WIT Packages

A WIT package is a set of one or more WIT (Wasm Interface Type) files containing a related set of interfaces and worlds. WIT is an IDL (interface definition language) for the Component Model. Packages provide a way for worlds and interfaces to refer to each other, and thus for an ecosystem of components to share common definitions.

A WIT package is not a world. It's a way of grouping related interfaces and worlds together for ease of discovery and reference, more like a namespace.

  • The WebAssembly System Interface (WASI) defines a number of packages, including one named wasi:clocks. Our HTTP proxy world could import the wall-clock interface from the wasi:clocks package, rather than having to define a custom clock interface.

ⓘ For a more formal definition of what a WIT package is, take a look at the WIT specification.