add client sample (#55)

* add mcp Client example

* Add sample links for weather-stdio-server and kotlin-mcp-client to main readme

Author: devcrocod

README.md

@@ -14,6 +14,8 @@ The Model Context Protocol allows applications to provide context for LLMs in a
 ## Samples
 
 - [kotlin-mcp-server](./samples/kotlin-mcp-server): shows how to set up a Kotlin MCP server with different tools and other features.
+- [weather-stdio-server](./samples/weather-stdio-server): shows how to build a Kotlin MCP server providing weather forecast and alerts using STDIO transport.
+- [kotlin-mcp-client](./samples/kotlin-mcp-client): demonstrates building an interactive Kotlin MCP client that connects to an MCP server via STDIO and integrates with Anthropic’s API.
 
 ## Installation
 

samples/kotlin-mcp-client/.gitignore

@@ -0,0 +1,42 @@
+.gradle
+build/
+!gradle/wrapper/gradle-wrapper.jar
+!**/src/main/**/build/
+!**/src/test/**/build/
+
+### IntelliJ IDEA ###
+.idea/
+*.iws
+*.iml
+*.ipr
+out/
+!**/src/main/**/out/
+!**/src/test/**/out/
+
+### Kotlin ###
+.kotlin
+
+### Eclipse ###
+.apt_generated
+.classpath
+.factorypath
+.project
+.settings
+.springBeans
+.sts4-cache
+bin/
+!**/src/main/**/bin/
+!**/src/test/**/bin/
+
+### NetBeans ###
+/nbproject/private/
+/nbbuild/
+/dist/
+/nbdist/
+/.nb-gradle/
+
+### VS Code ###
+.vscode/
+
+### Mac OS ###
+.DS_Store

samples/kotlin-mcp-client/README.md

@@ -0,0 +1,69 @@
+# Kotlin MCP Client
+
+This project demonstrates how to build a Model Context Protocol (MCP) client in Kotlin that interacts with an MCP server
+via a STDIO transport layer while leveraging Anthropic's API for natural language processing. The client uses the MCP
+Kotlin SDK to communicate with an MCP server that exposes various tools, and it uses Anthropic's API to process user
+queries and integrate tool responses into the conversation.
+
+For more information about the MCP SDK and protocol, please refer to
+the [MCP documentation](https://modelcontextprotocol.io/introduction).
+
+## Prerequisites
+
+- **Java 17 or later**
+- **Gradle** (or the Gradle wrapper provided with the project)
+- An Anthropic API key set in your environment variable `ANTHROPIC_API_KEY`
+- Basic understanding of MCP concepts and Kotlin programming
+
+## Overview
+
+The client application performs the following tasks:
+
+- **Connecting to an MCP server** —
+  launches an MCP server process (implemented in JavaScript, Python, or Java) using STDIO transport.
+  It connects to the server, retrieves available tools, and converts them to Anthropic’s tool format.
+- **Processing queries** — 
+  accepts user queries, sends them to Anthropic’s API along with the registered tools, and handles responses.
+  If the response indicates a tool should be called, it invokes the corresponding MCP tool and continues the
+  conversation based on the tool’s result.
+- **Interactive chat loop** —
+  runs an interactive command-line loop, allowing users to continuously submit queries and receive responses.
+
+## Building and Running
+
+Use the Gradle wrapper to build the application. In a terminal, run:
+
+```shell
+./gradlew clean build -x test
+```
+
+To run the client, execute the jar file and provide the path to your MCP server script.
+
+To run the client with any MCP server:
+
+```shell
+java -jar build/libs/<your-jar-name>.jar path/to/server.jar # jvm server
+java -jar build/libs/<your-jar-name>.jar path/to/server.py # python server
+java -jar build/libs/<your-jar-name>.jar path/to/build/index.js # node server
+```
+
+> [!NOTE]
+> The client uses STDIO transport, so it launches the MCP server as a separate process.
+> Ensure the server script is executable and is a valid `.js`, `.py`, or `.jar` file.
+
+## Configuration for Anthropic
+
+Ensure your Anthropic API key is available in your environment:
+
+```shell
+export ANTHROPIC_API_KEY=your_anthropic_api_key_here
+```
+
+The client uses `AnthropicOkHttpClient.fromEnv()` to automatically load the API key from `ANTHROPIC_API_KEY` and
+`ANTHROPIC_AUTH_TOKEN` environment variables.
+
+## Additional Resources
+
+- [MCP Specification](https://spec.modelcontextprotocol.io/)
+- [Kotlin MCP SDK](https://github.com/modelcontextprotocol/kotlin-sdk)
+- [Anthropic Java SDK](https://github.com/anthropics/anthropic-sdk-java/tree/main)

samples/kotlin-mcp-client/build.gradle.kts

@@ -0,0 +1,31 @@
+plugins {
+    kotlin("jvm") version "2.1.10"
+    application
+    id("com.github.johnrengelman.shadow") version "8.1.1"
+}
+
+application {
+    mainClass.set("io.modelcontextprotocol.sample.client.MainKt")
+}
+
+
+group = "org.example"
+version = "0.1.0"
+
+val mcpVersion = "0.3.0"
+val slf4jVersion = "2.0.9"
+val anthropicVersion = "0.8.0"
+
+dependencies {
+    implementation("io.modelcontextprotocol:kotlin-sdk:$mcpVersion")
+    implementation("org.slf4j:slf4j-nop:$slf4jVersion")
+    implementation("com.anthropic:anthropic-java:$anthropicVersion")
+}
+
+tasks.test {
+    useJUnitPlatform()
+}
+
+kotlin {
+    jvmToolchain(17)
+}

samples/kotlin-mcp-client/gradle.properties

@@ -0,0 +1 @@
+kotlin.code.style=official

samples/kotlin-mcp-client/gradle/wrapper/gradle-wrapper.jar

@@ -0,0 +1,7 @@
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.13-bin.zip
+networkTimeout=10000
+validateDistributionUrl=true
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists