Introduction

What is Fusion?

Fusion Framework is a cross-platform backend framework built on a shared Rust core and FMA (Fusion Module Architecture).

You write class-based HTTP APIs in your preferred language. Routing, request parsing, response serialization, settings, and header helpers run in the Rust engine — language bindings stay thin and focused on developer experience.

Current framework package version in the open-source repository: 1.2.6.

Why Fusion exists

Teams often need the same HTTP semantics in more than one language. Fusion keeps one core for routing and serialization while exposing idiomatic APIs in Python, TypeScript/Node.js, and C#. Applications are composed from route modules and optional reusable packages instead of a single unstructured script.

Fusion is developed by Cipher Unit.

Language support

Recommended learning path

Read in this order — architecture first, then the CLI, then your language:

1. Architecture overview — mental model of the stack
2. Workspace and crates — core vs bindings
3. FMA — how modules and packages fit together
4. What Fusion is not — scope boundaries
5. Fusion Tool — scaffold projects and manage environments
6. Language guide: Python · TypeScript · C#
7. Settings and configuration — fusion.<env>.json, FUSION_ENV, overlays
8. Router · Middleware · language Config
9. Reusable packages
10. Best practices · Troubleshooting

Tooling

• Fusion Tool — the official CLI for scaffolding projects, managing environments, and running project commands
• Fusion Desktop — a graphical interface for managing Fusion backends on Windows and Linux

Fusion is open source under the BSD License. Learn more about the team at cipherunit.xyz.

Versioning

Fusion is a young framework, so we use a deliberate versioning strategy while the core stabilizes.

The goal is continuous improvement toward a reliable foundation for production backends.