feat: Add support for trackStreamMetricsOf method

packages/sdk/server-ai/src/LDAIConfigMapper.ts

@@ -27,6 +27,10 @@ export class LDAIConfigMapper {
  return undefined;
  }
 
+ /**
+ * @deprecated Use `VercelProvider.toVercelAISDK()` from the `@launchdarkly/server-sdk-ai-vercel` package instead.
+ * This method will be removed in a future version.
+ */
  toVercelAISDK<TMod>(
  provider: VercelAISDKProvider<TMod> | Record<string, VercelAISDKProvider<TMod>>,
  options?: VercelAISDKMapOptions | undefined,

packages/sdk/server-ai/src/LDAIConfigTrackerImpl.ts

@@ -119,6 +119,60 @@ export class LDAIConfigTrackerImpl implements LDAIConfigTracker {
  return result;
  }
 
+ trackStreamMetricsOf<TStream>(
+ streamCreator: () => TStream,
+ metricsExtractor: (stream: TStream) => Promise<LDAIMetrics>,
+ ): TStream {
+ const startTime = Date.now();
+
+ try {
+ // Create the stream synchronously
+ const stream = streamCreator();
+
+ // Start background metrics tracking (fire and forget)
+ this._trackStreamMetricsInBackground(stream, metricsExtractor, startTime);
+
+ // Return stream immediately for consumption
+ return stream;
+ } catch (error) {
+ // Track error if stream creation fails
+ this.trackDuration(Date.now() - startTime);
+ this.trackError();
+ throw error;
+ }
+ }
+
+ private async _trackStreamMetricsInBackground<TStream>(
+ stream: TStream,
+ metricsExtractor: (stream: TStream) => Promise<LDAIMetrics>,
+ startTime: number,
+ ): Promise<void> {
+ try {
+ // Wait for metrics to be available
+ const metrics = await metricsExtractor(stream);
+
+ // Track final duration
+ const duration = Date.now() - startTime;
+ this.trackDuration(duration);
+
+ // Track success/error based on metrics
+ if (metrics.success) {
+ this.trackSuccess();
+ } else {
+ this.trackError();
+ }
+
+ // Track token usage if available
+ if (metrics.usage) {
+ this.trackTokens(metrics.usage);
+ }
+ } catch (error) {
+ // If metrics extraction fails, track error
+ // but don't throw - stream consumption should not be affected
+ this.trackError();
+ }
+ }
+
  async trackOpenAIMetrics<
  TRes extends {
  usage?: {

packages/sdk/server-ai/src/api/config/LDAIConfig.ts

@@ -76,6 +76,9 @@ export interface LDAIConfig {
  *
  * WARNING: this method can throw an exception if a Vercel AI SDK model cannot be determined.
  *
+ * @deprecated Use `VercelProvider.toVercelAISDK()` from the `@launchdarkly/server-sdk-ai-vercel` package instead.
+ * This method will be removed in a future version.
+ *
  * @param provider A Vercel AI SDK Provider or a map of provider names to Vercel AI SDK Providers.
  * @param options Optional mapping options.
  * @returns A configuration directly usable in Vercel AI SDK generateText() and streamText()

packages/sdk/server-ai/src/api/config/LDAIConfigTracker.ts

@@ -106,6 +106,32 @@ export interface LDAIConfigTracker {
  func: () => Promise<TRes>,
  ): Promise<TRes>;
 
+ /**
+ * Track metrics for a streaming AI operation.
+ *
+ * This function will track the duration of the operation, extract metrics using the provided
+ * metrics extractor function, and track success or error status accordingly.
+ *
+ * Unlike trackMetricsOf, this method is designed for streaming operations where:
+ * - The stream is created and returned immediately (synchronously)
+ * - Metrics are extracted asynchronously in the background once the stream completes
+ * - Duration is tracked from stream creation to metrics extraction completion
+ *
+ * The stream is returned immediately so the caller can begin consuming it without waiting.
+ * Metrics extraction happens in the background and does not block stream consumption.
+ *
+ * If the stream creator throws, then this method will also throw and record an error.
+ * If metrics extraction fails, the error is logged but does not affect stream consumption.
+ *
+ * @param streamCreator Function that creates and returns the stream (synchronous)
+ * @param metricsExtractor Function that asynchronously extracts metrics from the stream
+ * @returns The stream result (returned immediately, not a Promise)
+ */
+ trackStreamMetricsOf<TStream>(
+ streamCreator: () => TStream,
+ metricsExtractor: (stream: TStream) => Promise<LDAIMetrics>,
+ ): TStream;
+
  /**
  * Track an OpenAI operation.
  *
@@ -187,6 +213,9 @@ export interface LDAIConfigTracker {
  * In the case the provided function throws, this function will record the duration and an error.
  * A failed operation will not have any token usage data.
  *
+ * @deprecated Use `trackStreamMetricsOf()` with `VercelProvider.createStreamMetricsExtractor()` from the
+ * `@launchdarkly/server-sdk-ai-vercel` package instead. This method will be removed in a future version.
+ *
  * @param func Function which executes the operation.
  * @returns The result of the operation.
  */

packages/sdk/server-ai/src/api/config/VercelAISDK.ts

@@ -1,11 +1,23 @@
 import { type LDMessage } from './LDAIConfig';
 
+/**
+ * @deprecated Use `VercelAISDKProvider` from the `@launchdarkly/server-sdk-ai-vercel` package instead.
+ * This type will be removed in a future version.
+ */
 export type VercelAISDKProvider<TMod> = (modelName: string) => TMod;
 
+/**
+ * @deprecated Use `VercelAISDKMapOptions` from the `@launchdarkly/server-sdk-ai-vercel` package instead.
+ * This type will be removed in a future version.
+ */
 export interface VercelAISDKMapOptions {
  nonInterpolatedMessages?: LDMessage[] | undefined;
 }
 
+/**
+ * @deprecated Use `VercelAISDKConfig` from the `@launchdarkly/server-sdk-ai-vercel` package instead.
+ * This type will be removed in a future version.
+ */
 export interface VercelAISDKConfig<TMod> {
  model: TMod;
  messages?: LDMessage[] | undefined;