Overview
The Call Center module transforms every computer into a powerful softphone, enabling sales reps and support staff to make and receive calls directly in their browser without additional hardware.
A key architectural decision was implementing Convex for real-time state management. With 9 dedicated Convex tables, the system handles agent availability, call queues, active calls, SMS threads, and contact tab synchronization—all with sub-second reactivity across all connected agents.
Key Features
Browser-Based Softphone
Complete phone functionality in the browser:
- Click-to-dial from any lead or customer record
- Incoming call routing with caller ID and customer lookup
- Transfer, hold, and conference calling
- Voicemail with transcription
Call Recording & Transcription
Every call is automatically:
- Recorded and stored securely in S3
- Transcribed using speech-to-text
- Indexed for searchability
- Linked to the relevant customer record
Quality Monitoring
Tools for managers to ensure call quality with structured scorecards covering greeting, product knowledge, problem resolution, professionalism, and closing—each rated 1-5 with feedback and coaching notes.
Real-time Dashboard
Live visibility into call center operations:
- Active calls with duration
- Agent availability status
- Queue depth and wait times
- Historical metrics and trends
SMS Platform
Two-way SMS messaging with real-time inbox:
- Real-time Inbox: Convex-powered message threads with instant updates
- Thread Locking: Prevents multiple agents from responding to same conversation
- Canned Responses: Pre-built templates for common scenarios
- DNC Compliance: Full audit trail for Do Not Call/Text with timestamps and source
- Grammar Suggestions: AI-powered writing assistance via Gemini
AI-Powered Features
Leveraging Google Gemini and OpenAI for intelligent automation:
- Call Audio Grading: AI analyzes call recordings and scores agent performance
- Agent Performance Summaries: Automated insights on individual agent trends
- Group Performance Analysis: AI-generated reports on team metrics
- Real-time Transcription: Calls transcribed for searchability and review
- Grammar Suggestions: AI proofreads SMS messages before sending
Convex Real-time Architecture
The call center uses Convex for all real-time state, with PostgreSQL as the permanent archive:
9 Convex Tables
| Table | Purpose |
|---|---|
agent_status | Tracks agent availability (available/busy/away) |
incoming_call_queue | Queue of incoming calls waiting for agents |
user_contact_tabs | Persists open contact tabs across devices |
active_calls | Prevents double-dial by tracking live calls |
call_queue | "Next Call" queue for outbound campaigns |
transfer_queue | Pending call transfers between agents |
agent_skills | Skill-based routing for transfers |
sms_messages | Hot storage for active SMS threads |
sms_thread_locks | Real-time locking for conversation editing |
Why Convex + PostgreSQL?
- Convex: Hot ephemeral state that needs sub-second reactivity
- PostgreSQL: Permanent archive, complex queries, reporting
New SMS → Postgres (archive) → Convex (hot) → Real-time UI
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Hydrate last 10 messages
Technical Architecture
Twilio Integration
The Twilio Voice SDK enables browser-based calling via WebRTC. Agents initialize a Device with JWT token authentication, register event handlers for incoming calls and disconnects, and can make outbound calls with custom parameters (phone number, lead ID) that flow through to webhooks.
Real-time State Synchronization
Convex mutations provide instant updates across all connected agents. When one agent changes status or takes a call, all subscribed clients see the update immediately—no manual pub/sub required.
The hybrid architecture uses:
- Convex: Real-time state (agent status, call queue, SMS threads)
- Ably: Event broadcasting for specific notifications
- PostgreSQL: Permanent storage and complex reporting queries
Call Flow
sequenceDiagram
participant Customer
participant Twilio
participant API
participant Agent
Customer->>Twilio: Incoming Call
Twilio->>API: Webhook: incoming call
API->>API: Lookup customer, find available agent
API->>Twilio: TwiML: route to agent
Twilio->>Agent: Ring browser softphone
Agent->>Twilio: Accept call
Twilio->>Customer: Connected
Note over Customer,Agent: Call in progress
Agent->>Twilio: End call
API->>API: Save recording, create activity
Results
The Call Center module has transformed communication efficiency:
- 100% call capture: No more missed calls or lost leads
- 3x faster customer lookup with automatic caller ID matching
- Quality improvements through systematic call review
- Complete audit trail of all customer communications
