REI3
A sober business-app builder with forms, reports, roles, workflows, and no per-user meter.
Technical Profile & Specs
verified 2026-08-10
- Cost
- $0 / forever (Open Source)
- License
- MIT
- Hosting Model
- Self-host (your server)
- Platforms
- desktopmobilewebself-hostedone-click install
- Installation
- Native Linux/Windows server package or Docker Compose, connected to PostgreSQL
- Operational Setup
- You must provision PostgreSQL and configure a server/reverse proxy; it is not a managed one-click workspace
- Where Your Data Lives
- Human-readable application records and configuration live in a PostgreSQL database controlled by the operator
- The Catch / Trade-off
- It produces capable browser-based business apps but not AppSheet's native-feeling mobile client, offline behavior, and spreadsheet expression model.
Replaces 6 paid apps
up to $488/mo ($5,856/yr) in subscriptions
REI3 FAQ
Common questions
Is REI3 free and open source?+
REI3 is an open-source tool licensed under MIT that runs on self-host. A sober business-app builder with forms, reports, roles, workflows, and no per-user meter.
What paid software does REI3 replace?+
REI3 serves as a free replacement for 6 paid SaaS applications: AppSheet, Bubble, Caspio, Knack, Quickbase, Softr, saving up to $488/month ($5,856/year) in subscription bills.
How do you install and set up REI3?+
Installation: Native Linux/Windows server package or Docker Compose, connected to PostgreSQL. Setup notes: You must provision PostgreSQL and configure a server/reverse proxy; it is not a managed one-click workspace
What is the catch or trade-off with REI3?+
It produces capable browser-based business apps but not AppSheet's native-feeling mobile client, offline behavior, and spreadsheet expression model.