Migration Guide

This guide covers API and configuration changes when upgrading between FLARE releases.

Upgrading from 2.7.0/2.7.1 to 2.7.2

Recipe API Changes

initial_model renamed to model

The initial_model parameter in all recipes has been renamed to model for clarity:

# Before (2.7.0/2.7.1)
recipe = FedAvgRecipe(
    ...
    initial_model=SimpleNetwork(),
)

# After (2.7.2)
recipe = FedAvgRecipe(
    ...
    model=SimpleNetwork(),
)

The model parameter now also accepts dict-based configuration with optional pretrained checkpoint:

recipe = FedAvgRecipe(
    ...
    model={"path": "my_module.MyModel", "args": {"hidden_size": 256}},
    initial_ckpt="pretrained.pt",
)

PTFedAvgEarlyStopping merged into PTFedAvg

PTFedAvgEarlyStopping has been merged into PTFedAvg with InTime aggregation support. A backward-compatible alias is provided, but new code should use PTFedAvg:

# Before
from nvflare.app_opt.pt.fedavg_early_stopping import PTFedAvgEarlyStopping
controller = PTFedAvgEarlyStopping(...)

# After
from nvflare.app_opt.pt.fedavg import PTFedAvg
controller = PTFedAvg(...)

MONAI Integration

The separate nvflare-monai wheel package is deprecated. Use the Client API directly for MONAI integration. See the updated examples in examples/advanced/monai/ and the MONAI Migration Guide.

New Features (No Migration Required)

The following 2.7.2 features work automatically with no code changes:

  • TensorDownloader: Transparent memory optimization for PyTorch model weight transfer. See FLARE Tensor Downloader.

  • Server-side memory cleanup: Automatic garbage collection and heap trimming. See Memory Management.

Backward Compatibility

  • Job Config API: Existing FedJob-based configurations continue to work alongside the new Recipe API.

  • Config-based Jobs: JSON/YAML configuration-based jobs continue to work as before.

  • Executor/ModelLearner APIs: Still functional but no longer the recommended pattern. Use Recipe API + Client API for new projects.

For the full list of changes, see the What’s New in 2.7.2 release notes.

Upgrading from 2.5/2.6 to 2.7

FLARE 2.7.0 introduced several major changes:

  • Job Recipe API (technical preview): A higher-level API for creating FL jobs. See NVFlare Job Recipe.

  • Client API is now the recommended pattern for all new FL jobs.

  • Hierarchical FL: New relay-based communication hierarchy for large-scale deployments. See Hierarchical FLARE.

  • Edge & Mobile: Federated training on mobile devices (iOS/Android) with ExecuTorch. See Mobile Federated Training (iOS / Android).

  • File Streaming: Pull-based file download for large model transfers. See FLARE File Streaming.

For migrating from the older FLAdminAPI to the Client API, see Migrating to FLARE API.

For the full list of 2.7.0 changes, see What’s New in FLARE v2.7.0.