Component-native transport-agnostic RPC protocol and framework based on WebAssembly Interface Types (WIT)
A Bytecode Alliance hosted project
wRPC facilitates execution of arbitrary functionality defined in WIT over network or other means of communication.
Main use cases for wRPC are:
- out-of-tree WebAssembly runtime plugins
- distributed WebAssembly component communication
Even though wRPC is designed for Wasm components first and foremost, it is fully usable outside of WebAssembly context and can serve as a general-purpose RPC framework.
wRPC uses component model value definiton encoding on the wire.
wRPC supports both dynamic (based on e.g. runtime WebAssembly component type introspection) and static use cases.
For static use cases, wRPC provides WIT binding generators for:
- Rust
- Go
wRPC fully supports the unreleased native WIT stream and future data types along with all currently released WIT functionality.
See specification for more info.
-
Using
cargo:cargo install wrpc
-
Using
nix:nix profile install github:bytecodealliance/wrpc
or, without installing:
nix shell github:bytecodealliance/wrpc -
You can also download individual binaries from the release page
wRPC usage examples for different programming languages can be found at examples.
There are 2 different kinds of examples:
- Native wRPC applications, tied to a particular wRPC transport (like Unix Domain Sockets, TCP, QUIC or NATS.io)
- Generic Wasm components, that need to run in a Wasm runtime. Those can be executed, for example, using
wrpc-wasmtime, to polyfill imports at runtime and serve exports using wRPC.
-
For Rust components and wRPC applications:
rust>= 1.82 -
For NATS.io transport:
nats-server>= 2.10.20 ordocker>= 24.0.6 (or any other OCI runtime)
Nix users can run nix develop anywhere in the repository to get all dependencies correctly set up
In this example we will serve and invoke a simple hello application.
We will use the following two Rust components:
We will have to build these components first:
-
Build Wasm
helloclient:cargo build --release -p hello-component-client --target wasm32-wasip2
Output is in target/wasm32-wasip2/release/hello-component-client.wasm
-
Build Wasm
helloserver:cargo build --release -p hello-component-server --target wasm32-wasip2
Output is in target/wasm32-wasip2/release/hello_component_server.wasm
NB: Rust uses
_separators in the filename, because a component is built as a reactor-style library
We will use the following two Rust wRPC applications using TCP transport:
[::1]:7761is used as the default address
-
Serve Wasm
helloserver via TCPwrpc-wasmtime tcp serve ./target/wasm32-wasip2/release/hello_component_server.wasm
- Sample output:
INFO wrpc_wasmtime_cli: serving instance function name="hello"
-
Call Wasm
helloserver using a Wasmhelloclient via TCP:wrpc-wasmtime tcp run ./target/wasm32-wasip2/release/hello-component-client.wasm
- Sample output in the client:
hello from Rust
- Sample output in the server:
INFO wrpc_wasmtime_cli: serving instance function invocation
INFO wrpc_wasmtime_cli: successfully served instance function invocation
-
Call the Wasm
helloserver using a native wRPChelloclient via TCP:cargo run -p hello-tcp-client
-
Serve native wRPC
helloserver via TCP:cargo run -p hello-tcp-server [::1]:7762
-
Call native wRPC
helloserver using native wRPChelloclient via TCP:cargo run -p hello-tcp-client [::1]:7762
-
Call native wRPC
helloserver using Wasmhelloclient via TCP:wrpc-wasmtime tcp run --import [::1]:7762 ./target/wasm32-wasip2/release/hello-component-client.wasm
Using NATS.io transport
We will use the following two Rust wRPC applications using NATS.io transport:
-
Run NATS.io (more thorough documentation available here):
- using standalone binary:
nats-server
- using Docker:
docker run --rm -it --name nats-server -p 4222:4222 nats:2.10.20-alpine3.20
-
Serve Wasm
helloserver via NATS.iowrpc-wasmtime nats serve --export rust ./target/wasm32-wasip2/release/hello_component_server.wasm
- Sample output:
INFO async_nats: event: connected
INFO wrpc_wasmtime_cli: serving instance function name="hello"
-
Call Wasm
helloserver using a Wasmhelloclient via NATS.io:wrpc-wasmtime nats run --import rust ./target/wasm32-wasip2/release/hello-component-client.wasm
- Sample output in the client:
INFO async_nats: event: connected
hello from Rust
- Sample output in the server:
INFO wrpc_wasmtime_cli: serving instance function invocation
INFO wrpc_wasmtime_cli: successfully served instance function invocation
-
Call the Wasm
helloserver using a native wRPChelloclient via NATS.io:cargo run -p hello-nats-client rust
-
Serve native wRPC
helloserver via NATS.io:cargo run -p hello-nats-server native
-
Call both the native wRPC
helloserver and Wasmhelloserver using native wRPChelloclient via NATS.io:cargo run -p hello-nats-client rust native
-
Call native wRPC
helloserver using Wasmhelloclient via NATS.io:wrpc-wasmtime nats run --import native ./target/wasm32-wasip2/release/hello-component-client.wasm
This repository contains (for all supported languages):
- core libraries and abstractions
- binding generators
- WebAssembly runtime integrations
- wRPC transport implementations
wit-bindgen-wrpc aims to closely match UX of wit-bindgen and therefore includes a subtree merge of the project, which is occasionally merged into this tree.
- wRPC binding generators among other tests, are tested using the
wit-bindgentest suite wit-bindgendocumentation is reused where applicable
👋 Welcome, new contributors!
Whether you're a seasoned developer or just getting started, your contributions are valuable to us. Don't hesitate to jump in, explore the project, and make an impact. To start contributing, please check out our Contribution Guidelines.