Skip to content


Switch branches/tags

Latest commit


Git stats


Failed to load latest commit information.
Latest commit message
Commit time


WebAssembly (WASM) is the future of cloud-native infrastructure extensibility.

WASM is a safe, secure, and dynamic way of extending infrastructure with the language of your choice. WASM tool chains compile your code from any of the supported languages into a type-safe, binary format that can be loaded dynamically in a WASM sandbox/VM.

In this repo, you will find tooling, SDKs, an OCI-compatible specification, and examples for working with WASM and specifically WASM on Envoy Proxy based frameworks (like Gloo API Gateway or Istio Service Mesh -- but not limited to those).

One of the projects for working with WASM and Envoy proxy is WebAssembly Hub.

WebAssembly Hub is a meeting place for the community to share and consume WebAssembly Envoy extensions. You can easily search and find extensions that meet the functionality you want to add and give them a try.

Please see the announcement blog that goes into more detail on the motivation for WebAssembly Hub and how we see it driving the future direction of Envoy-based networking projects/products including API Gateways and Service Mesh.

In this Repo


In the /spec folder of this repo, you'll find an OCI image specification for WebAssembly modules. This specification is an extension to OCI and describes how a WASM module is packaged with the appropriate metadata so that it can be distributed and loaded into Envoy-based frameworks/service meshes. For example, some of the metadata include the root-id of the module, the ABI versions that are targeted in Envoy, and basic name of the module. Please see the spec for more details.


In the /sdks folder of this repo, you'll find a listing of the available SDKs for building Envoy Proxy based WASM modules. These SDKs implement the Envoy hooks for Envoy extension points in a language-specific way. The following exist today (with more on the way):

  • C++
  • Rust
  • AssemblyScript
  • TinyGo


In the /tools folder, you'll find a set of tools for working with WASM modules. Specifically, tools to do the following:

  • Bootstrap a new WASM project with boilerplate/version alignment/tool chain
  • Test that a WASM module can correctly be loaded into Envoy
  • Build your project with the specific tool chain
  • Publish your WASM module as a WASM OCI image to an OCI-compatible registry or WebAssembly Hub
  • Load your WASM module into an Envoy-based framework like Gloo or Istio

Other Resources


The WASM projects in this repository are made up of a collaboration between and the wider WebAssembly community.

Please join the Slack @ #wasm to participate!