Open-source alternative
Replace Google Calendar with Mailflare office
The best open-source alternative to Google Calendar is Mailflare (or synct) with genoffice, self-hosted on Railway. Got a domain? Do this, boom, and you're good until you see revenue. Mailflare, synct, and genoffice are the side-hustle office: email, calendar (including a Google Calendar off-ramp), a booking page, and an AI replacement for the rest of Workspace or Microsoft 365.
Estimated save $1,380 a year.
Open the stackStart on Railway
How Google Calendar compares
| Google Calendar | Mailflare office | |
|---|---|---|
| Pricing model | Hosted subscription | Open-source or fair-code license; you pay the host |
| Hosting | Vendor cloud | Self-hosted on Railway or any VPS |
| Rough monthly cost | Public list price not verified this run | Hosting only — no SaaS seat meter in this repo |
- Mailflare
Email, calendar, and a database-backed booking page on Cloudflare Workers
- synct
Combines calendars so Mailflare bookings sync to Google or Outlook / Microsoft 365; each event shows where it lives
- genoffice
AI Office suite — docs, sheets, slides — that replaces the rest of Workspace / Microsoft 365
- Cal.com
Open-source booking if you want a second scheduler
FAQ
- Is it free?
- The Mailflare office licenses are open source or fair-code. You still pay hosting (Railway or any VPS) and any APIs the stack calls. There is no Google Calendar seat or task bill on this path.
- Can I migrate from Google Calendar?
- Yes. Start with the workflows or data you actually use, then cut over. The Mailflare office stack page has the agent prompt and the cost table; most teams rebuild the slice that matters and leave old Google Calendar links until they expire.
- How do I deploy it?
- Open the Mailflare office stack, copy the agent prompt, and deploy on Railway (one service, PORT, and a volume when the app needs disk). Step 1 of 2. One Railway project deploys synct (web + worker + Postgres) and genoffice. Use the button to start that project on Railway. A one-click template ships when it is published. Mailflare stays on Cloudflare — that is step 2.
- What does this replace?
- Google Workspace / M365 + Calendly / Google Calendar. The published small-team estimate on this stack is $1,380 a year.
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