# mlflow
pip install git+https://github.com/mlflow/mlflow.git@refs/pull/19249/merge
# mlflow-skinny
pip install git+https://github.com/mlflow/mlflow.git@refs/pull/19249/merge#subdirectory=libs/skinny

%sh curl -LsSf https://raw.githubusercontent.com/mlflow/mlflow/HEAD/dev/install-skinny.sh | sh -s pull/19249/merge

Related Issues/PRs

What changes are proposed in this pull request?

Automatically wrap async functions when they are passed to predict_fn in mlflow.genai.evaluate

How is this PR tested?

• Existing unit/integration tests
• New unit/integration tests
• Manual tests

import asyncio

import mlflow
import pandas as pd
from mlflow.genai.scorers import scorer


async def async_predict_fn(question: str) -> str:
    await asyncio.sleep(0.1)
    return f"Answer to: {question}"


@scorer
def length_scorer(inputs, outputs):
    return len(outputs)


data = pd.DataFrame([
    {"inputs": {"question": "What is MLflow?"}},
    {"inputs": {"question": "What is Python?"}},
])

result = mlflow.genai.evaluate(
    data=data,
    predict_fn=async_predict_fn,
    scorers=[length_scorer],
)

print(f"Metrics: {result.metrics}")

traces = mlflow.search_traces(run_id=result.run_id, return_type="list")
print(f"\nFirst trace assessments:")
for assessment in traces[0].info.assessments:
    print(f"  {assessment.name}: {assessment.feedback.value}")

outputs:

2025/12/05 10:09:14 INFO mlflow.genai.utils.data_validation: Testing model prediction with the first sample in the dataset. To disable this check, set the MLFLOW_GENAI_EVAL_SKIP_TRACE_VALIDATION environment variable to True.
2025/12/05 10:09:15 INFO mlflow.store.db.utils: Creating initial MLflow database tables...
2025/12/05 10:09:15 INFO mlflow.store.db.utils: Updating database tables
2025/12/05 10:09:15 INFO alembic.runtime.migration: Context impl SQLiteImpl.
2025/12/05 10:09:15 INFO alembic.runtime.migration: Will assume non-transactional DDL.
2025/12/05 10:09:15 INFO alembic.runtime.migration: Context impl SQLiteImpl.
2025/12/05 10:09:15 INFO alembic.runtime.migration: Will assume non-transactional DDL.

✨ Evaluation completed.

Metrics and evaluation results are logged to the MLflow run:
  Run name: sneaky-sow-347
  Run ID: 8b770a04ae284df9b6e343f3a9cc5aaa

To view the detailed evaluation results with sample-wise scores,
open the Traces tab in the Run page in the MLflow UI.

Metrics: {'length_scorer/mean': np.float64(26.0)}

First trace assessments:
  length_scorer: 26

Does this PR require documentation update?

• No. You can skip the rest of this section.
• Yes. I've updated:
  • Examples
  • API references
  • Instructions

Release Notes

Is this a user-facing change?

• No. You can skip the rest of this section.
• Yes. Give a description of this change to be included in the release notes for MLflow users.

Automatically wrap async functions when they are passed to predict_fn in mlflow.genai.evaluate

What component(s), interfaces, languages, and integrations does this PR affect?

Components

• area/tracking: Tracking Service, tracking client APIs, autologging
• area/models: MLmodel format, model serialization/deserialization, flavors
• area/model-registry: Model Registry service, APIs, and the fluent client calls for Model Registry
• area/scoring: MLflow Model server, model deployment tools, Spark UDFs
• area/evaluation: MLflow model evaluation features, evaluation metrics, and evaluation workflows
• area/gateway: MLflow AI Gateway client APIs, server, and third-party integrations
• area/prompts: MLflow prompt engineering features, prompt templates, and prompt management
• area/tracing: MLflow Tracing features, tracing APIs, and LLM tracing functionality
• area/projects: MLproject format, project running backends
• area/uiux: Front-end, user experience, plotting, JavaScript, JavaScript dev server
• area/build: Build and test infrastructure for MLflow
• area/docs: MLflow documentation pages

How should the PR be classified in the release notes? Choose one:

• rn/none - No description will be included. The PR will be mentioned only by the PR number in the "Small Bugfixes and Documentation Updates" section
• rn/breaking-change - The PR will be mentioned in the "Breaking Changes" section
• rn/feature - A new user-facing feature worth mentioning in the release notes
• rn/bug-fix - A user-facing bug fix worth mentioning in the release notes
• rn/documentation - A user-facing documentation change worth mentioning in the release notes

Should this PR be included in the next patch release?

Yes should be selected for bug fixes, documentation updates, and other small changes. No should be selected for new features and larger changes. If you're unsure about the release classification of this PR, leave this unchecked to let the maintainers decide.

• Yes (this PR will be cherry-picked and included in the next patch release)
• No (this PR will be included in the next minor release)