UnleashSDK Skill

When to Use This Skill

Load this skill when:

• Enabling/disabling features at runtime without redeployment
• Rolling out features gradually to a percentage of users
• Running A/B tests or controlled experiments
• Creating killswitches for risky features
• Targeting feature flags to specific user segments

Installation

box install unleashsdk

Configuration

config/modules/unleashsdk.cfc

function configure() {
    return {
        // Unleash server URL
        url        : getSystemSetting( "UNLEASH_URL",    "https://unleash.example.com/api" ),
        // Client API token
        apiToken   : getSystemSetting( "UNLEASH_TOKEN",  "" ),
        // Application identifier — shown in Unleash UI
        appName    : getSystemSetting( "APP_NAME",       "myapp" ),
        // Environment (matches Unleash environment activation)
        environment: getSystemSetting( "APP_ENV",        "production" ),
        // How often to sync flags from server (seconds)
        refreshInterval : 15,
        // Cache TTL (seconds) — use cached values when server unreachable
        cacheTTL        : 60
    }
}

Core API

Injection

property name="unleash" inject="UnleashClient@unleashsdk";

Check if a Feature is Enabled

// Simple check
if ( unleash.isEnabled( "new-dashboard" ) ) {
    // render new dashboard
}

// With context (user ID, session ID, properties)
if ( unleash.isEnabled( "beta-checkout", {
    userId    : security.getCurrentUser().getId(),
    sessionId : session.id,
    properties: {
        role  : security.getCurrentUser().getRole(),
        plan  : security.getCurrentUser().getPlan()
    }
} ) ) {
    // show beta checkout flow
}

Get a Variant (A/B Testing)

var variant = unleash.getVariant( "checkout-button-color", {
    userId : security.getCurrentUser().getId()
} )

// variant.name   = "blue" | "green" | "disabled"
// variant.enabled = true/false
// variant.payload = { type: "string", value: "#0070f3" }

if ( variant.enabled ) {
    prc.buttonColor = variant.payload.value
} else {
    prc.buttonColor = "default"
}

Production Patterns

Feature Flag in a Handler

function checkout( event, rc, prc ) {
    var userId = security.getCurrentUser().getId()

    // Feature flag controls which checkout version to render
    if ( unleash.isEnabled( "new-checkout-v2", { userId: userId } ) ) {
        prc.layout = "v2"
        event.setView( "checkout/v2/index" )
    } else {
        prc.layout = "v1"
        event.setView( "checkout/v1/index" )
    }
}

Gradual Rollout Service

class FeatureService {

    property name="unleash" inject="UnleashClient@unleashsdk";

    boolean function useNewSearch() {
        return unleash.isEnabled( "new-search-engine", {
            userId    : security.getCurrentUser().getId(),
            sessionId : session.id
        } )
    }

    struct function getCheckoutVariant() {
        var variant = unleash.getVariant( "checkout-experiment", {
            userId : security.getCurrentUser().getId()
        } )
        return {
            name   : variant.enabled ? variant.name : "control",
            config : variant.enabled ? variant.payload : {}
        }
    }
}

Killswitch / Emergency Disable

function run( event, rc, prc ) {
    if ( !unleash.isEnabled( "data-export-feature" ) ) {
        event.renderData(
            type       = "json",
            statusCode = 503,
            data       = { error: "This feature is temporarily disabled." }
        )
        return
    }

    // ... proceed with export
}

Automated A/B Test Tracking

function trackAndRoute( event, rc, prc ) {
    var variant = unleash.getVariant( "pricing-page", {
        userId : security.getCurrentUser().getId()
    } )

    // Record which variant the user saw
    analyticsService.track( "pricing_variant_shown", {
        userId  : security.getCurrentUser().getId(),
        variant : variant.name
    } )

    if ( variant.name == "v2" ) {
        event.setView( "pricing/v2" )
    } else {
        event.setView( "pricing/v1" )
    }
}

Best Practices

• Always provide a default — isEnabled() returns false if the server is unreachable; design safe defaults
• Use user context for consistent per-user bucketing in gradual rollouts
• Use getVariant() for experiments, not just isEnabled() — variants carry payload and support multi-arm tests
• Store the API token in an environment variable — never commit it to source control
• Use feature flags as killswitches for risky features — wrap expensive or experimental code paths
• Clean up stale flags — remove flags from code once a rollout is complete (100% or 0%)
• Test the false path — ensure the application works correctly when a flag is disabled

Documentation

• unleashsdk: https://github.com/coldbox-modules/unleashsdk
• Unleash feature flags: https://docs.getunleash.io