export declare function getProviderFirstEventTimeoutFallbackMs(provider: string): number | undefined;
/**
 * Returns the idle timeout used for provider streaming transports.
 *
 * `SKC_OPENAI_STREAM_IDLE_TIMEOUT_MS` is honored first; `PI_OPENAI_STREAM_IDLE_TIMEOUT_MS` is a backward-compatible alias.
 * Set `PI_STREAM_IDLE_TIMEOUT_MS=0` to disable the watchdog.
 *
 * Providers that legitimately stream much slower than the global default can pass
 * `fallbackMs` to widen the floor used when neither env var nor caller option is set.
 * Caller options still take precedence; env overrides still trump the fallback.
 */
export declare function getStreamIdleTimeoutMs(fallbackMs?: number): number | undefined;
/**
 * Returns the idle timeout used for OpenAI-family streaming transports.
 *
 * Honors `SKC_OPENAI_STREAM_IDLE_TIMEOUT_MS` first (`PI_OPENAI_STREAM_IDLE_TIMEOUT_MS` is the legacy alias). Set `=0` to disable.
 */
export declare function getOpenAIStreamIdleTimeoutMs(): number | undefined;
/**
 * Returns the timeout used while waiting for the first stream event.
 * The first token can legitimately take longer than later inter-event gaps,
 * so the default never undershoots the steady-state idle timeout.
 *
 * Set `PI_STREAM_FIRST_EVENT_TIMEOUT_MS=0` to disable the watchdog.
 *
 * Providers whose first response can legitimately take longer (heavy reasoning,
 * slow cold-start proxies) can pass `fallbackMs` to widen the floor used when
 * neither env var nor caller option is set. Caller options still take precedence;
 * env overrides still trump the fallback.
 */
export declare function getStreamFirstEventTimeoutMs(idleTimeoutMs?: number, fallbackMs?: number): number | undefined;
export type Watchdog = NodeJS.Timeout | undefined;
/**
 * Starts a watchdog that aborts a request if no first stream event arrives in time.
 * Call `markFirstEventReceived()` as soon as the first event is observed.
 */
export declare function createWatchdog(timeoutMs: number | undefined, onTimeout: () => void): Watchdog;
export interface IdleTimeoutIteratorOptions {
    watchdog?: Watchdog;
    idleTimeoutMs?: number;
    firstItemTimeoutMs?: number;
    errorMessage: string;
    firstItemErrorMessage?: string;
    onIdle?: () => void;
    onFirstItemTimeout?: () => void;
    /**
     * Optional semantic-progress predicate. Non-progress items are still yielded,
     * but they do not reset the idle deadline. This prevents provider
     * keepalive/no-op events from keeping a stalled tool call alive forever.
     */
    isProgressItem?: (item: unknown) => boolean;
    /**
     * Cancel iteration as soon as this signal aborts. Required for caller-driven
     * cancellation (ESC) when the underlying transport does not surface signal
     * aborts to the iterator (HTTP/2 proxies, native sockets, mocked fetch).
     * Without this, the consumer sleeps on iterator.next() until the idle/first
     * -event watchdog fires — observable as the issue #912 "Working… forever"
     * symptom on the github-copilot provider.
     */
    abortSignal?: AbortSignal;
}
/**
 * Yields items from an async iterable while enforcing a maximum idle gap between items.
 *
 * The first item may use a shorter timeout so stuck requests can be aborted and retried
 * before any user-visible content has streamed.
 */
export declare function iterateWithIdleTimeout<T>(iterable: AsyncIterable<T>, options: IdleTimeoutIteratorOptions): AsyncGenerator<T>;