Span Methods

TypeScript

Laminar.setSpanAttributes(attributes)

Set attributes on the current span.

await observe({ name: 'process' }, async () => {
  Laminar.setSpanAttributes({
    'document.pages': 10,
    'document.language': 'en',
  });
});

Parameters:

Name	Type	Description
attributes	Record<typeof LaminarAttributes[keyof typeof LaminarAttributes], AttributeValue>	Key-value pairs

Returns: void

---

Laminar.setSpanOutput(output)

Explicitly set span output.

await observe({ name: 'complex_operation' }, async () => {
  const result = await doWork();
  Laminar.setSpanOutput(result.summary); // Record only the summary
  return result;
});

Parameters:

Name	Type	Default	Description
output	any	—	Output payload (JSON-serialized)

Returns: void

Note: No-op if output is null or undefined.

---

Laminar.setSpanTags(tags)

Set tags on the current span (deduplicated).

await observe({ name: 'process' }, async () => {
  if (input.length > 10000) {
    Laminar.setSpanTags(['long-input']);
  }
});

Parameters:

Name	Type	Default	Description
tags	string[]	—	Tags to set (deduplicated)

Returns: void

Note: Laminar.addSpanTags(...) is not available in the TypeScript SDK—use setSpanTags(...).

---

Laminar.event(options)

Add an event to the current span, or create a span if none exists.

await observe({ name: 'workflow' }, async () => {
  Laminar.event({
    name: 'checkpoint_reached',
    attributes: { step: 5 },
  });
});

Parameters:

Name	Type	Default	Description
options.name	string	—	Event name (required)
options.attributes	Record<string, AttributeValue>	—	Event attributes
options.timestamp	TimeInput	OTEL now	Custom timestamp
options.sessionId	string	—	Session ID
options.userId	string	—	User ID

Returns: void

---

span.end(endTime?)

End a manually created span.

const span = Laminar.startSpan({ name: 'operation' });
try {
  await doWork();
} finally {
  span.end(); // Always end in finally block
}

Parameters:

Name	Type	Default	Description
endTime	TimeInput	OTEL now	End timestamp

Returns: void

Note: Pops active context if span was activated via startActiveSpan.

---

span.recordException(exception, time?)

Record an exception on the span.

const span = Laminar.startSpan({ name: 'risky_operation' });
try {
  await riskyWork();
} catch (error) {
  span.recordException(error);
  throw error;
} finally {
  span.end();
}

Parameters:

Name	Type	Default	Description
exception	Exception	—	Error/exception to record
time	TimeInput	OTEL now	Timestamp

Returns: void

---

span.setAttributes(attributes)

Set attributes directly on a span object.

const span = Laminar.startSpan({ name: 'operation' });
span.setAttributes({ 'operation.status': 'success' });
span.end();

Parameters:

Name	Type	Description
attributes	SpanAttributes	Key-value pairs

Returns: this

Python

Laminar.set_span_attributes(attributes)

Set attributes on the current span.

@observe()
def process_document(doc):
    Laminar.set_span_attributes({
        "document.pages": len(doc.pages),
        "document.language": doc.detected_language,
    })

Parameters:

Name	Type	Description
attributes	dict[Attributes or str, Any]	Key-value pairs. Keys can be Attributes enum or strings. Non-primitive values JSON-serialized.

Returns: None

Note: No-op if no active span.

---

Laminar.set_span_output(output)

Explicitly set span output.

@observe()
def complex_operation():
    result = do_many_things()
    Laminar.set_span_output(result.summary)  # Record only summary
    return result

Parameters:

Name	Type	Default	Description
output	Any	None	Output value (JSON-serialized, truncated if >10MB)

Returns: None

Note: No-op if no active span.

---

Laminar.set_span_tags(tags)

Set tags on the current span (deduplicated).

@observe()
def process_input(text: str):
    if len(text) > 10000:
        Laminar.set_span_tags(["long-input"])

Parameters:

Name	Type	Description
tags	list[str]	Tags to set (deduplicated)

Returns: None

---

Laminar.add_span_tags(tags)

Add (union) tags onto the current span.

@observe()
def process_input(text: str):
    if len(text) > 10000:
        Laminar.add_span_tags(["long-input"])

Parameters:

Name	Type	Description
tags	list[str]	Tags to add

Returns: None

Note: Warns if not list[str].

---

Laminar.event(name, attributes=None, timestamp=None, *, user_id=None, session_id=None)

Add an event to the active span (creates and ends a span if none is active).

from lmnr import Laminar, observe

@observe()
def workflow():
    Laminar.event("checkpoint_reached", attributes={"step": 5})

Parameters:

Name	Type	Default	Description
name	str	—	Event name
attributes	dict[str, AttributeValue] | None	None	Event attributes
timestamp	datetime | int | None	None	Timestamp (defaults to OTEL now)
user_id	str | None	None	User ID
session_id	str | None	None	Session ID

Returns: None

---

span.end(end_time=None)

End a manually created span.

span = Laminar.start_span(name="operation")
try:
    do_work()
finally:
    span.end()  # Always end in finally block

Parameters:

Name	Type	Default	Description
end_time	int | None	None	End timestamp (defaults to OTEL now)

Returns: None

---

span.record_exception(exception, attributes=None, timestamp=None, escaped=False)

Record an exception on the span.

with Laminar.start_as_current_span(name="risky_operation") as span:
    try:
        risky_work()
    except Exception as e:
        span.record_exception(e)
        raise

Parameters:

Name	Type	Default	Description
exception	BaseException	—	Exception to record
attributes	dict[str, AttributeValue] | None	None	Additional exception attributes
timestamp	int | None	None	Timestamp (defaults to OTEL now)
escaped	bool	False	Mark as escaped exception

Returns: None

---

span.set_attributes(attributes)

Set many attributes directly on a span object.

span.set_attributes({
    "operation.status": "success",
    "operation.items_count": 42,
})

Parameters:

Name	Type	Description
attributes	dict[str, AttributeValue]	Key-value pairs

Returns: None

---

span.set_attribute(key, value)

Set a single attribute on a span object.

span.set_attribute("operation.status", "success")

Parameters:

Name	Type	Description
key	str	Attribute key
value	AttributeValue	Attribute value

Returns: None