import type { Message } from "../types";
/**
 * Infer whether the current request to Copilot is user-initiated or agent-initiated.
 * Accepts `unknown[]` because providers may pass pre-converted message shapes.
 */
export type CopilotInitiator = "user" | "agent";
export type CopilotPremiumRequests = number;
export type CopilotDynamicHeaders = {
    headers: Record<string, string>;
    initiator: CopilotInitiator;
    premiumRequests: CopilotPremiumRequests;
};
export declare function resolveGitHubCopilotBaseUrl(baseUrl: string | undefined, apiKey: string | undefined): string | undefined;
export declare function inferCopilotInitiator(messages: unknown[]): CopilotInitiator;
/** Check whether any message in the conversation contains image content. */
export declare function hasCopilotVisionInput(messages: Message[]): boolean;
/**
 * Resolve an explicitly configured Copilot initiator header, if present.
 * Handles case-insensitive X-Initiator keys and returns the last valid value.
 */
export declare function getCopilotInitiatorOverride(headers: Record<string, string> | undefined): CopilotInitiator | undefined;
export type CopilotPlanTier = "free" | "paid";
export declare function getCopilotPremiumMultiplier(premiumMultiplier: number | undefined, planTier?: string): number;
export declare function getCopilotPremiumRequests(params: {
    initiator: CopilotInitiator;
    premiumMultiplier?: number;
    planTier?: string;
}): CopilotPremiumRequests;
/**
 * Build dynamic Copilot headers that vary per-request.
 * Static headers (User-Agent, Editor-Version, etc.) come from model.headers.
 */
export declare function buildCopilotDynamicHeaders(params: {
    messages: unknown[];
    hasImages: boolean;
    premiumMultiplier?: number;
    headers?: Record<string, string>;
    initiatorOverride?: CopilotInitiator;
    planTier?: string;
}): CopilotDynamicHeaders;