/**
 * Constants used throughout the library
 */
/**
 * Metadata keys for storing decorator information
 */
export declare const METADATA_KEYS: {
    /** Key for storing ApiSse decorator metadata */
    readonly API_SSE: "api-sse";
    /** Key for storing SSE endpoint configuration */
    readonly SSE_CONFIG: "sse-config";
    /** Key for storing event type mappings */
    readonly SSE_EVENTS: "sse-events";
};
/**
 * Default SSE configuration values
 */
export declare const SSE_DEFAULTS: {
    /** Default retry interval in milliseconds */
    readonly RETRY_INTERVAL: 3000;
    /** Default connection timeout in milliseconds */
    readonly CONNECTION_TIMEOUT: 30000;
    /** Default keep-alive interval in milliseconds */
    readonly KEEP_ALIVE_INTERVAL: 15000;
    /** Default maximum number of retry attempts */
    readonly MAX_RETRIES: 5;
};
/**
 * HTTP headers commonly used with SSE
 */
export declare const SSE_HEADERS: {
    /** Content-Type for Server-Sent Events */
    readonly CONTENT_TYPE: "text/event-stream";
    /** Cache control header */
    readonly CACHE_CONTROL: "no-cache";
    /** Connection header */
    readonly CONNECTION: "keep-alive";
    /** Access control headers for CORS */
    readonly ACCESS_CONTROL_ALLOW_ORIGIN: "*";
    readonly ACCESS_CONTROL_ALLOW_HEADERS: "Cache-Control";
};
/**
 * OpenAPI specification constants
 */
export declare const OPENAPI_CONSTANTS: {
    /** Media type for SSE in OpenAPI specs */
    readonly SSE_MEDIA_TYPE: "text/event-stream";
    /** Schema reference prefix */
    readonly SCHEMA_REF_PREFIX: "#/components/schemas/";
    /** Extension key for SSE metadata */
    readonly SSE_EXTENSION: "x-sse-events";
};
/**
 * Event field names in SSE format
 */
export declare const SSE_EVENT_FIELDS: {
    /** Event type field */
    readonly EVENT: "event";
    /** Data field */
    readonly DATA: "data";
    /** ID field */
    readonly ID: "id";
    /** Retry field */
    readonly RETRY: "retry";
};