Interoptopus 🐙

Productive, performant, robust interop for Rust. Pick three.

With Interoptopus you can write code like this:

#[ffi(service)]
pub struct Hello {}

#[ffi]
impl Hello {
    pub fn world() -> Result<Self, Error> { Ok(Self {}) }
}

and then call it from your other language like this:

var service = Hello.World();

Its key features include:

• Nanosecond fast.
• Supports structs, data-enums, callbacks, services, async, idiomatic error handling, and much more ...
• Bidirectional interop, export your Rust library, or load foreign code into your Rust app.
• Painless workflow, no external tooling required.
• Polyglot core, first-class support for C#, can support any other language.

Getting Started

Read our documentation here.

Feature Flags

Gated behind feature flags, these enable:

• macros - Proc macros such as #[ffi].
• serde - Serde attributes on internal types.
• tokio - Convenience support for async services via Tokio.
• unstable-plugins - Experimental 'reverse interop' plugins. Not semver stable!

Supported Languages

Language	Backend Crate	Status
C#	interoptopus_csharp	✅
C	interoptopus_c	⏯️
Python	interoptopus_cpython	⏯️
Other	Write your own backend1

^✅ Tier 1 target. Active maintenance and production use. Full support of all features.
^⏯️ Tier 2 target. Currently suspended, contributors wanted!
¹ You can implement basic support for a new language in just a few hours, no pull request needed.

Performance

In essence, plain calls are near-zero overhead (1-10ns), as are most structs, enums and services. If serialization is involved it scales with payload size. Using the .NET runtime as a plugin adds ~20 MB overhead.

For more details see our benchmark numbers here.

Further Reading

• See our changelog.
• Read the FAQ.

Contributing

PRs are very welcome!

• Submit small bug fixes directly. Major changes should be issues first.
• New features or patterns must be materialized in the reference project and accompanied by at least a C# interop test.