React SDK - Installation

The @westyx-nexus/sdk-react package is hosted on the GitLab npm Package Registry. It is public - no token is required to install.

1. Configure npm to look at the registry

Add (or merge) the following to your project’s .npmrc:

@westyx-nexus:registry=https://gitlab.com/api/v4/projects/81979839/packages/npm/

Commit the .npmrc to source control. It contains no credentials - every developer on the team automatically picks up the right registry.

2. Install the package

npm install @westyx-nexus/sdk-react

Pin to a specific version:

npm install @westyx-nexus/sdk-react@0.10.0

Requirements

React 18.0 or newer (uses useSyncExternalStore - React 18 baseline)
A modern browser environment with fetch streaming support - ReadableStream response bodies (Chrome, Firefox, Safari, Edge - all evergreens)
TypeScript users: 4.7+ for full type compatibility (peer of React 18 typings)

Use a public API key

Browser SDKs must use a wxp_... (public) key. Secret keys (wxs_...) are rejected at runtime.The API key is sent in the X-Nexus-API-Key header on every request, including the SSE /stream connection - the SDK uses fetch-based streaming, not the browser EventSource API, so the key never appears in the URL, server access logs, or browser history.

The SDK enforces this via:

A branded TypeScript type (PublicApiKey) - gives you a compile-time hint when typing strictly
A runtime guard in the SDK constructor - throws a descriptive error before any network call
A backend reject - a request carrying an wxs_... key against a browser/public surface returns 400 Bad Request

import { assertPublicKey } from '@westyx-nexus/sdk-react';

const apiKey: string = process.env.REACT_APP_NEXUS_API_KEY!;
assertPublicKey(apiKey);  // narrows to PublicApiKey, throws if not wxp_

Importing

The package exposes both ESM and CJS builds:

import { NexusProvider } from '@westyx-nexus/sdk-react';

const { NexusProvider } = require('@westyx-nexus/sdk-react');

The package’s exports map handles the format selection automatically.

SSR / Next.js

NexusProvider opens a fetch-based SSE stream on mount, which is browser-only (the SDK skips it during SSR). Use 'use client' (Next.js App Router) on the file containing NexusProvider, or render it under a client-only boundary.

Verifying connectivity

Before writing any code, confirm your endpoint and API key work with a plain curl:

curl -s \
  -H "X-Nexus-API-Key: wxp_..." \
  https://your-service.westyx.dev/v1/sync

A valid response returns a JSON snapshot with your configs and flags (browser SDKs use public keys - secrets are never included). An HTTP 401 means the key is wrong; HTTP 404 means the slug is wrong.

Troubleshooting

Could not resolve '@westyx-nexus/sdk-react' - your .npmrc is not picked up. Confirm it’s at the project root next to package.json, and check npm config get registry @westyx-nexus.
401 Unauthorized when running npm install - the registry might be configured with an old path. Switch to the numeric-ID variant above.
Browser SDKs require a public key at runtime - replace your wxs_... key with a wxp_... key from the same service in the Westyx Nexus admin UI.

Overview

Backend SDKs

Browser SDKs

OpenFeature Providers

React SDK - Installation

1. Configure npm to look at the registry

2. Install the package

Requirements

Use a public API key

Importing

SSR / Next.js

Verifying connectivity

Troubleshooting

​1. Configure npm to look at the registry

​2. Install the package

​Requirements

​Use a public API key

​Importing

​SSR / Next.js

​Verifying connectivity

​Troubleshooting

1. Configure npm to look at the registry

2. Install the package

Requirements

Use a public API key

Importing

SSR / Next.js

Verifying connectivity

Troubleshooting