phone/softphone registration, priority, DND
|
|
- **Contact** — Phone number management with routing preferences
|
|
|
|
## Project Structure
|
|
|
|
```
|
|
hold-slayer/
|
|
├── main.py # FastAPI app + lifespan (service wiring)
|
|
├── config.py # Pydantic settings from .env
|
|
├── core/
|
|
│ ├── gateway.py # Top-level gateway orchestrator
|
|
│ ├── sippy_engine.py # Sippy B2BUA SIP engine
|
|
│ ├── media_pipeline.py # PJSUA2 audio routing
|
|
│ ├── call_manager.py # Active call state management
|
|
│ └── event_bus.py # Async pub/sub event bus
|
|
├── services/
|
|
│ ├── hold_slayer.py # IVR navigation + hold detection + SPEAK
|
|
│ ├── receptionist.py # AI Receptionist state machine
|
|
│ ├── routing.py # Smart routing (rules, DND, ring chain)
|
|
│ ├── tts.py # Rhema TTS client (OpenAI-compatible)
|
|
│ ├── audio_classifier.py # Waveform analysis (music/speech/DTMF)
|
|
│ ├── call_flow_learner.py # Auto-learns IVR trees from calls
|
|
│ ├── call_persistence.py # Writes calls + transcript chunks on hangup
|
|
│ ├── llm_client.py # OpenAI-compatible LLM client
|
|
│ ├── transcription.py # Speaches/Whisper STT
|
|
│ ├── recording.py # Call recording management
|
|
│ ├── call_analytics.py # Call metrics and insights
|
|
│ └── notification.py # WebSocket + SMS notifications
|
|
├── api/
|
|
│ ├── calls.py # Call management endpoints
|
|
│ ├── call_history.py # History, transcript, recording playback
|
|
│ ├── call_flows.py # Call flow CRUD
|
|
│ ├── devices.py # Device registration
|
|
│ ├── routing.py # Routing rules CRUD + per-device DND
|
|
│ ├── websocket.py # Real-time event stream
|
|
│ └── deps.py # FastAPI dependency injection
|
|
├── dashboard/ # SvelteKit UI (built to dashboard/build)
|
|
│ └── src/routes/
|
|
│ ├── +page.svelte # Live monitor
|
|
│ ├── history/ # Call history list
|
|
│ ├── calls/[call_id]/ # Detail page + transcript playback
|
|
│ └── routing/ # Rules editor + DND toggles
|
|
├── mcp_server/
|
|
│ └── server.py # MCP tools + resources (10 tools)
|
|
├── models/
|
|
│ ├── call.py # Call state models
|
|
│ ├── call_flow.py # IVR tree models
|
|
│ ├── routing.py # Routing rule / match / action models
|
|
│ ├── events.py # Event type definitions
|
|
│ ├── device.py # Device models
|
|
│ └── contact.py # Contact models
|
|
├── db/
|
|
│ └── database.py # SQLAlchemy async (PostgreSQL/SQLite)
|
|
└── tests/
|
|
├── test_audio_classifier.py # 18 tests — waveform analysis
|
|
├── test_call_flows.py # 10 tests — call flow models
|
|
├── test_hold_slayer.py # 20 tests — IVR nav, EventBus, CallManager
|
|
├── test_services.py # 27 tests — LLM, notifications, recording,
|
|
│ # analytics, learner, EventBus
|
|
├── test_tts.py # 4 tests — Rhema TTS client
|
|
├── test_routing.py # 8 tests — rules evaluator
|
|
└── test_receptionist.py # 7 tests — receptionist decision logic
|
|
```
|
|
|
|
## Quick Start
|
|
|
|
### 1. Install
|
|
|
|
```bash
|
|
python -m venv .venv
|
|
source .venv/bin/activate
|
|
pip install -e ".[dev]"
|
|
```
|
|
|
|
### 2. Configure
|
|
|
|
```bash
|
|
cp .env.example .env
|
|
# Edit .env with your SIP trunk credentials, LLM endpoint, etc.
|
|
```
|
|
|
|
### 3. Build the dashboard (optional but recommended)
|
|
|
|
```bash
|
|
cd dashboard
|
|
npm install
|
|
npm run build
|
|
cd ..
|
|
```
|
|
|
|
The gateway serves the built UI at `/dashboard` automatically when
|
|
`dashboard/build/` exists. Skip this step if you only need the REST/WS API.
|
|
|
|
### 4. Run
|
|
|
|
```bash
|
|
uvicorn main:app --host 0.0.0.0 --port 8100
|
|
```
|
|
|
|
### 5. Test
|
|
|
|
```bash
|
|
pytest tests/ -v
|
|
```
|
|
|
|
## Usage
|
|
|
|
### REST API
|
|
|
|
**Launch Hold Slayer on a number:**
|
|
|
|
```bash
|
|
curl -X POST http://localhost:8000/api/calls/hold-slayer \
|
|
-H "Content-Type: application/json" \
|
|
-d '{
|
|
"number": "+18005551234",
|
|
"intent": "dispute Amazon charge from December 15th",
|
|
"call_flow_id": "chase_bank_main",
|
|
"transfer_to": "sip_phone"
|
|
}'
|
|
```
|
|
|
|
**Check call status:**
|
|
|
|
```bash
|
|
curl http://localhost:8000/api/calls/call_abc123
|
|
```
|
|
|
|
**Browse call history (persisted in the database):**
|
|
|
|
```bash
|
|
curl http://localhost:8000/api/calls/history?limit=50
|
|
curl http://localhost:8000/api/calls/call_abc123/transcript
|
|
curl -O http://localhost:8000/api/calls/call_abc123/recording # WAV
|
|
```
|
|
|
|
**Create a smart-routing rule:**
|
|
|
|
```bash
|
|
curl -X POST http://localhost:8000/api/routing/rules \
|
|
-H "Content-Type: application/json" \
|
|
-d '{
|
|
"name": "Block tollfree at night",
|
|
"priority": 10,
|
|
"enabled": true,
|
|
"match": {
|
|
"caller_pattern": "+1800*",
|
|
"time_range": {"start": "22:00", "end": "06:00", "tz": "America/Toronto", "days": [0,1,2,3,4,5,6]}
|
|
},
|
|
"action": {"type": "reject", "message": "Office is closed."}
|
|
}'
|
|
```
|
|
|
|
**Toggle Do Not Disturb on a device:**
|
|
|
|
```bash
|
|
curl -X PATCH http://localhost:8000/api/routing/devices/dev_abc123/dnd \
|
|
-H "Content-Type: application/json" \
|
|
-d '{"enabled": true}'
|
|
```
|
|
|
|
### WebSocket — Real-Time Events
|
|
|
|
```javascript
|
|
const ws = new WebSocket("ws://localhost:8000/ws/events");
|
|
ws.onmessage = (msg) => {
|
|
const event = JSON.parse(msg.data);
|
|
// event.type: "human_detected", "hold_detected", "ivr_step", etc.
|
|
// event.call_id: which call this is about
|
|
// event.data: type-specific payload
|
|
};
|
|
```
|
|
|
|
### MCP — AI Assistant Integration
|
|
|
|
The MCP server exposes 10 tools that any MCP-compatible assistant can use:
|
|
|
|
| Tool | Description |
|
|
|------|-------------|
|
|
| `make_call` | Dial a number through the SIP trunk |
|
|
| `end_call` | Hang up an active call |
|
|
| `send_dtmf` | Send touch-tone digits to navigate menus |
|
|
| `get_call_status` | Check current state of a call |
|
|
| `get_call_transcript` | Get live transcript of a call |
|
|
| `get_call_recording` | Get recording metadata and file path |
|
|
| `list_active_calls` | List all calls in progress |
|
|
| `get_call_summary` | Analytics summary (hold times, success rates) |
|
|
| `search_call_history` | Search past calls by number or company |
|
|
| `learn_call_flow` | Build a reusable call flow from exploration data |
|
|
|
|
## How It Works
|
|
|
|
### Outbound (Hold Slayer)
|
|
|
|
1. **You request a call** — via REST API, MCP tool, or dashboard
|
|
2. **Gateway dials out** — Sippy B2BUA places the call through your SIP trunk
|
|
3. **Audio classifier listens** — Real-time waveform analysis detects IVR prompts, hold music, ringing, silence, and live speech
|
|
4. **Transcription runs** — Speaches/Whisper converts audio to text in real-time
|
|
5. **IVR navigator decides** — If a stored call flow exists, it follows the steps (including SPEAK steps that synthesize speech via Rhema TTS). If not, the LLM analyzes the transcript and picks the right menu option
|
|
6. **Hold detection** — When hold music is detected, the system waits patiently and monitors for transitions
|
|
7. **Human detection** — The classifier detects the transition from music/silence to live speech
|
|
8. **Transfer** — Your desk phone rings. Pick up and you're talking to the agent. Zero hold time.
|
|
|
|
### Inbound (AI Receptionist + Smart Routing)
|
|
|
|
1. **SIP INVITE arrives** — Sippy surfaces it to the gateway instead of auto-answering
|
|
2. **Routing rules evaluate** — Caller pattern, DNIS, and time-of-day rules run in priority order. A `reject` or `dnd` action declines the call immediately.
|
|
3. **Receptionist answers** — TTS plays the greeting; the call's audio tap captures the caller's response
|
|
4. **Intent capture** — The utterance is transcribed and the LLM extracts intent, urgency, and a recommended action (ring / message / reject)
|
|
5. **Final decision** — Routing rules win on conflict; otherwise the LLM's recommendation is followed
|
|
6. **Route or take a message** — `ring_chain` tries devices in priority order (skipping any in DND); if nobody picks up (or the action is `take_message`), the receptionist records up to 90s, transcribes it, and emits a `RECEPTIONIST_MESSAGE_SAVED` event
|
|
|
|
## Configuration
|
|
|
|
All configuration is via environment variables (see `.env.example`):
|
|
|
|
| Variable | Description | Default |
|
|
|----------|-------------|---------|
|
|
| `SIP_TRUNK_HOST` | Your SIP provider hostname | — |
|
|
| `SIP_TRUNK_USERNAME` | SIP auth username | — |
|
|
| `SIP_TRUNK_PASSWORD` | SIP auth password | — |
|
|
| `SIP_TRUNK_DID` | Your phone number (E.164) | — |
|
|
| `GATEWAY_SIP_PORT` | Port for device registration | `5080` |
|
|
| `SPEACHES_URL` | Speaches/Whisper STT endpoint | `http://localhost:22070` |
|
|
| `LLM_BASE_URL` | OpenAI-compatible LLM endpoint | `http://localhost:11434/v1` |
|
|
| `LLM_MODEL` | Model name for IVR analysis | `llama3` |
|
|
| `TTS_BASE_URL` | Rhema TTS endpoint (OpenAI-compatible) | `http://localhost:8000` |
|
|
| `TTS_MODEL` | TTS model ID | `speaches-ai/Kokoro-82M-v1.0-ONNX` |
|
|
| `TTS_VOICE` | Default Kokoro voice | `af_heart` |
|
|
| `TTS_API_KEY` | Optional bearer token for Rhema | — |
|
|
| `RECEPTIONIST_ENABLED` | Answer inbound calls with the AI receptionist | `true` |
|
|
| `RECEPTIONIST_GREETING_TEMPLATE` | Spoken greeting | `"Hi, you've reached Robert's line. Who's calling, and what's this about?"` |
|
|
| `RECEPTIONIST_MESSAGE_MAX_SECONDS` | Voicemail cap | `90` |
|
|
| `DATABASE_URL` | PostgreSQL or SQLite connection | SQLite fallback |
|
|
|
|
## Tech Stack
|
|
|
|
- **Python 3.13** + **asyncio** — Single-process async architecture
|
|
- **FastAPI** — REST API + WebSocket server
|
|
- **SvelteKit** — Dashboard UI (built static, served by FastAPI at `/dashboard`)
|
|
- **Sippy B2BUA** — SIP call control and DTMF
|
|
- **PJSUA2** — Media pipeline, conference bridge, recording, WAV playback
|
|
- **Speaches** (Whisper) — Speech-to-text
|
|
- **Rhema** (Kokoro) — Text-to-speech (OpenAI-compatible `/v1/audio/speech`)
|
|
- **Ollama / vLLM / OpenAI** — LLM for IVR menu analysis and receptionist intent capture
|
|
- **SQLAlchemy** — Async database (PostgreSQL or SQLite)
|
|
- **MCP (Model Context Protocol)** — AI assistant integration
|
|
|
|
## Documentation
|
|
|
|
Full documentation is in [`/docs`](docs/README.md):
|
|
|
|
- [Architecture](docs/architecture.md) — System design, data flow, threading model
|
|
- [Core Engine](docs/core-engine.md) — SIP engine, media pipeline, call manager, event bus
|
|
- [Hold Slayer Service](docs/hold-slayer-service.md) — IVR navigation, hold detection, human detection
|
|
- [Audio Classifier](docs/audio-classifier.md) — Waveform analysis, feature extraction, classification
|
|
- [Services](docs/services.md) — LLM client, transcription, recording, analytics, notifications
|
|
- [Call Flows](docs/call-flows.md) — Call flow model, step types, auto-learner
|
|
- [API Reference](docs/api-reference.md) — REST endpoints, WebSocket, request/response schemas
|
|
- [MCP Server](docs/mcp-server.md) — MCP tools and resources for AI assistants
|
|
- [Configuration](docs/configuration.md) — All environment variables, deployment options
|
|
- [Development](docs/development.md) — Setup, testing, contributing
|
|
|
|
## Build Phases
|
|
|
|
### Phase 1: Core Engine ✅
|
|
|
|
- [x] Extract EventBus to dedicated module with typed filtering
|
|
- [x] Implement Sippy B2BUA SIP engine (signaling, DTMF, bridging)
|
|
- [x] Implement PJSUA2 media pipeline (conference bridge, audio tapping, recording)
|
|
- [x] Call manager with active call state tracking
|
|
- [x] Gateway orchestrator wiring all components
|
|
|
|
### Phase 2: Intelligence Layer ✅
|
|
|
|
- [x] LLM client (OpenAI-compatible — Ollama, vLLM, LM Studio, OpenAI)
|
|
- [x] Hold Slayer IVR navigation with LLM fallback for LISTEN steps
|
|
- [x] Call Flow Learner — auto-builds reusable IVR trees from exploration
|
|
- [x] Recording service with date-organized WAV storage
|
|
- [x] Call analytics with hold time stats, per-company patterns
|
|
- [x] Audio classifier with spectral analysis, DTMF detection, hold-to-human transition
|
|
|
|
### Phase 3: API & Integration ✅
|
|
|
|
- [x] REST API — calls, call flows, devices, DTMF
|
|
- [x] WebSocket real-time event streaming
|
|
- [x] MCP server with 16 tools + 3 resources
|
|
- [x] Notification service (WebSocket + SMS)
|
|
- [x] Service wiring in main.py lifespan
|
|
- [x] 75 passing tests across 4 test files
|
|
|
|
### Phase 4: Production Hardening 🔜
|
|
|
|
- [ ] Alembic database migrations
|
|
- [ ] API authentication (API keys / JWT)
|
|
- [ ] Rate limiting on API endpoints
|
|
- [ ] Structured JSON logging
|
|
- [ ] Health check endpoints for all dependencies
|
|
- [ ] Graceful degradation (classifier works without STT, etc.)
|
|
- [ ] Docker Compose (Hold Slayer + PostgreSQL)
|
|
|
|
### Phase 5: Additional Services 🚧
|
|
|
|
- [x] AI Receptionist — answer inbound calls, screen callers, take messages
|
|
- [x] Smart Routing — time-of-day rules, device priority, DND
|
|
- [x] TTS/Speech — play prompts into calls (SPEAK step support, Rhema/Kokoro)
|
|
- [ ] Spam Filter — detect robocalls using caller ID + audio patterns
|
|
- [ ] Noise Cancellation — RNNoise integration in media pipeline
|
|
|
|
### Phase 6: Dashboard & UX 🚧
|
|
|
|
- [x] Web dashboard with real-time call monitor
|
|
- [x] Call history with transcript playback (click-to-seek)
|
|
- [x] Routing rules editor + per-device DND toggles
|
|
- [ ] Call flow visual editor (drag-and-drop IVR tree builder)
|
|
- [ ] Analytics dashboard with hold time graphs
|
|
- [ ] Mobile app (or PWA) for on-the-go control
|
|
|
|
## License
|
|
|
|
MIT
|