feat: add opentelemetry tracing to agent-api

Author: sinedied

packages/agent-api/host.json

@@ -1,5 +1,6 @@
 {
   "version": "2.0",
+  "telemetryMode": "OpenTelemetry",
   "logging": {
     "applicationInsights": {
       "samplingSettings": {

packages/agent-api/package.json

@@ -3,7 +3,7 @@
   "version": "1.0.0",
   "description": "Azure Functions API for Contoso Burgers AI Agent",
   "private": true,
-  "main": "./dist/src/functions/*.js",
+  "main": "./dist/src/{tracing.js,functions/*.js}",
   "scripts": {
     "build": "tsc",
     "watch": "tsc -w",
@@ -18,13 +18,19 @@
   "dependencies": {
     "@azure/functions": "^4.0.0",
     "@azure/identity": "^4.2.0",
+    "@azure/monitor-opentelemetry": "^1.12.0",
     "@azure/storage-blob": "^12.17.0",
     "@langchain/azure-cosmosdb": "^0.2.2",
     "@langchain/core": "^0.3.18",
     "@langchain/langgraph": "^0.4.9",
     "@langchain/mcp-adapters": "^0.6.0",
     "@langchain/openai": "^0.6.9",
     "@microsoft/ai-chat-protocol": "^1.0.0-beta.20240814.1",
+    "@opentelemetry/exporter-trace-otlp-http": "^0.203.0",
+    "@opentelemetry/instrumentation": "^0.200.0",
+    "@opentelemetry/sdk-trace-base": "^1.30.1",
+    "@opentelemetry/sdk-trace-node": "^2.0.1",
+    "@traceloop/instrumentation-langchain": "^0.18.0",
     "langchain": "^0.3.6"
   },
   "devDependencies": {

packages/agent-api/src/tracing.ts

@@ -0,0 +1,40 @@
+// OpenTelemetry tracing setup
+// This file is loaded automatically by the Azure Functions host,
+// as configured in package.json "main" field.
+
+import { useAzureMonitor } from "@azure/monitor-opentelemetry";
+import { OTLPTraceExporter } from "@opentelemetry/exporter-trace-otlp-http";
+import { NodeTracerProvider } from "@opentelemetry/sdk-trace-node";
+import { BatchSpanProcessor } from "@opentelemetry/sdk-trace-base";
+import { LangChainInstrumentation } from "@traceloop/instrumentation-langchain";
+import { registerInstrumentations } from "@opentelemetry/instrumentation";
+
+let isTracingInitialized = false;
+if (!isTracingInitialized) {
+  // Initialize tracing and export to Azure Monitor or OTLP endpoint
+  // When running locally, you can use a local OpenTelemetry collector to receive the traces,
+  // for example VS Code AI Toolkit's extension trace collector:
+  // https://marketplace.visualstudio.com/items?itemName=ms-windows-ai-studio.windows-ai-studio
+  const appInsightsConnectionString = process.env["APPLICATIONINSIGHTS_CONNECTION_STRING"];
+  if (appInsightsConnectionString) {
+    useAzureMonitor({
+      azureMonitorExporterOptions: { connectionString: appInsightsConnectionString }
+    });
+  } else {
+    console.warn("Using local OTLP endpoint at http://localhost:4318, run a local OpenTelemetry collector to receive the traces");
+
+    const exporter = new OTLPTraceExporter({
+      url: "http://localhost:4318/v1/traces",
+    });
+    const provider = new NodeTracerProvider({
+      spanProcessors: [new BatchSpanProcessor(exporter as any) as any],
+    });
+    provider.register();
+  }
+
+  registerInstrumentations({
+    instrumentations: [new LangChainInstrumentation()],
+  });
+
+  isTracingInitialized = true;
+}