HKUDS/nanobot · error · ValueError

model_preset name 'default' is reserved for agents.defaults

Error message

model_preset name 'default' is reserved for agents.defaults

What it means

In Config._validate_model_preset, a model_preset is literally named 'default', which is reserved because agents.defaults implicitly defines the default preset — a user preset with that key would create a name collision. The input at fault is the model_preset key "default" in model_presets.

Solutions

1. Rename the preset to something else, e.g. 'my-default'
2. Delete the 'default' preset and set its parameters in agents.defaults
3. Reference the implicit default via model_preset: "default" or by omitting it

When it happens

Trigger: Thrown at nanobot/config/schema.py:469 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/16331ba876a69906. Report an issue: GitHub.

Appendix: source

Thrown at nanobot/config/schema.py:469

            _resolve_tool_config_refs()
        super().__init__(**values)

    def bind_source_path(self, path: Path) -> None:
        """Record the config file that owns instance-level runtime data."""
        self._source_path = path.expanduser().resolve(strict=False)

    @property
    def runtime_data_dir(self) -> Path | None:
        """Return the active instance data directory when loaded from a config path."""
        return self._source_path.parent if self._source_path is not None else None

    @model_validator(mode="after")
    def _validate_model_preset(self) -> "Config":
        # Keep persisted names accepted by previous releases loadable. New
        # names are normalized and checked case-insensitively at mutation
        # boundaries, where conflicts can be reported without breaking startup.
        if "default" in self.model_presets:
            raise ValueError("model_preset name 'default' is reserved for agents.defaults")
        name = self.agents.defaults.model_preset
        if name and name != "default" and name not in self.model_presets:
            raise ValueError(f"model_preset {name!r} not found in model_presets")
        dream_name = self.agents.defaults.dream.model_override
        if dream_name and dream_name != "default" and dream_name not in self.model_presets:
            raise ValueError(f"Dream model preset {dream_name!r} not found in model_presets")
        for fallback in self.agents.defaults.fallback_models:
            if isinstance(fallback, str) and fallback not in self.model_presets:
                raise ValueError(f"fallback_models entry {fallback!r} not found in model_presets")
        return self

    def resolve_default_preset(self) -> ModelPresetConfig:
        """Return the implicit `default` preset from agents.defaults fields."""
        d = self.agents.defaults
        return ModelPresetConfig(
            model=d.model, provider=d.provider, max_tokens=d.max_tokens,
            context_window_tokens=d.context_window_tokens,
            temperature=d.temperature, reasoning_effort=d.reasoning_effort,

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