/**
 * GitHub release lookup and checksum helpers for binary install/update.
 * End-user updates resolve versions from GitHub, not the npm registry.
 */
import type { UpdateChannel } from "../config/update-channel";
export declare const RELEASE_REPO = "Yeachan-Heo/gajae-code";
export declare const GITHUB_API_ORIGIN = "https://api.github.com";
export declare const GITHUB_RELEASE_DOWNLOAD_ORIGIN = "https://github.com/Yeachan-Heo/gajae-code/releases/download";
export declare const BINARY_SHA256_ASSET = "gajae-release-binaries.sha256";
export declare const BINARY_MANIFEST_ASSET = "gajae-release-binaries-v1.json";
export interface GithubReleaseInfo {
    tag: string;
    version: string;
    channel: UpdateChannel;
    htmlUrl?: string;
    warnings: string[];
}
export type GithubFetch = (input: string | URL | Request, init?: RequestInit) => Promise<Response>;
export interface GithubReleaseLookupOptions {
    channel?: UpdateChannel;
    fetchImpl?: GithubFetch;
    lookupEnv?: (name: string) => string | undefined;
    apiOrigin?: string;
    timeoutMs?: number;
    useAmbientToken?: boolean;
}
export declare function isSafeReleaseTag(tag: string): boolean;
export declare function versionFromTag(tag: string): string;
export declare function githubReleaseHeaders(token: string | undefined): Record<string, string>;
export declare function fetchGithubChannelRelease(options?: GithubReleaseLookupOptions): Promise<GithubReleaseInfo>;
export declare function parseChecksumForAsset(text: string, assetName: string): string | undefined;
export declare function parseManifestChecksum(payload: unknown, assetName: string): string | undefined;
export declare function sha256Buffer(bytes: Uint8Array): string;
export declare function sha256File(filePath: string): Promise<string>;
export declare function fetchOptionalText(url: string, options?: {
    fetchImpl?: GithubFetch;
    lookupEnv?: (name: string) => string | undefined;
    timeoutMs?: number;
}): Promise<string | undefined>;
export declare function verifyDownloadedBinaryChecksum(options: {
    tag: string;
    assetName: string;
    filePath: string;
    fetchImpl?: GithubFetch;
    lookupEnv?: (name: string) => string | undefined;
    downloadOrigin?: string;
}): Promise<"verified">;