Introducing Flag Delivery v2 (FDv2) for the Python SDK (Early Access) | LaunchDarkly
Product Updates
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November 18, 2025
Feature Flags
Introducing Flag Delivery v2 (FDv2) for the Python SDK (Early Access)
Flag Delivery v2 (FDv2) is now available in Early Access for the LaunchDarkly Python SDK v9.13.0, bringing faster initialization, smarter data handling, and improved resiliency to feature flag delivery.
FDv2 introduces several key enhancements:
- Two-phase initialization: Start quickly from a polling data source, then synchronize from a long-lived streaming connection.
- Data-saving mode: Resume from a previously saved state during reconnects to reduce bandwidth and processing time.
- File-based initialization: Initialize from a local file first, then connect to LaunchDarkly APIs for updates.
- Automatic failover: Seamlessly switch to polling if the streaming connection fails.
- Improved flag caching: When using a persistent store in non-daemon mode, flag data is no longer limited by cache TTL.
Together, these improvements make flag delivery faster, more reliable, and more efficient across all environments.
Availability
Early Access — Data-saving mode is only available to members of LaunchDarkly’s Early Access Program (EAP). If you want access to this feature, join the EAP.
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