76 releases

0.12.21 Jun 22, 2023
0.12.13 May 27, 2023
0.11.65 Mar 7, 2023
0.11.62 Oct 13, 2022
0.11.36 Jul 8, 2022

#21 in WebAssembly

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Used in 192 crates (5 directly)




WASIX adds extensions on WASIX and is managed by the wasix.org community

WASI(X) API Bindings for Rust

Crates.io version Download docs.rs docs

WASI API Bindings for Rust

Crates.io version Download docs.rs docs

WASI(X) Extensions Spec

WASI(X) is maintained by wasix.org.

The intent of WASIX (pronounced "was-x") is to extend the WASI proposal and complete the ABI sufficiently now to build useful and productive applications today - it is not intended as a fork but rather to be a superset on top of WASI. Therefore it maintains full forwards and backwards compatibility with the preview1 version of WASI and stabilizes it for the long term.

WASIX is published on crates.io

Current Extensions

Below are the current extensions supported by WASIX, they are all fully tested and incorporated into supporting runtime(s):

  • full support for efficient multithreading including joins, signals and getpid
  • pthreads support (now extended from the WASI threads spec)
  • full support for sockets (socket, bind, connect, resolve)
    • IPv4, IPv6
    • UDP, TCP
    • Multicast, Anycast
    • RAW sockets
  • current directory support (chdir) integrated with the runtime
  • setjmp / longjmp support (used extensively in libc ) via asyncify
  • process forking (fork and vfork )
  • subprocess spawning and waiting (exec , wait )
  • TTY support
  • asynchronous polling of sockets and files
  • pipe and event support (pipe, event )
  • DNS resolution support (resolve )

WASI(X) Contributions

All contributions are welcome on extending WASI(X) with other extension(s). Just submit your pull request here and we will review via normal GitHub processes.


Long-term Support

WASIX will receive long term support by this community with a guarantee of backwards compatibility on the ABI. Runtime(s) that support this ABI are assured of its stability just as standard libraries and libraries can also count on that same stability to join the dots and make the connections.

Major bug fixes and/or zero day vulnerabilities will be addressed promptly here with careful consideration for resolving issues without compromising the long-term support goal.

Dependency Graph



First you can depend on this crate via Cargo.toml:

wasix = "0.11"

Next you can use the APIs in the root of the module like so:

fn main() {
    let stdout = 1;
    let message = "Hello, World!\n";
    let data = [wasix::Ciovec {
        buf: message.as_ptr(),
        buf_len: message.len(),
    wasix::fd_write(stdout, &data).unwrap();

Next you can use a tool like cargo wasix to compile and run your project:

To compile Rust projects to wasm using WASI, use the wasm32-wasix target, like this:

$ wasmer run my-all
   Compiling wasix v0.11.0
   Compiling wasi v0.11.0+wasix-snapshot-preview1
   Compiling wut v0.1.0 (/code)
    Finished dev [unoptimized + debuginfo] target(s) in 0.34s
     Running `/.cargo/bin/cargo-wasix target/wasm64-wasix/debug/wut.wasm`
     Running `target/wasm64-wasix/debug/wut.wasm`
Hello, World!


The bulk of the wasix crate is generated by the witx-bindgen tool, which lives at crates/witx-bindgen and is part of the cargo workspace.

The src/lib_generated.rs file can be re-generated with the following command:

cargo run -p witx-bindgen -- crates/witx-bindgen/WASI/phases/snapshot/witx/wasix_v1.witx > src/lib_generated.rs

Note that this uses the WASIX standard repository as a submodule. If you do not have this submodule present in your source tree, run:

git submodule update --init


This project is licensed under the Apache 2.0 license with the LLVM exception. See LICENSE for more details.


Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in this project by you, as defined in the Apache-2.0 license, shall be licensed as above, without any additional terms or conditions.


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