WASI
WASI, the WebAssembly System Interface, is a standardized collection of interfaces that enables WebAssembly programs to access operating-system-like resources portably.
Server-Side WebAssembly
WASI 1.0 is a planned stable version of the WebAssembly System Interface intended to begin long-term stability guarantees.
- How it is used
- Connects Wasm guests to host-provided system capabilities for server, CLI, HTTP, and composed-component applications.
- How deep it goes
- Explains capability setup, component worlds, version differences, inspection, and composition, while deferring full standardization of many proposed interfaces.
- Examples
- Uses Hello World standard output, a WASI command component, and SmartCMS story-file access composed with a key-value store.
- What you can do after
- Operate/configure it by linking WASI in a host, granting stdout or read-only directories, inspecting WIT, and running components with Wasmtime.
Refactoring to Rust
WASI is a standardized system interface that allows WebAssembly programs to access operating-system-like services in a portable way.
- How it is used
- Enables Wasm modules to run outside the browser and support gradual integration with existing applications.
- How deep it goes
- Explains host interfaces, module swapping, and sandboxed memory; stops short of a WASI protocol specification.
- Examples
- Uses WasmEdge installation and a CLI search tool that consumes Wasm.
- What you can do after
- Apply it via the WasmEdge SDK and runtime to consume Wasm modules in an application.
Logs and Telemetry
WASI is a standardized system interface that provides WebAssembly programs with controlled access to operating-system-like capabilities.
- How it is used
- Invokes WebAssembly extensions when shell execution or host operating-system features are unsuitable, particularly in constrained containers.
- How deep it goes
- Explains controlled communication, deployment benefits, development requirements, and operational drawbacks without detailing WASI APIs.
- Examples
- Uses the exec-wasi plugin and distroless-container process capture to contrast WebAssembly execution with shell-based exec.
- What you can do after
- Operate/configure Fluent Bit to invoke WebAssembly solutions where shell-based execution conflicts with container constraints.
Related concepts
- WebAssemblyused by · WebAssembly is a portable, compact binary instruction format and execution environment for safely and efficiently running compiled code in browsers and other hosts.
- futureuses · A future is an abstraction representing an asynchronous computation or its result, which may not be complete or available yet.
- WebAssembly runtimeimplemented by · A WebAssembly runtime is software that loads, instantiates, and executes WebAssembly modules while providing execution services and mediating access to host resources.
- async streamuses · An async stream is a typed asynchronous sequence whose values are produced and consumed incrementally over time.
- JavaScript runtimeimplemented by · A JavaScript runtime is an execution environment that runs JavaScript code and provides the language engine and host APIs needed to interact with its platform.
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