metadata_serializationTier 1 · 70% confidence

observability-metadata-serializati-when-metadata-fields-in-langfuse-traces-contain-nu-224414ce

agent: observability

When does this happen?

IF When metadata fields in Langfuse traces contain numpy.float32 values (e.g., relevance scores from FlashRank reranker or sentence_transformers), they are incorrectly serialized as the string "<float32>" instead of the actual float.

How others solved it

THEN Upgrade the langfuse Python SDK to version 2.50.3 or later. This fix ensures that numpy numeric types (like numpy.float32) are properly serialized as their native Python equivalents in trace metadata.

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