diff --git a/README.md b/README.md index 55a17ad..1f3aed5 100644 --- a/README.md +++ b/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 diff --git a/samples/kotlin-mcp-client/.gitignore b/samples/kotlin-mcp-client/.gitignore new file mode 100644 index 0000000..108d567 --- /dev/null +++ b/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 \ No newline at end of file diff --git a/samples/kotlin-mcp-client/README.md b/samples/kotlin-mcp-client/README.md new file mode 100644 index 0000000..3842ea0 --- /dev/null +++ b/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/.jar path/to/server.jar # jvm server +java -jar build/libs/.jar path/to/server.py # python server +java -jar build/libs/.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) diff --git a/samples/kotlin-mcp-client/build.gradle.kts b/samples/kotlin-mcp-client/build.gradle.kts new file mode 100644 index 0000000..cf616f8 --- /dev/null +++ b/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) +} diff --git a/samples/kotlin-mcp-client/gradle.properties b/samples/kotlin-mcp-client/gradle.properties new file mode 100644 index 0000000..7fc6f1f --- /dev/null +++ b/samples/kotlin-mcp-client/gradle.properties @@ -0,0 +1 @@ +kotlin.code.style=official diff --git a/samples/kotlin-mcp-client/gradle/wrapper/gradle-wrapper.jar b/samples/kotlin-mcp-client/gradle/wrapper/gradle-wrapper.jar new file mode 100644 index 0000000..9bbc975 Binary files /dev/null and b/samples/kotlin-mcp-client/gradle/wrapper/gradle-wrapper.jar differ diff --git a/samples/kotlin-mcp-client/gradle/wrapper/gradle-wrapper.properties b/samples/kotlin-mcp-client/gradle/wrapper/gradle-wrapper.properties new file mode 100644 index 0000000..37f853b --- /dev/null +++ b/samples/kotlin-mcp-client/gradle/wrapper/gradle-wrapper.properties @@ -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 diff --git a/samples/kotlin-mcp-client/gradlew b/samples/kotlin-mcp-client/gradlew new file mode 100755 index 0000000..faf9300 --- /dev/null +++ b/samples/kotlin-mcp-client/gradlew @@ -0,0 +1,251 @@ +#!/bin/sh + +# +# Copyright © 2015-2021 the original authors. +# +# Licensed under the Apache License, Version 2.0 (the "License"); +# you may not use this file except in compliance with the License. +# You may obtain a copy of the License at +# +# https://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, +# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +# See the License for the specific language governing permissions and +# limitations under the License. +# +# SPDX-License-Identifier: Apache-2.0 +# + +############################################################################## +# +# Gradle start up script for POSIX generated by Gradle. +# +# Important for running: +# +# (1) You need a POSIX-compliant shell to run this script. If your /bin/sh is +# noncompliant, but you have some other compliant shell such as ksh or +# bash, then to run this script, type that shell name before the whole +# command line, like: +# +# ksh Gradle +# +# Busybox and similar reduced shells will NOT work, because this script +# requires all of these POSIX shell features: +# * functions; +# * expansions «$var», «${var}», «${var:-default}», «${var+SET}», +# «${var#prefix}», «${var%suffix}», and «$( cmd )»; +# * compound commands having a testable exit status, especially «case»; +# * various built-in commands including «command», «set», and «ulimit». +# +# Important for patching: +# +# (2) This script targets any POSIX shell, so it avoids extensions provided +# by Bash, Ksh, etc; in particular arrays are avoided. +# +# The "traditional" practice of packing multiple parameters into a +# space-separated string is a well documented source of bugs and security +# problems, so this is (mostly) avoided, by progressively accumulating +# options in "$@", and eventually passing that to Java. +# +# Where the inherited environment variables (DEFAULT_JVM_OPTS, JAVA_OPTS, +# and GRADLE_OPTS) rely on word-splitting, this is performed explicitly; +# see the in-line comments for details. +# +# There are tweaks for specific operating systems such as AIX, CygWin, +# Darwin, MinGW, and NonStop. +# +# (3) This script is generated from the Groovy template +# https://github.com/gradle/gradle/blob/HEAD/platforms/jvm/plugins-application/src/main/resources/org/gradle/api/internal/plugins/unixStartScript.txt +# within the Gradle project. +# +# You can find Gradle at https://github.com/gradle/gradle/. +# +############################################################################## + +# Attempt to set APP_HOME + +# Resolve links: $0 may be a link +app_path=$0 + +# Need this for daisy-chained symlinks. +while + APP_HOME=${app_path%"${app_path##*/}"} # leaves a trailing /; empty if no leading path + [ -h "$app_path" ] +do + ls=$( ls -ld "$app_path" ) + link=${ls#*' -> '} + case $link in #( + /*) app_path=$link ;; #( + *) app_path=$APP_HOME$link ;; + esac +done + +# This is normally unused +# shellcheck disable=SC2034 +APP_BASE_NAME=${0##*/} +# Discard cd standard output in case $CDPATH is set (https://github.com/gradle/gradle/issues/25036) +APP_HOME=$( cd -P "${APP_HOME:-./}" > /dev/null && printf '%s\n' "$PWD" ) || exit + +# Use the maximum available, or set MAX_FD != -1 to use that value. +MAX_FD=maximum + +warn () { + echo "$*" +} >&2 + +die () { + echo + echo "$*" + echo + exit 1 +} >&2 + +# OS specific support (must be 'true' or 'false'). +cygwin=false +msys=false +darwin=false +nonstop=false +case "$( uname )" in #( + CYGWIN* ) cygwin=true ;; #( + Darwin* ) darwin=true ;; #( + MSYS* | MINGW* ) msys=true ;; #( + NONSTOP* ) nonstop=true ;; +esac + +CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar + + +# Determine the Java command to use to start the JVM. +if [ -n "$JAVA_HOME" ] ; then + if [ -x "$JAVA_HOME/jre/sh/java" ] ; then + # IBM's JDK on AIX uses strange locations for the executables + JAVACMD=$JAVA_HOME/jre/sh/java + else + JAVACMD=$JAVA_HOME/bin/java + fi + if [ ! -x "$JAVACMD" ] ; then + die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME + +Please set the JAVA_HOME variable in your environment to match the +location of your Java installation." + fi +else + JAVACMD=java + if ! command -v java >/dev/null 2>&1 + then + die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH. + +Please set the JAVA_HOME variable in your environment to match the +location of your Java installation." + fi +fi + +# Increase the maximum file descriptors if we can. +if ! "$cygwin" && ! "$darwin" && ! "$nonstop" ; then + case $MAX_FD in #( + max*) + # In POSIX sh, ulimit -H is undefined. That's why the result is checked to see if it worked. + # shellcheck disable=SC2039,SC3045 + MAX_FD=$( ulimit -H -n ) || + warn "Could not query maximum file descriptor limit" + esac + case $MAX_FD in #( + '' | soft) :;; #( + *) + # In POSIX sh, ulimit -n is undefined. That's why the result is checked to see if it worked. + # shellcheck disable=SC2039,SC3045 + ulimit -n "$MAX_FD" || + warn "Could not set maximum file descriptor limit to $MAX_FD" + esac +fi + +# Collect all arguments for the java command, stacking in reverse order: +# * args from the command line +# * the main class name +# * -classpath +# * -D...appname settings +# * --module-path (only if needed) +# * DEFAULT_JVM_OPTS, JAVA_OPTS, and GRADLE_OPTS environment variables. + +# For Cygwin or MSYS, switch paths to Windows format before running java +if "$cygwin" || "$msys" ; then + APP_HOME=$( cygpath --path --mixed "$APP_HOME" ) + CLASSPATH=$( cygpath --path --mixed "$CLASSPATH" ) + + JAVACMD=$( cygpath --unix "$JAVACMD" ) + + # Now convert the arguments - kludge to limit ourselves to /bin/sh + for arg do + if + case $arg in #( + -*) false ;; # don't mess with options #( + /?*) t=${arg#/} t=/${t%%/*} # looks like a POSIX filepath + [ -e "$t" ] ;; #( + *) false ;; + esac + then + arg=$( cygpath --path --ignore --mixed "$arg" ) + fi + # Roll the args list around exactly as many times as the number of + # args, so each arg winds up back in the position where it started, but + # possibly modified. + # + # NB: a `for` loop captures its iteration list before it begins, so + # changing the positional parameters here affects neither the number of + # iterations, nor the values presented in `arg`. + shift # remove old arg + set -- "$@" "$arg" # push replacement arg + done +fi + + +# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script. +DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"' + +# Collect all arguments for the java command: +# * DEFAULT_JVM_OPTS, JAVA_OPTS, and optsEnvironmentVar are not allowed to contain shell fragments, +# and any embedded shellness will be escaped. +# * For example: A user cannot expect ${Hostname} to be expanded, as it is an environment variable and will be +# treated as '${Hostname}' itself on the command line. + +set -- \ + "-Dorg.gradle.appname=$APP_BASE_NAME" \ + -classpath "$CLASSPATH" \ + org.gradle.wrapper.GradleWrapperMain \ + "$@" + +# Stop when "xargs" is not available. +if ! command -v xargs >/dev/null 2>&1 +then + die "xargs is not available" +fi + +# Use "xargs" to parse quoted args. +# +# With -n1 it outputs one arg per line, with the quotes and backslashes removed. +# +# In Bash we could simply go: +# +# readarray ARGS < <( xargs -n1 <<<"$var" ) && +# set -- "${ARGS[@]}" "$@" +# +# but POSIX shell has neither arrays nor command substitution, so instead we +# post-process each arg (as a line of input to sed) to backslash-escape any +# character that might be a shell metacharacter, then use eval to reverse +# that process (while maintaining the separation between arguments), and wrap +# the whole thing up as a single "set" statement. +# +# This will of course break if any of these variables contains a newline or +# an unmatched quote. +# + +eval "set -- $( + printf '%s\n' "$DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS" | + xargs -n1 | + sed ' s~[^-[:alnum:]+,./:=@_]~\\&~g; ' | + tr '\n' ' ' + )" '"$@"' + +exec "$JAVACMD" "$@" diff --git a/samples/kotlin-mcp-client/gradlew.bat b/samples/kotlin-mcp-client/gradlew.bat new file mode 100644 index 0000000..9d21a21 --- /dev/null +++ b/samples/kotlin-mcp-client/gradlew.bat @@ -0,0 +1,94 @@ +@rem +@rem Copyright 2015 the original author or authors. +@rem +@rem Licensed under the Apache License, Version 2.0 (the "License"); +@rem you may not use this file except in compliance with the License. +@rem You may obtain a copy of the License at +@rem +@rem https://www.apache.org/licenses/LICENSE-2.0 +@rem +@rem Unless required by applicable law or agreed to in writing, software +@rem distributed under the License is distributed on an "AS IS" BASIS, +@rem WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +@rem See the License for the specific language governing permissions and +@rem limitations under the License. +@rem +@rem SPDX-License-Identifier: Apache-2.0 +@rem + +@if "%DEBUG%"=="" @echo off +@rem ########################################################################## +@rem +@rem Gradle startup script for Windows +@rem +@rem ########################################################################## + +@rem Set local scope for the variables with windows NT shell +if "%OS%"=="Windows_NT" setlocal + +set DIRNAME=%~dp0 +if "%DIRNAME%"=="" set DIRNAME=. +@rem This is normally unused +set APP_BASE_NAME=%~n0 +set APP_HOME=%DIRNAME% + +@rem Resolve any "." and ".." in APP_HOME to make it shorter. +for %%i in ("%APP_HOME%") do set APP_HOME=%%~fi + +@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script. +set DEFAULT_JVM_OPTS="-Xmx64m" "-Xms64m" + +@rem Find java.exe +if defined JAVA_HOME goto findJavaFromJavaHome + +set JAVA_EXE=java.exe +%JAVA_EXE% -version >NUL 2>&1 +if %ERRORLEVEL% equ 0 goto execute + +echo. 1>&2 +echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH. 1>&2 +echo. 1>&2 +echo Please set the JAVA_HOME variable in your environment to match the 1>&2 +echo location of your Java installation. 1>&2 + +goto fail + +:findJavaFromJavaHome +set JAVA_HOME=%JAVA_HOME:"=% +set JAVA_EXE=%JAVA_HOME%/bin/java.exe + +if exist "%JAVA_EXE%" goto execute + +echo. 1>&2 +echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME% 1>&2 +echo. 1>&2 +echo Please set the JAVA_HOME variable in your environment to match the 1>&2 +echo location of your Java installation. 1>&2 + +goto fail + +:execute +@rem Setup the command line + +set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar + + +@rem Execute Gradle +"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %* + +:end +@rem End local scope for the variables with windows NT shell +if %ERRORLEVEL% equ 0 goto mainEnd + +:fail +rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of +rem the _cmd.exe /c_ return code! +set EXIT_CODE=%ERRORLEVEL% +if %EXIT_CODE% equ 0 set EXIT_CODE=1 +if not ""=="%GRADLE_EXIT_CONSOLE%" exit %EXIT_CODE% +exit /b %EXIT_CODE% + +:mainEnd +if "%OS%"=="Windows_NT" endlocal + +:omega diff --git a/samples/kotlin-mcp-client/settings.gradle.kts b/samples/kotlin-mcp-client/settings.gradle.kts new file mode 100644 index 0000000..39d0cc2 --- /dev/null +++ b/samples/kotlin-mcp-client/settings.gradle.kts @@ -0,0 +1,11 @@ +rootProject.name = "kotlin-mcp-client" + +plugins { + id("org.gradle.toolchains.foojay-resolver-convention") version "0.8.0" +} + +dependencyResolutionManagement { + repositories { + mavenCentral() + } +} diff --git a/samples/kotlin-mcp-client/src/main/kotlin/io/modelcontextprotocol/sample/client/MCPClient.kt b/samples/kotlin-mcp-client/src/main/kotlin/io/modelcontextprotocol/sample/client/MCPClient.kt new file mode 100644 index 0000000..6221b47 --- /dev/null +++ b/samples/kotlin-mcp-client/src/main/kotlin/io/modelcontextprotocol/sample/client/MCPClient.kt @@ -0,0 +1,176 @@ +package io.modelcontextprotocol.sample.client + +import com.anthropic.client.okhttp.AnthropicOkHttpClient +import com.anthropic.core.JsonValue +import com.anthropic.models.messages.* +import com.fasterxml.jackson.core.type.TypeReference +import com.fasterxml.jackson.databind.ObjectMapper +import io.modelcontextprotocol.kotlin.sdk.Implementation +import io.modelcontextprotocol.kotlin.sdk.TextContent +import io.modelcontextprotocol.kotlin.sdk.client.Client +import io.modelcontextprotocol.kotlin.sdk.client.StdioClientTransport +import kotlinx.coroutines.runBlocking +import kotlinx.io.asSink +import kotlinx.io.asSource +import kotlinx.io.buffered +import kotlinx.serialization.json.JsonObject +import kotlin.jvm.optionals.getOrNull + +class MCPClient : AutoCloseable { + // Configures using the `ANTHROPIC_API_KEY` and `ANTHROPIC_AUTH_TOKEN` environment variables + private val anthropic = AnthropicOkHttpClient.fromEnv() + + // Initialize MCP client + private val mcp: Client = Client(clientInfo = Implementation(name = "mcp-client-cli", version = "1.0.0")) + + private val messageParamsBuilder: MessageCreateParams.Builder = MessageCreateParams.builder() + .model(Model.CLAUDE_3_5_SONNET_20241022) + .maxTokens(1024) + + // List of tools offered by the server + private lateinit var tools: List + + private fun JsonObject.toJsonValue(): JsonValue { + val mapper = ObjectMapper() + val node = mapper.readTree(this.toString()) + return JsonValue.fromJsonNode(node) + } + + // Connect to the server using the path to the server + suspend fun connectToServer(serverScriptPath: String) { + try { + // Build the command based on the file extension of the server script + val command = buildList { + when (serverScriptPath.substringAfterLast(".")) { + "js" -> add("node") + "py" -> add(if (System.getProperty("os.name").lowercase().contains("win")) "python" else "python3") + "jar" -> addAll(listOf("java", "-jar")) + else -> throw IllegalArgumentException("Server script must be a .js, .py or .jar file") + } + add(serverScriptPath) + } + + // Start the server process + val process = ProcessBuilder(command).start() + + // Setup I/O transport using the process streams + val transport = StdioClientTransport( + input = process.inputStream.asSource().buffered(), + output = process.outputStream.asSink().buffered() + ) + + // Connect the MCP client to the server using the transport + mcp.connect(transport) + + // Request the list of available tools from the server + val toolsResult = mcp.listTools() + tools = toolsResult?.tools?.map { tool -> + ToolUnion.ofTool( + Tool.builder() + .name(tool.name) + .description(tool.description ?: "") + .inputSchema( + Tool.InputSchema.builder() + .type(JsonValue.from(tool.inputSchema.type)) + .properties(tool.inputSchema.properties.toJsonValue()) + .putAdditionalProperty("required", JsonValue.from(tool.inputSchema.required)) + .build() + ) + .build() + ) + } ?: emptyList() + println("Connected to server with tools: ${tools.joinToString(", ") { it.tool().get().name() }}") + } catch (e: Exception) { + println("Failed to connect to MCP server: $e") + throw e + } + } + + // Process a user query and return a string response + suspend fun processQuery(query: String): String { + // Create an initial message with a user's query + val messages = mutableListOf( + MessageParam.builder() + .role(MessageParam.Role.USER) + .content(query) + .build() + ) + + // Send the query to the Anthropic model and get the response + val response = anthropic.messages().create( + messageParamsBuilder + .messages(messages) + .tools(tools) + .build() + ) + + val finalText = mutableListOf() + response.content().forEach { content -> + when { + // Append text outputs from the response + content.isText() -> finalText.add(content.text().getOrNull()?.text() ?: "") + + // If the response indicates a tool use, process it further + content.isToolUse() -> { + val toolName = content.toolUse().get().name() + val toolArgs = + content.toolUse().get()._input().convert(object : TypeReference>() {}) + + // Call the tool with provided arguments + val result = mcp.callTool( + name = toolName, + arguments = toolArgs ?: emptyMap() + ) + finalText.add("[Calling tool $toolName with args $toolArgs]") + + // Add the tool result message to the conversation + messages.add( + MessageParam.builder() + .role(MessageParam.Role.USER) + .content( + """ + "type": "tool_result", + "tool_name": $toolName, + "result": ${result?.content?.joinToString("\n") { (it as TextContent).text ?: "" }} + """.trimIndent() + ) + .build() + ) + + // Retrieve an updated response after tool execution + val aiResponse = anthropic.messages().create( + messageParamsBuilder + .messages(messages) + .build() + ) + + // Append the updated response to final text + finalText.add(aiResponse.content().first().text().getOrNull()?.text() ?: "") + } + } + } + + return finalText.joinToString("\n", prefix = "", postfix = "") + } + + // Main chat loop for interacting with the user + suspend fun chatLoop() { + println("\nMCP Client Started!") + println("Type your queries or 'quit' to exit.") + + while (true) { + print("\nQuery: ") + val message = readLine() ?: break + if (message.lowercase() == "quit") break + val response = processQuery(message) + println("\n$response") + } + } + + override fun close() { + runBlocking { + mcp.close() + anthropic.close() + } + } +} \ No newline at end of file diff --git a/samples/kotlin-mcp-client/src/main/kotlin/io/modelcontextprotocol/sample/client/main.kt b/samples/kotlin-mcp-client/src/main/kotlin/io/modelcontextprotocol/sample/client/main.kt new file mode 100644 index 0000000..6d76180 --- /dev/null +++ b/samples/kotlin-mcp-client/src/main/kotlin/io/modelcontextprotocol/sample/client/main.kt @@ -0,0 +1,13 @@ +package io.modelcontextprotocol.sample.client + +import kotlinx.coroutines.runBlocking + +fun main(args: Array) = runBlocking { + if (args.isEmpty()) throw IllegalArgumentException("Usage: java -jar /build/libs/kotlin-mcp-client-0.1.0-all.jar ") + val serverPath = args.first() + val client = MCPClient() + client.use { + client.connectToServer(serverPath) + client.chatLoop() + } +} \ No newline at end of file