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Version: Config V1 (legacy)

OpenFeature Provider for Rust

Build Status crates.io docs.rs

ConfigCat OpenFeature Provider for Rust on GitHub

Getting started​

1. Install the provider​

Run the following Cargo command in your project directory:

cargo add configcat-openfeature-provider

Or add the following to your Cargo.toml:

[dependencies]
configcat-openfeature-provider = "0.1"

2. Initialize the provider​

The ConfigCatProvider needs a pre-configured ConfigCat Rust SDK client:

use std::time::Duration;
use configcat::{Client, PollingMode};
use open_feature::OpenFeature;
use configcat_openfeature_provider::ConfigCatProvider;

#[tokio::main]
async fn main() {
    // Acquire an OpenFeature API instance.
    let mut api = OpenFeature::singleton_mut().await;

    // Configure the ConfigCat SDK.
    let configcat_client = Client::builder("<YOUR-CONFIGCAT-SDK-KEY>")
        .polling_mode(PollingMode::AutoPoll(Duration::from_secs(60)))
        .build()
        .unwrap();

    // Configure the provider.
    api.set_provider(ConfigCatProvider::new(configcat_client)).await;

    // Create a client.
    let client = api.create_client();
}

For more information about all the configuration options, see the Rust SDK documentation.

3. Evaluate your feature flag​

let is_awesome_feature_enabled = client
    .get_bool_value("isAwesomeFeatureEnabled", None, None)
    .await
    .unwrap_or(false);

if is_awesome_feature_enabled {
    do_the_new_thing();
} else {
    do_the_old_thing();
}

Evaluation Context​

An evaluation context in the OpenFeature specification is a container for arbitrary contextual data that can be used as a basis for feature flag evaluation. The ConfigCat provider translates these evaluation contexts to ConfigCat User Objects.

The following table shows how the different context attributes are mapped to User Object attributes.

Evaluation contextUser ObjectRequired
targeting_keyidentifier☑
Emailemail
Countrycountry
Any othercustom

To evaluate feature flags for a context, use the OpenFeature Evaluation API:

let context = EvaluationContext::default()
    .with_targeting_key("#SOME-USER-ID#")
    .with_custom_field("Email", "[email protected]")
    .with_custom_field("Country", "CountryID")
    .with_custom_field("Rating", 4.5)
    .with_custom_field("Roles", ["Role1", "Role2"]);

let is_awesome_feature_enabled = client
    .get_bool_value("isAwesomeFeatureEnabled", Some(&context), None)
    .await
    .unwrap_or(false);

Look under the hood​