/**
 * Used to interact with call functionality, including starting calls with other users.
 * @module
 */
/** Modalities that can be associated with a call. */
export declare enum CallModalities {
    /** Indicates that the modality is unknown or undefined. */
    Unknown = "unknown",
    /** Indicates that the call includes audio. */
    Audio = "audio",
    /** Indicates that the call includes video. */
    Video = "video",
    /** Indicates that the call includes video-based screen sharing. */
    VideoBasedScreenSharing = "videoBasedScreenSharing",
    /** Indicates that the call includes data sharing or messaging. */
    Data = "data"
}
/** Represents parameters for {@link startCall | StartCall}. */
export interface StartCallParams {
    /**
     * Comma-separated list of user IDs representing the participants of the call.
     *
     * @remarks
     * Currently the User ID field supports the Microsoft Entra UserPrincipalName,
     * typically an email address, or in case of a PSTN call, it supports a pstn
     * mri 4:\<phonenumber>.
     */
    targets: string[];
    /**
     * List of modalities for the call. Defaults to [“audio”].
     */
    requestedModalities?: CallModalities[];
    /**
     * An optional parameter that informs about the source of the deep link
     */
    source?: string;
}
/**
 * Starts a call with other users
 *
 * @param startCallParams - Parameters for the call
 *
 * @throws Error if call capability is not supported
 * @throws Error if host notifies of a failed start call attempt in a legacy Teams environment
 * @returns always true if the host notifies of a successful call inititation
 */
export declare function startCall(startCallParams: StartCallParams): Promise<boolean>;
/**
 * Checks if the call capability is supported by the host
 * @returns boolean to represent whether the call capability is supported
 *
 * @throws Error if {@linkcode app.initialize} has not successfully completed
 */
export declare function isSupported(): boolean;