/**
 * SSE Stream Interceptor
 *
 * A zero-overhead TransformStream that taps Anthropic SSE streaming responses
 * to extract telemetry data (token usage, model info, content blocks, thinking
 * blocks, tool use) while passing every byte through to the client unmodified
 * and without delay.
 *
 * The interceptor buffers partial SSE events internally (chunks may split
 * across event boundaries) but never holds back any bytes from the readable
 * side of the stream.
 *
 * Usage:
 *   const { stream, telemetry } = createSSEInterceptor();
 *   upstreamResponse.body.pipeThrough(stream).pipeTo(clientWritable);
 *   const data = await telemetry; // resolves on stream end
 */
import type { SSEInterceptorOptions, SSEInterceptorResult } from "../types/index.js";
/**
 * Create an SSE interceptor that extracts telemetry from an Anthropic
 * streaming response while passing all bytes through unmodified.
 *
 * ```ts
 * const { stream, telemetry } = createSSEInterceptor();
 * upstreamResponse.body
 *   .pipeThrough(stream)
 *   .pipeTo(clientWritable);
 *
 * const data = await telemetry;
 * console.log(data.usage.totalTokens);
 * ```
 */
export declare function createSSEInterceptor(options?: SSEInterceptorOptions): SSEInterceptorResult;