baggage.rst

opentelemetry.baggage package

The baggage API stores name/value pairs inside an OpenTelemetry Context. The helper functions in :mod:`opentelemetry.baggage` return updated context objects; they do not mutate the current context in place.

This distinction matters when reading baggage with baggage.get_all():

• baggage.get_all() reads from the current context.
• baggage.get_all(context=ctx) reads from the explicit context you pass in.
• baggage.set_baggage(...) returns a new context containing the baggage entry, but that returned context is not made current unless you explicitly attach it.

Example:

from opentelemetry import baggage, context

ctx = baggage.set_baggage("foo", "bar")

print(baggage.get_all())
# {}

print(baggage.get_all(context=ctx))
# {'foo': 'bar'}

To make a context returned by set_baggage become the current context, attach it and later detach it with the value that attach returns:

from opentelemetry import baggage, context

ctx = baggage.set_baggage("foo", "bar")
token = context.attach(ctx)
try:
    print(baggage.get_all())
    # {'foo': 'bar'}
finally:
    context.detach(token)

Always pair context.attach with context.detach. Dropping the token can leak baggage into later work on the same execution unit.

Passing context=... to another API is also different from attaching that context. For example, tracer.start_as_current_span(..., context=ctx) uses ctx as the parent span context, but does not by itself make ctx the current execution context for subsequent calls to baggage.get_all(). If you want both behaviors, attach the context before entering the span scope.

Subpackages

.. toctree::

   baggage.propagation

Module contents

.. automodule:: opentelemetry.baggage