GrowthBook Files

Release Highlights

Holdouts Holdout experiments measure the long-term impact of features by maintaining a control group that doesn't receive new functionality. While most users experience your latest features and improvements, a small percentage remains on the original version, providing a baseline to measure cumulative effects over time.

Experiment Dashboards Experiment Dashboards let you create tailored views of an experiment. Highlight key insights, add context, and share a clear story with your team. Dashboards are available for all Enterprise customers. We have a lot planned for this in the future, so stay tuned!

Vercel Native Integration We're excited to announce that GrowthBook is now available as a native integration in the Experimentation category on the Vercel Marketplace! This integration makes it easier than ever to add feature flagging and A/B testing to your Vercel projects, with streamlined setup, unified billing, and ultra-low latency performance.

AI Features This release deeply integrates AI to help accelerate your workflows within GrowthBook. Auto-summarize experiment results, get help writing SQL, improve hypotheses, and detect similar past experiments, and more. These features are available to everyone, even self-hosted (just supply an OpenAI key).

Pre-computed Dimensions You can now pick a set of key experiment dimensions and pre-compute them along with the main experiment results. This allows for more efficient database queries, and instant dimension breakdowns in the UI.

FerretDB Support FerretDB is a MongoDB-compatible database that is open source and free to use. It serves as a drop-in replacement for MongoDB, converting MongoDB wire protocol queries to SQL and using PostgreSQL as its backend storage engine.

Sanity CMS Integration Sanity is a real-time content backend for all your text and assets. You can now use GrowthBook feature flags to seamlessly test different content variations within Sanity.

MCP Updates We've updated our MCP Server to allow creating experiments directly from your AI tool of choice without needing to context switch to GrowthBook. This change unlocks a bunch of new exciting workflows and we can't wait to see how you use it!

New Experiment Results Tooltip We've completely redesigned the tooltip when mousing over experiment results. The new design provides more context and insights at a glance, making it easier to understand the impact of your experiments.

SQL Auto-Complete We've added context-aware SQL auto-complete suggestions for table and column names to help you write queries faster and with fewer errors.

Official Segments and Dimensions You can now mark specific segments and user dimensions as Official via the GrowthBook API. This will give them a little badge in the UI and lock down editing to prevent unwanted changes. Use this to differentiate important segments and dimensions from ad-hoc or exploratory ones.

Self-Hosting Improvements For anyone self-hosting GrowthBook, we've greatly improved observability and customization. We now support full monitoring and tracing of all background jobs, plus distributed tracing within the Python stats engine. We also added a number of new env vars to more easily split the GrowthBook monolith into microservices for those that need extra scalability.

SDK Updates

• React - Full React 19 Typescript support
• Golang - SSE streaming fixes
• PHP - sticky bucketing fixes
• Java - new caching and refresh options, memory optimizations
• Flutter - many bug fixes and updates
• C sharp - SSE streaming, attribute targeting fixes
• Swift - sticky bucket fixes, support for bearer auth, logging improvements, and memory optimization
• Kotlin - async-safe sticky bucketing, new streamingHost setting, suspend entry points to avoid blocking
• Flutter - TTL-based fetch option, cache improvements, attribute targeting fixes
• Edge - many new options for advanced integrations

REST API Updates

• New GET /settings endpoint to fetch all of your organization's current settings
• Fix PUT /metric/:id endpoint that was ignoring the archived setting
• New GET /feature/:id/revisions endpoint to fetch all revisions for a specific feature with pagination
• New endpoints to create, update, and delete dimensions and segments
• Ability to archive fact tables and fact metrics

Plus a lot more

• New is:watched filter on experiment search
• Enable encryption option for back-end SDKs
• Add user-agent header to all HTTP requests (webhooks, etc.)
• Various date and timezone fixes
• Various SQL editing and schema browser fixes
• Properly close MySQL connections
• Ability to remove LIMIT 5 when testing SQL queries
• Use Webhook Secrets by default for new webhooks
• ClickHouse - add support for new JSON data types
• Wrap user-supplied SQL in parentheses to avoid edge cases
• Fix divide-by-zero bug in stats engine
• Jira integration update to support a custom field
• Fix stale feature detection logic
• New Big Number visualization type in the SQL Explorer
• Enable the schema browser for self-hosted orgs that use config.yml
• Improve fact metric query performance by filtering rows earlier
• Fix broken SRM check when one variation has 0 users
• Fix bugs with quantile and percentile capped metric settings
• Audit log entries now show the full date time instead of "X days ago"
• Power calculator fixes
• Allow manual seed selection for feature rollout rules
• Skip feature.updated webhooks until draft changes are actually published
• Improve handling of unit quantiles when "ignore zero" is set
• Persist last viewed tab on the experiment list

New Contributors

• @nodirnasirov made their first contribution in https://github.com/growthbook/growthbook/pull/4296
• @kweic made their first contribution in https://github.com/growthbook/growthbook/pull/4315
• @denisov-vlad made their first contribution in https://github.com/growthbook/growthbook/pull/4351
• @Khrol made their first contribution in https://github.com/growthbook/growthbook/pull/4339
• @benruehl made their first contribution in https://github.com/growthbook/growthbook/pull/4254

Plus a ton of returning contributors: @jdorn @royalfig @tzjames @ahdriel @mknowlton89 @madhuchavva @bryce-fitzsimons @natasha-growthbook @Auz @lukesonnet @Kevin-Chant @lukebrawleysmith @Hephaest @gazzdingo @ari-party @msamper @itsgrimetime

Full Changelog: https://github.com/growthbook/growthbook/compare/v4.0.0...v4.1.0