run-llama/llama_index · error · ValueError

All memory blocks must have unique names.

Error message

All memory blocks must have unique names.

What it means

Error "All memory blocks must have unique names." thrown in run-llama/llama_index.

Source

Thrown at llama-index-core/llama_index/core/memory/memory.py:284

    def validate_memory(cls, values: dict) -> dict:
        # Validate token limit
        token_limit = values.get("token_limit", -1)
        if token_limit < 1:
            raise ValueError("Token limit must be set and greater than 0.")

        tokenizer_fn = values.get("tokenizer_fn")
        if tokenizer_fn is None:
            values["tokenizer_fn"] = get_tokenizer()

        if values.get("token_flush_size", -1) < 1:
            values["token_flush_size"] = int(token_limit * 0.1)
        elif values.get("token_flush_size", -1) > token_limit:
            values["token_flush_size"] = int(token_limit * 0.1)

        # validate all blocks have unique names
        block_names = [block.name for block in values.get("memory_blocks", [])]
        if len(block_names) != len(set(block_names)):
            raise ValueError("All memory blocks must have unique names.")

        return values

    @classmethod
    def from_defaults(  # type: ignore[override]
        cls,
        session_id: Optional[str] = None,
        chat_history: Optional[List[ChatMessage]] = None,
        token_limit: int = DEFAULT_TOKEN_LIMIT,
        memory_blocks: Optional[List[BaseMemoryBlock[Any]]] = None,
        tokenizer_fn: Optional[Callable[[str], List]] = None,
        chat_history_token_ratio: float = 0.7,
        token_flush_size: int = DEFAULT_FLUSH_SIZE,
        memory_blocks_template: RichPromptTemplate = DEFAULT_MEMORY_BLOCKS_TEMPLATE,
        insert_method: InsertMethod = InsertMethod.SYSTEM,
        image_token_size_estimate: int = 256,
        audio_token_size_estimate: int = 256,
        video_token_size_estimate: int = 256,

View on GitHub (pinned to afd0fef371)

Solutions

1. Give each memory block a unique name in the memory_blocks list.
2. Rename or remove duplicate memory blocks so all names are distinct.

When it happens

Trigger: Thrown at llama-index-core/llama_index/core/memory/memory.py:284 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of run-llama/llama_index@afd0fef371 (2026-08-15). Data as JSON: /api/errors/a1ad419026f988c0. Report an issue: GitHub.