/**
 * Gateway provider from env — the launch knob a HOST embeds pi-gui with.
 *
 * pi bakes each provider's base URL into its definition; there is no env var that moves it.
 * A host that routes model traffic through its own Anthropic-Messages-compatible endpoint
 * (a local proxy, a relay, any LiteLLM-style gateway) therefore needs exactly one seam: set
 * `PI_GUI_GATEWAY_URL` and pi-gui registers an IN-MEMORY provider pointed there — nothing is
 * written to `~/.pi`, and none of this engages when the variable is absent, so standalone
 * use is byte-for-byte unaffected.
 *
 *   PI_GUI_GATEWAY_URL       endpoint origin (anthropic-messages wire)
 *   PI_GUI_GATEWAY_KEY       credential, read at request time (sent as x-api-key)
 *   PI_GUI_GATEWAY_MODELS    comma-separated model ids, VERBATIM on the wire
 *                            (e.g. "google/gemini-3.5-flash,claude-sonnet-5")
 *   PI_GUI_GATEWAY_PROVIDER  pi-local provider id, default "gateway" — only an addressing
 *                            prefix ("<provider>/<model-id>"), never sent upstream
 *   PI_GUI_MODEL             default model override, e.g. "gateway/google/gemini-3.5-flash"
 *
 * Both hosting shapes consume the same config: the pi runtime (TUI/print/rpc) via
 * `pi.registerProvider(...)` with {@link gatewayProviderConfig}, and the bare pi-agent-core
 * `run` path via {@link gatewayProvider}. Kept import-light on purpose — pi-ai is loaded
 * lazily so `pi-gui mcp` and plain env parsing never pay for it.
 */
import type { Api, Provider } from "@earendil-works/pi-ai";
export declare const GATEWAY_URL_ENV = "PI_GUI_GATEWAY_URL";
export declare const GATEWAY_KEY_ENV = "PI_GUI_GATEWAY_KEY";
export declare const GATEWAY_MODELS_ENV = "PI_GUI_GATEWAY_MODELS";
export declare const GATEWAY_PROVIDER_ENV = "PI_GUI_GATEWAY_PROVIDER";
export interface GatewayConfig {
    /** pi-local provider id (addressing prefix only). */
    providerId: string;
    /** Endpoint origin the anthropic-messages wire is sent to. */
    baseUrl: string;
    /** Model ids offered, verbatim wire ids. */
    models: string[];
}
/** Parse the knob. Null when the knob is off (no URL) or unusable (no models — warned once). */
export declare function gatewayFromEnv(env?: NodeJS.ProcessEnv): GatewayConfig | null;
/** The default model spec for a gateway launch: PI_GUI_MODEL wins, else the first roster entry. */
export declare function gatewayDefaultModel(cfg: GatewayConfig, env?: NodeJS.ProcessEnv): string;
/**
 * Plain config for the pi runtime's `pi.registerProvider(id, config)` (TUI/print/rpc path).
 * The `$ENV` apiKey form defers the credential read to request time, so a key rotated by the
 * host between requests is picked up without a relaunch.
 */
export declare function gatewayProviderConfig(cfg: GatewayConfig): {
    name: string;
    baseUrl: string;
    apiKey: string;
    api: Api;
    models: Array<{
        id: string;
        name: string;
        reasoning: boolean;
        input: ("text" | "image")[];
        cost: {
            input: number;
            output: number;
            cacheRead: number;
            cacheWrite: number;
        };
        contextWindow: number;
        maxTokens: number;
    }>;
};
/**
 * A live pi-ai Provider for the bare pi-agent-core `run` path (which never reads pi's
 * models.json or extension registrations). Reuses the builtin anthropic provider's stream
 * implementation — same wire, different endpoint + credential source.
 */
export declare function gatewayProvider(cfg: GatewayConfig): Promise<Provider>;