Registry / devops / svelte-adapter-uws

svelte-adapter-uws

library0.5.8jsnpmunverified

svelte-adapter-uws is a SvelteKit adapter that runs the app on uWebSockets.js, a high-performance C++ HTTP server with native WebSocket support. Current version is 0.5.8, with active development. It targets Node.js >=22 and requires ws (for WebSocket polyfill), Svelte 4 or 5, and @sveltejs/kit 2. Notably faster than the default Node adapter, especially for WebSocket-heavy applications, due to uWebSockets.js's low-level, event-driven architecture. Ships TypeScript definitions.

devops

npm install svelte-adapter-uws

github ↗package ↗homepage ↗

INSTALL

IMPORT

SIG · SVELTE-ADAPTER-UWS

svelte-adapter-uws

devopsjavascriptv0.5.8

harness data pending

Install & Compatibility

Where this runs

No compatibility data collected yet for this library.

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

adapter

✓ import adapter from 'svelte-adapter-uws';

✗ import { adapter } from 'svelte-adapter-uws';

Default export; named export does not exist.

AdapterOptions

✓ import type { AdapterOptions } from 'svelte-adapter-uws';

✗ import { AdapterOptions } from 'svelte-adapter-uws';

Type-only export; use 'import type' for TypeScript.

adapter (CommonJS)

✓ const adapter = require('svelte-adapter-uws').default;

✗ const adapter = require('svelte-adapter-uws');

CJS require must access .default due to ESM-first packaging.

Configuration using adapter with custom port, WebSocket, and uWS options.

// svelte.config.js import adapter from 'svelte-adapter-uws'; export default { kit: { adapter: adapter({ port: 3000, websocket: { // WebSocket options (optional) maxPayloadLength: 16 * 1024 * 1024, idleTimeout: 120 }, uws: { // uWebSockets.js options (optional) compression: 'shared', maxBackPressure: 1024 * 1024 } }) } };

Debug

Known issues

breakingNode.js version requirement changed from >=18 to >=22 in v0.5.0.

fix

Upgrade Node.js to 22 or later.

affects: >=0.5.0

breakingAdapter options renamed: 'wsOptions' became 'websocket' in v0.4.0.

fix

Rename 'wsOptions' key to 'websocket'.

affects: >=0.4.0

deprecatedSupport for SvelteKit 1.x was dropped in v0.5.0.

fix

Upgrade to @sveltejs/kit ^2.0.0.

affects: >=0.5.0

gotchauWebSockets.js does not support HTTP/1.1 keep-alive; connections are terminated after each request unless WebSocket upgrade.

fix

Use WebSocket for persistent connections or disable keep-alive expectations.

affects: >=0

gotchaThe 'ws' package is a peer dependency for WebSocket support but uWebSockets.js has its own WebSocket implementation; conflict may occur if both are used.

fix

Avoid using 'ws' directly; rely on adapter's WebSocket abstraction.

affects: >=0

Errors

Common errors & fixes

Error: Cannot find module 'svelte-adapter-uws'

Package not installed or missing from dependencies.

fix

Run 'npm install svelte-adapter-uws' and ensure it's in package.json dependencies.

TypeError: adapter is not a function

Importing named export 'adapter' instead of default export.

fix

Use 'import adapter from 'svelte-adapter-uws'' (no curly braces).

Error: This adapter requires Node.js version >=22.0.0

Running on an older Node.js version.

fix

Upgrade Node.js to v22 or later.

Error: Invalid WebSocket options (must be an object)

Passing non-object value to 'websocket' option in adapter config.

fix

Ensure adapter({ websocket: { ... } }) with an object value.

Upgrade

Version history

0.5.8latest on npm

Audit

Dependencies

wsrequiredWebSocket polyfill for uWS

svelterequiredRequired Svelte version

@sveltejs/kitrequiredRequired SvelteKit version

Agent activity

8 hits · last 30 days

node

Resources

githubhttps://github.com/lanteanio/svelte-adapter-uws ↗

packagesvelte-adapter-uws ↗

homepagehttps://github.com/lanteanio/svelte-adapter-uws#readme ↗