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Node.js WASI

Node.js module implementing the WebAssembly System Interface for POSIX-like OS access.

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Field note

What it does

The node:wasi module provides an implementation of the WebAssembly System Interface specification, giving WebAssembly applications access to the underlying operating system via POSIX-like functions. Stability: 1 - Experimental.

Capabilities

Available capabilities

WASM Import Object GenerationPOSIX-like File System AccessPreopened DirectoriesPOSIX-like OS accessWASI Preview 1 SupportCapabilities-based security model

Tags

Tags

ExperimentalWASI

Ways to use it

Ways to use it

sdk

JavaScript / node:wasi

Product features

Product features

Class: WASI #

wasi.finalizeBindings(instance[, options])

Finalizes WASI bindings for a WebAssembly instance.

wasi.getImportObject()

Returns the import object used to instantiate a WebAssembly instance.

wasi.initialize(instance)

Initializes a WebAssembly instance without calling _start.

new WASI([options]) #

Node.js v26.7.0 documentation

Security #

wasi.start(instance)

Starts a WebAssembly instance with WASI bindings.

Class: WASI

Constructed via new WASI([options]) with version, args, env and preopens options.

wasi.finalizeBindings(instance[, options]) #

wasi.getImportObject() #

wasi.wasiImport

Property exposing the WASI import object.

wasi.initialize(instance) #

wasi.start(instance) #

wasi.wasiImport #

WebAssembly System Interface (WASI) #