Flipt is an open source developer friendly feature flagging solution, that allows for easy management and fast feature evaluation.

This provider is an implementation on top of the official Flipt Node Server Side SDK.

$ npm install @openfeature/flipt-provider

Both the OpenFeature SDK and the Flipt Node Server SDK are required as peer dependencies.

Please make sure to install @flipt/flipt-io at versions >= 1.0.0, as the client API is different in earlier versions.

The peer dependency will also enforce the above version.

To initialize the OpenFeature client with Flipt, you can use the following code snippet:

import { FliptProvider } from '@openfeature/flipt';

const provider = new FliptProvider('namespace-of-choice', { url: 'http://your.upstream.flipt.host' });
OpenFeature.setProvider(provider);

After the provider gets initialized, you can start evaluations of feature flags like so:

const client = OpenFeature.getClient();
const details = await client.getStringDetails('nonExistent', 'default', {
  targetingKey: 'myentity',
  email: 'john@flipt.io',
});

OpenFeature standardizes the evaluation context to include a targetingKey, and some other additional arbitrary properties that each provider can use fit for their use case.

For Flipt, we translate the targetingKey as the entityId, and the rest of the OpenFeature evaluation context as the context in Flipt vernacular. You can find the meaning of those two words here in our API docs.

For example, an OpenFeature Evaluation context that has this structure:

{
  "targetingKey": "my-targeting-id",
  "email": "john@flipt.io",
  "userId": "this-very-long-user-id"
}

will get transformed to the following for Flipt:

{
  "entityId": "my-targeting-id",
  "context": {
    "email": "john@flipt.io",
    "userId": "this-very-long-user-id"
  }
}

Run nx package providers-flipt to build the library.

Run nx test providers-flipt to execute the unit tests via Jest.