# How to Vibe Code Your Own Zeeg (and Stop Paying for It) > AI Voice Agent and Appointment Scheduling Software - Site: https://zeeg.me - Category: Scheduling & AI Voice CRM - Verdict: **Serious undertaking** (45/100 vibecodeable) - Estimated effort: 2-3 months of focused part-time work ## Verdict Build a subset or keep paying; the telephony voice pipeline and multi-calendar synchronization logic require sustained engineering effort. While spinning up a basic React booking page and a Postgres database takes a weekend, replicating Zeeg's core value requires weaving together bi-directional CalDAV/Graph calendar sync with strict locking to prevent double-booking, alongside a real-time WebRTC/SIP telephony stack driven by an AI voice agent. Managing audio lag under 600ms, token refreshes across disparate calendar providers, and GDPR-compliant transcript storage turns this into a multi-month engineering project. ### What you can't replicate - German regulatory compliance guarantees and embedded enterprise trust - Zero-latency telephony integration without carrier edge routing issues ## What it does An all-in-one AI-powered scheduling and CRM booking platform that combines online calendar management with 24/7 inbound and outbound AI voice agents. ### Core features - Online appointment scheduling (1:1, group, round-robin, collective) - Multi-calendar bidirectional sync (Google, Outlook, iCloud, Exchange) - 24/7 AI Voice Agent for inbound/outbound phone answering and qualification - CRM database to store contact transcripts, recordings, and lead data - Automated lead routing and qualification forms - Workflow automation and webhook triggers ## The business ### Pricing - Starter: Free — Ideal for individuals starting with automated scheduling - Professional: €12/mo — For solopreneurs with advanced requirements - Business: €20/mo — For small teams in medium businesses - Scale: €40/mo — For growing, multi-team organizations - Enterprise: Custom — For large organizations with dedicated support ### Funding €1.1M raised. - Pre-Seed / Seed Investors: High-Tech Gründerfonds (HTGF), Backbone Ventures Founded 2023. Team size: ~14. ## The hard parts - Real-time multi-calendar conflict resolution and timezone math across Round-Robin slots - Orchestrating an ultra-low-latency Speech-to-Text, LLM dialogue, and Text-to-Speech voice pipeline under ~600ms - Managing telephony trunking and WebRTC audio streams for live phone sessions - Enforcing strict European GDPR data residency and secure anonymization of transcripts ## How to vibe code Zeeg ### Prerequisites - Node.js (free): Required runtime for executing the Next.js and backend orchestration services. - GitHub (free): Source control and deployment pipeline connector. - Vapi Account (Usage-based (~$0.05/min)): Provides the low-latency voice agent infrastructure and telephony trunking. ### Recommended AI tools - Claude Code: Best-in-class agentic coding tool for scaffolding multi-file full-stack apps and debugging complex calendar sync state machines. - Cursor: Essential for iterative UI development on booking pages and form builders. ### Stack - Frontend: Next.js - Backend: Next.js API Routes / Node.js - Database: Neon - Auth: better-auth - Payments: Stripe - Other: Vapi, Resend, Vercel AI SDK ### Hosting - Vercel (Hosting the Next.js frontend and serverless API endpoints): $0-20/mo - Neon (Serverless Postgres database for user calendars, bookings, and CRM records): $0/mo (Free tier) ### Build guide 1. **Project Scaffolding & Database Schema** — Initialize the Next.js application with TypeScript, Tailwind CSS, and configure the Neon Postgres connection using Drizzle ORM. ``` Create a new Next.js 16 project with Tailwind CSS 4 and TypeScript. Configure Drizzle ORM to connect to a Neon Postgres database. Define the database schema for users, calendar_connections, event_types, bookings, and crm_contacts. Include relational fields for user-to-event types and bookings-to-contacts. Set up better-auth for email/password and Google OAuth authentication. Ensure all migration files are structured correctly and include an initialization script. ``` 2. **Calendar Integration & Free/Busy Slot Engine** — Implement OAuth flows for Google and Outlook calendars, along with an availability calculation engine that aggregates busy times. ``` Build OAuth integration routes for Google Calendar and Microsoft Graph API to securely store encrypted refresh tokens in the database. Write a robust backend service that queries external calendar free/busy endpoints given a time range and timezone. Implement an availability calculation algorithm that subtracts busy intervals from an organizer's defined weekly availability rules, returning a list of bookable time slots for any given date. ``` 3. **Booking Page UI & Slot Reservation Flow** — Create public booking pages where clients can select a date, time, fill custom questions, and lock in a meeting slot. ``` Develop a dynamic public booking page route at `[username]/[eventSlug]` using Next.js App Router. Build client components for a monthly calendar date picker and time slot grid that adapts to the visitor's local timezone. Implement a reservation transaction endpoint that validates slot availability against race conditions in Neon Postgres, creates a calendar event on the host's connected calendar, and records the booking entry in the database. ``` 4. **AI Voice Agent Integration** — Integrate Vapi to handle inbound phone calls, execute tool calls for checking availability, and automatically book meetings. ``` Integrate the Vapi SDK and webhook endpoints to manage AI voice assistant calls. Create a server-side tool definition endpoint that Vapi can invoke during a live voice call to check real-time calendar availability and execute a booking confirmation function. Store call transcripts, audio recordings, and mapped lead data into the crm_contacts table upon call completion. ``` 5. **CRM Database, Lead Routing & Notifications** — Build the internal CRM dashboard to view leads, transcripts, and trigger automated confirmation emails via Resend. ``` Build a protected CRM dashboard route listing all booked contacts, call transcripts, and meeting statuses. Implement lead routing rules based on custom questionnaire attributes. Configure Resend integration to automatically dispatch HTML confirmation emails with calendar attachments (.ics files) to both the host and the attendee immediately upon booking confirmation. ``` ### Cost vs paying **Starting costs (one-time):** - Custom domain name: $12/yr - Total: ~$12 one-time **Ongoing costs (monthly):** - Vercel Hobby/Pro hosting: $0-20/mo - Vapi AI Voice / Telephony usage: ~$10/mo - Neon Database: $0/mo - Total: ~$15-30/mo - Paying for the SaaS instead: €10-€20/mo - Build time: 40-60 hours - AI tool credits: $20/mo - Break-even: Never (subscription is cheaper unless building for deep technical education) ## Sources - [Zeeg Official Website & Public Pricing Pages](https://zeeg.me) - [The SaaS News — Zeeg Secures €1.1M Pre-Seed Funding](https://www.thesaasnews.com/news/zeeg-secures-1-1m-pre-seed-funding) - [Tracxn — Zeeg Company Profile & Financials](https://tracxn.com/d/company/zeeg.me)