/**
 * Conservative chars-per-token approximation used for compaction triggering
 * and request-size diagnostics. Uses 3 chars/token (slightly over-counts vs
 * the conventional 4) so trigger thresholds fire before provider rejection
 * rather than after.
 */
export declare const CHARS_PER_TOKEN = 3;
export declare function estimateTokens(chars: number): number;
export interface TokenEstimatedRequest {
    systemPrompt?: string;
    messages: readonly unknown[];
    tools?: readonly unknown[];
}
/**
 * Estimate the complete provider request payload so request execution and
 * pre-request policies use the same definition of input utilization.
 */
export declare function estimateRequestInputTokens(request: TokenEstimatedRequest): number;