# context
## <ApiType type="Function" slug="propagated_context" symbolName="propagated_context" /> propagated_context
Attach a parent context or extract context from carrier headers.
This context manager is used to establish trace context continuity,
typically on the server side when receiving requests. It either extracts
context from incoming headers or attaches a pre-existing context.
<ParametersTable
parameters={[
{
"name": "parent",
"type_info": {
"type_str": "Context | None",
"description": null,
"kind": "union",
"base_type": {
"type_str": "Union",
"description": null,
"kind": "simple",
"symbol_name": "Union",
"doc_url": "https://docs.python.org/3/library/typing.html#typing.Union"
},
"parameters": [
{
"type_str": "Context",
"description": null,
"kind": "simple",
"symbol_name": "Context",
"doc_url": null
},
{
"type_str": "None",
"description": null,
"kind": "simple",
"symbol_name": "None",
"doc_url": "https://docs.python.org/3/library/constants.html#None"
}
],
"doc_url": null
},
"default": "None",
"description": "Pre-existing OTEL context to attach. Mutually exclusive with extract_from."
},
{
"name": "extract_from",
"type_info": {
"type_str": "Mapping[str, Any] | None",
"description": null,
"kind": "union",
"base_type": {
"type_str": "Union",
"description": null,
"kind": "simple",
"symbol_name": "Union",
"doc_url": "https://docs.python.org/3/library/typing.html#typing.Union"
},
"parameters": [
{
"type_str": "Mapping[str, Any]",
"description": null,
"kind": "generic",
"base_type": {
"type_str": "Mapping",
"description": null,
"kind": "simple",
"symbol_name": "Mapping",
"doc_url": null
},
"parameters": [
{
"type_str": "str",
"description": null,
"kind": "simple",
"symbol_name": "str",
"doc_url": "https://docs.python.org/3/library/stdtypes.html#str"
},
{
"type_str": "Any",
"description": null,
"kind": "simple",
"symbol_name": "Any",
"doc_url": "https://docs.python.org/3/library/typing.html#typing.Any"
}
],
"doc_url": null
},
{
"type_str": "None",
"description": null,
"kind": "simple",
"symbol_name": "None",
"doc_url": "https://docs.python.org/3/library/constants.html#None"
}
],
"doc_url": null
},
"default": "None",
"description": "Dictionary of headers to extract context from (e.g., request.headers).\nMutually exclusive with parent."
}
]}
/>
<ReturnTable
returnType={{
"type_info": {
"type_str": "Iterator[None]",
"description": null,
"kind": "generic",
"base_type": {
"type_str": "Iterator",
"description": null,
"kind": "simple",
"symbol_name": "Iterator",
"doc_url": null
},
"parameters": [
{
"type_str": "None",
"description": null,
"kind": "simple",
"symbol_name": "None",
"doc_url": "https://docs.python.org/3/library/constants.html#None"
}
],
"doc_url": null
}
}}
/>