#opinionated #microservices #included #batteries #cali #connection #grpc


Cali is a batteries included, opinionated rust based microservice framework

2 releases

0.2.1 Nov 6, 2023
0.2.0 Nov 1, 2023

#791 in HTTP server

Used in 2 crates

MIT license

226 lines


An opinionated GRPC/JSON Backend Web-framework for Rust.


  • Easy to use CLI to create a new project, scaffold out components.
  • Simple decorate attribute on application main function to setup config, database connections, external service connections GRPC

Structure Methodology

A typical cali project is split into application interfaces, and application logic.

Application interfaces are concerned with how the application connects to the outside world.

Application logic is split into business logic contexts in the spirit of Domain Driven Design.

Cali takes an opinionated stance in a few regards, and I'll provide some short motivations on why certain decisions were made.

  1. Cali splits every business logic unit into it's own crate. Being built on Rust, we are perpetually tied to language's issues. We get a great compiler, but a slow one. Optimising rust build times is not impossible, but it isn't trivial. Cali aims to make Rust more accessible to people coming from environment with hot reloading and rapid development times. We can't quite get there without significant effort. A simple yet effective solution is to just structure our projects into smaller units. These units move together, and by doing things this way I hope cali will make the swift from monolith -> to macroservice -> microservice (and back) easier. Your application is forced to be modular and composable. Hopefully this will assist in refactoring efforts (which if we face it, is inevitable), only time will tell.
  2. Cali tries to make rust development less verbose. This is achieved via Rust's super powerful macro system. Consequently, most gory details are abstracted away from the user. Rust purests might miss that and the control that comes with that. I have and will try to allow some way to hook into this for those interested in having more control, optimizing for scale is a personal effort for every team and the framework will try to accommodate that, but when caught between a situation where some optimization might require adding complexity to the use of the framework, Cali will choose ease of use. That's not to say Cali doesn't aim to be performant, but if you are the one in a million company that needs that, maybe you should consider rolling your own setup.
  3. Cali is meant to disprove the point that writing backend code is the sole domain of higher level languages. Rust is not the best language, but it's ideas are an improvement on the standard paradigms, and developers can learn a lot from using the language. It improves the way developers think, and will benefit you in the long run. Fight me.


~1M SLoC