leviath-cli 0.3.9

//! Config and models endpoints.

use axum::extract::State;
use axum::http::StatusCode;
use axum::response::Json;

use super::types::*;
use crate::config::Config;

/// Every `[model_providers]` entry as the API reports it, name-sorted.
///
/// Sorted because the config holds them in a `HashMap`, whose iteration order
/// differs between two calls on one machine, and a list that reorders itself
/// under a form is a list nobody can edit.
fn gateways_of(c: &Config) -> Vec<GatewayInfo> {
    let mut gateways: Vec<GatewayInfo> = c
        .model_providers
        .iter()
        .map(|(name, p)| GatewayInfo {
            name: name.clone(),
            base_url: p.base_url.clone(),
            has_api_key: p.api_key.is_some(),
            script: p.script.clone(),
            // Names only. See `GatewayInfo::extra_keys`: these values are
            // forwarded into a script and routinely hold credentials.
            extra_keys: {
                let mut keys: Vec<String> = p.extra.keys().cloned().collect();
                keys.sort();
                keys
            },
        })
        .collect();
    gateways.sort_by(|a, b| a.name.cmp(&b.name));
    gateways
}

/// Redacted view of a config — booleans for keys, never their values.
fn redact(c: &Config) -> RedactedConfig {
    RedactedConfig {
        default_provider: c.default_provider.clone(),
        has_anthropic_key: c.providers.anthropic_api_key.is_some(),
        has_openai_key: c.providers.openai_api_key.is_some(),
        has_google_key: c.providers.google_api_key.is_some(),
        has_openrouter_key: c.openrouter_api_key.is_some(),
        ollama_base_url: c.ollama_base_url.clone(),
        gateways: gateways_of(c),
        agent_paths: c.agent_paths.clone(),
        mcp_server_count: c.mcp_servers.len(),
        api_version: API_VERSION.to_string(),
        capabilities: API_CAPABILITIES.iter().map(|c| c.to_string()).collect(),
        limits: ApiLimits::current(),
    }
}

pub(super) async fn get_config(State(state): State<AppState>) -> Json<RedactedConfig> {
    Json(redact(&state.config))
}

/// `PUT /api/config` (admin-only). Loads the on-disk config, applies every
/// present field, and writes it back with the file's `0600` permissions — the
/// same file `lev setup` and MCP admin edits. Returns the new redacted config.
pub(super) async fn put_config(
    State(state): State<AppState>,
    Json(req): Json<WriteConfigReq>,
) -> Result<Json<RedactedConfig>, (StatusCode, Json<ErrorResponse>)> {
    let path = &state.mcp.config_path;
    let mut config = Config::load_from_path_public(path).map_err(|e| {
        err(
            StatusCode::INTERNAL_SERVER_ERROR,
            format!("failed to read config: {e}"),
        )
    })?;

    if let Some(v) = req.default_provider {
        config.default_provider = v;
    }
    if let Some(v) = req.default_model {
        config.default_model = Some(v);
    }
    if let Some(v) = req.anthropic_key {
        config.providers.anthropic_api_key = Some(v);
    }
    if let Some(v) = req.openai_key {
        config.providers.openai_api_key = Some(v);
    }
    if let Some(v) = req.google_key {
        config.providers.google_api_key = Some(v);
    }
    if let Some(v) = req.openrouter_key {
        config.openrouter_api_key = Some(v);
    }
    if let Some(v) = req.ollama_base_url {
        config.ollama_base_url = Some(v);
    }
    // Field by field, like everything above: a gateway names only what it is
    // changing, so a console can edit a base URL without knowing the key or
    // sending it back through the browser.
    for gateway in req.gateways.unwrap_or_default() {
        let entry = config.model_providers.entry(gateway.name).or_default();
        if let Some(v) = gateway.base_url {
            entry.base_url = Some(v);
        }
        if let Some(v) = gateway.api_key {
            entry.api_key = Some(v);
        }
        if let Some(v) = gateway.script {
            entry.script = Some(v);
        }
    }
    // Removals run last, so one request that both edits and deletes cannot
    // depend on which half was applied first.
    for name in req.remove_gateways.unwrap_or_default() {
        config.model_providers.remove(&name);
    }

    config.save_to_path_public(path).map_err(|e| {
        err(
            StatusCode::INTERNAL_SERVER_ERROR,
            format!("failed to write config: {e}"),
        )
    })?;
    Ok(Json(redact(&config)))
}

/// Format-only validation of a provider key (no network call, no persistence).
fn validate_key_format(provider: &str, key: &str) -> (bool, Option<String>) {
    match provider {
        "anthropic" => {
            if key.starts_with("sk-ant-") {
                (true, None)
            } else {
                (
                    false,
                    Some("Anthropic keys start with `sk-ant-`.".to_string()),
                )
            }
        }
        "openai" => {
            if key.starts_with("sk-") {
                (true, None)
            } else {
                (false, Some("OpenAI keys start with `sk-`.".to_string()))
            }
        }
        "google" | "openrouter" => {
            if key.trim().is_empty() {
                (false, Some("Key must not be empty.".to_string()))
            } else {
                (true, None)
            }
        }
        // A custom gateway is custom precisely because its key has no house
        // format to check, so an unknown name is no longer a rejection: the
        // only thing that can be said about the key is that it is not empty.
        _ => match key.trim().is_empty() {
            true => (false, Some("Key must not be empty.".to_string())),
            false => (true, None),
        },
    }
}

/// Format-only check of a gateway's base URL.
///
/// Shape only, like the key check beside it: no request is made, because
/// `POST /api/config/validate` promises not to touch the network and a form
/// that hangs on an unreachable host is worse than one that says nothing. The
/// scheme is what people actually get wrong - a bare `api.example.com`, or an
/// `ollama serve` address pasted without one.
fn validate_base_url(url: &str) -> (bool, Option<String>) {
    let trimmed = url.trim();
    if trimmed.is_empty() {
        return (false, Some("Base URL must not be empty.".to_string()));
    }
    match trimmed.starts_with("http://") || trimmed.starts_with("https://") {
        true => (true, None),
        false => (
            false,
            Some("Base URL must start with `http://` or `https://`.".to_string()),
        ),
    }
}

pub(super) async fn validate_config_key(Json(req): Json<ValidateKeyReq>) -> Json<ValidateKeyResp> {
    // The URL is checked first: a gateway with both wrong is more usefully
    // told about the address than about the key, since the key cannot be
    // judged beyond being present.
    if let Some(base_url) = &req.base_url {
        let (valid, message) = validate_base_url(base_url);
        if !valid {
            return Json(ValidateKeyResp { valid, message });
        }
    }
    let (valid, message) = validate_key_format(&req.provider, &req.key);
    Json(ValidateKeyResp { valid, message })
}

pub(super) async fn get_models(State(state): State<AppState>) -> Json<Vec<ModelEntry>> {
    models_with(&state, &leviath_providers::provider::build_http_client).await
}

/// [`get_models`], with client construction injected so the "no usable HTTPS
/// client" answer is reachable from a test.
pub(super) async fn models_with(
    state: &AppState,
    build_client: leviath_providers::provider::HttpClientFactory<'_>,
) -> Json<Vec<ModelEntry>> {
    // Nothing to list if no client could be built; the endpoint answers with an
    // empty set rather than failing the request, matching how it treats a
    // provider whose `list_models` errors.
    let Ok(registry) = crate::commands::run::session::build_provider_registry_from_config_with(
        &state.config,
        build_client,
    ) else {
        return Json(Vec::new());
    };
    let mut models = Vec::new();

    for provider_name in registry.provider_names() {
        let provider = registry
            .get(provider_name)
            .expect("provider_names returns registered names");
        if let Ok(list) = provider.list_models().await {
            for m in list {
                models.push(ModelEntry {
                    id: m.id,
                    provider: m.provider,
                    display_name: m.display_name,
                    max_context_tokens: m.capabilities.max_context_tokens,
                    max_output_tokens: m.capabilities.max_output_tokens,
                    supports_tools: m.capabilities.supports_tools,
                });
            }
        }
    }

    Json(models)
}

#[cfg(test)]
mod tests {
    use super::*;
    use axum::Router;
    use axum::body::Body;
    use axum::http::Request;
    use axum::routing::get;
    use std::sync::Arc;
    use tokio::sync::broadcast;
    use tower::ServiceExt;

    use crate::commands::serve::types::ServerEvent;
    use crate::config::Config;

    /// A default config whose ollama endpoint cannot answer.
    ///
    /// Ollama is always registered, so on a machine running `ollama serve` its
    /// `list_models` *succeeds* and the `if let Ok(list)` in `models_with` never
    /// takes its other arm - which made `cargo xtask coverage --package
    /// leviath-cli` fail locally while passing in CI, where nothing is
    /// listening. Port 1 is reserved and never bound, so the result stops
    /// depending on what happens to be running on the developer's machine.
    fn state_without_a_reachable_ollama() -> AppState {
        let (tx, _) = broadcast::channel::<ServerEvent>(64);
        AppState {
            config: Arc::new(Config {
                ollama_base_url: Some("http://127.0.0.1:1".to_string()),
                ..Config::default()
            }),
            event_tx: tx,
            control: crate::commands::serve::testutil::no_daemon_client(),
            mcp: crate::commands::serve::mcp::McpAdmin::default(),
            limits: Default::default(),
        }
    }

    fn test_state() -> AppState {
        let (tx, _) = broadcast::channel::<ServerEvent>(64);
        AppState {
            config: Arc::new(Config::default()),
            event_tx: tx,
            control: crate::commands::serve::testutil::no_daemon_client(),
            mcp: crate::commands::serve::mcp::McpAdmin::default(),
            limits: Default::default(),
        }
    }

    fn test_state_with_keys() -> AppState {
        let (tx, _) = broadcast::channel::<ServerEvent>(64);
        AppState {
            config: Arc::new(Config {
                providers: crate::config::ProviderConfig {
                    anthropic_api_key: Some("sk-ant-test".to_string()),
                    openai_api_key: Some("sk-openai-test".to_string()),
                    google_api_key: None,
                    claude_code_enabled: false,
                    claude_code_binary: None,
                    claude_code_effort: None,
                    anthropic_cache_ttl: None,
                    fallback_order: Vec::new(),
                },
                openrouter_api_key: Some("sk-or-test".to_string()),
                ollama_base_url: Some("http://localhost:11434".to_string()),
                mcp_servers: vec![],
                ..Default::default()
            }),
            event_tx: tx,
            control: crate::commands::serve::testutil::no_daemon_client(),
            mcp: crate::commands::serve::mcp::McpAdmin::default(),
            limits: Default::default(),
        }
    }

    // ─── get_config endpoint ──────────────────────────────────────────────────

    #[tokio::test]
    async fn get_config_default_returns_ok() {
        let app = Router::new()
            .route("/api/config", get(get_config))
            .with_state(test_state());
        let req = Request::builder()
            .uri("/api/config")
            .body(Body::empty())
            .unwrap();
        let resp = app.oneshot(req).await.unwrap();
        assert_eq!(resp.status(), axum::http::StatusCode::OK);
        let body = axum::body::to_bytes(resp.into_body(), usize::MAX)
            .await
            .unwrap();
        let config: RedactedConfig = serde_json::from_slice(&body).unwrap();
        assert_eq!(config.default_provider, "anthropic");
        assert!(!config.has_anthropic_key);
        assert!(!config.has_openai_key);
        assert!(!config.has_openrouter_key);
        assert!(config.ollama_base_url.is_none());
    }

    /// The console used to feature-detect by calling a route and reading a 404
    /// as "unsupported" - which is also what a missing run looks like, and
    /// costs one round trip per feature.
    #[tokio::test]
    async fn get_config_advertises_the_api_version_capabilities_and_limits() {
        let app = Router::new()
            .route("/api/config", get(get_config))
            .with_state(test_state());
        let req = Request::builder()
            .uri("/api/config")
            .body(Body::empty())
            .unwrap();
        let resp = app.oneshot(req).await.unwrap();
        let body = axum::body::to_bytes(resp.into_body(), usize::MAX)
            .await
            .unwrap();
        let config: RedactedConfig = serde_json::from_slice(&body).unwrap();

        assert_eq!(config.api_version, API_VERSION);
        for expected in [
            "runs.envelope",
            "runs.search",
            "runs.files.listing",
            "blueprints.envelope",
            "context.history.page",
        ] {
            assert!(
                config.capabilities.iter().any(|c| c == expected),
                "missing capability {expected}"
            );
        }

        // The numbers are what make this useful rather than decorative: a
        // client that knows a feature exists still has to know its caps, and
        // every one it guesses would be hardcoded and eventually wrong.
        assert_eq!(
            config.limits.max_limit,
            crate::commands::serve::runs::MAX_LIMIT
        );
        assert_eq!(
            config.limits.max_file_bytes,
            crate::commands::serve::agents::MAX_FILE_READ_BYTES
        );
        assert_eq!(
            config.limits.max_tracked_modified_files,
            leviath_core::run_meta::MAX_TRACKED_MODIFIED_FILES
        );
    }

    #[tokio::test]
    async fn get_config_with_keys_shows_has_key_true() {
        let app = Router::new()
            .route("/api/config", get(get_config))
            .with_state(test_state_with_keys());
        let req = Request::builder()
            .uri("/api/config")
            .body(Body::empty())
            .unwrap();
        let resp = app.oneshot(req).await.unwrap();
        assert_eq!(resp.status(), axum::http::StatusCode::OK);
        let body = axum::body::to_bytes(resp.into_body(), usize::MAX)
            .await
            .unwrap();
        let config: RedactedConfig = serde_json::from_slice(&body).unwrap();
        assert!(config.has_anthropic_key);
        assert!(config.has_openai_key);
        assert!(config.has_openrouter_key);
        assert_eq!(
            config.ollama_base_url.as_deref(),
            Some("http://localhost:11434")
        );
        // Must not contain actual key values
        let raw = std::str::from_utf8(&body).unwrap();
        assert!(!raw.contains("sk-ant-test"));
        assert!(!raw.contains("sk-openai-test"));
    }

    #[tokio::test]
    async fn get_config_agent_paths_included() {
        let (tx, _) = broadcast::channel::<ServerEvent>(64);
        let state = AppState {
            config: Arc::new(Config {
                agent_paths: vec![
                    std::path::PathBuf::from("/my/agents"),
                    std::path::PathBuf::from("/other/agents"),
                ],
                ..Default::default()
            }),
            event_tx: tx,
            control: crate::commands::serve::testutil::no_daemon_client(),
            mcp: crate::commands::serve::mcp::McpAdmin::default(),
            limits: Default::default(),
        };
        let app = Router::new()
            .route("/api/config", get(get_config))
            .with_state(state);
        let req = Request::builder()
            .uri("/api/config")
            .body(Body::empty())
            .unwrap();
        let resp = app.oneshot(req).await.unwrap();
        let body = axum::body::to_bytes(resp.into_body(), usize::MAX)
            .await
            .unwrap();
        let config: RedactedConfig = serde_json::from_slice(&body).unwrap();
        assert_eq!(config.agent_paths.len(), 2);
    }

    // ─── get_models endpoint ──────────────────────────────────────────────────

    /// AppState whose registry has a provider that actually enumerates models,
    /// so the `/api/models` handler's list-building loop runs. `claude-code`
    /// needs no API key and `list_models` returns its three known models.
    fn test_state_listing_models() -> AppState {
        let (tx, _) = broadcast::channel::<ServerEvent>(64);
        AppState {
            config: Arc::new(Config {
                providers: crate::config::ProviderConfig {
                    claude_code_enabled: true,
                    ..Config::default().providers
                },
                ..Config::default()
            }),
            event_tx: tx,
            control: crate::commands::serve::testutil::no_daemon_client(),
            mcp: crate::commands::serve::mcp::McpAdmin::default(),
            limits: Default::default(),
        }
    }

    #[tokio::test]
    async fn get_models_returns_ok() {
        // A reachable ollama would make `list_models` succeed and leave the
        // other arm of `if let Ok(list)` unrun - see `state_without_a_reachable_ollama`.
        let app = Router::new()
            .route("/api/models", get(get_models))
            .with_state(state_without_a_reachable_ollama());
        let req = Request::builder()
            .uri("/api/models")
            .body(Body::empty())
            .unwrap();
        let resp = app.oneshot(req).await.unwrap();
        assert_eq!(resp.status(), axum::http::StatusCode::OK);
        let body = axum::body::to_bytes(resp.into_body(), usize::MAX)
            .await
            .unwrap();
        let models: Vec<serde_json::Value> = serde_json::from_slice(&body).unwrap();
        // With default config (no API keys, claude-code off), providers may
        // return empty lists, but the endpoint itself should succeed.
        let _ = models;
    }

    #[tokio::test]
    async fn get_models_enumerates_when_a_provider_lists_models() {
        let app = Router::new()
            .route("/api/models", get(get_models))
            .with_state(test_state_listing_models());
        let req = Request::builder()
            .uri("/api/models")
            .body(Body::empty())
            .unwrap();
        let resp = app.oneshot(req).await.unwrap();
        assert_eq!(resp.status(), axum::http::StatusCode::OK);
        let body = axum::body::to_bytes(resp.into_body(), usize::MAX)
            .await
            .unwrap();
        let models: Vec<serde_json::Value> = serde_json::from_slice(&body).unwrap();
        // claude-code enumerates its three known models, so the handler's
        // per-model mapping loop actually runs and produces entries.
        assert!(!models.is_empty());
        assert!(models.iter().any(|m| m["provider"] == "claude-code"));
        assert!(models.iter().all(|m| m["id"].is_string()));
    }

    #[test]
    fn redacted_config_hides_keys() {
        let config = RedactedConfig {
            default_provider: "anthropic".to_string(),
            has_anthropic_key: true,
            has_openai_key: false,
            has_google_key: false,
            has_openrouter_key: false,
            ollama_base_url: None,
            gateways: Vec::new(),
            agent_paths: vec![],
            mcp_server_count: 2,
            api_version: API_VERSION.to_string(),
            capabilities: API_CAPABILITIES.iter().map(|c| c.to_string()).collect(),
            limits: ApiLimits::current(),
        };
        let json = serde_json::to_string(&config).unwrap();
        // Must NOT contain actual key values
        assert!(!json.contains("sk-"));
        assert!(json.contains("\"has_anthropic_key\":true"));
        assert!(json.contains("\"has_openai_key\":false"));
        assert!(json.contains("\"mcp_server_count\":2"));
    }

    #[test]
    fn redacted_config_with_ollama_url() {
        let config = RedactedConfig {
            default_provider: "ollama".to_string(),
            has_anthropic_key: false,
            has_openai_key: false,
            has_google_key: false,
            has_openrouter_key: false,
            ollama_base_url: Some("http://localhost:11434".to_string()),
            gateways: Vec::new(),
            agent_paths: vec![],
            mcp_server_count: 0,
            api_version: API_VERSION.to_string(),
            capabilities: API_CAPABILITIES.iter().map(|c| c.to_string()).collect(),
            limits: ApiLimits::current(),
        };
        let json = serde_json::to_string(&config).unwrap();
        assert!(json.contains("\"ollama_base_url\":\"http://localhost:11434\""));
    }

    // ─── put_config endpoint ──────────────────────────────────────────────────

    fn state_with_config_path(path: std::path::PathBuf) -> AppState {
        let (tx, _) = broadcast::channel::<ServerEvent>(64);
        AppState {
            config: Arc::new(Config::default()),
            event_tx: tx,
            control: crate::commands::serve::testutil::no_daemon_client(),
            mcp: crate::commands::serve::mcp::McpAdmin {
                config_path: path,
                ..Default::default()
            },
            limits: Default::default(),
        }
    }

    async fn put_config_request(state: AppState, body: &str) -> axum::http::Response<Body> {
        let app = Router::new()
            .route("/api/config", axum::routing::put(put_config))
            .with_state(state);
        let req = Request::builder()
            .method("PUT")
            .uri("/api/config")
            .header("content-type", "application/json")
            .body(Body::from(body.to_string()))
            .unwrap();
        app.oneshot(req).await.unwrap()
    }

    #[tokio::test]
    async fn put_config_writes_all_present_fields_and_redacts() {
        let dir = tempfile::tempdir().unwrap();
        let path = dir.path().join("config.toml");
        Config::default().save_to_path_public(&path).unwrap();

        let body = serde_json::json!({
            "default_provider": "openai",
            "default_model": "gpt-5",
            "anthropic_key": "sk-ant-x",
            "openai_key": "sk-openai-x",
            "google_key": "g-x",
            "openrouter_key": "or-x",
            "ollama_base_url": "http://ollama:11434"
        })
        .to_string();
        let resp = put_config_request(state_with_config_path(path.clone()), &body).await;
        assert_eq!(resp.status(), axum::http::StatusCode::OK);

        let bytes = axum::body::to_bytes(resp.into_body(), usize::MAX)
            .await
            .unwrap();
        let raw = std::str::from_utf8(&bytes).unwrap();
        assert!(!raw.contains("sk-ant-x"), "must not leak key values");
        let rc: RedactedConfig = serde_json::from_slice(&bytes).unwrap();
        assert!(
            rc.has_anthropic_key && rc.has_openai_key && rc.has_google_key && rc.has_openrouter_key
        );
        assert_eq!(rc.default_provider, "openai");

        let saved = Config::load_from_path_public(&path).unwrap();
        assert_eq!(
            saved.providers.anthropic_api_key.as_deref(),
            Some("sk-ant-x")
        );
        assert_eq!(
            saved.providers.openai_api_key.as_deref(),
            Some("sk-openai-x")
        );
        assert_eq!(saved.providers.google_api_key.as_deref(), Some("g-x"));
        assert_eq!(saved.openrouter_api_key.as_deref(), Some("or-x"));
        assert_eq!(saved.default_model.as_deref(), Some("gpt-5"));
        assert_eq!(
            saved.ollama_base_url.as_deref(),
            Some("http://ollama:11434")
        );
    }

    #[tokio::test]
    async fn put_config_empty_body_leaves_existing_config_untouched() {
        let dir = tempfile::tempdir().unwrap();
        let path = dir.path().join("config.toml");
        let base = Config {
            providers: crate::config::ProviderConfig {
                anthropic_api_key: Some("sk-ant-keep".to_string()),
                openai_api_key: None,
                google_api_key: None,
                claude_code_enabled: false,
                claude_code_binary: None,
                claude_code_effort: None,
                anthropic_cache_ttl: None,
                fallback_order: Vec::new(),
            },
            ..Default::default()
        };
        base.save_to_path_public(&path).unwrap();

        let resp = put_config_request(state_with_config_path(path.clone()), "{}").await;
        assert_eq!(resp.status(), axum::http::StatusCode::OK);
        let saved = Config::load_from_path_public(&path).unwrap();
        assert_eq!(
            saved.providers.anthropic_api_key.as_deref(),
            Some("sk-ant-keep")
        );
    }

    /// A gateway can be created, then edited field by field, then removed,
    /// without the caller ever holding its key.
    ///
    /// This is the whole point of the partial update reaching gateways: a
    /// browser form that had to send the key back to change a URL would have
    /// to have been given the key, which `GET /api/config` deliberately never
    /// does.
    #[tokio::test]
    async fn put_config_edits_a_gateway_without_being_told_its_key() {
        let dir = tempfile::tempdir().unwrap();
        let path = dir.path().join("config.toml");
        Config::default().save_to_path_public(&path).unwrap();
        let state = || state_with_config_path(path.clone());

        // Create.
        let resp = put_config_request(
            state(),
            r#"{"gateways":[{"name":"groq","base_url":"https://api.groq.com","api_key":"sk-secret","script":"groq.rhai"}]}"#,
        )
        .await;
        assert_eq!(resp.status(), axum::http::StatusCode::OK);
        let saved = Config::load_from_path_public(&path).unwrap();
        assert_eq!(
            saved.model_providers["groq"].script.as_deref(),
            Some("groq.rhai"),
            "the script backing the gateway is written too"
        );

        // Edit only the URL. The key is not sent, and must survive.
        let resp = put_config_request(
            state(),
            r#"{"gateways":[{"name":"groq","base_url":"https://eu.groq.com"}]}"#,
        )
        .await;
        assert_eq!(resp.status(), axum::http::StatusCode::OK);
        let saved = Config::load_from_path_public(&path).unwrap();
        let gateway = &saved.model_providers["groq"];
        assert_eq!(gateway.base_url.as_deref(), Some("https://eu.groq.com"));
        assert_eq!(
            gateway.api_key.as_deref(),
            Some("sk-secret"),
            "an unsent key is left alone, not cleared"
        );

        // A second gateway leaves the first alone.
        let resp = put_config_request(state(), r#"{"gateways":[{"name":"other"}]}"#).await;
        assert_eq!(resp.status(), axum::http::StatusCode::OK);
        let saved = Config::load_from_path_public(&path).unwrap();
        assert_eq!(saved.model_providers.len(), 2);

        // Remove takes a list of its own, because omitting a gateway above
        // means "leave it alone" and so can never mean "delete it".
        let resp = put_config_request(state(), r#"{"remove_gateways":["other"]}"#).await;
        assert_eq!(resp.status(), axum::http::StatusCode::OK);
        let saved = Config::load_from_path_public(&path).unwrap();
        assert!(saved.model_providers.contains_key("groq"));
        assert!(!saved.model_providers.contains_key("other"));
    }

    /// The response a write returns reports the gateway the same redacted way
    /// a read does, so a form can render straight from it.
    #[tokio::test]
    async fn put_config_returns_the_gateway_redacted() {
        let dir = tempfile::tempdir().unwrap();
        let path = dir.path().join("config.toml");
        Config::default().save_to_path_public(&path).unwrap();

        let resp = put_config_request(
            state_with_config_path(path),
            r#"{"gateways":[{"name":"groq","api_key":"sk-secret"}]}"#,
        )
        .await;
        let body = axum::body::to_bytes(resp.into_body(), usize::MAX)
            .await
            .unwrap();
        let json: serde_json::Value = serde_json::from_slice(&body).unwrap();
        assert_eq!(json["gateways"][0]["name"], serde_json::json!("groq"));
        assert_eq!(json["gateways"][0]["has_api_key"], serde_json::json!(true));
        assert!(
            !String::from_utf8_lossy(&body).contains("sk-secret"),
            "the write's own response must not hand the key back"
        );
    }

    #[tokio::test]
    async fn put_config_read_failure_is_500() {
        // config_path points at a directory, so reading it as a file fails.
        let dir = tempfile::tempdir().unwrap();
        let resp = put_config_request(state_with_config_path(dir.path().to_path_buf()), "{}").await;
        assert_eq!(resp.status(), axum::http::StatusCode::INTERNAL_SERVER_ERROR);
    }

    #[tokio::test]
    async fn put_config_write_failure_is_500() {
        // The config file's parent is itself a file, so saving fails while
        // reading (a non-existent file) succeeds as defaults.
        let dir = tempfile::tempdir().unwrap();
        let blocker = dir.path().join("blocker");
        std::fs::write(&blocker, b"x").unwrap();
        let path = blocker.join("config.toml");
        let resp = put_config_request(state_with_config_path(path), "{}").await;
        assert_eq!(resp.status(), axum::http::StatusCode::INTERNAL_SERVER_ERROR);
    }

    // ─── config key validation ────────────────────────────────────────────────

    #[test]
    fn validate_key_format_covers_every_provider() {
        assert_eq!(validate_key_format("anthropic", "sk-ant-1"), (true, None));
        assert!(!validate_key_format("anthropic", "nope").0);
        assert_eq!(validate_key_format("openai", "sk-1"), (true, None));
        assert!(!validate_key_format("openai", "nope").0);
        assert_eq!(validate_key_format("google", "g"), (true, None));
        assert!(!validate_key_format("google", "  ").0);
        assert_eq!(validate_key_format("openrouter", "or"), (true, None));
        // A name this build does not know is a custom gateway, not a mistake.
        // Its key has no house format, so the only judgement available is
        // whether one was given at all.
        assert_eq!(validate_key_format("my-gateway", "anything"), (true, None));
        assert!(!validate_key_format("my-gateway", "   ").0);
    }

    // ─── custom gateways ──────────────────────────────────────────────────────

    /// The key never leaves the process, and neither does anything in `extra`.
    ///
    /// `extra` is forwarded into a provider script, so people keep credentials
    /// there. Reporting its names is what a form needs; reporting its values
    /// would be the same disclosure the `has_*_key` booleans exist to prevent.
    #[test]
    fn a_gateways_secrets_are_reported_as_presence_not_value() {
        let mut config = Config::default();
        config.model_providers.insert(
            "groq".to_string(),
            crate::config::ModelProviderConfig {
                script: Some("groq.rhai".to_string()),
                api_key: Some("sk-secret-value".to_string()),
                base_url: Some("https://api.groq.com".to_string()),
                rate_limit: None,
                extra: [(
                    "signing_secret".to_string(),
                    toml::Value::String("hunter2".to_string()),
                )]
                .into_iter()
                .collect(),
            },
        );

        let redacted = redact(&config);
        let gateway = &redacted.gateways[0];
        assert_eq!(gateway.name, "groq");
        assert_eq!(gateway.base_url.as_deref(), Some("https://api.groq.com"));
        assert!(gateway.has_api_key);
        assert_eq!(gateway.extra_keys, vec!["signing_secret".to_string()]);

        // The whole serialized document, because a leak anywhere in it is a
        // leak: a field added later would otherwise carry the value silently.
        let json = serde_json::to_string(&redacted).expect("serializes");
        assert!(!json.contains("sk-secret-value"), "{json}");
        assert!(!json.contains("hunter2"), "{json}");
    }

    /// Name-sorted, because the config holds gateways in a `HashMap` and a
    /// list that reorders itself between two reads cannot be edited in a form.
    #[test]
    fn gateways_are_reported_in_a_stable_order() {
        let mut config = Config::default();
        for name in ["zulu", "alpha", "mike"] {
            config
                .model_providers
                .insert(name.to_string(), Default::default());
        }
        let names: Vec<String> = gateways_of(&config).into_iter().map(|g| g.name).collect();
        assert_eq!(names, vec!["alpha", "mike", "zulu"]);
    }

    #[test]
    fn a_config_with_no_gateways_reports_none() {
        assert_eq!(gateways_of(&Config::default()), Vec::new());
    }

    /// A base URL is checked for shape only, and the scheme is the part people
    /// actually leave off.
    #[test]
    fn a_base_url_is_checked_for_its_scheme() {
        assert_eq!(validate_base_url("https://api.example.com"), (true, None));
        assert_eq!(validate_base_url("http://localhost:11434"), (true, None));
        assert!(!validate_base_url("api.example.com").0);
        assert!(!validate_base_url("  ").0);
    }

    #[tokio::test]
    async fn validate_config_key_endpoint_returns_result() {
        let app = Router::new().route(
            "/api/config/validate",
            axum::routing::post(validate_config_key),
        );
        let req = Request::builder()
            .method("POST")
            .uri("/api/config/validate")
            .header("content-type", "application/json")
            .body(Body::from(
                serde_json::json!({"provider":"anthropic","key":"bad"}).to_string(),
            ))
            .unwrap();
        let resp = app.oneshot(req).await.unwrap();
        assert_eq!(resp.status(), axum::http::StatusCode::OK);
        let bytes = axum::body::to_bytes(resp.into_body(), usize::MAX)
            .await
            .unwrap();
        let v: ValidateKeyResp = serde_json::from_slice(&bytes).unwrap();
        assert!(!v.valid);
        assert!(v.message.is_some());
    }

    /// A gateway is checked on its URL as well as its key, and the URL is what
    /// answers when it is wrong.
    #[tokio::test]
    async fn validate_config_key_endpoint_checks_a_gateways_base_url() {
        let check = |body: serde_json::Value| async move {
            let app = Router::new().route(
                "/api/config/validate",
                axum::routing::post(validate_config_key),
            );
            let req = Request::builder()
                .method("POST")
                .uri("/api/config/validate")
                .header("content-type", "application/json")
                .body(Body::from(body.to_string()))
                .unwrap();
            let resp = app.oneshot(req).await.unwrap();
            let bytes = axum::body::to_bytes(resp.into_body(), usize::MAX)
                .await
                .unwrap();
            serde_json::from_slice::<ValidateKeyResp>(&bytes).unwrap()
        };

        // A URL with no scheme is rejected, and the message names the URL
        // rather than the key, which is the part that is fine.
        let bad = check(serde_json::json!({
            "provider": "my-gateway",
            "key": "anything",
            "base_url": "api.example.com",
        }))
        .await;
        assert!(!bad.valid);
        assert!(
            bad.message.unwrap_or_default().contains("Base URL"),
            "the address is what is wrong"
        );

        // A good URL falls through to the key check, which for a custom
        // gateway only asks that a key was given at all.
        let good = check(serde_json::json!({
            "provider": "my-gateway",
            "key": "anything",
            "base_url": "https://api.example.com",
        }))
        .await;
        assert!(good.valid, "{:?}", good.message);

        // And an empty key still fails once the URL is fine.
        let empty = check(serde_json::json!({
            "provider": "my-gateway",
            "key": "  ",
            "base_url": "https://api.example.com",
        }))
        .await;
        assert!(!empty.valid);
    }

    #[tokio::test]
    async fn the_models_endpoint_is_empty_when_no_https_client_can_be_built() {
        let state = test_state();
        let Json(models) = super::models_with(&state, &|_t| {
            Err(leviath_providers::provider::malformed_url_error())
        })
        .await;
        assert!(models.is_empty());
    }
}