What is Featurevisor?

Featurevisor is a solution for managing your feature flags, experiments, and remote config. It's built for developers, by developers.

Workflow can be broken down into 3 steps:

• 1️⃣ Manage feature flags, experiments, and remote config in your Git repository
• 2️⃣ Trigger CI/CD pipeline to generate and upload datafiles (static JSON files) to your CDN
• 3️⃣ Fetch and evaluate datafiles in your applications using Featurevisor SDKs

More documentation available at https://featurevisor.com.

Supported features:

• 🚩 Feature flags: classic on/off switches
• 🆎 Experimentation: a/b and multivariate tests
• 👥 Segmentation: reusable conditions for targeting groups of users
• ↗️ Gradual rollouts: avoid big bang releases, and go from 0% to 100% rollout gradually
• 🔧 Variables: store key/value pairs for remote config namespaced under each feature
• 🎯 Consistent bucketing: makes sure same user gets same variation across devices/sessions
• 🌏 Multiple environments: Go beyond just staging and production to fit your needs
• 🏷️ Tagging: Load only features relevant to your application, avoiding bloat
• 👁️ Tracking: Track experiment activations with your favourite analytics tool

SDK support:

• JavaScript (both Node.js and browser environments)
• Swift
• React
• Vue.js

Swift and Kotlin SDKs are coming soon for native apps.

Quick start

You are recommended to see a more detailed quick start guide here: https://featurevisor.com/docs/quick-start/.

The whole process can be broken down into 3 steps:

Step 1: Create a Featurevisor project

Use npx to scaffold a new Featurevisor project:

$ mkdir my-featurevisor-project && cd my-featurevisor-project

$ npx @featurevisor/cli init
$ npm install

You can now create and manage your feature flags, experiments, and remote config in this directory expressed as YAMLs.

See the building block guides here:

• Attributes: building block for conditions
• Segments: conditions for targeting users
• Features: feature flags and variables with rollout rules

Step 2: Build and deploy datafiles

Once the project is ready, you can build your datafiles (JSON files containing configuration of your feature flags):

$ npx featurevisor build

You will find the output in dist directory, that you can upload to your CDN.

See further guides here:

• Building datafiles: how to build datafiles
• Deploying datafiles: how to deploy datafiles to your CDN

A fully functioning example for deploying with Cloudflare and GitHub Actions (for free) is available here.

Step 3: Consume datafiles with Featurevisor SDKs

You can now consume the datafiles from your CDN in your applications directly using Featurevisor SDKs.

For Node.js and browser environments, install the JavaScript SDK:

$ npm install --save @featurevisor/sdk

Now you can initialize the SDK with the URL of your datafile, and evaluate your feature flags:

import { createInstance } from "@featurevisor/sdk";

// Initialize the SDK
const f = createInstance({
  datafileUrl: "https://cdn.yoursite.com/datafile.json",
  onReady: () => console.log("Datafile has been fetched and SDK is ready"),
});

// Evaluate a feature flag
const featureKey = "myFeature";
const context = {
  userId: "user-123",
  country: "nl",
};

const isEnabled = f.isEnabled(featureKey, context);
const variation = f.getVariation(featureKey, context);
const variable  = f.getVariable(featureKey, "someVariableKey", context);

Learn more about SDK usage here: https://featurevisor.com/docs/sdks/.

Packages

Package	Version	Description
@featurevisor/cli		CLI package
@featurevisor/core		Core package used by CLI
@featurevisor/react		React package
@featurevisor/sdk		Universal SDK for both Node.js and browser
@featurevisor/site		Static site generator for your project
@featurevisor/types		Common typings
@featurevisor/vue		Vue.js package

License

MIT © Fahad Heylaal

Change Log

All notable changes to this project will be documented in this file. See Conventional Commits for commit guidelines.

1.35.3 (2025-04-12)

Note: Version bump only for package @featurevisor/sdk

1.35.2 (2025-03-31)

Bug Fixes

• variable evaluation when variation is overridden from rule (#352) (9c7039d)

1.35.0 (2025-03-13)

Note: Version bump only for package @featurevisor/sdk

1.33.0 (2025-03-08)

Features

• allow deprecating variables (#345) (cecbf5b)

1.32.0 (2025-02-26)

Note: Version bump only for package @featurevisor/sdk

1.31.0 (2025-02-13)

Features

• variables schema as dictionary (#343) (18e8aed)

1.30.1 (2025-02-08)

Bug Fixes

• single function to evaluate flag, variation, and variable (#341) (ebba884)

1.29.3 (2025-01-30)

Bug Fixes

• matched rules with percentage of 0 should be disabled (#340) (07f1682)

1.29.2 (2025-01-25)

Note: Version bump only for package @featurevisor/sdk

1.29.1 (2025-01-23)

Bug Fixes

• convert to datafile schema v2 internally (#337) (3441369)

1.28.0 (2025-01-21)

Features

• datafile schema v2 (#334) (ee91c78)

1.27.6 (2025-01-20)

Bug Fixes

• in operator with non-existent context value (#335) (08f6f38)

1.27.5 (2024-12-21)

Note: Version bump only for package @featurevisor/sdk

1.27.4 (2024-12-01)

Bug Fixes

• non-existent property in context when checking in and noIn conditions (#328) (fc85214)

1.27.2 (2024-08-28)

Bug Fixes

• ESM bundle for SDK (#324) (54556ea)

1.20.0 (2024-04-30)

Features

• allow evaluating in CLI with more verbosity (#300) (8c3a096)

1.17.0 (2024-04-07)

Features

• evaluate features in CLI (#295) (5a3332a)

1.16.0 (2024-04-05)

Features

• Added export of emitter module (#294) (aaf0afc)

1.11.1 (2024-03-14)

Bug Fixes

• move to next condition if parsing fails (#279) (9f198e2)

1.3.0 (2024-01-23)

Note: Version bump only for package @featurevisor/sdk

1.2.3 (2024-01-18)

Bug Fixes

• rule percentage checks are now inclusive of end range (#248) (339231c)

1.2.2 (2024-01-17)

Note: Version bump only for package @featurevisor/sdk

1.2.0 (2024-01-16)

Note: Version bump only for package @featurevisor/sdk

1.0.2 (2024-01-04)

Note: Version bump only for package @featurevisor/sdk

1.0.1 (2024-01-02)

Bug Fixes

• forcing variation with variable overrides (#236) (76cac7e)

0.69.0 (2023-12-13)

Note: Version bump only for package @featurevisor/sdk

0.68.0 (2023-12-13)

Note: Version bump only for package @featurevisor/sdk

0.67.0 (2023-12-13)

Note: Version bump only for package @featurevisor/sdk

0.66.0 (2023-12-13)

Note: Version bump only for package @featurevisor/sdk

0.65.0 (2023-12-13)

Note: Version bump only for package @featurevisor/sdk

0.64.0 (2023-11-29)

Note: Version bump only for package @featurevisor/sdk

0.63.0 (2023-11-29)

Note: Version bump only for package @featurevisor/sdk

0.62.0 (2023-11-19)

Note: Version bump only for package @featurevisor/sdk

0.61.0 (2023-11-14)

Features

• filter tests and support verbosity for debugging (#212) (414ef6d)

0.60.1 (2023-11-14)

Bug Fixes

• using not operator in feature rules (#211) (dd7fda3)

0.60.0 (2023-11-07)

Note: Version bump only for package @featurevisor/sdk

0.59.0 (2023-10-31)

Note: Version bump only for package @featurevisor/sdk

0.58.0 (2023-10-29)

Note: Version bump only for package @featurevisor/sdk

0.57.0 (2023-10-26)

Note: Version bump only for package @featurevisor/sdk

0.56.2 (2023-10-26)

Bug Fixes

• evaluate variables overridden from rules with no variations (#189) (3144f20)

0.56.0 (2023-10-25)

Note: Version bump only for package @featurevisor/sdk

0.55.0 (2023-10-19)

Note: Version bump only for package @featurevisor/sdk

0.54.0 (2023-10-17)

Note: Version bump only for package @featurevisor/sdk

0.53.0 (2023-10-13)

Note: Version bump only for package @featurevisor/sdk

0.52.0 (2023-10-12)

Features

• add support for null, more specific validation of value type in segment (#170) (16a47c5)

0.51.0 (2023-10-05)

Note: Version bump only for package @featurevisor/sdk

0.50.0 (2023-10-01)

Note: Version bump only for package @featurevisor/sdk

0.49.0 (2023-09-30)

Features

• allow single segments to be defined without needing arrays (#159) (b3ad42c)

0.48.0 (2023-09-25)

Note: Version bump only for package @featurevisor/sdk

0.47.7 (2023-09-19)

Note: Version bump only for package @featurevisor/sdk

0.47.6 (2023-09-16)

Note: Version bump only for package @featurevisor/sdk

0.47.5 (2023-09-16)

Note: Version bump only for package @featurevisor/sdk

0.47.4 (2023-09-16)

Note: Version bump only for package @featurevisor/sdk

0.47.3 (2023-09-16)

Note: Version bump only for package @featurevisor/sdk

0.47.2 (2023-09-16)

Note: Version bump only for package @featurevisor/sdk

0.47.1 (2023-09-12)

Note: Version bump only for package @featurevisor/sdk

0.47.0 (2023-09-05)

Features

• use Prettier v2.x (#143) (ddca499)

0.46.2 (2023-08-31)

Note: Version bump only for package @featurevisor/sdk

0.46.1 (2023-08-31)

Note: Version bump only for package @featurevisor/sdk

0.46.0 (2023-08-27)

Features

• onReady method for SDK as Promise (#133) (e8dd395)

0.45.0 (2023-08-20)

Note: Version bump only for package @featurevisor/sdk

0.44.0 (2023-08-07)

Features

• make getFeature() method public (#122) (e56455e)

0.43.0 (2023-08-05)

Features

• Support deprecating features (#117) (992740d)

0.42.1 (2023-08-01)

Bug Fixes

• break in switch statement of logger handler (#116) (d836263)

0.42.0 (2023-07-23)

Note: Version bump only for package @featurevisor/sdk

0.41.0 (2023-07-23)

Note: Version bump only for package @featurevisor/sdk

0.40.1 (2023-07-23)

Note: Version bump only for package @featurevisor/sdk

0.40.0 (2023-07-16)

Note: Version bump only for package @featurevisor/sdk

0.39.1 (2023-07-16)

Bug Fixes

• SDK README updates (#106) (1c6ac53)

0.39.0 (2023-07-16)

Features

• drop type specific activate methods (#105) (5faca24)

0.38.0 (2023-07-16)

Features

• SDK to support isEnabled() checks (#104) (4f52136)

0.37.0 (2023-07-14)

Features

• renamed Attributes (object) to Context (#101) (c392ad5)

0.36.0 (2023-07-13)

Note: Version bump only for package @featurevisor/sdk

0.35.0 (2023-07-13)

Features

• Evaluation details in SDK (#99) (016c73d)

0.34.0 (2023-07-08)

Note: Version bump only for package @featurevisor/sdk

0.33.0 (2023-07-06)

Note: Version bump only for package @featurevisor/sdk

0.32.0 (2023-07-02)

Features

• make segments testable (#95) (15eae3c)

0.31.0 (2023-06-24)

Note: Version bump only for package @featurevisor/sdk

0.30.1 (2023-06-14)

Note: Version bump only for package @featurevisor/sdk

0.30.0 (2023-06-10)

Note: Version bump only for package @featurevisor/sdk

0.29.0 (2023-06-10)

Features

• drop Allocation.percentage in datafiles (#80) (b43da69)

0.28.1 (2023-06-08)

Note: Version bump only for package @featurevisor/sdk

0.28.0 (2023-06-08)

Features

• make bucketing key configurable (#79) (c05f0da)

0.27.0 (2023-05-24)

Note: Version bump only for package @featurevisor/sdk

0.26.0 (2023-05-24)

Note: Version bump only for package @featurevisor/sdk

0.25.0 (2023-05-22)

Note: Version bump only for package @featurevisor/sdk

0.24.0 (2023-05-21)

Features

• ranges in datafiles as tuples (#74) (07a3d92)

0.23.0 (2023-05-20)

Note: Version bump only for package @featurevisor/sdk

0.22.0 (2023-05-20)

Note: Version bump only for package @featurevisor/sdk

0.21.0 (2023-05-14)

Note: Version bump only for package @featurevisor/sdk

0.20.2 (2023-05-14)

Note: Version bump only for package @featurevisor/sdk

0.20.1 (2023-05-13)

Bug Fixes

• remove duplicate redundant types (#69) (9501802)

0.20.0 (2023-05-13)

Features

• SDK Instance from a single class (#68) (1ab1d49)

0.19.0 (2023-05-13)

Features

• Date comparison operators (#67) (b555f39)

0.18.0 (2023-05-12)

Features

• Initial features (#66) (ec91d6e)

0.17.0 (2023-05-12)

Features

• sticky features (#65) (eb4ff69)

0.16.0 (2023-04-30)

Features

• Mutually exclusive experiments via Groups (#63) (f3c8523)

0.15.0 (2023-04-23)

Note: Version bump only for package @featurevisor/sdk

0.14.1 (2023-04-22)

Bug Fixes

• do not require variation type in Feature's YAML (#57) (2e7c0cf)

0.14.0 (2023-04-21)

Features

• React integration package (#56) (d0f6ad8)

0.13.0 (2023-04-19)

Features

• Event listeners (#55) (eaeb7f6)

0.12.1 (2023-04-18)

Bug Fixes

• use compare-versions package to reduce sdk bundle size (#53) (d921436)

0.12.0 (2023-04-17)

Features

• Allow overriding variation for specific rules (#51) (e6447df)

0.11.0 (2023-04-17)

Features

• refresh datafile (#52) (d09b966)

0.10.1 (2023-04-17)

Note: Version bump only for package @featurevisor/sdk

0.10.0 (2023-04-15)

Features

• intercept attributes (#48) (4e08784)

0.9.0 (2023-04-15)

Features

• Introduce logging (#47) (810e813)

0.8.0 (2023-04-09)

Note: Version bump only for package @featurevisor/sdk

0.7.0 (2023-03-25)

Features

• Introduce semver operators (#30) (b2841c3)

0.6.0 (2023-03-25)

Features

• Introduce new JSON type for variables (#28) (49ff4cb)

0.5.3 (2023-03-25)

Note: Version bump only for package @featurevisor/sdk

0.5.2 (2023-03-25)

Bug Fixes

• return defaultVariation when feature cannot be bucketed (#26) (47363c9)

0.5.0 (2023-03-22)

Features

• Variable overrides at rule level (#23) (c4792a0)

0.4.0 (2023-03-19)

Features

• Create SDK instance for fetching datafile (#19) (4560fb2)

0.3.0 (2023-03-17)

Features

• support objects as variables (#18) (c1b6160)

0.2.0 (2023-03-16)

Features

• NOT operator (#16) (9c7b239)

0.1.0 (2023-03-05)

Note: Version bump only for package @featurevisor/sdk

0.0.4 (2023-03-05)

Note: Version bump only for package @featurevisor/sdk

0.0.3 (2023-03-05)

Bug Fixes

• publish access (ea5cd7c)

0.0.2 (2023-03-05)

Note: Version bump only for package @featurevisor/sdk

0.0.1 (2023-03-05)

Bug Fixes

• linting (230bfa0)