MLflow
Data & MLThe open source developer platform to build AI agents and models with confidence. Enhance your AI applications with end-to-end tracking, observability, and evaluations, all in one integrated platform.
Release History
v3.10.09 fixes41 featuresMLflow 3.10.0 introduces major features like organization support for multi-workspace tracking, advanced multi-turn conversation evaluation, and automatic LLM trace cost tracking. The release also includes a significant navigation bar redesign and a new one-click demo experiment.
v3.10.0rc06 featuresMLflow 3.10.0rc0 introduces major features like Organization Support for multi-workspace tracking, enhanced conversation simulation, and automatic LLM cost tracking. This release candidate also includes a new demo command and navigation redesign for better usability.
v3.9.03 fixes17 featuresMLflow 3.9.0 introduces significant enhancements to GenAI capabilities, including the MLflow Assistant chatbot, Trace Overview Dashboard, and a revamped AI Gateway integrated into the tracking server. This release also focuses heavily on evaluation tooling with new LLM judges, judge builders, and distributed tracing support.
v3.9.0rc07 featuresMLflow 3.9.0rc0 is a pre-release introducing significant GenAI features like the MLflow Assistant, Trace Overview Dashboard, integrated AI Gateway, and LLM Judge capabilities.
v3.8.15 fixesMLflow 3.8.1 primarily delivers several bug fixes across tracking, models, prompts, and UI components, along with minor documentation updates.
v3.8.023 fixes23 featuresMLflow 3.8.0 introduces major new capabilities such as prompt model configuration, in‑progress trace display, DeepEval/RAGAS judges integration, and two new conversational scorers, while also adding numerous tracking, tracing, and evaluation enhancements and fixing a wide range of bugs.
v3.8.0rc05 featuresMLflow 3.8.0rc0 introduces prompt model configuration, in‑progress trace display, DeepEval judges integration, and two new conversational scorers, with no breaking changes.
v3.7.0Breaking36 fixes15 featuresMLflow 3.7.0 adds major GenAI observability features such as an Experiment Prompts UI, multi-turn evaluation, trace comparison, and new auto-tracing SDKs, while introducing breaking changes like SQLite becoming the default tracking backend and removal of deprecated model flavors. It also includes numerous bug fixes and enhancements across tracking, evaluation, tracing, and UI components.
v2.22.42 fixes1 featurePatch 2.22.4 backports fixes for Unity Catalog Volumes path handling and Spark UDFs, and adds a regex constant for model version source validation.
v3.7.0rc0Breaking4 featuresMLflow 3.7.0rc0 introduces trace comparison, multi‑turn evaluation, full‑text UI search, and a Gemini TypeScript SDK, while changing the default backend to SQLite and removing the deprecated `diviner` and `promptflow` flavors.
v3.6.0Breaking25 fixes40 featuresMLflow 3.6.0 introduces full OpenTelemetry support, a new Agent Server, extensive tracing and evaluation enhancements, and numerous UI and framework integrations, while deprecating several flavors and changing span naming conventions.
v3.6.0rc0Breaking6 featuresMLflow 3.6.0rc0 adds full OpenTelemetry support, session‑level trace UI, a new experiment tab layout, Vercel AI TypeScript tracing, cost tracking for LLM judges, and an Agent Server, while deprecating the filesystem backend and removing span name deduplication.
v3.5.116 fixes4 featuresMLflow 3.5.1 is a patch release that adds new CLI and deployment features, introduces a monitoring API, and includes numerous bug fixes across evaluation, tracing, tracking, and UI components.
v3.5.028 fixes19 featuresMLflow 3.5.0 adds major tracing, prompt optimization, UI onboarding, and security middleware features, along with numerous enhancements and bug fixes across tracing, tracking, evaluation, and model registry.
v3.5.0rc05 featuresMLflow 3.5.0rc0 introduces Claude Code SDK tracing, UI enhancements, evaluation datasets UI, GEPA prompt optimization, and a default security middleware layer for the tracking server.
v3.4.017 fixes28 featuresMLflow 3.4.0rc0 adds extensive new capabilities—including OpenTelemetry metrics export, MCP server integration, a custom judges API, and experiment types UI—while delivering numerous feature enhancements and bug fixes across evaluation, tracing, CLI, tracking, and model registry.
v3.4.0rc08 featuresMLflow 3.4.0rc0 introduces major new capabilities including OpenTelemetry metrics, MCP server integration, a custom judges API, correlations backend, evaluation datasets, Databricks backend support, Claude autologging, and Strands agent tracing.
v2.22.21 fixA lightweight patch release backports the fix from issue #15970 to v2.22.2.
v3.3.25 fixes1 featureMLflow 3.3.2 adds dataset name persistence for evaluation and includes several bug fixes and documentation updates.
v3.3.14 fixesMLflow 3.3.1 primarily delivers bug fixes, including corrections to the mlflow.genai.datasets attribute, UI tag display, and dspy tracing performance.
v3.3.08 fixes10 featuresMLflow 3.3.0 adds webhooks, Agno tracing, open‑source GenAI evaluation, a revamped trace UI, and switches the default tracking server to FastAPI + Uvicorn while delivering numerous bug fixes and new feature enhancements.
v3.3.0rc05 featuresMLflow 3.3.0rc0 introduces model registry webhooks, Agno tracing integration, open‑source GenAI evaluation, a revamped trace table UI, and switches the default Tracking Server to FastAPI + Uvicorn.
v3.2.021 fixes26 featuresMLflow 3.2.0 introduces major GenAI tracing enhancements, feedback tracking, UI redesigns, Polars dataset support, and a suite of new features and bug fixes, while adding optional usage tracking.
v3.2.0rc04 fixes15 featuresMLflow 3.2.0 introduces extensive GenAI tracing enhancements, new feedback tracking, UI improvements, Polars dataset support, and several feature additions and bug fixes, all without breaking changes.
v3.1.4MLflow 3.1.4 is a minor release that adds several major features and improvements along with small bug fixes and documentation updates.
v3.1.35 fixes2 featuresMLflow 3.1.3 introduces artifact permission handling and OpenAI ChatCompletions parsing support while fixing bugs in deployments, model registry, evaluation, and tracking.
v3.1.25 fixesMLflow 3.1.2 is a patch release that fixes several bugs in tracking, models, and tracing components.
nightlyAutomated nightly build of MLflow (commit bdc041eb85cb37856e16b14a22c5b09c92c18e5a) containing the latest changes from the master branch; no specific changelog items are listed.
v3.1.16 fixes2 featuresMLflow 3.1.1 adds a larger prompt limit, pagination for history retrieval, and several bug fixes including artifact download support and security hardening.
v3.0.12 fixes1 featureMLflow 3.0.1 adds a larger prompt text limit (5K→100K) and fixes bedrock provider compatibility, along with assorted small bug fixes and documentation updates.
v3.0.0The provided release notes only reference the v3.1.0 tag on the MLflow GitHub repository and contain no specific change details.
v3.1.0Breaking9 fixes25 featuresMLflow 3 introduces a model‑centric GenAI architecture with new LoggedModel entity, prompt optimization, enhanced tracing, and many integrations, while also delivering several breaking changes that necessitate migration steps.
v2.22.13 fixes1 featureMLflow 2.22.1 adds DBR 15.4 support for spark_udf in the DBConnect client and includes several bug fixes across Model Registry, Tracking, and documentation.
v3.0.0rc1MLflow 3.0.0rc1 release candidate is now available; upgrade with `pip install mlflow==3.0.0rc1` and refer to the documentation for details.
v3.0.0rc3MLflow 3.0.0rc3 release candidate is now available; upgrade via pip and refer to the documentation for details.
v3.1.0rc0MLflow 3.1.0rc0 release candidate is now available; upgrade with pip install mlflow==3.1.0rc0.
v3.0.0rc2MLflow 3.0.0rc2 release candidate is now available; upgrade with `pip install mlflow==3.0.0rc2` and refer to the documentation for details.
v2.22.06 fixes8 featuresMLflow 2.22.0 adds new tracing capabilities, Gemini embeddings, ADLS artifact support, and several bug fixes and UI improvements.
v3.0.0rc0MLflow 3.0.0rc0 release candidate is now available for upgrade via pip.
v2.21.33 fixes1 featureMLflow 2.21.3 adds a `return_type` argument to the search_traces API and includes several bug fixes for Spark model handling and other minor issues.
v2.21.21 fix1 featureMLflow 2.21.2 introduces a bug fix for Databricks trace export connection exhaustion and adds result‑table logging for DSPy optimizer tracking.
v2.21.15 fixes3 featuresMLflow 2.21.1 adds DSPy evaluation logging, run creation on DSPy compile, and a Java‑less SageMaker container option, while fixing several tracing, tracking, and UI bugs.
v2.21.0Breaking14 fixes13 featuresMLflow 2.21.0 introduces a redesigned documentation site, a Prompt Registry, FastAPI‑based inference server, enhanced tracing, and numerous new integrations and bug fixes.
v2.21.0rc03 featuresMLflow 2.21.0rc0 introduces a redesigned documentation site, migrates the scoring server to FastAPI, and adds enhanced tracing capabilities, while deprecating Recipes and fastai/f2o flavors.
v2.20.32 fixes4 featuresMLflow 2.20.3 adds GPU metrics for AMD/HIP GPUs, txtai tracing, Google GenAI SDK support, and Anthropic Claude 3.7 thinking block, while fixing LangGraph tracing and numerous minor bugs.
v2.20.22 fixes4 featuresMLflow 2.20.2 adds tracing support for generator functions, enhances ChatAgent and Langgraph connectors, introduces VariantType in spark_udf, and includes several bug fixes and documentation updates.
v2.20.13 fixes3 featuresMLflow 2.20.1 is a patch release that adds Spark_udf support for model signatures, helper connectors for ChatAgent with LangChain/LangGraph, and default RUC/Lift curves for CatBoost classifiers, while fixing several bugs including Pydantic 1.x compatibility and LiteLLM tracing issues.
v2.20.08 fixes11 featuresMLflow 2.20.0 introduces type‑hint‑based model signatures, Bedrock/Groq tracing, inline Jupyter trace rendering, uv‑powered model validation, a new chat panel, and several API enhancements along with numerous bug fixes.
v2.20.0rc012 featuresMLflow 2.20.0rc0 introduces type‑hint based model signatures, Bedrock/Groq tracing, inline notebook trace rendering, uv‑accelerated model validation, a new chat panel in the Trace UI, and several enhancements such as the ChatAgent base class and improved Spark UDF handling.
Common Errors
MlflowTracingException2 reportsMlflowTracingException often arises when the tracing data required by online scoring or similar features is not found in the configured MLflow tracking store. Ensure that MLflow is properly configured with a valid tracking URI (e.g., pointing to your database) and that the necessary tracing spans or data are successfully logged during the model serving process. Verify network connectivity and permissions to the tracking store if the setup is distributed.
FileNotFoundError1 reportFileNotFoundError in mlflow often occurs due to absolute paths being used when logging models or artifacts, especially the model's code dependencies (model_code_path). The fix is to ensure that paths for dependencies are relative to the model's root directory during logging, and to use mlflow.get_model_uri() to construct the correct absolute path to the model rather than hardcoding it, especially when loading the model in a different environment.
MlflowInvalidInputException1 reportThe "MlflowInvalidInputException" often arises when the input data format or schema during inference doesn't match the model's expected input schema. To resolve this, ensure that the inference request's data types, column names, and structure precisely align with the model's training data and signature registered in MLflow. Inspect the model's signature and transform your input data accordingly before making inference requests.
NotImplementedError1 reportNotImplementedError in mlflow arises when a requested feature, like a specific model flavor or functionality within a tracking component, hasn't been fully implemented in the current version. To resolve this, either implement the missing functionality by subclassing the appropriate mlflow component and providing the necessary logic or switch to a different approach (e.g., a supported model flavor) that avoids the unimplemented feature. Check the mlflow documentation or source code to identify the expected implementation details.
NoCredentialsError1 reportThe "NoCredentialsError" in mlflow typically arises when your program doesn't have the necessary AWS credentials to access S3 or other cloud storage used for artifact logging. To fix it, explicitly configure AWS credentials by setting the AWS_ACCESS_KEY_ID, AWS_SECRET_ACCESS_KEY, and AWS_REGION environment variables, or by configuring an IAM role if running in an AWS environment like EC2 or EKS. Alternatively, configure a default AWS profile using the AWS CLI.
MaxRetryError1 reportMaxRetryError in mlflow often arises from a misconfigured or inaccessible tracking server, especially when secrets or environment variables are used for authentication or communication. Verify that the MLflow tracking server URL is correct, reachable from where the mlflow client is running, and that any required environment variables (e.g., those needed for webhook authentication) are properly set and exported to the environment. If using a secret, ensure the secret is correctly configured in both the server and client environments.
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