GrowthBook

Online documentation | Hex.pm

NOTE: This library is in active development, and the API may change.

GrowthBook is a GrowthBook SDK for Elixir/OTP.

This SDK follows the guidelines set out in GrowthBook's documentation, and the API is tested on conformance with the test cases from the JS SDK.

To ensure an Elixir-friendly API, the implementation deviates from the official SDK in the following ways:

• Instead of tuple-lists, this library uses actual tuples
• Comparisons with undefined are implemented by using :undefined
• Function names are converted to snake_case, and is_ prefix is replaced with a ? suffix
• Instead of classes, a Context struct is used (similar to %Plug.Conn{} in plug)
• There may be some discrepancies between handling of Truthy values between the JS and Elixir SDKs (if you notice this, a issue, or better, a PR is welcome)

What is GrowthBook?

GrowthBook is an open source A/B testing platform. The platform works significantly different from other A/B testing platforms, most notably: it is language agnostic.

Clients by default work offline, and manage their own data. This means that you are free to implement A/B tests server-side, or client-side without worrying about things like "anti-flicker" scripts, or the added latency of JS embeds.

Furthermore, GrowthBook supports both experiments (A/B tests and multivariate tests) and feature flags. Because all logic to run experiments and feature flags is contained in the library, there is virtually no added latency to running experiments or using feature flags.

Usage

# Create a context, which can be reused for multiple users
config = Jason.decode!("""
{
  "overrides": {
    "checkout-v2": {
      "status": "running",
      "coverage": 1,
      "weights": [0.5, 0.5],
      "force": 0
    }
  }
}
""")

features_config = Jason.decode!("""
{
  "features": {
    "send-reminder": {
      "defaultValue": false,
      "rules": [{ "condition": { "browser": "chrome" }, "force": true }]
    },
    "add-to-cart-btn-color": {
      "rules": [{ "variations": [{ "color": "red" }, { "color": "green" }] }]
    }
  }
}
""")

overrides = GrowthBook.Config.experiment_overrides_from_config(config)
features = GrowthBook.Config.features_from_config(features_config)

context = %GrowthBook.Context{
  enabled?: true,
  features: features,
  overrides: overrides,
  attributes: %{
    "id" => "12345",
    "country_code" => "NL",
    "browser" => "chrome"
  }
}

# Use a feature toggle
if GrowthBook.feature(context, "send-reminder").on? do
  Logger.info("Sending reminder")
end

# Use a feature's value
color = GrowthBook.feature(context, "add-to-cart-btn-color").value["color"]
Logger.info("Color: " <> color)

# Run an inline experiment
if GrowthBook.run(context, %GrowthBook.Experiment{
  key: "checkout-v2",
  coverage: 1,
  variations: [1, 2]
}).in_experiment? do
  Logger.info("In experiment")
end

Installation

Add growthbook to your list of dependencies in mix.exs:

def deps do
  [
    {:growthbook, "~> 0.1"}
  ]
end

License

This library is MIT licensed. See the LICENSE file in this repository for details.