Hmbown/CodeWhale · error

invalid model id for `model_context_windows`

Error message

invalid model id for `model_context_windows`

What it means

Keys of the form model_context_windows.<provider>.<model> are validated before the window value: the model id may not be the literal `auto` and may not contain whitespace or control characters. `auto` is a reserved sentinel and malformed ids would create entries that never match a real model.

Solutions

1. Use the exact model id without spaces (quote the whole key in your shell)
2. Do not use `auto` as a model key; set the provider-level default context_window instead
3. Verify the model id matches what the provider API returns (e.g. gpt-4o, not "gpt 4o")

Example fix

// before
codewhale config set 'model_context_windows.openai.auto' 128000
// after
codewhale config set 'model_context_windows.openai.gpt-4o' 128000

if model.eq_ignore_ascii_case("auto") || model.chars().any(|c| c.is_whitespace() || c.is_control()) {
    return Err("invalid model id for model_context_windows");
}

fn valid_model_key(model: &str) -> bool {
    !model.eq_ignore_ascii_case("auto") && !model.chars().any(|c| c.is_whitespace() || c.is_control())
}

match config.set_model_context_window(provider, model, value) {
    Err(e) if e.to_string().contains("invalid model id") => eprintln!("use exact model id, no spaces, not 'auto'"),
    other => other?,
}

When it happens

Trigger: set_model_context_window called with model == "auto" (case-insensitive) or a model string containing spaces/tabs/control characters — e.g. `config set model_context_windows.openai.some model 200000`.

Common situations: Trying to set a wildcard/default window using `auto`; pasting a model name with a stray space or line break from docs; shell quoting issues injecting whitespace into the key.

Understand the failure class

Background: "invalid id" errors: invalid identifier format — why libraries reject IDs before lookup, and how to fix them — this error's family across 37 libraries.

Related errors

• fleet task worker.model cannot be empty
• Invalid configured model
• .model_context_windows. must be greater than 0
• agent profile provider cannot be empty
• agent profile provider must be a simple provider id

AI-assisted analysis of Hmbown/CodeWhale@73e0f67d83 (2026-09-22). Data as JSON: /api/errors/e356c19bdcb5998b. Report an issue: GitHub.

Appendix: source

Thrown at crates/config/src/lib.rs:2670

            "kind"
        } else {
            ProviderConfigField::parse(field_key).map_or(field_key, |field| field.key())
        };
        table.remove(leg);
    }

    /// Write one `[providers.<id>.model_context_windows]` entry (#6108),
    /// whether `<id>` is a built-in provider key or a named custom table.
    fn set_model_context_window(
        &mut self,
        provider_id: &str,
        model: &str,
        value: &str,
    ) -> Result<()> {
        if model.eq_ignore_ascii_case("auto")
            || model.chars().any(|c| c.is_whitespace() || c.is_control())
        {
            bail!("invalid model id for `model_context_windows`");
        }
        let window = parse_context_window(value)?;
        if let Some(kind) = builtin_provider_kind_for_config_id(provider_id) {
            self.providers
                .for_provider_mut(kind)
                .model_context_windows
                .insert(model.to_string(), window);
            return Ok(());
        }
        let table = self.custom_provider_table_mut(provider_id)?;
        let windows = table
            .entry("model_context_windows".to_string())
            .or_insert_with(|| toml::Value::Table(toml::value::Table::new()));
        windows
            .as_table_mut()
            .with_context(|| {
                format!("providers.{provider_id}.model_context_windows must be a table")
            })?

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