/**
 * Curator P3-6: shared builder for the `NoOutputGeneratedError` sentinel
 * chunk. Each provider's stream-transformation generator catches the AI
 * SDK's `NoOutputGeneratedError` and yields this sentinel so downstream
 * telemetry has finish reason + token usage + provider error context
 * instead of just `{ noOutput: true, errorType: "..." }`.
 *
 * The AI SDK rejects `result.finishReason` / `result.totalUsage` in this
 * branch today (see `ai/src/generate-text/stream-text.ts` ~L1078); we
 * still attempt to await them so a future SDK version surfacing partial
 * values populates the sentinel automatically. When they reject we keep
 * conservative defaults (`finishReason: "error"`, zero usage).
 */
import type { StreamNoOutputSentinel, StreamNoOutputSentinelResultLike } from "../types/index.js";
export declare function buildNoOutputSentinel(error: unknown, result?: StreamNoOutputSentinelResultLike, 
/**
 * Reviewer follow-up: AI SDK v6 wraps the AI SDK's
 * `NoOutputGeneratedError` without preserving the underlying provider
 * error in `error.cause`, and rejects `result.finishReason` /
 * `result.totalUsage` with the wrapped error too. To differentiate
 * content-filter / stop-sequence / provider-crash, providers can
 * capture the upstream error (e.g. via streamText's `onError`
 * callback) and pass it here. When provided, it takes precedence
 * over the AI SDK error for `providerError` and `modelResponseRaw`.
 */
underlyingError?: unknown): Promise<StreamNoOutputSentinel>;
/**
 * Curator P3-6 (round-2): the AI SDK v6 path that sets
 * `NoOutputGeneratedError` does NOT throw it from `result.textStream`
 * iteration — it sets the error as a *promise rejection* on
 * `result.finishReason` / `result.totalUsage` / `result.steps` (see
 * `ai/src/generate-text/stream-text.ts` ~L1078). Providers that only
 * catch errors thrown from `for await (chunk of result.textStream)` will
 * miss the production trigger entirely: the stream completes silently
 * with 0 chunks and the rejection bubbles as an unhandled rejection.
 *
 * This helper surfaces the rejection by awaiting `result.finishReason`
 * after the stream completes. Providers must call this AFTER iterating
 * the textStream when 0 chunks were yielded — the returned sentinel
 * (if non-null) carries the enriched metadata Curator's report needed.
 */
export declare function detectPostStreamNoOutput(result: StreamNoOutputSentinelResultLike, 
/**
 * Optional provider-captured underlying error (e.g. from streamText's
 * `onError` callback). When provided, the resulting sentinel will carry
 * the real provider error in `providerError` / `modelResponseRaw`
 * instead of the AI SDK's generic "No output generated" message.
 */
underlyingError?: unknown): Promise<{
    sentinel: StreamNoOutputSentinel;
    error: Error;
} | null>;
/**
 * Reviewer follow-up: every provider's post-stream NoOutput detect must
 * stamp the active OTel span so Pipeline B (`ContextEnricher.onEnd()` →
 * `applyNonErrorLangfuseLevel`) surfaces a WARNING-level Langfuse
 * observation with the enriched status message. Without this, only
 * `StreamHandler`-based providers produced the rich telemetry; the
 * provider-specific paths (openAI, openaiCompatible, litellm,
 * huggingFace, openRouter, anthropicBaseProvider) yielded the sentinel
 * to direct stream consumers but Pipeline B saw nothing.
 *
 * Stamps three attributes:
 *   - `neurolink.no_output = true` (Pipeline B trigger)
 *   - `langfuse.status_message` (enriched, with finishReason + tokens)
 *   - `neurolink.no_output.finish_reason` (raw finish reason)
 *
 * Safe to call when tracing isn't initialized — silently no-ops.
 */
export declare function stampNoOutputSpan(sentinel: StreamNoOutputSentinel): void;
/**
 * Build the OTel `langfuse.status_message` summary string for a no-output
 * stream. Used by `StreamHandler.createTextStream` and any future provider
 * that wants to stamp the active span with the same enriched message.
 *
 * Reviewer follow-up: AI SDK v4 used `promptTokens` / `completionTokens`,
 * v6 uses `inputTokens` / `outputTokens`. Read both shapes so the message
 * is correct whichever version surfaced partial usage data.
 */
export declare function buildNoOutputStatusMessage(finishReason: unknown, usage: unknown): string;