OpenFeature Provider (Ruby)

Overview

This guide covers using Mixpanel’s Feature Flags through the OpenFeature standard with the Mixpanel Ruby OpenFeature provider. OpenFeature provides a vendor-agnostic API for feature flag evaluation, allowing you to switch between providers without changing your application code.

For the native Mixpanel SDK approach, see the Feature Flags (Ruby) guide.

Prerequisites

Enterprise subscription plan with Feature Flags enabled
Ruby 3.1.0 or higher
Project Token from your Mixpanel Project Settings

Installation

Add to your Gemfile:

gem 'mixpanel-ruby-openfeature'
gem 'openfeature-sdk'
gem 'mixpanel-ruby'

Then run:

bundle install

Quick Start

require 'mixpanel-ruby'
require 'mixpanel/openfeature'
 
# 1. Create the provider with local evaluation
provider = Mixpanel::OpenFeature::Provider.from_local(
  'YOUR_PROJECT_TOKEN',
  { poll_interval: 300 }
)
 
# 2. Register the provider with OpenFeature
OpenFeature::SDK.configure do |config|
  config.set_provider(provider)
end
 
# 3. Get a client and evaluate flags
client = OpenFeature::SDK.build_client
 
show_new_feature = client.fetch_boolean_value(flag_key: 'new-feature-flag', default_value: false)
 
if show_new_feature
  puts 'New feature is enabled!'
end

Initialization

Local Evaluation (Recommended)

Downloads flag definitions and evaluates them locally with no per-evaluation network requests.

⚠️

Targeting by Mixpanel cohorts and sticky variants are not supported in Local Evaluation mode.

provider = Mixpanel::OpenFeature::Provider.from_local(
  'YOUR_PROJECT_TOKEN',
  { poll_interval: 300 }
)

Remote Evaluation

Sends each flag check to Mixpanel’s servers.

provider = Mixpanel::OpenFeature::Provider.from_remote(
  'YOUR_PROJECT_TOKEN',
  {}
)

Using an Existing Tracker

tracker = Mixpanel::Tracker.new('YOUR_PROJECT_TOKEN', nil, local_flags_config: { poll_interval: 300 })
tracker.local_flags.start_polling_for_definitions!
 
provider = Mixpanel::OpenFeature::Provider.new(tracker.local_flags)

Usage

Flag Types and Evaluation Methods

Mixpanel Flag Type	Variant Values	OpenFeature Method
Feature Gate	`true` / `false`	`fetch_boolean_value`
Experiment	boolean, string, number, or JSON object	`fetch_boolean_value`, `fetch_string_value`, `fetch_number_value`, or `fetch_object_value`
Dynamic Config	JSON object	`fetch_object_value`

client = OpenFeature::SDK.build_client
 
# Feature Gate
is_feature_on = client.fetch_boolean_value(flag_key: 'new-checkout', default_value: false)
 
# Experiment with string variants
button_color = client.fetch_string_value(flag_key: 'button-color-test', default_value: 'blue')
 
# Experiment with number variants
max_items = client.fetch_number_value(flag_key: 'max-items', default_value: 10)
 
# Dynamic Config
feature_config = client.fetch_object_value(
  flag_key: 'homepage-layout',
  default_value: { 'layout' => 'grid', 'items_per_row' => 3 }
)

Evaluation Context

context = OpenFeature::SDK::EvaluationContext.new(
  targeting_key: 'user-123',
  email: 'user@example.com',
  plan: 'premium'
)
 
value = client.fetch_boolean_value(
  flag_key: 'premium-feature',
  default_value: false,
  evaluation_context: context
)

Unlike some providers, targetingKey is not used as a special bucketing key. It is passed as another context property. Mixpanel’s server-side configuration determines which properties are used for targeting and bucketing.

Full Resolution Details

details = client.fetch_boolean_details(flag_key: 'my-feature', default_value: false)
 
puts details.value
puts details.variant
puts details.reason
puts details.error_code

Accessing the Mixpanel Tracker

provider.mixpanel.track('user-123', 'Page View', { 'page' => '/home' })

Rails Integration

# config/initializers/openfeature.rb
provider = Mixpanel::OpenFeature::Provider.from_local(
  ENV['MIXPANEL_TOKEN'],
  { poll_interval: 300 }
)
 
OpenFeature::SDK.configure do |config|
  config.set_provider(provider)
end
 
at_exit { provider.shutdown }

Shutdown

provider.shutdown

Error Handling

Error Code	When
`PROVIDER_NOT_READY`	Flags evaluated before the provider has finished initializing
`FLAG_NOT_FOUND`	The requested flag does not exist in Mixpanel
`TYPE_MISMATCH`	The flag value type does not match the requested type

Troubleshooting

Flags Always Return Default Values

Provider not ready: Flag definitions are fetched asynchronously. Allow time for the initial fetch.
Invalid project token: Verify the token matches your Mixpanel project.
Flag not configured: Verify the flag exists and is enabled.

Type Mismatch Errors

Verify the flag’s value type matches your evaluation method. Use fetch_object_value for JSON objects.

Feature Flags (Ruby)PHP

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