feat: Implements MCP client (#43)

Signed-off-by: John McBride <john@zuplo.com>

Author: jpmcb

examples/clients/ping/README.md

@@ -0,0 +1,24 @@
+# MCP Client Ping Example
+
+This example demonstrates how to use the MCP client to connect to and ping an MCP server.
+
+## Prerequisites
+
+Make sure the calculator MCP server is running:
+
+```bash
+cd ../calculator
+npm install
+npm run dev
+```
+
+The server should be running on `http://localhost:3000`. Otherwise, use `BASE_URL` to set
+the URL to a different MCP server.
+
+## Running the Example
+
+```bash
+npm install
+npm run build
+npm start
+```

examples/clients/ping/package-lock.json

@@ -0,0 +1,13 @@
+{
+  "name": "@zuplo/mcp example ping client",
+  "private": true,
+  "type": "module",
+  "scripts": {
+    "build": "tsc",
+    "start": "node dist/index.js",
+    "clean": "rm -rf ./dist/ && rm -rf ./node_modules/"
+  },
+  "dependencies": {
+    "@zuplo/mcp": "file:../../../"
+  }
+}

examples/clients/ping/package.json

@@ -0,0 +1,36 @@
+import { MCPClient } from "@zuplo/mcp/client";
+import { ConsoleLogger } from "@zuplo/mcp/logger";
+import { HTTPClientTransport } from "@zuplo/mcp/transport/httpclient";
+
+const logger = new ConsoleLogger();
+const client = new MCPClient({
+  name: "Ping client",
+  version: "0.0.0",
+  logger,
+});
+
+const url = process.env.BASE_URL || "http://localhost:3000/mcp"
+
+try {
+  const transport = new HTTPClientTransport({
+    url,
+    logger,
+  });
+
+  await client.connect(transport);
+  const initResult = await client.initialize();
+
+  logger.info("Connected successfully!", {
+    serverInfo: initResult.serverInfo,
+    protocolVersion: initResult.protocolVersion,
+  });
+
+  logger.info("Attempting ping ...");
+  await client.ping();
+  logger.info("Ping successful!");
+} catch (error) {
+  logger.error("Error running client example:", error);
+} finally {
+  await client.disconnect();
+  logger.info("Disconnected from server");
+}

examples/clients/ping/src/index.ts

@@ -1,5 +1,5 @@
 {
-  "extends": "../../tsconfig.base.json",
+  "extends": "../../../tsconfig.base.json",
   "compilerOptions": {
     "outDir": "./dist",
     "rootDir": "./src"
@@ -8,6 +8,6 @@
     "./src/**/*"
   ],
   "references": [
-    { "path": "../../" }
+    { "path": "../../../" }
   ]
 }

examples/output-schema-calculator/tsconfig.json renamed to examples/clients/ping/tsconfig.json

@@ -0,0 +1,26 @@
+# MCP Client Tools Call Example
+
+This example demonstrates how to use the MCP client to connect to and call tools.
+
+## Prerequisites
+
+Make sure the calculator server is running:
+
+```bash
+cd ../calculator
+npm install
+npm run dev
+```
+
+The server should be running on `http://localhost:3000`. Otherwise, use `BASE_URL` to set
+the URL to a different MCP server.
+
+Note!!! This example expects a server with an "add" and "divide" tool that accepts 2 arguments: `a` and `b`.
+
+## Running the Example
+
+```bash
+npm install
+npm run build
+npm start
+```

examples/clients/tools-call/README.md

@@ -0,0 +1,13 @@
+{
+  "name": "@zuplo/mcp example tool call client",
+  "private": true,
+  "type": "module",
+  "scripts": {
+    "build": "tsc",
+    "start": "node dist/index.js",
+    "clean": "rm -rf ./dist/ && rm -rf ./node_modules/"
+  },
+  "dependencies": {
+    "@zuplo/mcp": "file:../../../"
+  }
+}

examples/clients/tools-call/package-lock.json

@@ -0,0 +1,46 @@
+import { MCPClient } from "@zuplo/mcp/client";
+import { ConsoleLogger } from "@zuplo/mcp/logger";
+import { HTTPClientTransport } from "@zuplo/mcp/transport/httpclient";
+
+const logger = new ConsoleLogger();
+const client = new MCPClient({
+  name: "Ping client",
+  version: "0.0.0",
+  logger,
+});
+
+// This MCP client is intended to be tested against a calculator MCP server
+// with tools "add" and "divide".
+// The divide tool uses 0 as a denominator to simulating throwing an error.
+const url = process.env.BASE_URL || "http://localhost:3000/mcp"
+
+try {
+  // Create transport to connect to the calculator server
+  const transport = new HTTPClientTransport({
+    url,
+    logger,
+  });
+
+  await client.connect(transport);
+  const initResult = await client.initialize();
+
+  logger.info("Connected successfully!", {
+    serverInfo: initResult.serverInfo,
+    protocolVersion: initResult.protocolVersion,
+  });
+
+  const addResult = await client.callTool("add", { a: 5, b: 3 });
+  logger.info("5 + 3 =", addResult);
+
+  // Test error handling - division by zero
+  try {
+    const divideResult = await client.callTool("divide", { a: 10, b: 0 });
+    logger.info("10 ÷ 0 =", divideResult);
+  } catch (error) {
+    logger.info("Expected error for division by zero:", error);
+  }
+} catch (error) {
+  logger.error("Error running client example:", error);
+} finally {
+  await client.disconnect();
+}

examples/clients/tools-call/package.json

@@ -1,5 +1,5 @@
 {
-  "extends": "../../tsconfig.base.json",
+  "extends": "../../../tsconfig.base.json",
   "compilerOptions": {
     "outDir": "./dist",
     "rootDir": "./src"
@@ -8,6 +8,6 @@
     "./src/**/*"
   ],
   "references": [
-    { "path": "../../" }
+    { "path": "../../../" }
   ]
 }