Span

A Span represents a single operation within an agent execution. Spans form a parent-child hierarchy within a trace, allowing you to understand the execution flow.

Span Attributes

Attribute	Type	Default	Description
span_id	str	Required	Unique span identifier
trace_id	str	Required	Parent trace ID (groups related spans)
parent_span_id	Optional[str]	None	Parent span ID (None for root spans)
name	str	Required	Operation name (e.g., OpenAIChat.invoke, get_weather)
status_code	str	Required	Status: OK, ERROR, or UNSET
status_message	Optional[str]	None	Status message (typically error details)
duration_ms	int	Required	Execution time in milliseconds
start_time	datetime	Required	When the span started
end_time	datetime	Required	When the span completed
attributes	Optional[dict]	None	OpenTelemetry attributes (tokens, params, etc.)
events	Optional[list]	None	Span events
kind	Optional[str]	None	Span kind (e.g., INTERNAL, CLIENT)

Common Span Names

Spans are automatically created for various operations:

Span Name Pattern	Description
{AgentName}.run	Agent execution
{TeamName}.run	Team execution
{ModelName}.invoke	LLM model call
{tool_name}	Tool execution

Attributes by Operation Type

The attributes field contains OpenTelemetry semantic attributes that vary by operation:

LLM Spans

Attribute	Description
llm.token_count.prompt	Input token count
llm.token_count.completion	Output token count
llm.model_name	Model identifier
llm.provider	Model provider name

Tool Spans

Attribute	Description
tool.name	Tool function name
tool.parameters	Tool input parameters (JSON)

Methods

to_dict()

Convert the span to a dictionary.

span_dict = span.to_dict()

Returns: dict

from_dict()

Create a span from a dictionary.

span = Span.from_dict(data)

Parameters:

• data (dict): Dictionary containing span data

Returns: Span

Usage

from agno.db.sqlite import SqliteDb

db = SqliteDb(db_file="tmp/traces.db")

# Get all spans for a trace
spans = db.get_spans(trace_id=trace.trace_id)

for span in spans:
    print(f"Span: {span.name}")
    print(f"  Duration: {span.duration_ms}ms")
    print(f"  Status: {span.status_code}")
    
    # Check for token usage (LLM spans)
    if span.attributes:
        tokens = span.attributes.get("llm.token_count.completion")
        if tokens:
            print(f"  Tokens: {tokens}")

Building a Span Tree

def print_span_tree(spans, parent_id=None, indent=0):
    """Recursively print spans as a tree."""
    for span in spans:
        if span.parent_span_id == parent_id:
            prefix = "  " * indent + ("└─ " if indent > 0 else "")
            print(f"{prefix}{span.name} ({span.duration_ms}ms)")
            print_span_tree(spans, span.span_id, indent + 1)

# Get spans and print tree
spans = db.get_spans(trace_id=trace.trace_id)
print_span_tree(spans)

See Also

• Trace Reference - Complete execution trace
• DB Functions - Query functions for traces and spans