/**
 * ConversationCustomMetadata — protobuf schema matching convos-ios
 * Stored in XMTP group's appData field (max 8KB).
 *
 * Encoding: protobuf → optional DEFLATE compress → base64url
 */
export interface EncryptedImageRef {
    url: string;
    salt: Uint8Array;
    nonce: Uint8Array;
}
export interface ConversationProfile {
    inboxId: string;
    name?: string;
    image?: string;
    encryptedImage?: EncryptedImageRef;
}
export interface AgentDmInfo {
    originConversationId?: string;
}
export interface ConversationCustomMetadata {
    tag: string;
    profiles: ConversationProfile[];
    expiresAtUnix?: number;
    imageEncryptionKey?: Uint8Array;
    encryptedGroupImage?: EncryptedImageRef;
    emoji?: string;
    agentDm?: AgentDmInfo;
    participationMode?: number;
    spaceUrl?: string;
}
/**
 * Parse appData string into ConversationCustomMetadata.
 * Returns empty metadata if appData is empty or invalid.
 */
export declare function parseAppData(appData: string): ConversationCustomMetadata;
/**
 * Parse appData for read-modify-write operations that must preserve the invite
 * tag. Empty appData is allowed, but invalid/non-empty appData throws so callers
 * don't accidentally write back metadata with an empty tag.
 */
export declare function parseAppDataForWrite(appData: string): ConversationCustomMetadata;
/**
 * Serialize ConversationCustomMetadata to an appData string.
 * Throws if result exceeds 8KB.
 */
export declare function serializeAppData(metadata: ConversationCustomMetadata): string;
/**
 * Upsert a profile in the metadata. If a profile with the same inboxId exists,
 * it is updated. Otherwise, a new profile is added.
 */
export declare function upsertProfile(metadata: ConversationCustomMetadata, profile: ConversationProfile): ConversationCustomMetadata;
/**
 * Remove a profile from the metadata by inbox ID.
 */
export declare function removeProfile(metadata: ConversationCustomMetadata, inboxId: string): ConversationCustomMetadata;
/**
 * Get a profile by inbox ID.
 */
export declare function getProfile(metadata: ConversationCustomMetadata, inboxId: string): ConversationProfile | undefined;