mem0ai/mem0 · error · ValueError

Metadata cannot be done for procedural memory.

Error message

Metadata cannot be done for procedural memory.

What it means

Error "Metadata cannot be done for procedural memory." thrown in mem0ai/mem0.

Source

Thrown at mem0/memory/main.py:2021

        parsed_messages = [
            {"role": "system", "content": prompt or PROCEDURAL_MEMORY_SYSTEM_PROMPT},
            *messages,
            {
                "role": "user",
                "content": "Create procedural memory of the above conversation.",
            },
        ]

        try:
            procedural_memory = self.llm.generate_response(messages=parsed_messages)
            procedural_memory = remove_code_blocks(procedural_memory)
        except Exception as e:
            logger.error(f"Error generating procedural memory summary: {e}")
            raise

        if metadata is None:
            raise ValueError("Metadata cannot be done for procedural memory.")

        metadata = {**metadata, "memory_type": MemoryType.PROCEDURAL.value}
        embeddings = self.embedding_model.embed(procedural_memory, memory_action="add")
        memory_id = self._create_memory(procedural_memory, {procedural_memory: embeddings}, metadata=metadata)
        capture_event("mem0._create_procedural_memory", self, {"memory_id": memory_id, "sync_type": "sync"})

        result = {"results": [{"id": memory_id, "memory": procedural_memory, "event": "ADD"}]}

        return result

    def _update_memory(self, memory_id, data, existing_embeddings, metadata=None):
        logger.info(f"Updating memory with {data=}")

        try:
            existing_memory = self.vector_store.get(vector_id=memory_id)
        except Exception:
            # Backing-store failure, not a bad memory_id: re-raise the original so the REST layer maps it to 5xx, not 4xx.
            logger.error(f"Error getting memory with ID {memory_id} during update.")

View on GitHub (pinned to 001c235229)

Solutions

1. Do not pass metadata for procedural memories; metadata updates are only supported for semantic memories.

When it happens

Trigger: Thrown at mem0/memory/main.py:2021 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/c3794667dd129411. Report an issue: GitHub.