1# UniFFI - a multi-language bindings generator for Rust
2
3UniFFI is a toolkit for building cross-platform software components in Rust.
4
5For the impatient, see [**the UniFFI user guide**](https://mozilla.github.io/uniffi-rs/)
6or [**the UniFFI examples**](https://github.com/mozilla/uniffi-rs/tree/main/examples#example-uniffi-components).
7
8By writing your core business logic in Rust and describing its interface in an "object model",
9you can use UniFFI to help you:
10
11* Compile your Rust code into a shared library for use on different target platforms.
12* Generate bindings to load and use the library from different target languages.
13
14You can describe your object model in an [interface definition file](https://mozilla.github.io/uniffi-rs/udl_file_spec.html)
15or [by using proc-macros](https://mozilla.github.io/uniffi-rs/proc_macro/index.html).
16
17UniFFI is currently used extensively by Mozilla in Firefox mobile and desktop browsers;
18written once in Rust, auto-generated bindings allow that functionality to be called
19from both Kotlin (for Android apps) and Swift (for iOS apps).
20It also has a growing community of users shipping various cool things to many users.
21
22UniFFI comes with support for **Kotlin**, **Swift**, **Python** and **Ruby** with 3rd party bindings available for **C#** and **Golang**.
23Additional foreign language bindings can be developed externally and we welcome contributions to list them here.
24See [Third-party foreign language bindings](#third-party-foreign-language-bindings).
25
26## User Guide
27
28You can read more about using the tool in [**the UniFFI user guide**](https://mozilla.github.io/uniffi-rs/).
29
30We consider it ready for production use, but UniFFI is a long way from a 1.0 release with lots of internal work still going on.
31We try hard to avoid breaking simple consumers, but more advanced things might break as you upgrade over time.
32
33### Etymology and Pronunciation
34
35ˈjuːnɪfaɪ. Pronounced to rhyme with "unify".
36
37A portmanteau word that also puns with "unify", to signify the joining of one codebase accessed from many languages.
38
39uni - [Latin ūni-, from ūnus, one]
40FFI - [Abbreviation, Foreign Function Interface]
41
42## Alternative tools
43
44Other tools we know of which try and solve a similarly shaped problem are:
45
46* [Diplomat](https://github.com/rust-diplomat/diplomat/) - see our [writeup of
47  the different approach taken by that tool](docs/diplomat-and-macros.md)
48* [Interoptopus](https://github.com/ralfbiedert/interoptopus/)
49
50(Please open a PR if you think other tools should be listed!)
51
52## Third-party foreign language bindings
53
54* [Kotlin Multiplatform support](https://gitlab.com/trixnity/uniffi-kotlin-multiplatform-bindings). The repository contains Kotlin Multiplatform bindings generation for UniFFI, letting you target both JVM and Native.
55* [Go bindings](https://github.com/NordSecurity/uniffi-bindgen-go)
56* [C# bindings](https://github.com/NordSecurity/uniffi-bindgen-cs)
57* [Dart bindings](https://github.com/NiallBunting/uniffi-rs-dart)
58
59### External resources
60
61There are a few third-party resources that make it easier to work with UniFFI:
62
63* [Plugin support for `.udl` files](https://github.com/Lonami/uniffi-dl) for the IDEA platform ([*uniffi-dl* in the JetBrains marketplace](https://plugins.jetbrains.com/plugin/20527-uniffi-dl)). It provides syntax highlighting, code folding, code completion, reference resolution and navigation (among others features) for the [UniFFI Definition Language (UDL)](https://mozilla.github.io/uniffi-rs/).
64* [cargo swift](https://github.com/antoniusnaumann/cargo-swift), a cargo plugin to build a Swift Package from Rust code. It provides an init command for setting up a UniFFI crate and a package command for building a Swift package from Rust code - without the need for additional configuration or build scripts.
65* [Cargo NDK Gradle Plugin](https://github.com/willir/cargo-ndk-android-gradle) allows you to build Rust code using [`cargo-ndk`](https://github.com/bbqsrc/cargo-ndk), which generally makes Android library builds less painful.
66* [`uniffi-starter`](https://github.com/ianthetechie/uniffi-starter) is a minimal project demonstrates a wide range of UniFFI in a complete project in a compact manner. It includes a full Android library build process, an XCFramework generation script, and example Swift package structure.
67
68(Please open a PR if you think other resources should be listed!)
69
70## Contributing
71
72If this tool sounds interesting to you, please help us develop it! You can:
73
74* View the [contributor guidelines](./docs/contributing.md).
75* File or work on [issues](https://github.com/mozilla/uniffi-rs/issues) here in GitHub.
76* Join discussions in the [#uniffi:mozilla.org](https://matrix.to/#/#uniffi:mozilla.org)
77  room on Matrix.
78
79## Code of Conduct
80
81This project is governed by Mozilla's [Community Participation Guidelines](./CODE_OF_CONDUCT.md).
82