/**
 * MCP Telemetry
 *
 * Structured event emitter for MCP operations. Supports multiple
 * subscribers and provides convenience methods for common event types.
 *
 * @example
 * ```typescript
 * const telemetry = McpTelemetry.getInstance();
 *
 * // Register a JSON-lines handler
 * telemetry.on(McpTelemetry.createJsonLogHandler());
 *
 * // Emit events
 * telemetry.toolInvoke('stripe', 'create_customer', 'tenant-1', 'pro');
 * telemetry.toolComplete('stripe', 'create_customer', true, 42, {
 *   tenant: 'tenant-1',
 * });
 * ```
 */
export type McpEventType = 'tool.invoke' | 'tool.complete' | 'tool.error' | 'pipeline.start' | 'pipeline.complete' | 'server.start' | 'server.stop' | 'server.health' | 'auth.validate' | 'cache.hit' | 'cache.miss';
export interface McpEvent {
    type: McpEventType;
    timestamp: number;
    server?: string;
    tool?: string;
    tenant?: string;
    tier?: string;
    durationMs?: number;
    success?: boolean;
    cached?: boolean;
    error?: string;
    metadata?: Record<string, unknown>;
}
export type McpEventHandler = (event: McpEvent) => void;
/**
 * Simple event emitter for MCP telemetry.
 * Supports multiple subscribers and structured event types.
 * Default handler logs to structured JSON on stderr.
 */
export declare class McpTelemetry {
    private handlers;
    private static instance;
    static getInstance(): McpTelemetry;
    /** Register an event handler. Returns an unsubscribe function. */
    on(handler: McpEventHandler): () => void;
    /** Emit an event to all registered handlers. */
    emit(event: McpEvent): void;
    /** Convenience: emit a tool invocation event. */
    toolInvoke(server: string, tool: string, tenant?: string, tier?: string): void;
    /** Convenience: emit a tool completion event. */
    toolComplete(server: string, tool: string, success: boolean, durationMs: number, opts?: {
        tenant?: string;
        cached?: boolean;
        error?: string;
    }): void;
    /** Create a JSON-lines log handler (writes to stderr). */
    static createJsonLogHandler(): McpEventHandler;
    /**
     * Create an OpenTelemetry-compatible span handler stub.
     * Pass your own tracer instance to wire real OTel export.
     */
    static createOtelHandler(tracer?: OtelTracerLike): McpEventHandler;
    /** Reset singleton (for testing). */
    static reset(): void;
}
/** Minimal OTel tracer shape  -  avoids requiring @opentelemetry/api as a dependency. */
interface OtelTracerLike {
    startSpan(name: string): {
        end(): void;
        setAttribute(key: string, value: unknown): void;
    };
}
export {};
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