HKUDS/nanobot · error · ValueError

model must be a non-empty string

Error message

model must be a non-empty string

What it means

Raised by ModelRuntime.select_model when the model argument fails the isinstance-str check or is blank after stripping. It guards the runtime model override path (which also clears model_preset); None or empty model names from config or SDK calls are rejected before the runtime is rebuilt.

Solutions

1. Pass a concrete non-empty model identifier such as "gpt-4o" or "claude-sonnet-4-20250514"
2. If the value comes from user input, validate it is a non-empty string before calling select_model
3. To select by preset instead, call select_preset with a preset name

When it happens

Trigger: Thrown at nanobot/agent/model_runtime.py:144 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of HKUDS/nanobot@42f37dc4c0 (2026-08-26). Data as JSON: /api/errors/60fcff9fb1a2b63d. Report an issue: GitHub.

Appendix: source

Thrown at nanobot/agent/model_runtime.py:144

            presets=self._model_presets,
            provider=self._runtime.provider,
            loader=self._preset_snapshot_loader,
        )
        runtime = self.resolve_snapshot(snapshot)
        self._resolved_presets[normalized] = runtime
        return runtime

    def select_preset(self, name: str | None) -> LLMRuntime:
        """Select a named preset as the default for future turns."""
        runtime = self.resolve_preset(name)
        self._runtime = runtime
        self._tracks_provider_generation = False
        return runtime

    def select_model(self, model: str) -> LLMRuntime:
        """Change the default model without reconstructing downstream consumers."""
        if not isinstance(cast(object, model), str) or not model.strip():
            raise ValueError("model must be a non-empty string")
        self._runtime = replace(
            self._runtime,
            model=model.strip(),
            model_preset=None,
        )
        return self._runtime

    def select_context_window(self, context_window_tokens: int) -> LLMRuntime:
        """Change the default context limit for future admissions."""
        raw_context_window = cast(object, context_window_tokens)
        if not isinstance(raw_context_window, int) or isinstance(
            raw_context_window,
            bool,
        ):
            raise TypeError("context_window_tokens must be an integer")
        self._runtime = replace(
            self._runtime,
            context_window_tokens=context_window_tokens,

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