Nest.js SDK Getting Started

To use the DevCycle Server SDK in your project, import the DevCycleModule from the @devcycle/nestjs-server-sdk. We recommend adding the module to the imports of your root app module, so that the DevCycle client is available globally within your application.

Example:

import { DevCycleModule } from '@devcycle/nestjs-server-sdk'

DevCycleModule.forRoot({
  key: '<DEVCYCLE_SDK_SERVER_KEY>'
})

You may also use forRootAsync if you would like to use a factory to inject dependencies. For example, using Nest's ConfigService to populate the SDK key:

import { ConfigService } from '@nestjs/config'

DevCycleModule.forRootAsync({
  useFactory: (config: ConfigService) => ({
    key: config.get('DEVCYCLE_SDK_SERVER_KEY'),
  }),
  inject: [ConfigService]
}),

User Factory

To use the decorators provided by the SDK, you will need to define a userFactory when registering the DevCycleModule. The userFactory is a function which accepts the current ExecutionContext as a parameter and returns a DevCycle User object. The user factory will be evaluated as a global interceptor, and the resulting user will be used when evaluating variables with the @VariableValue and @RequireVariableValue decorators.

DevCycleUser Typescript Schema

import { DevCycleModule } from '@devcycle/nestjs-server-sdk'
import { ExecutionContext } from '@nestjs/common'

DevCycleModule.forRoot({
  key: '<DEVCYCLE_SDK_SERVER_KEY>',
  userFactory: (context: ExecutionContext) => {
    // Example building a user object based on the request context
    const req = context.switchToHttp().getRequest()
    return {
      user_id: req.user.id,
      email: req.user.email,
    }
  }
})

Initialization Options

The SDK exposes various initialization options which can be set when registering the DevCycleModule:

import { DevCycleModule } from '@devcycle/nestjs-server-sdk'

DevCycleModule.forRoot({
  key: '<DEVCYCLE_SDK_SERVER_KEY>',
  options: {
    logLevel: 'debug'
  }
})

DevCycle Option	Type	Description
logger	DevCycleLogger	Logger override to replace default logger
logLevel	String	Set log level of the default logger. Options are: debug, info, warn, error. Defaults to info.
configPollingIntervalMS	Number	Controls the polling interval in milliseconds to fetch new environment config changes, defaults to 10 seconds, minimum value is 1 second.
configPollingTimeoutMS	Number	Controls the request timeout to fetch new environment config changes, defaults to 5 seconds, must be less than the configPollingIntervalMS value, minimum value is 1 second.
eventFlushIntervalMS	Number	Controls the interval between flushing events to the DevCycle servers, defaults to 30 seconds.
disableAutomaticEventLogging	Boolean	Disables logging of sdk generated events (e.g. aggVariableEvaluated, aggVariableDefaulted) to DevCycle.
disableCustomEventLogging	Boolean	Disables logging of custom events, from track() method, and user data to DevCycle.
flushEventQueueSize	Number	Controls the maximum size the event queue can grow to until a flush is forced. Defaults to 1000.
maxEventQueueSize	Number	Controls the maximum size the event queue can grow to until events are dropped. Defaults to 2000.
apiProxyURL	String	Allows the SDK to communicate with a proxy of DevCycle bucketing API / client SDK API.