---
title: Javascript-SDK - 4.1.0
slug: feature-experimentation/release-notes/javascript-sdk-4-1-0
docTags: 
createdAt: 2026-07-20T15:45:26.673Z
---

\## \[4.1.0] - July 7, 2020

\### New Features

\- Added support for JSON feature variables: new methods \`getFeatureVariableJSON\` and \`getAllFeatureVariables\` (\[#467]\([https://github.com/optimizely/javascript-sdk/pull/467](https://github.com/optimizely/javascript-sdk/pull/467)), \[#470]\([https://github.com/optimizely/javascript-sdk/pull/470](https://github.com/optimizely/javascript-sdk/pull/470)))
\- Added support for authenticated datafiles when running in Node.js. Pass \`datafileAccessToken\` within \`datafileOptions\` to request an authenticated datafile using the token (\[#498]\([https://github.com/optimizely/javascript-sdk/pull/498](https://github.com/optimizely/javascript-sdk/pull/498)), \[#502]\([https://github.com/optimizely/javascript-sdk/pull/502](https://github.com/optimizely/javascript-sdk/pull/502))):
\`\`\`js
const optimizelySDK = require('@optimizely/optimizely-sdk');
var optimizelyClientInstance = optimizely.createInstance(\{
sdkKey: '',
datafileOptions: \{
datafileAccessToken: '',
}
});
\`\`\`

\### Bug fixes

\- Fixed audience evaluation log level: changed from \`INFO\` to \`DEBUG\` (\[#496]\([https://github.com/optimizely/javascript-sdk/pull/496](https://github.com/optimizely/javascript-sdk/pull/496)))
\- Temporarily disabled React Native FSC tests (\[#514]\([https://github.com/optimizely/javascript-sdk/pull/514](https://github.com/optimizely/javascript-sdk/pull/514)))
\- Changed \`getFeatureVariableJson\` to \`getFeatureVariableJSON\` (\[#516]\([https://github.com/optimizely/javascript-sdk/pull/516](https://github.com/optimizely/javascript-sdk/pull/516)))

[https://github.com/optimizely/javascript-sdk/releases/tag/v4.1.0](https://github.com/optimizely/javascript-sdk/releases/tag/v4.1.0)