Architecture Overview

System Architecture

TalkifAI is composed of four independently deployed services:

                    ┌──────────────────────────────┐
                    │       End User Browser        │
                    │   or Phone (via SIP carrier)  │
                    └──────────────┬───────────────┘
                                   │
                    ┌──────────────▼───────────────┐
                    │       TalkifAI Studio         │
                    │    (Next.js 15 - App Router)  │
                    │                               │
                    │  • User authentication        │
                    │  • Agent configuration UI     │
                    │  • Organization management    │
                    │  • LiveKit token generation   │
                    │  • Call session tracking      │
                    │  • Telephony webhooks         │
                    └──────────────┬───────────────┘
                                   │
              ┌────────────────────┼────────────────────┐
              │                    │                    │
              ▼                    ▼                    ▼
  ┌───────────────────┐  ┌─────────────────┐  ┌────────────────────┐
  │  Voice Agent      │  │  Billing        │  │  Marketing Site    │
  │  Runtime          │  │  Service        │  │  (Next.js)         │
  │  (Python/FastAPI  │  │  (Python/FastAPI│  │                    │
  │   + LiveKit)      │  │   + Redis)      │  │  • Landing pages   │
  │                   │  │                 │  │  • Public demo     │
  │  • STT/LLM/TTS    │  │  • Credits      │  │  • Marketing       │
  │  • Session mgmt   │  │  • Usage track  │  └────────────────────┘
  │  • Function calls │  │  • Auto top-up  │
  │  • Recordings     │  │  • Cost calc    │
  │  • Transcripts    │  └─────────────────┘
  └───────────────────┘
              │
              ▼
  ┌───────────────────┐
  │   LiveKit Server  │
  │   (WebRTC/SIP)    │
  └───────────────────┘

Services

TalkifAI Studio

Main Next.js app — dashboard, agent builder, auth, API endpoints.

Voice Agent Runtime

Python service running the actual voice agents on LiveKit.

Billing Service

FastAPI service managing credits, usage, and payments.

Security

Authentication, encryption, and multi-tenant isolation.

Database Architecture

All services share a PostgreSQL database (Neon serverless) via Prisma ORM. Key tables:

Table	Purpose
`user`	User accounts
`organization`	Tenant workspaces
`member`	User-org relationships + roles
`Agent`	Voice agent configurations
`PhoneNumber`	BYOC phone numbers
`CarrierCredentials`	Encrypted SIP credentials
`UserVoiceSession`	Call session records
`DeveloperQuota`	Monthly usage limits
`ApiKeys`	Organization API keys (encrypted)
`CustomFunction`	Custom webhook functions
`PostCallAnalysisForm`	QA form definitions

Infrastructure

Component	Technology	Hosting
Studio Frontend/Backend	Next.js 15	Vercel
Voice Agent Runtime	Python + FastAPI	Google Cloud VM
Billing Service	Python + FastAPI	Google Cloud Run
Database	PostgreSQL (Neon)	Neon Cloud
Cache	Redis	Google Cloud Memorystore
Recordings	GCS Buckets	Google Cloud Storage
LiveKit Server	LiveKit Cloud	LiveKit Cloud
Status Page	BetterStack	BetterStack

Scale Characteristics

Metric	Value
LiveKit rooms per node	3,000
Participants per node	6,000
Concurrent users (horizontal)	10,000+
Batch calls per day	100,000+
DB connection pool	5 (Neon limit)
Redis cache TTL	30 seconds (credits)

​System Architecture

​Services