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.

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.

Appendix: 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:

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