Add CLI and config file support

cli/package.json

@@ -0,0 +1,24 @@
+{
+  "name": "@modelcontextprotocol/inspector-cli",
+  "version": "0.5.1",
+  "description": "CLI for the Model Context Protocol inspector",
+  "license": "MIT",
+  "author": "Nicolas Barraud",
+  "homepage": "https://github.com/nbarraud",
+  "main": "build/index.js",
+  "type": "module",
+  "bin": {
+    "mcp-inspector-cli": "build/index.js"
+  },
+  "files": [
+    "build"
+  ],
+  "scripts": {
+    "build": "tsc"
+  },
+  "devDependencies": {},
+  "dependencies": {
+    "commander": "^13.1.0",
+    "spawn-rx": "^5.1.2"
+  }
+}

cli/src/client/connection.ts

@@ -0,0 +1,51 @@
+import { Client } from "@modelcontextprotocol/sdk/client/index.js";
+import type { Transport } from "@modelcontextprotocol/sdk/shared/transport.js";
+import { McpResponse } from "./types.js";
+
+export const validLogLevels = [
+  "trace",
+  "debug",
+  "info",
+  "warn",
+  "error",
+] as const;
+
+export type LogLevel = (typeof validLogLevels)[number];
+
+export async function connect(
+  client: Client,
+  transport: Transport,
+): Promise<void> {
+  try {
+    await client.connect(transport);
+  } catch (error) {
+    throw new Error(
+      `Failed to connect to MCP server: ${error instanceof Error ? error.message : String(error)}`,
+    );
+  }
+}
+
+export async function disconnect(transport: Transport): Promise<void> {
+  try {
+    await transport.close();
+  } catch (error) {
+    throw new Error(
+      `Failed to disconnect from MCP server: ${error instanceof Error ? error.message : String(error)}`,
+    );
+  }
+}
+
+// Set logging level
+export async function setLoggingLevel(
+  client: Client,
+  level: LogLevel,
+): Promise<McpResponse> {
+  try {
+    const response = await client.setLoggingLevel(level as any);
+    return response;
+  } catch (error) {
+    throw new Error(
+      `Failed to set logging level: ${error instanceof Error ? error.message : String(error)}`,
+    );
+  }
+}

cli/src/client/index.ts

@@ -0,0 +1,6 @@
+// Re-export everything from the client modules
+export * from "./connection.js";
+export * from "./prompts.js";
+export * from "./resources.js";
+export * from "./tools.js";
+export * from "./types.js";

cli/src/client/prompts.ts

@@ -0,0 +1,34 @@
+import { Client } from "@modelcontextprotocol/sdk/client/index.js";
+import { McpResponse } from "./types.js";
+
+// List available prompts
+export async function listPrompts(client: Client): Promise<McpResponse> {
+  try {
+    const response = await client.listPrompts();
+    return response;
+  } catch (error) {
+    throw new Error(
+      `Failed to list prompts: ${error instanceof Error ? error.message : String(error)}`,
+    );
+  }
+}
+
+// Get a prompt
+export async function getPrompt(
+  client: Client,
+  name: string,
+  args?: Record<string, string>,
+): Promise<McpResponse> {
+  try {
+    const response = await client.getPrompt({
+      name,
+      arguments: args || {},
+    });
+
+    return response;
+  } catch (error) {
+    throw new Error(
+      `Failed to get prompt: ${error instanceof Error ? error.message : String(error)}`,
+    );
+  }
+}

cli/src/client/resources.ts

@@ -0,0 +1,43 @@
+import { Client } from "@modelcontextprotocol/sdk/client/index.js";
+import { McpResponse } from "./types.js";
+
+// List available resources
+export async function listResources(client: Client): Promise<McpResponse> {
+  try {
+    const response = await client.listResources();
+    return response;
+  } catch (error) {
+    throw new Error(
+      `Failed to list resources: ${error instanceof Error ? error.message : String(error)}`,
+    );
+  }
+}
+
+// Read a resource
+export async function readResource(
+  client: Client,
+  uri: string,
+): Promise<McpResponse> {
+  try {
+    const response = await client.readResource({ uri });
+    return response;
+  } catch (error) {
+    throw new Error(
+      `Failed to read resource ${uri}: ${error instanceof Error ? error.message : String(error)}`,
+    );
+  }
+}
+
+// List resource templates
+export async function listResourceTemplates(
+  client: Client,
+): Promise<McpResponse> {
+  try {
+    const response = await client.listResourceTemplates();
+    return response;
+  } catch (error) {
+    throw new Error(
+      `Failed to list resource templates: ${error instanceof Error ? error.message : String(error)}`,
+    );
+  }
+}

cli/src/client/tools.ts

@@ -0,0 +1,95 @@
+import { Client } from "@modelcontextprotocol/sdk/client/index.js";
+import { Tool } from "@modelcontextprotocol/sdk/types.js";
+import { McpResponse } from "./types.js";
+
+type JsonSchemaType = {
+  type: "string" | "number" | "integer" | "boolean" | "array" | "object";
+  description?: string;
+  properties?: Record<string, JsonSchemaType>;
+  items?: JsonSchemaType;
+};
+
+export async function listTools(client: Client): Promise<McpResponse> {
+  try {
+    const response = await client.listTools();
+    return response;
+  } catch (error) {
+    throw new Error(
+      `Failed to list tools: ${error instanceof Error ? error.message : String(error)}`,
+    );
+  }
+}
+
+function convertParameterValue(value: string, schema: JsonSchemaType): unknown {
+  if (!value) {
+    return value;
+  }
+
+  if (schema.type === "number" || schema.type === "integer") {
+    return Number(value);
+  }
+
+  if (schema.type === "boolean") {
+    return value.toLowerCase() === "true";
+  }
+
+  if (schema.type === "object" || schema.type === "array") {
+    try {
+      return JSON.parse(value);
+    } catch (error) {
+      return value;
+    }
+  }
+
+  return value;
+}
+
+function convertParameters(
+  tool: Tool,
+  params: Record<string, string>,
+): Record<string, unknown> {
+  const result: Record<string, unknown> = {};
+  const properties = tool.inputSchema.properties || {};
+
+  for (const [key, value] of Object.entries(params)) {
+    const paramSchema = properties[key] as JsonSchemaType | undefined;
+
+    if (paramSchema) {
+      result[key] = convertParameterValue(value, paramSchema);
+    } else {
+      // If no schema is found for this parameter, keep it as string
+      result[key] = value;
+    }
+  }
+
+  return result;
+}
+
+export async function callTool(
+  client: Client,
+  name: string,
+  args: Record<string, string>,
+): Promise<McpResponse> {
+  try {
+    const toolsResponse = await listTools(client);
+    const tools = toolsResponse.tools as Tool[];
+    const tool = tools.find((t) => t.name === name);
+
+    let convertedArgs: Record<string, unknown> = args;
+
+    if (tool) {
+      // Convert parameters based on the tool's schema
+      convertedArgs = convertParameters(tool, args);
+    }
+
+    const response = await client.callTool({
+      name: name,
+      arguments: convertedArgs,
+    });
+    return response;
+  } catch (error) {
+    throw new Error(
+      `Failed to call tool ${name}: ${error instanceof Error ? error.message : String(error)}`,
+    );
+  }
+}

cli/src/client/types.ts

@@ -0,0 +1 @@
+export type McpResponse = Record<string, unknown>;

cli/src/error-handler.ts

@@ -0,0 +1,20 @@
+function formatError(error: unknown): string {
+  let message: string;
+
+  if (error instanceof Error) {
+    message = error.message;
+  } else if (typeof error === "string") {
+    message = error;
+  } else {
+    message = "Unknown error";
+  }
+
+  return message;
+}
+
+export function handleError(error: unknown): never {
+  const errorMessage = formatError(error);
+  console.error(errorMessage);
+
+  process.exit(1);
+}

cli/src/index.ts

@@ -0,0 +1,254 @@
+#!/usr/bin/env node
+
+import { Client } from "@modelcontextprotocol/sdk/client/index.js";
+import { Command } from "commander";
+import {
+  callTool,
+  connect,
+  disconnect,
+  getPrompt,
+  listPrompts,
+  listResources,
+  listResourceTemplates,
+  listTools,
+  LogLevel,
+  McpResponse,
+  readResource,
+  setLoggingLevel,
+  validLogLevels,
+} from "./client/index.js";
+import { handleError } from "./error-handler.js";
+import { packageInfo } from "./package-info.js";
+import { createTransport, TransportOptions } from "./transport.js";
+
+type Args = {
+  target: string[];
+  method?: string;
+  promptName?: string;
+  promptArgs?: Record<string, string>;
+  uri?: string;
+  logLevel?: LogLevel;
+  toolName?: string;
+  toolArgs?: Record<string, string>;
+};
+
+function createTransportOptions(target: string[]): TransportOptions {
+  if (target.length === 0) {
+    throw new Error(
+      "Target is required. Specify a URL or a command to execute.",
+    );
+  }
+
+  const [command, ...commandArgs] = target;
+
+  if (!command) {
+    throw new Error("Command is required.");
+  }
+
+  const isUrl = command.startsWith("http://") || command.startsWith("https://");
+
+  if (isUrl && commandArgs.length > 0) {
+    throw new Error("Arguments cannot be passed to a URL-based MCP server.");
+  }
+
+  return {
+    transportType: isUrl ? "sse" : "stdio",
+    command: isUrl ? undefined : command,
+    args: isUrl ? undefined : commandArgs,
+    url: isUrl ? command : undefined,
+  };
+}
+
+async function callMethod(args: Args): Promise<void> {
+  const transportOptions = createTransportOptions(args.target);
+  const transport = createTransport(transportOptions);
+  const client = new Client({
+    name: packageInfo.name,
+    version: packageInfo.version,
+  });
+
+  try {
+    await connect(client, transport);
+
+    let result: McpResponse;
+
+    // Tools methods
+    if (args.method === "tools/list") {
+      result = await listTools(client);
+    } else if (args.method === "tools/call") {
+      if (!args.toolName) {
+        throw new Error(
+          "Tool name is required for tools/call method. Use --tool-name to specify the tool name.",
+        );
+      }
+
+      result = await callTool(client, args.toolName, args.toolArgs || {});
+    }
+    // Resources methods
+    else if (args.method === "resources/list") {
+      result = await listResources(client);
+    } else if (args.method === "resources/read") {
+      if (!args.uri) {
+        throw new Error(
+          "URI is required for resources/read method. Use --uri to specify the resource URI.",
+        );
+      }
+
+      result = await readResource(client, args.uri);
+    } else if (args.method === "resources/templates/list") {
+      result = await listResourceTemplates(client);
+    }
+    // Prompts methods
+    else if (args.method === "prompts/list") {
+      result = await listPrompts(client);
+    } else if (args.method === "prompts/get") {
+      if (!args.promptName) {
+        throw new Error(
+          "Prompt name is required for prompts/get method. Use --prompt-name to specify the prompt name.",
+        );
+      }
+
+      result = await getPrompt(client, args.promptName, args.promptArgs || {});
+    }
+    // Logging methods
+    else if (args.method === "logging/setLevel") {
+      if (!args.logLevel) {
+        throw new Error(
+          "Log level is required for logging/setLevel method. Use --log-level to specify the log level.",
+        );
+      }
+
+      result = await setLoggingLevel(client, args.logLevel);
+    } else {
+      throw new Error(
+        `Unsupported method: ${args.method}. Supported methods include: tools/list, tools/call, resources/list, resources/read, resources/templates/list, prompts/list, prompts/get, logging/setLevel`,
+      );
+    }
+
+    console.log(JSON.stringify(result, null, 2));
+  } finally {
+    try {
+      await disconnect(transport);
+    } catch (disconnectError) {
+      throw disconnectError;
+    }
+  }
+}
+
+function parseKeyValuePair(
+  value: string,
+  previous: Record<string, string> = {},
+): Record<string, string> {
+  const parts = value.split("=");
+  const key = parts[0];
+  const val = parts.slice(1).join("=");
+
+  if (val === undefined || val === "") {
+    throw new Error(
+      `Invalid parameter format: ${value}. Use key=value format.`,
+    );
+  }
+
+  return { ...previous, [key as string]: val };
+}
+
+function parseArgs(): Args {
+  const program = new Command();
+
+  // Find if there's a -- in the arguments and split them
+  const argSeparatorIndex = process.argv.indexOf("--");
+  let preArgs = process.argv;
+  let postArgs: string[] = [];
+
+  if (argSeparatorIndex !== -1) {
+    preArgs = process.argv.slice(0, argSeparatorIndex);
+    postArgs = process.argv.slice(argSeparatorIndex + 1);
+  }
+
+  program
+    .name("inspector-cli")
+    .allowUnknownOption()
+    .argument("<target...>", "Command and arguments or URL of the MCP server")
+    //
+    // Method selection
+    //
+    .option("--method <method>", "Method to invoke")
+    //
+    // Tool-related options
+    //
+    .option("--tool-name <toolName>", "Tool name (for tools/call method)")
+    .option(
+      "--tool-args <pairs...>",
+      "Tool arguments as key=value pairs",
+      parseKeyValuePair,
+      {},
+    )
+    //
+    // Resource-related options
+    //
+    .option("--uri <uri>", "URI of the resource (for resources/read method)")
+    //
+    // Prompt-related options
+    //
+    .option(
+      "--prompt-name <promptName>",
+      "Name of the prompt (for prompts/get method)",
+    )
+    .option(
+      "--prompt-args <pairs...>",
+      "Prompt arguments as key=value pairs",
+      parseKeyValuePair,
+      {},
+    )
+    //
+    // Logging options
+    //
+    .option(
+      "--log-level <level>",
+      "Logging level (for logging/setLevel method)",
+      (value: string) => {
+        if (!validLogLevels.includes(value as any)) {
+          throw new Error(
+            `Invalid log level: ${value}. Valid levels are: ${validLogLevels.join(", ")}`,
+          );
+        }
+
+        return value as LogLevel;
+      },
+    );
+
+  // Parse only the arguments before --
+  program.parse(preArgs);
+
+  const options = program.opts() as Omit<Args, "target">;
+  let remainingArgs = program.args;
+
+  // Add back any arguments that came after --
+  const finalArgs = [...remainingArgs, ...postArgs];
+
+  if (!options.method) {
+    throw new Error(
+      "Method is required. Use --method to specify the method to invoke.",
+    );
+  }
+
+  return {
+    target: finalArgs,
+    ...options,
+  };
+}
+
+async function main(): Promise<void> {
+  process.on("uncaughtException", (error) => {
+    handleError(error);
+  });
+
+  try {
+    const args = parseArgs();
+    await callMethod(args);
+  } catch (error) {
+    handleError(error);
+  }
+}
+
+main();

cli/src/package-info.ts

@@ -0,0 +1,24 @@
+import { readFileSync } from "fs";
+import { dirname, resolve } from "path";
+import { fileURLToPath } from "url";
+
+type PackageInfo = {
+  name: string;
+  version: string;
+  description: string;
+};
+
+function getPackageInfo(): PackageInfo {
+  const __filename = fileURLToPath(import.meta.url);
+  const __dirname = dirname(__filename);
+  const packageJsonPath = resolve(__dirname, "..", "..", "package.json");
+  const packageJson = JSON.parse(readFileSync(packageJsonPath, "utf-8"));
+
+  return {
+    name: packageJson.name,
+    version: packageJson.version,
+    description: packageJson.description,
+  };
+}
+
+export const packageInfo: PackageInfo = getPackageInfo();

cli/src/transport.ts

@@ -0,0 +1,76 @@
+import { SSEClientTransport } from "@modelcontextprotocol/sdk/client/sse.js";
+import {
+  getDefaultEnvironment,
+  StdioClientTransport,
+} from "@modelcontextprotocol/sdk/client/stdio.js";
+import type { Transport } from "@modelcontextprotocol/sdk/shared/transport.js";
+import { findActualExecutable } from "spawn-rx";
+
+export type TransportOptions = {
+  transportType: "sse" | "stdio";
+  command?: string;
+  args?: string[];
+  url?: string;
+};
+
+function createSSETransport(options: TransportOptions): Transport {
+  const baseUrl = new URL(options.url ?? "");
+  const sseUrl = new URL("/sse", baseUrl);
+
+  return new SSEClientTransport(sseUrl);
+}
+
+function createStdioTransport(options: TransportOptions): Transport {
+  let args: string[] = [];
+
+  if (options.args !== undefined) {
+    args = options.args;
+  }
+
+  const processEnv: Record<string, string> = {};
+
+  for (const [key, value] of Object.entries(process.env)) {
+    if (value !== undefined) {
+      processEnv[key] = value;
+    }
+  }
+
+  const defaultEnv = getDefaultEnvironment();
+
+  const env: Record<string, string> = {
+    ...processEnv,
+    ...defaultEnv,
+  };
+
+  const { cmd: actualCommand, args: actualArgs } = findActualExecutable(
+    options.command ?? "",
+    args,
+  );
+
+  return new StdioClientTransport({
+    command: actualCommand,
+    args: actualArgs,
+    env,
+    stderr: "pipe",
+  });
+}
+
+export function createTransport(options: TransportOptions): Transport {
+  const { transportType } = options;
+
+  try {
+    if (transportType === "stdio") {
+      return createStdioTransport(options);
+    }
+
+    if (transportType === "sse") {
+      return createSSETransport(options);
+    }
+
+    throw new Error(`Unsupported transport type: ${transportType}`);
+  } catch (error) {
+    throw new Error(
+      `Failed to create transport: ${error instanceof Error ? error.message : String(error)}`,
+    );
+  }
+}

cli/tsconfig.json

@@ -0,0 +1,17 @@
+{
+  "compilerOptions": {
+    "target": "ES2022",
+    "module": "NodeNext",
+    "moduleResolution": "NodeNext",
+    "outDir": "./build",
+    "rootDir": "./src",
+    "strict": true,
+    "esModuleInterop": true,
+    "skipLibCheck": true,
+    "forceConsistentCasingInFileNames": true,
+    "resolveJsonModule": true,
+    "noUncheckedIndexedAccess": true
+  },
+  "include": ["src/**/*"],
+  "exclude": ["node_modules", "packages", "**/*.spec.ts", "build"]
+}