DocsObservabilityFeaturesLog Levels

Log Levels

Traces can have a lot of observations (data model). You can differentiate the importance of observations with the level attribute to control the verbosity of your traces and highlight errors and warnings. Available levels: DEBUG, DEFAULT, WARNING, ERROR.

In addition to the level, you can also include a statusMessage to provide additional context.

Trace log level and statusMessage

When using the @observe() decorator:

from langfuse import observe, get_client   @observe() def my_function():  langfuse = get_client()    # ... processing logic ...  # Update the current span with a warning level  langfuse.update_current_span(  level="WARNING",  status_message="This is a warning"  )

When creating spans or generations directly:

from langfuse import get_client   langfuse = get_client()   # Using context managers (recommended) with langfuse.start_as_current_span(name="my-operation") as span:  # Set level and status message on creation  with span.start_as_current_span(  name="potentially-risky-operation",  level="WARNING",  status_message="Operation may fail"  ) as risky_span:  # ... do work ...    # Or update level and status message later  risky_span.update(  level="ERROR",  status_message="Operation failed with unexpected input"  )   # You can also update the currently active span without a direct reference with langfuse.start_as_current_span(name="another-operation"):  # ... some processing ...  langfuse.update_current_span(  level="DEBUG",  status_message="Processing intermediate results"  )

Levels can also be set when creating generations:

langfuse = get_client()   with langfuse.start_as_current_generation(  name="llm-call",  model="gpt-4o",  level="DEFAULT" # Default level ) as generation:  # ... make LLM call ...    if error_detected:  generation.update(  level="ERROR",  status_message="Model returned malformed output"  )

Filter Trace by Log Level

When viewing a single trace, you can filter the observations by log level.

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