REI3 is a free and open-source low-code platform for building and self-hosting powerful multi-user business applications on-premise or in the cloud.

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🚀 Overview

REI3 is an open low-code development platform that empowers users to create custom multi-user applications featuring data stores, forms, workflows, calculations, and integrations. It replaces inefficient spreadsheet-based workflows with professional, secure, and scalable business software that users fully own and control.

The platform solves the challenge of developing tailored business applications without deep coding expertise or reliance on expensive proprietary SaaS tools. It's built for individuals, small teams, enterprises, and MSPs who need internal tools, project management, CRM, ticketing systems, or even apps to sell—providing full data sovereignty, compliance features, and extensibility.

Developed since 2019 by Gabriel Victor Herbert, REI3 aims to democratize low-code development with a fully open, self-hostable alternative that's enterprise-ready, supporting features like E2EE, MFA, and clustering while remaining free with no user limits.

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✨ Key Features

• Fast low-code app building with forms, data stores, business rules, Gantt charts, diagrams, and calculations

• Advanced workflows: dynamic forms, PDF exports, notifications, role-based access control (RBAC)

• Security & compliance: end-to-end encryption (E2EE), MFA, brute-force protection, LDAP integration, password policies

• Integrations & usability: REST/CSV/ICS APIs, full-text search, PWA for mobile, diverse inputs (signatures, QR codes), multi-core optimization

• Pre-built apps: Tasks, simple CRM, shift planner, time tracker, projects, tickets, knowledge base, Kanban, file sharing, IT assets, news, bookmarks, absence management, password safe

• Optional: clustering, branding, transparent PostgreSQL access

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🛠 Tech Stack

• Frontend: Vue.js, HTML, CSS, JavaScript

• Backend: Go (Golang)

• Database: PostgreSQL

• Auth: Built-in with MFA, roles, LDAP support

• Hosting: Self-hosted (Docker, Linux/Windows binaries, portable), ImageMagick/Ghostscript optional

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👥 Who Is This For?

This project is useful for:

• Developers who want to prototype and build low-code apps rapidly

• Teams looking for self-hosted alternatives to SaaS like Airtable, Monday.com, or Jira

• Indie makers building and sharing/selling custom business applications

• Businesses and MSPs needing compliant internal tools without vendor lock-in

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📸 Screenshots / Demo

• Live demo: https://demo.rei3.de/

• GitHub: https://github.com/r3-team/r3

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🔥 Project Status

• 🟢 Actively building

Last updated: 2026-03-24

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❓ FAQ

Is this project free?

Yes / Open Source — MIT license, unlimited users, free forever. Optional paid enterprise services for support/clustering.

(Briefly: Core platform is completely free and open-source.)

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Is the source code available?

Yes — link to repository https://github.com/r3-team/r3

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Can I contribute?

Yes — Fork the repo, submit pull requests to main branch. Follow four-digit versioning (MAJOR.MINOR.PATCH.BUILD). Report issues, join https://community.rei3.de forum for feedback/discussion.

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📬 Contact & Links

• Website: https://rei3.de/

• GitHub: https://github.com/r3-team/r3

• Twitter/X: N/A

• Email: Contact via https://leansw.de/en/contact

• Other: Community Forum https://community.rei3.de | Docs https://rei3.de/en/docs | YouTube https://www.youtube.com/channel/UCKb1YPyUV-O4GxcCdHc4Csw

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