/**
 * Vertex authentication helpers for the realtime voice agent.
 *
 * The Gemini Live WebSocket authenticates to Vertex via Application Default
 * Credentials (ADC). These helpers materialise ADC from the split
 * `GOOGLE_AUTH_*` env fields when no credentials file is configured, and remove
 * any Gemini Developer API key from the environment so `@google/genai` uses
 * Vertex/ADC auth (not an API key) for the realtime WebSocket.
 *
 * See docs/features/livekit-voice-agent.md.
 */
/**
 * Materialise Vertex ADC from the split `GOOGLE_AUTH_*` env fields.
 *
 * The google realtime plugin authenticates Vertex via ADC (it does not accept
 * inline credentials), so this writes a temp service-account JSON and points
 * `GOOGLE_APPLICATION_CREDENTIALS` at it — unless ADC is already configured.
 * No-op when `GOOGLE_APPLICATION_CREDENTIALS` is set or the `GOOGLE_AUTH_*`
 * fields are absent (auth then relies on ambient ADC).
 */
export declare function ensureVertexAdc(): void;
/**
 * Force pure Vertex/ADC auth for the Gemini Live WebSocket.
 *
 * `@google/genai` 1.52+ uses a Gemini Developer API key for the realtime
 * WebSocket auth even when `vertexai: true` and project/location are set, which
 * Vertex rejects at the handshake (WS close 1006). The realtime worker only
 * ever talks to Vertex, so remove these keys (only affects this process).
 */
export declare function clearGeminiApiKeyEnv(): void;