* feat(langfuse): Add support for custom masking function
Allow users to pass a custom masking function via metadata to selectively
redact sensitive data (credit cards, emails, PII) before sending to Langfuse.
Usage:
```python
def mask_pii(data):
if isinstance(data, str):
data = re.sub(r'\b\d{4}[\s-]?\d{4}[\s-]?\d{4}[\s-]?\d{4}\b', '[CARD]', data)
return data
litellm.completion(
model="gpt-4",
messages=[...],
metadata={"langfuse_masking_function": mask_pii}
)
```
* fix(langfuse): Isolate masking function from other logging integrations
Extract langfuse_masking_function from metadata early in the flow and store
it in a dedicated key (_langfuse_masking_function) that only the Langfuse
logger knows to look for. This prevents the callable from leaking to other
logging integrations (Datadog, S3, etc.) which would serialize it as
"<function at 0x...>".
Changes:
- scrub_sensitive_keys_in_metadata() now extracts and stores the function
- Langfuse logger looks in the dedicated key first, falls back to metadata
- Added tests to verify isolation works correctly
d693596e87