---
title: JudgmentBaggagePropagator
seo:
  title: JudgmentBaggagePropagator — Python SDK
  description: W3C Baggage propagator that uses the Judgment context. (Python SDK)
description: W3C Baggage propagator that uses the Judgment context.
---

Serializes and deserializes baggage entries to/from the `baggage`
HTTP header. Respects size limits defined by the W3C Baggage
specification (8 KB header, 4 KB per entry, 180 entries max).

## Attributes

| Prop | Type | Default | Description |
| - | - | - | - |
| `fields?` | `Set[str]` | - | |

***

## inject()

Write baggage entries into the carrier as a `baggage` header.

```python
def inject(carrier, context=None, setter=_default_setter) -> None:
```

### Parameters

| Prop | Type | Default | Description |
| - | - | - | - |
| `carrier` | `object` | - | |
| `context?` | `Optional[Context]` | `None` | |
| `setter?` | `Setter` | `_default_setter` | |

### Returns

`None`

***

## extract()

Parse the `baggage` header from the carrier into the context.

```python
def extract(carrier, context=None, getter=_default_getter) -> Context:
```

### Parameters

| Prop | Type | Default | Description |
| - | - | - | - |
| `carrier` | `object` | - | |
| `context?` | `Optional[Context]` | `None` | |
| `getter?` | `Getter` | `_default_getter` | |

### Returns

`Context`

***

## \_resolve\_context()

```python
def _resolve_context(context) -> Context:
```

### Parameters

| Prop | Type | Default | Description |
| - | - | - | - |
| `context` | `Optional[Context]` | - | |

### Returns

`Context`

***

## \_format\_baggage()

```python
def _format_baggage(baggage_entries) -> str:
```

### Parameters

| Prop | Type | Default | Description |
| - | - | - | - |
| `baggage_entries` | `Mapping[str, object]` | - | |

### Returns

`str`

***

## \_extract\_first\_element()

```python
def _extract_first_element(items) -> Optional[CarrierT]:
```

### Parameters

| Prop | Type | Default | Description |
| - | - | - | - |
| `items` | `Optional[Iterable[CarrierT]]` | - | |

### Returns

`Optional[CarrierT]`