MLflow 3.2.0rc0 Release

[Serena Ruan]

Hi all, we are excited to announce the release of MLflow 3.2.0rc0! MLflow 3.2.0rc0 includes several major features and improvements.

Major New Features

• Tracing TypeScript SDK: MLflow Tracing now supports the TypeScript SDK, allowing developers to trace GenAI applications in TypeScript environments. (#16871, @B-Step62)
• Semantic Kernel Tracing: MLflow now provides automatic tracing support for Semantic Kernel, simplifying trace capture for SK-based workflows. (#16469, @michael-berk)
• Feedback Tracking: MLflow OSS now natively supports tracking human feedbacks, ground truths, LLM judges on traces, providing integrated quality monitoring and feedback management capabilities. (#16743, @BenWilson2)
• MLflow UI Improvements: The MLflow UI now features **a redesigned experiment home view** and includes enhancements like pagination on the model page for better usability. (#16464, @frontsideair, #15801, @Flametaa)
• Updated Trace UI: The Trace UI now has image support when rendering chat messages for OpenAI, Langchain, and Anthropic! Additionally, we're introducing a "summary view" which is a simplified, flat representation of the important spans in a trace. The full detail view is still available in a separate tab.
• PII Masking in Tracing: Added support for masking personally identifiable information (PII) via a custom span post-processor. (#16344, @B-Step62)
• Polars Dataset Support: MLflow now supports Polars datasets, expanding compatibility with performant DataFrame libraries. (#13006, @AlpAribal)

Usage Tracking (New in 3.2.0)

• Starting with version 3.2.0, MLflow will begin collecting anonymized usage data about how core features of the platform are used. This data contains **no sensitive or personally identifiable information**, and users can opt out of data collection at any time. Check MLflow documentation for more details. If you have questions or feedback, please visit this Github Issue. (#16439, @serena-ruan)

Features:

- [Tracing] Include mlflow-tracing as a dependency of mlflow (#16589, @B-Step62)
- [Tracing] Convert DatabricksRM output to MLflow document format (#16866, @WeichenXu123)
- [Tracing] Add unified token usage tracking for Bedrock LLMs (#16351, @mohammadsubhani)
- [Tracing] Token usage tracking for agent frameworks including Anthropic, Autogen, LlamaIndex etc. (#16251, #16362, #16246, #16258, #16313, #16312, #16340, #16357, #16358, @joelrobin18, #16387, @sanatb187)
- [Tracing] Render multi-modal trace for LangChain (#16799, @B-Step62)
- [Tracing] Support async tracing for Gemini (#16632, @B-Step62)
- [Tracing] Support global sampling for tracing (#16700, @B-Step62)
- [Tracing] ResponsesAgent tracing aggregation (#16787, @bbqiu)
- [Tracing] Add Agent and LLM complete name (#16613, @joelrobin18)
- [Tracking] Allow setting thread-local tracing destination via mlflow.tracing.set_destination (#16859, @WeichenXu123)
- [Tracking] Introduce MLFLOW_DISABLE_SCHEMA_DETAILS environment variable to toggle detailed schema errors (#16631, @NJAHNAVI2907)
- [Tracking] Add support for chat-style prompts with structured output with prompt object (#16341, @harshilprajapati96)
- [Tracking] Add support for responses.parse calls in oai autologger (#16245, @dipakkrishnan)
- [Evaluation] Replace guideline_adherence to guidelines (#16856, @smoorjani)
- [UI] Add tag filter to the experiments page (#16648, @frontsideair)
- [UI] Add ability to the UI to edit experiment tags (#16614, @frontsideair)
- [Scoring] Make spark_udf support 'uv' env manager (#16292, @WeichenXu123)

Bug fixes:

- [Tracking / UI] Add missing default headers and replace absolute URLs in new browser client requests (GraphQL & logged models) (#16840, @danilopeixoto)
- [Tracking] Fix tracking_uri positional argument bug in artifact repositories (#16878, @copilot-swe-agent)
- [Models] Fix UnionType support for Python 3.10 style union syntax (#16882, @harupy)
- [Tracing / Tracking] Fix OpenAI autolog Pydantic validation for enum values (#16862, @mohammadsubhani)
- [Tracking] Fix tracing for Anthropic and Langchain combination (#15151, @maver1ck)
- [Models] Fix OpenAI multimodal message logging support (#16795, @mohammadsubhani)
- [Tracing] Avoid using nested threading for Azure Databricks trace export (#16733, @TomeHirata)
- [Evaluation] Bug fix: Databricks GenAI evaluation dataset source returns string, instead of DatasetSource instance (#16712, @dbczumar)
- [Models] Fix `get_model_info` to provide logged model info (#16713, @harupy)
- [Evaluation] Fix serialization and deserialization for python scorers (#16688, @connorchenn)
- [UI] Fix GraphQL handler erroring on NaN metric values (#16628, @daniellok-db)
- [UI] Add back video artifact preview (#16620, @daniellok-db)
- [Tracing] Proper chat message reconstruction from OAI streaming response (#16519, @B-Step62)
- [Tracing] Convert trace column in search_traces() response to JSON string (#16523, @B-Step62)
- [Evaluation] Fix mlflow.evaluate crashes in \_get_binary_classifier_metrics due to … (#16485, @mohammadsubhani)

Documentation updates:

- [Docs] Overhaul of top level version management GenAI docs (#16728, @BenWilson2)
- [Docs] Fix Additional GenAI Docs pages (#16691, @BenWilson2)
- [Docs] Update the docs selector dropdown (#16280, @BenWilson2)
- [Docs] Update docs font sizing and link coloring (#16281, @BenWilson2)

For a comprehensive list of changes, see the release change log, and check out the latest documentation on mlflow.org.