mem0ai/mem0 · error · ValueError

Number of metadata items ({len(metadatas)}) does not match n

Error message

Number of metadata items ({len(metadatas)}) does not match number of texts ({len(texts)})

What it means

Error "Number of metadata items ({len(metadatas)}) does not match number of texts ({len(texts)})" thrown in mem0ai/mem0.

Source

Thrown at mem0/vector_stores/vertex_ai_vector_search.py:566

    ) -> List[str]:
        """Add texts to the vector store.

        Args:
            texts: List of texts to add
            metadatas: Optional list of metadata dicts
            ids: Optional list of IDs to use

        Returns:
            List[str]: List of IDs of the added texts

        Raises:
            ValueError: If texts is empty or lengths don't match
        """
        if not texts:
            raise ValueError("No texts provided")

        if metadatas and len(metadatas) != len(texts):
            raise ValueError(
                f"Number of metadata items ({len(metadatas)}) does not match number of texts ({len(texts)})"
            )

        if ids and len(ids) != len(texts):
            raise ValueError(f"Number of ids ({len(ids)}) does not match number of texts ({len(texts)})")

        logger.debug("Starting add_texts operation")
        logger.debug("Number of texts: %d", len(texts))
        logger.debug("Has metadatas: %s", metadatas is not None)
        logger.debug("Has ids: %s", ids is not None)

        if ids is None:
            ids = [str(uuid.uuid4()) for _ in texts]

        try:
            # Get embeddings
            embeddings = self.embedder.embed_documents(texts)

View on GitHub (pinned to 001c235229)

Solutions

1. Pass one metadata item per text so the counts match.

When it happens

Trigger: Thrown at mem0/vector_stores/vertex_ai_vector_search.py:566 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of mem0ai/mem0@001c235229 (2026-08-15). Data as JSON: /api/errors/ea92d5680fe07512. Report an issue: GitHub.