apps/opik-documentation/python-sdk-docs/source/message_processing_emulation/index.rst
.. currentmodule:: opik.message_processing.emulation.models
This module provides data models used for message processing emulation in Opik. These models represent the core data structures for traces, spans, and feedback scores that are used internally by the Opik SDK during evaluation.
The message processing emulation models are primarily used in evaluation contexts, particularly for task span evaluation where custom metrics need access to detailed execution information. These models provide a structured representation of:
.. toctree:: :maxdepth: 1
FeedbackScoreModel SpanModel TraceModel ExperimentItemModel local_recording
The models form a hierarchical relationship:
.. code-block:: text
TraceModel
├── spans: List[SpanModel]
│ ├── spans: List[SpanModel] (nested spans)
│ └── feedback_scores: List[FeedbackScoreModel]
└── feedback_scores: List[FeedbackScoreModel]
Import the models:
.. code-block:: python
from opik.message_processing.emulation.models import (
TraceModel,
SpanModel,
FeedbackScoreModel,
ExperimentItemModel
)
Task Span Evaluation
The primary use case for these models is in task span evaluation, where custom metrics analyze span data:
.. code-block:: python
from opik.evaluation.metrics import BaseMetric, score_result
from opik.message_processing.emulation.models import SpanModel
class CustomSpanMetric(BaseMetric):
def score(self, task_span: SpanModel) -> score_result.ScoreResult:
# Access span properties
span_name = task_span.name
input_data = task_span.input
output_data = task_span.output
# Perform evaluation logic
score_value = self.evaluate_span(span_name, input_data, output_data)
return score_result.ScoreResult(
value=score_value,
name=self.name,
reason=f"Evaluated span: {span_name}"
)
Analyzing Trace Structure
You can traverse and analyze the hierarchical structure of traces:
.. code-block:: python
def analyze_trace_structure(trace: TraceModel):
print(f"Trace: {trace.name}")
print(f"Total spans: {len(trace.spans)}")
for span in trace.spans:
print(f" Span: {span.name} (type: {span.type})")
# Analyze nested spans
for nested_span in span.spans:
print(f" Nested: {nested_span.name}")
Working with Feedback Scores
Both traces and spans can contain feedback scores from evaluations:
.. code-block:: python
def collect_all_scores(trace: TraceModel):
all_scores = []
# Collect trace-level scores
all_scores.extend(trace.feedback_scores)
# Collect span-level scores
for span in trace.spans:
all_scores.extend(span.feedback_scores)
# Recursively collect from nested spans
for nested_span in span.spans:
all_scores.extend(nested_span.feedback_scores)
return all_scores
Integration with Evaluation System
----------------------------------
These models are automatically populated and used by the Opik evaluation system:
1. **Trace Creation**: When you run ``opik.evaluate()``, traces are automatically created
2. **Span Population**: Individual function calls become spans within the trace
3. **Task Span Evaluation**: Metrics with ``task_span`` parameters receive ``SpanModel`` objects
4. **Score Attachment**: Feedback scores are automatically attached to the appropriate traces and spans
You typically don't need to create these models manually - they're generated automatically during evaluation. However, understanding their structure is essential for writing effective task span evaluation metrics.
Use Cases
---------
These models are commonly used for:
- **Custom Evaluation Metrics**: Analyzing detailed execution data in custom metrics
- **Performance Analysis**: Understanding execution patterns and performance characteristics
- **Debugging**: Investigating issues in complex operations
- **Cost Tracking**: Aggregating usage and cost information across operations
- **Quality Assessment**: Evaluating the quality of individual steps and overall operations
Module Reference
----------------
For detailed API documentation, see the following class reference pages:
- :doc:`TraceModel <../message_processing_emulation/TraceModel>`
- :doc:`SpanModel <../message_processing_emulation/SpanModel>`
- :doc:`FeedbackScoreModel <../message_processing_emulation/FeedbackScoreModel>`
- :doc:`ExperimentItemModel <../message_processing_emulation/ExperimentItemModel>`