/**
 * Tiered timeouts (1.38.1, design/17 §5B). The task-level `timeoutSec` only bounds the *whole* run;
 * it can't tell apart a gateway that never accepts the connection from one that accepts it, opens the
 * SSE stream, then hangs forever without emitting a token (the most common gateway-stall symptom).
 * Two finer levels close that gap, each retryable as a transient `network` failure:
 *
 * - **connect**: `fetch` hasn't returned response headers in time.
 * - **first-token**: the SSE stream is open but no content delta has arrived (see brain read loops).
 *
 * Both default to `undefined` (disabled) so existing behavior is unchanged.
 */
export interface BrainTimeoutConfig {
    /** Abort the request if `fetch` doesn't return response headers within this many ms. Retryable. */
    connectTimeoutMs?: number;
    /**
     * After the stream opens, cancel it if no content delta (text / thinking / tool input) arrives
     * within this many ms → `BrainError("network", "first-token timeout")`. For reasoning models the
     * **first thinking delta also counts** as the first token, so a long-thinking model isn't killed
     * for being slow to its first *visible* word (design/17 O5).
     */
    firstTokenTimeoutMs?: number;
    /**
     * **Idle / mid-stream stall watchdog** (1.40.1, design/24 — gap found in the Claude Code source study).
     * After the first delta, re-armed on every delta; if the stream then goes silent for this many ms
     * (a gateway that hung mid-output) → `reader.cancel()` + `BrainError("network", "stream idle timeout")`.
     * Complements `firstTokenTimeoutMs`: that one tolerates a long *first* token (reasoning), this one
     * catches a stall *after* output has started, where a healthy stream emits steadily. Default off.
     */
    idleTimeoutMs?: number;
}
/**
 * A per-fetch-attempt abort controller that fires on a connect timeout while still forwarding an
 * outer (task) abort. The returned `signal` governs the **whole** request including the streamed body
 * — so once headers arrive, call `clearTimer()` (NOT `dispose()`) to stop the connect timer while
 * keeping the outer-abort link alive for the body read; call `dispose()` only when the request is
 * fully done or being discarded.
 */
export declare function makeConnectController(connectTimeoutMs: number | undefined, outerSignal: AbortSignal | undefined): {
    signal: AbortSignal;
    timedOut: () => boolean;
    clearTimer: () => void;
    dispose: () => void;
};
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