Instrument fetch (undici) for HTTP client spans

CHANGELOG.md

@@ -2,6 +2,9 @@
 
 ## [Unreleased]
 
+### Features Added
+- Instrument outgoing `fetch` (undici) requests so HTTP client spans are captured for `fetch`-based clients such as the OpenAI SDK used by LangChain
+
 ### Other Changes
 - Remove the unused `AZURE_MONITOR_DISTRO_VERSION` env var and its constant; the distro reports its version via `MICROSOFT_OPENTELEMETRY_VERSION`
 

package.json

@@ -98,6 +98,7 @@
     "@opentelemetry/instrumentation-mysql": "^0.64.0",
     "@opentelemetry/instrumentation-pg": "^0.70.0",
     "@opentelemetry/instrumentation-redis": "^0.66.0",
+    "@opentelemetry/instrumentation-undici": "^0.29.0",
     "@opentelemetry/instrumentation-winston": "^0.62.0",
     "@opentelemetry/resource-detector-azure": "^0.26.0",
     "@opentelemetry/resources": "^2.8.0",

src/distro/distro.ts

@@ -32,6 +32,7 @@ import {
 } from "../azureMonitor/index.js";
 import { isOtlpEnabled, createOtlpComponents } from "../otlp/index.js";
 import { A365Configuration, Agent365Exporter, A365SpanProcessor } from "../a365/index.js";
+import { resolveAgent365Endpoint } from "../a365/exporter/utils.js";
 import { configureA365Logger } from "../a365/logging.js";
 import {
   GenAIMainAgentLogRecordProcessor,
@@ -62,6 +63,7 @@ let isShutdown = false;
 
 const A365_DISABLED_INSTRUMENTATIONS_BY_DEFAULT: ReadonlyArray<keyof InstrumentationOptions> = [
   "http",
+  "undici",
   "azureSdk",
   "mongoDb",
   "mySql",
@@ -79,6 +81,33 @@ const A365_DISABLED_INSTRUMENTATIONS_BY_DEFAULT: ReadonlyArray<keyof Instrumenta
  */
 const REDIS_LINKED_KEYS: ReadonlyArray<keyof InstrumentationOptions> = ["redis", "redis4"];
 
+/**
+ * Resolve the origin(s) of the A365 fetch-based exporter endpoint so the undici
+ * instrumentation can skip tracing our own telemetry export requests. Returns
+ * an empty list when the A365 exporter is not active or the endpoint cannot be
+ * resolved.
+ *
+ * @internal
+ */
+export function _resolveA365ExporterOrigins(a365Config: A365Configuration): string[] {
+  if (!a365Config.enabled || !a365Config.enableObservabilityExporter) {
+    return [];
+  }
+  let baseUrl = a365Config.domainOverride;
+  if (!baseUrl) {
+    try {
+      baseUrl = resolveAgent365Endpoint(a365Config.clusterCategory);
+    } catch {
+      return [];
+    }
+  }
+  try {
+    return [new URL(baseUrl).origin];
+  } catch {
+    return [];
+  }
+}
+
 /**
  * When A365 export is enabled, default to GenAI-focused telemetry by disabling
  * non-GenAI instrumentations unless callers explicitly configure them.
@@ -241,8 +270,13 @@ export function useMicrosoftOpenTelemetry(options?: MicrosoftOpenTelemetryOption
   );
 
   // ── Instrumentations, sampler, and views (always created) ─────────
+  // When the fetch-based A365 exporter is active, tell the undici
+  // instrumentation to skip its export requests so they are not traced as
+  // spurious client (dependency) spans on other exporters (e.g. Azure Monitor).
+  const ignoreUndiciOrigins = _resolveA365ExporterOrigins(a365Config);
   const instrumentations = createInstrumentations(config, {
     filterAzureMonitorRequests: azureMonitorEnabled,
+    ignoreUndiciOrigins,
   });
   const sampler = createSampler(config);
   const views: ViewOptions[] = createViews(config);

src/distro/instrumentations.ts

@@ -16,6 +16,11 @@ import type {
   IgnoreOutgoingRequestFunction,
 } from "@opentelemetry/instrumentation-http";
 import { HttpInstrumentation } from "@opentelemetry/instrumentation-http";
+import type {
+  UndiciInstrumentationConfig,
+  UndiciRequest,
+} from "@opentelemetry/instrumentation-undici";
+import { UndiciInstrumentation } from "@opentelemetry/instrumentation-undici";
 import { MongoDBInstrumentation } from "@opentelemetry/instrumentation-mongodb";
 import { MySQLInstrumentation } from "@opentelemetry/instrumentation-mysql";
 import { PgInstrumentation } from "@opentelemetry/instrumentation-pg";
@@ -43,10 +48,11 @@ import { logLevelToSeverityNumber } from "../azureMonitor/utils/logUtils.js";
  */
 export function createInstrumentations(
   config: InternalConfig,
-  options?: { filterAzureMonitorRequests?: boolean },
+  options?: { filterAzureMonitorRequests?: boolean; ignoreUndiciOrigins?: string[] },
 ): Instrumentation[] {
   const instrumentations: Instrumentation[] = [];
   const filterAzureMonitor = options?.filterAzureMonitorRequests ?? false;
+  const ignoreUndiciOrigins = options?.ignoreUndiciOrigins ?? [];
 
   // ── Trace instrumentations ──────────────────────────────────────
   if (config.instrumentationOptions.http?.enabled) {
@@ -67,6 +73,32 @@ export function createInstrumentations(
     instrumentations.push(new HttpInstrumentation(httpConfig));
   }
 
+  // Undici / global `fetch` — instruments outgoing requests the Node
+  // http/https instrumentation does not see (e.g. the OpenAI SDK's fetch calls).
+  if (config.instrumentationOptions.undici?.enabled) {
+    let undiciConfig = config.instrumentationOptions.undici as UndiciInstrumentationConfig;
+
+    // Undici does not honour tracing suppression, so requests made by our own
+    // fetch-based telemetry exporters (e.g. the A365 exporter) would otherwise
+    // be traced as spurious client spans. Skip requests to those origins while
+    // still delegating to any caller-provided ignore hook. Clone the config so
+    // the caller-owned object is never mutated.
+    if (ignoreUndiciOrigins.length > 0) {
+      const providedIgnoreRequestHook = undiciConfig.ignoreRequestHook;
+      undiciConfig = {
+        ...undiciConfig,
+        ignoreRequestHook: (request: UndiciRequest) => {
+          if (ignoreUndiciOrigins.includes(request.origin)) {
+            return true;
+          }
+          return providedIgnoreRequestHook ? providedIgnoreRequestHook(request) : false;
+        },
+      };
+    }
+
+    instrumentations.push(new UndiciInstrumentation(undiciConfig));
+  }
+
   if (config.instrumentationOptions.azureSdk?.enabled) {
     instrumentations.push(createAzureSdkInstrumentation(config.instrumentationOptions.azureSdk));
   }

src/shared/config.ts

@@ -34,7 +34,7 @@ export class InternalConfig {
   /** Azure Monitor Exporter Configuration */
   public azureMonitorExporterOptions: AzureMonitorExporterOptions;
   /**
-   * OpenTelemetry Instrumentations configuration included as part of Azure Monitor (azureSdk, http, mongoDb, mySql, postgreSql, redis, redis4)
+   * OpenTelemetry Instrumentations configuration included as part of Azure Monitor (azureSdk, http, undici, mongoDb, mySql, postgreSql, redis, redis4)
    */
   public instrumentationOptions: InstrumentationOptions;
   /** Enable Live Metrics feature */
@@ -82,6 +82,7 @@ export class InternalConfig {
     this.metricExportIntervalMillis = this.calculateMetricExportInterval();
     this.instrumentationOptions = {
       http: { enabled: true },
+      undici: { enabled: true },
       azureSdk: { enabled: true },
       mongoDb: { enabled: true },
       mySql: { enabled: true },

src/types.ts

@@ -2,6 +2,7 @@
 // Licensed under the MIT License.
 import type { AzureMonitorExporterOptions } from "@azure/monitor-opentelemetry-exporter";
 import type { InstrumentationConfig } from "@opentelemetry/instrumentation";
+import type { UndiciInstrumentationConfig } from "@opentelemetry/instrumentation-undici";
 import type { Resource } from "@opentelemetry/resources";
 import type { LogRecordProcessor } from "@opentelemetry/sdk-logs";
 import type { MetricReader, ViewOptions } from "@opentelemetry/sdk-metrics";
@@ -84,6 +85,13 @@ export interface InstrumentationOptions {
   azureSdk?: InstrumentationConfig;
   /** HTTP Instrumentation Config */
   http?: InstrumentationConfig;
+  /**
+   * Undici / global `fetch` Instrumentation Config.
+   * Instruments outgoing requests made via the global `fetch` API (undici),
+   * which the Node `http`/`https` instrumentation does not cover. Required for
+   * HTTP client spans from `fetch`-based clients such as the OpenAI SDK.
+   */
+  undici?: UndiciInstrumentationConfig;
   /** MongoDB Instrumentation Config */
   mongoDb?: InstrumentationConfig;
   /** MySQL Instrumentation Config */