Vercel SDK reference

Overview

This topic documents how to get started with the Vercel SDK, and links to reference information on all of the supported features.

Getting started

To install and configure the Vercel SDK in an existing project:

After you complete the Creating a Vercel integration process, follow these instructions to start using the LaunchDarkly Vercel SDK.

First, install the Vercel SDK as a dependency in your application using your application's dependency manager.

Here's how:

yarn add @launchdarkly/vercel-server-sdk
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Next, import the LaunchDarkly client in your application code:

import init from '@launchdarkly/vercel-server-sdk';
import { createClient } from '@vercel/edge-config';
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After you install and import the SDK, create an edge client using your Edge Config ID. Then, initialize an LDClient using your LaunchDarkly client-side SDK key and this edge client.

Here's how:

const edgeClient = createClient(process.env.EDGE_CONFIG);
const ldClient = init('sdk-key-123abc', edgeClient);
await ldClient.waitForInitialization();
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After you initialize the client, wait for the waitForInitialization function to resolve. When waitForInitialization is resolved, the client can serve feature flags.

Using the client, you can check which variation a particular context will receive for a given feature flag. In your Vercel Edge application, place the client.variation code so that it is invoked as needed.

Here is an example:

const ldContext = {
  kind: 'org',
  key: 'org-key-123abc',
  someAttribute: 'example-attribute-value',
};
const flagValue = await ldClient.variation('flag-key-123abc', ldContext, true);
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Promises and async

All asynchronous SDK methods that return a Promise are compatible with then/catch or async/await. You can use either.

Shutting down

Lastly, shut down the client when your application terminates. To learn more, read Shutting down.

Supported features

This SDK supports the following features:

• Anonymous contexts and users
• Configuration
• Evaluating flags
• Flag evaluation reasons
• Getting all flags
• Logging configuration
• Secure mode
• Shutting down
• User and context configuration