chore(build): build a universal ESM and CommonJS package

.github/workflows/check.yml

@@ -55,4 +55,4 @@ jobs:
           rm -rf node_modules
           npm pkg set scripts.prepare="exit 0"
           npm install --omit=dev
-      - run: npx -y @modelcontextprotocol/inspector --cli --method tools/list -- node dist/index.js --connectionString "mongodb://localhost"
+      - run: npx -y @modelcontextprotocol/inspector --cli --method tools/list -- node dist/esm/index.js --connectionString "mongodb://localhost"

.github/workflows/prepare_release.yaml

@@ -32,6 +32,7 @@ jobs:
         id: bump-version
         run: |
           echo "NEW_VERSION=$(npm version ${{ inputs.version }} --no-git-tag-version)" >> $GITHUB_OUTPUT
+          npm run build:update-version
       - name: Create release PR
         uses: peter-evans/create-pull-request@271a8d0340265f705b14b6d32b9829c1cb33d45e # 7.0.8
         id: create-pr

.smithery/Dockerfile

@@ -27,4 +27,4 @@ RUN npm ci --production --ignore-scripts
 # Expose no ports (stdio only)
 
 # Default command
-CMD ["node", "dist/index.js"]
+CMD ["node", "dist/esm/index.js"]

.smithery/smithery.yaml

@@ -40,7 +40,7 @@ startCommand:
     # A function that produces the CLI command to start the MCP on stdio.
     |-
     (config) => {
-      const args = ['dist/index.js'];
+      const args = ['dist/esm/index.js'];
       if (config) {
         if (config.atlasClientId) {
           args.push('--apiClientId');

.vscode/launch.json

@@ -18,7 +18,7 @@
       "request": "launch",
       "name": "Launch Program",
       "skipFiles": ["<node_internals>/**"],
-      "program": "${workspaceFolder}/dist/index.js",
+      "program": "${workspaceFolder}/dist/esm/index.js",
       "preLaunchTask": "tsc: build - tsconfig.build.json",
       "outFiles": ["${workspaceFolder}/dist/**/*.js"]
     }

CONTRIBUTING.md

@@ -33,7 +33,7 @@ This project implements a Model Context Protocol (MCP) server for MongoDB and Mo
    {
      "mcpServers": {
        "MongoDB": {
-         "command": "/path/to/mongodb-mcp-server/dist/index.js"
+         "command": "/path/to/mongodb-mcp-server/dist/esm/index.js"
        }
      }
    }
@@ -104,7 +104,7 @@ npm run inspect
 This is equivalent to:
 
 ```shell
-npx @modelcontextprotocol/inspector -- node dist/index.js
+npx @modelcontextprotocol/inspector -- node dist/esm/index.js
 ```
 
 ## Pull Request Guidelines

package.json

@@ -2,26 +2,45 @@
   "name": "mongodb-mcp-server",
   "description": "MongoDB Model Context Protocol Server",
   "version": "0.1.3",
-  "main": "dist/index.js",
+  "type": "module",
+  "exports": {
+    ".": {
+      "import": {
+        "types": "./dist/esm/lib.d.ts",
+        "default": "./dist/esm/lib.js"
+      },
+      "require": {
+        "types": "./dist/cjs/lib.d.ts",
+        "default": "./dist/cjs/lib.js"
+      }
+    }
+  },
+  "main": "./dist/cjs/lib.js",
+  "types": "./dist/cjs/lib.d.ts",
   "author": "MongoDB <[email protected]>",
   "homepage": "https://github.com/mongodb-js/mongodb-mcp-server",
   "repository": {
     "url": "https://github.com/mongodb-js/mongodb-mcp-server.git"
   },
   "bin": {
-    "mongodb-mcp-server": "dist/index.js"
+    "mongodb-mcp-server": "dist/esm/index.js"
   },
   "publishConfig": {
     "access": "public"
   },
-  "type": "module",
+  "files": [
+    "dist"
+  ],
   "scripts": {
     "prepare": "npm run build",
     "build:clean": "rm -rf dist",
-    "build:compile": "tsc --project tsconfig.build.json",
-    "build:chmod": "chmod +x dist/index.js",
-    "build": "npm run build:clean && npm run build:compile && npm run build:chmod",
-    "inspect": "npm run build && mcp-inspector -- dist/index.js",
+    "build:update-package-version": "tsx scripts/updatePackageVersion.ts",
+    "build:esm": "tsc --project tsconfig.esm.json",
+    "build:cjs": "tsc --project tsconfig.cjs.json",
+    "build:universal-package": "tsx scripts/createUniversalPackage.ts",
+    "build:chmod": "chmod +x dist/esm/index.js",
+    "build": "npm run build:clean && npm run build:esm && npm run build:cjs && npm run build:universal-package && npm run build:chmod",
+    "inspect": "npm run build && mcp-inspector -- dist/esm/index.js",
     "prettier": "prettier",
     "check": "npm run build && npm run check:types && npm run check:lint && npm run check:format",
     "check:lint": "eslint .",

scripts/createUniversalPackage.ts

@@ -0,0 +1,25 @@
+#!/usr/bin/env tsx
+
+import { writeFileSync, mkdirSync } from "fs";
+import { resolve } from "path";
+
+const distDir = resolve("dist");
+
+/**
+ * Node uses the package.json to know whether files with a .js extensions
+ * should be interpreted as CommonJS or ESM.
+ */
+// ESM package.json
+const esmPath = resolve(distDir, "esm", "package.json");
+mkdirSync(resolve(distDir, "esm"), { recursive: true });
+writeFileSync(esmPath, JSON.stringify({ type: "module" }));
+
+// CJS package.json
+const cjsPath = resolve(distDir, "cjs", "package.json");
+mkdirSync(resolve(distDir, "cjs"), { recursive: true });
+writeFileSync(cjsPath, JSON.stringify({ type: "commonjs" }));
+
+// Create a dist/index.js file that imports the ESM index.js file
+// To minimize breaking changes from pre-universal package time.
+const indexPath = resolve(distDir, "index.js");
+writeFileSync(indexPath, `import "./esm/index.js";`);

scripts/updatePackageVersion.ts

@@ -0,0 +1,22 @@
+#!/usr/bin/env node
+
+import { readFileSync, writeFileSync } from "fs";
+import { join } from "path";
+
+// Read package.json
+const packageJsonPath = join(import.meta.dirname, "..", "package.json");
+const packageJson = JSON.parse(readFileSync(packageJsonPath, "utf-8")) as {
+    version: string;
+};
+
+// Define the packageInfo.ts content
+const packageInfoContent = `// This file was generated by scripts/updatePackageVersion.ts - Do not edit it manually.
+export const packageInfo = {
+    version: "${packageJson.version}",
+    mcpServerName: "MongoDB MCP Server",
+};
+`;
+
+// Write to packageInfo.ts
+const packageInfoPath = join(import.meta.dirname, "..", "src", "common", "packageInfo.ts");
+writeFileSync(packageInfoPath, packageInfoContent);

src/common/packageInfo.ts

@@ -1,6 +1,5 @@
-import packageJson from "../../package.json" with { type: "json" };
-
+// This file was generated by scripts/updatePackageVersion.ts - Do not edit it manually.
 export const packageInfo = {
-    version: packageJson.version,
+    version: "0.1.3",
     mcpServerName: "MongoDB MCP Server",
 };

src/common/session.ts

@@ -2,7 +2,7 @@ import { NodeDriverServiceProvider } from "@mongosh/service-provider-node-driver
 import { ApiClient, ApiClientCredentials } from "./atlas/apiClient.js";
 import { Implementation } from "@modelcontextprotocol/sdk/types.js";
 import logger, { LogId } from "./logger.js";
-import EventEmitter from "events";
+import { EventEmitter } from "events";
 import { ConnectOptions } from "./config.js";
 import { setAppNameParamIfMissing } from "../helpers/connectionOptions.js";
 import { packageInfo } from "./packageInfo.js";

src/index.ts

@@ -9,50 +9,54 @@ import { packageInfo } from "./common/packageInfo.js";
 import { Telemetry } from "./telemetry/telemetry.js";
 import { createEJsonTransport } from "./helpers/EJsonTransport.js";
 
-try {
-    const session = new Session({
-        apiBaseUrl: config.apiBaseUrl,
-        apiClientId: config.apiClientId,
-        apiClientSecret: config.apiClientSecret,
-    });
-    const mcpServer = new McpServer({
-        name: packageInfo.mcpServerName,
-        version: packageInfo.version,
-    });
-
-    const telemetry = Telemetry.create(session, config);
-
-    const server = new Server({
-        mcpServer,
-        session,
-        telemetry,
-        userConfig: config,
-    });
-
-    const transport = createEJsonTransport();
-
-    const shutdown = () => {
-        logger.info(LogId.serverCloseRequested, "server", `Server close requested`);
-
-        server
-            .close()
-            .then(() => {
-                logger.info(LogId.serverClosed, "server", `Server closed successfully`);
-                process.exit(0);
-            })
-            .catch((err: unknown) => {
-                const error = err instanceof Error ? err : new Error(String(err));
-                logger.error(LogId.serverCloseFailure, "server", `Error closing server: ${error.message}`);
-                process.exit(1);
-            });
-    };
-
-    process.once("SIGINT", shutdown);
-    process.once("SIGTERM", shutdown);
-    process.once("SIGQUIT", shutdown);
-
-    await server.connect(transport);
-} catch (error: unknown) {
-    logger.emergency(LogId.serverStartFailure, "server", `Fatal error running server: ${error as string}`);
-    process.exit(1);
+async function main() {
+    try {
+        const session = new Session({
+            apiBaseUrl: config.apiBaseUrl,
+            apiClientId: config.apiClientId,
+            apiClientSecret: config.apiClientSecret,
+        });
+        const mcpServer = new McpServer({
+            name: packageInfo.mcpServerName,
+            version: packageInfo.version,
+        });
+
+        const telemetry = Telemetry.create(session, config);
+
+        const server = new Server({
+            mcpServer,
+            session,
+            telemetry,
+            userConfig: config,
+        });
+
+        const transport = createEJsonTransport();
+
+        const shutdown = () => {
+            logger.info(LogId.serverCloseRequested, "server", `Server close requested`);
+
+            server
+                .close()
+                .then(() => {
+                    logger.info(LogId.serverClosed, "server", `Server closed successfully`);
+                    process.exit(0);
+                })
+                .catch((err: unknown) => {
+                    const error = err instanceof Error ? err : new Error(String(err));
+                    logger.error(LogId.serverCloseFailure, "server", `Error closing server: ${error.message}`);
+                    process.exit(1);
+                });
+        };
+
+        process.once("SIGINT", shutdown);
+        process.once("SIGTERM", shutdown);
+        process.once("SIGQUIT", shutdown);
+
+        await server.connect(transport);
+    } catch (error: unknown) {
+        logger.emergency(LogId.serverStartFailure, "server", `Fatal error running server: ${error as string}`);
+        process.exit(1);
+    }
 }
+
+void main();

src/lib.ts

@@ -0,0 +1,4 @@
+export { Server, type ServerOptions } from "./server.js";
+export { Telemetry } from "./telemetry/telemetry.js";
+export { Session, type SessionOptions } from "./common/session.js";
+export type { UserConfig, ConnectOptions } from "./common/config.js";

tests/integration/build.test.ts

@@ -0,0 +1,46 @@
+import { createRequire } from "module";
+import path from "path";
+import { describe, it, expect } from "vitest";
+
+// Current directory where the test file is located
+const currentDir = import.meta.dirname;
+
+// Get project root (go up from tests/integration to project root)
+const projectRoot = path.resolve(currentDir, "../..");
+
+const esmPath = path.resolve(projectRoot, "dist/esm/lib.js");
+const cjsPath = path.resolve(projectRoot, "dist/cjs/lib.js");
+
+describe("Build Test", () => {
+    it("should successfully require CommonJS module", () => {
+        const require = createRequire(__filename);
+
+        const cjsModule = require(cjsPath) as Record<string, unknown>;
+
+        expect(cjsModule).toBeDefined();
+        expect(typeof cjsModule).toBe("object");
+    });
+
+    it("should successfully import ESM module", async () => {
+        const esmModule = (await import(esmPath)) as Record<string, unknown>;
+
+        expect(esmModule).toBeDefined();
+        expect(typeof esmModule).toBe("object");
+    });
+
+    it("should have matching exports between CommonJS and ESM modules", async () => {
+        // Import CommonJS module
+        const require = createRequire(__filename);
+        const cjsModule = require(cjsPath) as Record<string, unknown>;
+
+        // Import ESM module
+        const esmModule = (await import(esmPath)) as Record<string, unknown>;
+
+        // Compare exports
+        const cjsKeys = Object.keys(cjsModule).sort();
+        const esmKeys = Object.keys(esmModule).sort();
+
+        expect(cjsKeys).toEqual(esmKeys);
+        expect(cjsKeys).toEqual(["Server", "Session", "Telemetry"]);
+    });
+});

tsconfig.build.json

@@ -14,7 +14,9 @@
     "skipLibCheck": true,
     "resolveJsonModule": true,
     "allowSyntheticDefaultImports": true,
-    "typeRoots": ["./node_modules/@types", "./src/types"]
+    "typeRoots": ["./node_modules/@types", "./src/types"],
+    "declaration": true,
+    "declarationMap": true
   },
   "include": ["src/**/*.ts"]
 }

tsconfig.cjs.json

@@ -0,0 +1,8 @@
+{
+  "extends": "./tsconfig.build.json",
+  "compilerOptions": {
+    "module": "commonjs",
+    "moduleResolution": "node",
+    "outDir": "./dist/cjs"
+  }
+}

tsconfig.esm.json

@@ -0,0 +1,8 @@
+{
+  "extends": "./tsconfig.build.json",
+  "compilerOptions": {
+    "module": "esnext",
+    "moduleResolution": "bundler",
+    "outDir": "./dist/esm"
+  }
+}