Component Model design and specification
June 18, 2026 ยท View on GitHub
This repository is where the Component Model is being standardized. For a more user-focused explanation, take a look at the Component Model Documentation.
This repository contains:
- high-level goals, use cases, design choices and FAQ docs
- low-level WIT, text format, binary format, concurrency and ABI docs
- a growing WAST test suite
In the future, this repository will additionally contain a formal spec and a reference interpreter.
Milestones
The Component Model is currently being developed incrementally as part of WASI "Developer Preview" releases. The Component Model features enabled as part of a WASI Developer Preview release are kept stable by producer and consumer tools so that they can be used outside the browser in production settings to collect real-world feedback.
The current WASI Developer Preview releases are:
- 0.2.0: the first release based on the Component Model; includes
shared-nothing and shared-everything linking, a variety of high-level
value types,
resourcetypes with handles, and WIT. - 0.3.0: the first release with native concurrency support in the Component
Model and WIT; adds
asyncfunctions,streams andfutures as well as new ABI built-in functions (additions are marked by the ๐ emoji throughout the repo).
Subsequent WASI Developer Preview releases will include other emoji-gated features such as cooperative threads (๐งต).
Contributing
All Component Model work is done as part of the W3C WebAssembly Community Group. To contribute to any of these repositories, see the Community Group's Contributing Guidelines.