run-llama/llama_index · error · ValueError

Cannot call query engine without inputs

Error message

Cannot call query engine without inputs

What it means

Error "Cannot call query engine without inputs" thrown in run-llama/llama_index.

Source

Thrown at llama-index-core/llama_index/core/tools/retriever_tool.py:85

    @property
    def retriever(self) -> BaseRetriever:
        return self._retriever

    @property
    def metadata(self) -> ToolMetadata:
        return self._metadata

    def call(self, *args: Any, **kwargs: Any) -> ToolOutput:
        query_str = ""
        if args is not None:
            query_str += ", ".join([str(arg) for arg in args]) + "\n"
        if kwargs is not None:
            query_str += (
                ", ".join([f"{k!s} is {v!s}" for k, v in kwargs.items()]) + "\n"
            )
        if query_str == "":
            raise ValueError("Cannot call query engine without inputs")

        docs = self._retriever.retrieve(query_str)
        docs = self._apply_node_postprocessors(docs, QueryBundle(query_str))
        content = ""
        for doc in docs:
            assert isinstance(doc.node, (Node, TextNode))
            node_copy = doc.node.model_copy()
            content += node_copy.get_content(MetadataMode.LLM) + "\n\n"
        return ToolOutput(
            content=content,
            tool_name=self.metadata.get_name(),
            raw_input={"input": query_str},
            raw_output=docs,
        )

    async def acall(self, *args: Any, **kwargs: Any) -> ToolOutput:
        query_str = ""
        if args is not None:

View on GitHub (pinned to afd0fef371)

Solutions

1. Pass inputs when calling the retriever tool's query engine.
2. Verify the tool schema so the calling agent supplies the required input.

When it happens

Trigger: Thrown at llama-index-core/llama_index/core/tools/retriever_tool.py:85 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/84e1187412b28936. Report an issue: GitHub.