Change8

Migrating to MLflow v3.14.0

Version v3.14.0 introduces 3 breaking changes. This guide details how to update your code.

Released: 6/17/2026

3
Breaking Changes
3
Migration Steps
21
Affected Symbols

⚠️ Check Your Code

If you use any of these symbols, you need to read this guide:

mlflow.sklearnmlflow.pytorch.log_modelmlflow.pytorch.save_modelmlflow.lightgbm.log_modelmlflow.lightgbm.save_modelmlflow agent setup@mlflow.testEvaluationResultmlflow skills view/listOTLP trace ingestionMLFLOW_WORKSPACEPOST /mlflow/genai/evaluate/invokeMLFLOW_TRACE_LOCATIONgenai.evaluate()MlflowWalSpanExporterTypeScript SDK trace ingestionSpanType.GUARDRAILChrfScoreContextUtilizationGemini gateway providerAnthropic gateway provider

Breaking Changes

Issue #1

The default serialization_format for `mlflow.sklearn` log_model/save_model has changed from `cloudpickle` to `skops`.

Issue #2

The default serialization_format for `mlflow.pytorch.log_model` and `mlflow.pytorch.save_model` has changed to `"pt2"`.

Issue #3

The default serialization_format for `mlflow.lightgbm` log_model/save_model has changed to `"skops"`.

Migration Steps

  1. 1
    If using `mlflow.sklearn`, be aware that the default `serialization_format` is now `skops` instead of `cloudpickle`. Update code if explicit serialization format control is required.
  2. 2
    If using `mlflow.pytorch.log_model` or `mlflow.pytorch.save_model`, be aware that the default `serialization_format` is now `"pt2"`.
  3. 3
    If using `mlflow.lightgbm.log_model` or `mlflow.lightgbm.save_model`, be aware that the default `serialization_format` is now `"skops"`.

Release Summary

MLflow 3.14.0 introduces major GenAI features like one-command agent setup, durable tracing for Claude Code, Review Queues, and an LLM Playground. This release also updates default serialization formats for several model flavors, resulting in breaking changes.

Need More Details?

View the full release notes and all changes for MLflow v3.14.0.

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