JBRes-7677: langfuse example for mcp metrics in opentelemetry

Author: vova-jb

agents/agents-features/agents-features-opentelemetry/src/jvmMain/kotlin/ai/koog/agents/features/opentelemetry/integration/langfuse/Langfuse.kt

@@ -33,7 +33,10 @@ public fun OpenTelemetryConfig.addLangfuseExporter(
     timeout: Duration = 10.seconds,
     traceAttributes: List<CustomAttribute> = emptyList()
 ) {
-    val url = langfuseUrl ?: System.getenv()["LANGFUSE_HOST"] ?: "https://cloud.langfuse.com"
+    val url = langfuseUrl
+        ?: System.getenv()["LANGFUSE_HOST"]
+        ?: System.getenv()["LANGFUSE_BASE_URL"]
+        ?: "https://cloud.langfuse.com"
 
     logger.debug { "Configured endpoint for Langfuse telemetry: $url" }
 

examples/simple-examples/build.gradle.kts

@@ -6,6 +6,8 @@ plugins {
 
 dependencies {
     implementation(platform(libs.kotlin.bom))
+    implementation(libs.mcp.server)
+    implementation(libs.mcp.client)
 
     /*
      Koog dependencies from composite build.
@@ -14,6 +16,8 @@ dependencies {
     //noinspection UseTomlInstead
     implementation("ai.koog:koog-agents")
     //noinspection UseTomlInstead
+    implementation("ai.koog:agents-mcp-server")
+    //noinspection UseTomlInstead
     implementation("ai.koog:koog-ktor")
     //noinspection UseTomlInstead
     implementation("ai.koog:agents-features-sql")
@@ -137,3 +141,8 @@ registerRunExampleTask("runExampleAdvancedJokeAgentClient", "ai.koog.agents.exam
  ACP examples
 */
 registerRunExampleTask("runExampleAcpApp", "ai.koog.agents.example.acp.KoogAcpAppKt")
+
+/*
+ Langfuse examples
+*/
+registerRunExampleTask("runExampleLangfuseApp", "ai.koog.agents.example.features.langfuse.LangfuseKt")

examples/simple-examples/env.template.properties

@@ -4,11 +4,25 @@
 # Or, if you want to integrate with 1password, you can put reference, e.g. op://foo/bar:
 # FOO=op://foo/bar
 
-OPENAI_API_KEY=
+# https://platform.openai.com/api-keys
+OPENAI_API_KEY=sk-proj-...
 
 ANTHROPIC_API_KEY=
 
 AWS_ACCESS_KEY_ID=
 AWS_SECRET_ACCESS_KEY=
 AWS_BEDROCK_GUARDRAIL_ID=
 AWS_BEDROCK_GUARDRAIL_VERSION=
+
+# Langfuse credentials https://langfuse.com/faq/all/where-are-langfuse-api-keys
+# To run locally, first install Langfuse:
+#
+# git clone https://github.com/langfuse/langfuse.git
+# cd langfuse
+# docker compose up
+#
+# then open http://localhost:3000
+#
+LANGFUSE_SECRET_KEY=sk-lf-...
+LANGFUSE_PUBLIC_KEY=pk-lf-...
+LANGFUSE_HOST=http://localhost:3000

examples/simple-examples/gradle/libs.versions.toml

@@ -8,6 +8,7 @@ logback = "1.5.13"
 mockk = "1.13.8"
 opentelemetry = "1.51.0"
 oshai-logging = "7.0.7"
+mcp = "0.8.1"
 
 [libraries]
 kotlin-bom = { module = "org.jetbrains.kotlin:kotlin-bom", version.ref = "kotlin" }
@@ -23,6 +24,8 @@ opentelemetry-exporter-logging = { module = "io.opentelemetry:opentelemetry-expo
 opentelemetry-exporter-otlp = { module = "io.opentelemetry:opentelemetry-exporter-otlp" }
 opentelemetry-sdk = { module = "io.opentelemetry:opentelemetry-sdk" }
 oshai-kotlin-logging = { module = "io.github.oshai:kotlin-logging", version.ref = "oshai-logging" }
+mcp-client = { module = "io.modelcontextprotocol:kotlin-sdk-client", version.ref = "mcp" }
+mcp-server = { module = "io.modelcontextprotocol:kotlin-sdk-server", version.ref = "mcp" }
 
 [plugins]
 kotlin-jvm = { id = "org.jetbrains.kotlin.jvm", version.ref = "kotlin" }

examples/simple-examples/src/main/kotlin/ai/koog/agents/example/features/langfuse/Langfuse.kt

@@ -1,12 +1,21 @@
 package ai.koog.agents.example.features.langfuse
 
 import ai.koog.agents.core.agent.AIAgent
+import ai.koog.agents.core.tools.ToolRegistry
+import ai.koog.agents.core.tools.annotations.LLMDescription
+import ai.koog.agents.core.tools.annotations.Tool
+import ai.koog.agents.core.tools.reflect.tool
 import ai.koog.agents.example.ApiKeyService
 import ai.koog.agents.features.opentelemetry.feature.OpenTelemetry
 import ai.koog.agents.features.opentelemetry.integration.langfuse.addLangfuseExporter
+import ai.koog.agents.mcp.McpToolRegistryProvider
+import ai.koog.agents.mcp.server.startSseMcpServer
 import ai.koog.prompt.executor.clients.openai.OpenAIModels
 import ai.koog.prompt.executor.llms.all.simpleOpenAIExecutor
+import io.ktor.server.cio.*
 import io.opentelemetry.exporter.otlp.http.trace.OtlpHttpSpanExporter
+import kotlinx.coroutines.delay
+import kotlin.time.Duration.Companion.seconds
 
 /**
  * Example of Koog agents tracing to [Langfuse](https://langfuse.com/)
@@ -18,15 +27,22 @@ import io.opentelemetry.exporter.otlp.http.trace.OtlpHttpSpanExporter
  *  1. Set up a Langfuse project and credentials as described [here](https://langfuse.com/docs/get-started#create-new-project-in-langfuse)
  *  2. Get Langfuse credentials as described [here](https://langfuse.com/faq/all/where-are-langfuse-api-keys)
  *  3. Set `LANGFUSE_HOST`, `LANGFUSE_PUBLIC_KEY`, and `LANGFUSE_SECRET_KEY` environment variables
+ *  4. Set `OPENAI_API_KEY` from [here](https://platform.openai.com/account/api-keys)
  *
  * @see <a href="https://langfuse.com/docs/opentelemetry/get-started#opentelemetry-endpoint">Langfuse OpenTelemetry Docs</a>
  */
 suspend fun main() {
-    simpleOpenAIExecutor(ApiKeyService.openAIApiKey).use { executor ->
+    val server = startSseMcpServer(CIO, port = 30001, host = "localhost", ToolRegistry {
+        tool(::applyArithmetic)
+    })
+    delay(1.seconds)
+    try {
+        val tools = McpToolRegistryProvider.fromSseUrl("http://localhost:30001")
         val agent = AIAgent(
-            promptExecutor = executor,
-            llmModel = OpenAIModels.Chat.GPT4oMini,
-            systemPrompt = "You are a code assistant. Provide concise code examples."
+            promptExecutor = simpleOpenAIExecutor(ApiKeyService.openAIApiKey),
+            llmModel = OpenAIModels.Chat.GPT4_1Mini,
+            systemPrompt = "You are a code assistant. Provide concise code examples.",
+            toolRegistry = ToolRegistry { tool(::sin); tool(::cos) } + tools
         ) {
             install(OpenTelemetry) {
                 addLangfuseExporter()
@@ -35,8 +51,36 @@ suspend fun main() {
 
         println("Running agent with Langfuse tracing")
 
-        val result = agent.run("Tell me a joke about programming")
+        val result = agent.run("Compute (sin(1) + cos(2)) * 69 using available tools")
 
         println("Result: $result\nSee traces on the Langfuse instance")
+    } finally {
+        server.close()
     }
 }
+
+@Tool
+@LLMDescription("Calculates the result of an arithmetic expression")
+fun applyArithmetic(
+    @LLMDescription("Arithmetic operation: +-*/") op: String,
+    @LLMDescription("First operand") a: Double,
+    @LLMDescription("Second operand") b: Double
+): Double = when (op) {
+    "+" -> a + b
+    "-" -> a - b
+    "*" -> a * b
+    "/" -> a / b
+    else -> throw IllegalArgumentException("Unsupported operation: $op")
+}
+
+@Tool
+@LLMDescription("sin")
+fun sin(
+    @LLMDescription("Operand") x: Double
+): Double = kotlin.math.sin(x)
+
+@Tool
+@LLMDescription("cos")
+fun cos(
+    @LLMDescription("Operand") x: Double
+): Double = kotlin.math.cos(x)