Crate comlink 

Ergonomic Comlink RPC for Rust and WebAssembly: define a service as a trait, annotate it with service, and the macro generates a client and a service that speak comlink’s protocol over any endpoint (a Worker, a MessagePort, a window endpoint).

#[comlink::service]
pub trait Calculator {
    async fn add(&self, left: u32, right: u32) -> u32;
}

The macro emits CalculatorClient::wrap(&endpoint) for the calling side and CalculatorService::expose(implementation, &endpoint) for the serving side.

Arguments and return values cross as structured clones: JsValue-bearing types untouched, byte buffers as Uint8Array (Option<Vec<u8>> as Uint8Array or undefined), everything else through serde. A method returning Result maps onto the promise: Ok resolves with the encoded value, Err rejects with the encoded error, so a JavaScript peer just returns or throws. Every rejection decodes into the error type, a thrown Error first reduced to its message, so keep that type a serde one such as String. A remote panic or a released proxy arrives the same way, as an Err rather than the panic a non-Result method raises.

The raw bindings this is built on are re-exported as sys, for the parts of comlink the macro does not cover. The npm comlink package has to be resolvable by whatever bundler or module loader serves the generated JavaScript.

Re-exports

pub use comlink_sys as sys;

pub use futures;

Modules

client

The calling side of a generated client. Everything here but StreamReceiver exists for the code #[comlink::service] emits. A method returning Result takes its Ok from the promise’s resolution and its Err from the rejection.

ready

Comlink has no handshake, so a request posted before the remote’s expose listener attaches is lost. The serving side announces readiness with a sentinel once exposed; both comlink listeners ignore it (no type, no id).

Attribute Macros

service