/**
 * Observability interceptors for Weft workflows and activities.
 *
 * Creates an {@link Interceptor} implementation that propagates W3C trace
 * context, emits OpenTelemetry spans, and records metrics. When
 * `@opentelemetry/api` is not installed, all span operations are no-ops with
 * zero overhead.
 *
 * @module observability
 */
import type { Interceptor } from '../core/interceptor';
import { MetricsCollector as MetricsCollectorClass } from './metrics';
import type { ObservabilityOptions } from './types';
export { createMetricsCollectorExporter, createOpenTelemetryMetrics, METRICS, MetricsCollector, serializeMetricsSnapshotForPrometheus, } from './metrics';
export type { CounterMetric, GaugeMetric, HistogramMetric, MetricDefinition, MetricsSnapshot, MetricType, OpenTelemetryMetrics, PrometheusExporter, } from './metrics';
export { getOpenTelemetryApi } from './no-op-telemetry';
export type { OpenTelemetryApi, OpenTelemetryMeter, OpenTelemetrySpan, OpenTelemetryTracer, } from './no-op-telemetry';
export { extractTraceParent, formatTraceParent, generateSpanId, generateTraceId, injectTraceParent, parseTraceParent, } from './propagation';
export type { TraceContext } from './propagation';
export type { InterceptionContext, ObservabilityOptions } from './types';
/**
 * Create a unified interceptor for workflow and activity observability.
 *
 * Uses `@opentelemetry/api` directly for span creation. When the package is
 * not installed, falls back to no-op implementations with zero overhead.
 *
 * @example
 * ```ts
 * import { Engine, MemoryStorage, createObservabilityInterceptors } from '@lostgradient/weft';
 *
 * const { interceptor, metrics } = createObservabilityInterceptors({
 *   tracerName: 'my-app',
 *   recordPayloads: false,
 * });
 * await using engine = new Engine({
 *   storage: new MemoryStorage(),
 * });
 * engine.addInterceptor(interceptor);
 * void metrics;
 * ```
 */
export declare function createObservabilityInterceptors(options?: ObservabilityOptions): {
    interceptor: Interceptor;
    metrics: MetricsCollectorClass;
    /**
     * End the workflow root span. Usually wired automatically via `eventTarget`,
     * but exposed for callers that need to end spans manually.
     */
    endWorkflowSpan: (workflowId: string, status: 'ok' | 'error', errorMessage?: string) => void;
    /**
     * Evict workflow spans that have been open longer than `maxAgeMs` (default: 1 hour).
     * Call periodically to prevent unbounded growth from orphaned or long-running workflows.
     */
    evictStaleSpans: (maxAgeMs?: number) => number;
    /**
     * Unsubscribe any workflow lifecycle listeners registered on the `eventTarget`
     * and end any still-open workflow spans.
     */
    dispose: () => void;
};