Context Propagation

mollog supports context-local structured fields using Python contextvars.

This is useful for:

• request IDs in async services
• trace IDs in worker pools
• tenant or batch IDs in data pipelines
• any field that should follow the current execution flow without being passed manually every time

Bind fields globally for the current context

```python from mollog import bind_context, get_logger, reset_context

logger = get_logger("api") token = bind_context(request_id="req-7", trace_id="trace-9")

try: logger.info("accepted") finally: reset_context(token) ```

Use a scoped context

```python from mollog import get_logger, scoped_context

logger = get_logger("worker")

with scoped_context(batch="nightly", request_id="req-42"): logger.info("started") ```

Merge behavior

Field precedence is:

1. context-local fields
2. bound logger fields
3. per-call extra

Later sources overwrite earlier ones. That means explicit per-call values always win.