# Bullet Train Client [](https://gitter.im/SolidStateGroup/bullettrain?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge) [](https://badge.fury.io/js/bullet-train-nodejs) [](https://www.jsdelivr.com/package/npm/bullet-train-nodejs) The SDK clients for NodeJS [https://bullet-train.io/](https://www.bullet-train.io/). Bullet Train allows you to manage feature flags and remote config across multiple projects, environments and organisations. ## Getting Started These instructions will get you a copy of the project up and running on your local machine for development and testing purposes. See running in production for notes on how to deploy the project on a live system. ## Installing ### VIA npm ```npm i bullet-train-nodejs --save``` ## Usage ### Retrieving feature flags for your project *For full documentation visit [https://docs.bullet-train.io](https://docs.bullet-train.io)* ```javascript var bulletTrain = require("bullet-train-nodejs"); bulletTrain.init({ environmentID:"" }); bulletTrain.hasFeature("header", '') .then((featureEnabled) => { if (featureEnabled) { //Show my awesome cool new feature to this one user } }); bulletTrain.hasFeature("header") .then((featureEnabled) => { if (featureEnabled) { //Show my awesome cool new feature to the world } }); bulletTrain.getValue("header", '') .then((value) => { //Show some unique value to this user }); bulletTrain.getValue("header") .then((value) => { //Show a value to the world }); ``` ### Available Options | Property | Description | Required | Default Value | | ------------- |:-------------:| -----:| -----:| | ```environmentID``` | Defines which project environment you wish to get flags for. *example ACME Project - Staging.* | **YES** | null | ```onError``` | Callback function on failure to retrieve flags. ``` (error)=>{...} ``` | **NO** | null | ```defaultFlags``` | Defines the default flags if there are any | **NO** | null | ```api``` | Use this property to define where you're getting feature flags from, e.g. if you're self hosting. | **NO** | https://bullet-train-api.dokku1.solidstategroup.com/api/v1/ ### Available Functions | Property | Description | | ------------- |:-------------:| | ```init``` | Initialise the sdk against a particular environment | ```hasFeature(key)``` | Get the value of a particular feature e.g. ```bulletTrain.hasFeature("powerUserFeature") // true``` | ```hasFeature(key, userId)``` | Get the value of a particular feature for a user e.g. ```bulletTrain.hasFeature("powerUserFeature", 1234) // true``` | ```getValue(key)``` | Get the value of a particular feature e.g. ```bulletTrain.getValue("font_size") // 10``` | ```getValue(key, userId)``` | Get the value of a particular feature for a specificed userId e.g. ```bulletTrain.getValue("font_size", 1234) // 15``` | ```getFlags()``` | Trigger a manual fetch of the environment features, if a user is identified it will fetch their features | ```getFlagsForUser(userId)``` | Trigger a manual fetch of the environment features with a given userId | ```setTrait(userId, key, value)``` | Set the name/value pair for the specified userId | ```getTrait(userId, key)``` | Retrieve the value for the specified userId and Trait key ### Identifying users Identifying users allows you to target specific users from the [Bullet Train dashboard](https://www.bullet-train.io/). You can include an optional user identifier as part of the `hasFeature` and `getValue` methods to retrieve unique user flags and variables. ## Contributing Please read [CONTRIBUTING.md](https://gist.github.com/kyle-ssg/c36a03aebe492e45cbd3eefb21cb0486) for details on our code of conduct, and the process for submitting pull requests to us. ## Getting Help If you encounter a bug or feature request we would like to hear about it. Before you submit an issue please search existing issues in order to prevent duplicates. ## Get in touch If you have any questions about our projects you can email support@bullet-train.io. ## Useful links [Website](https://bullet-train.io) [Documentation](https://docs.bullet-train.io/) [Code Examples](https://github.com/BulletTrainHQ/bullet-train-docs) [Youtube Tutorials](https://www.youtube.com/channel/UCki7GZrOdZZcsV9rAIRchCw)