TypeScript MCP Server

Generate a TypeScript Model Context Protocol (MCP) server for providing context to Large Language Models (LLMs), and optionally deploy it to Amazon Bedrock AgentCore.

What is MCP?

The Model Context Protocol (MCP) is an open standard that allows AI assistants to interact with external tools and resources. It provides a consistent way for LLMs to:

• Execute tools (functions) that perform actions or retrieve information
• Access resources that provide context or data

Usage

Generate an MCP Server

You can generate a TypeScript MCP server in two ways:

VSCode

1. Install the Nx Console VSCode Plugin if you haven't already
2. Open the Nx Console in VSCode
3. Click Generate (UI) in the "Common Nx Commands" section
4. Search for @aws/nx-plugin - ts#mcp-server
5. Fill in the required parameters
6. Click Generate

CLI

pnpm

pnpm nx g @aws/nx-plugin:ts#mcp-server

yarn

yarn nx g @aws/nx-plugin:ts#mcp-server

npm

npx nx g @aws/nx-plugin:ts#mcp-server

bun

bunx nx g @aws/nx-plugin:ts#mcp-server

You can also perform a dry-run to see what files would be changed

pnpm

pnpm nx g @aws/nx-plugin:ts#mcp-server --dry-run

yarn

yarn nx g @aws/nx-plugin:ts#mcp-server --dry-run

npm

npx nx g @aws/nx-plugin:ts#mcp-server --dry-run

bun

bunx nx g @aws/nx-plugin:ts#mcp-server --dry-run

Tip

First use the ts#project generator to create a project to add your MCP server to.

Options

Parameter	Type	Default	Description
project Required	string	-	The project to add an MCP server to
computeType	string	BedrockAgentCoreRuntime	The type of compute to host your MCP server. Select None for no hosting.
name	string	-	The name of your MCP server (default: mcp-server)
iacProvider	string	CDK	The preferred IaC provider

Generator Output

The generator will add the following files to your existing TypeScript project:

• Directoryyour-project/

  • Directorysrc/

    • Directorymcp-server/ (or custom name if specified)

      • index.ts Exports your server
      • server.ts Main server definition
      • stdio.ts Entry point for STDIO transport, useful for simple local MCP servers
      • http.ts Entry point for Streamable HTTP transport, useful for hosting your MCP server
      • Directorytools/

        • add.ts Sample tool
      • Directoryresources/

        • sample-guidance.ts Sample resource
      • Dockerfile Entry point for hosting your MCP server (excluded when computeType is set to None)
  • package.json Updated with bin entry and MCP dependencies
  • project.json Updated with MCP server serve target

Infrastructure

Note

If you selected None for computeType, the generator will not vend any infrastructure as code.

Since this generator vends infrastructure as code based on your chosen iacProvider, it will create a project in packages/common which includes the relevant CDK constructs or Terraform modules.

The common infrastructure as code project is structured as follows:

CDK

• Directorypackages/common/constructs

  • Directorysrc

    • Directoryapp/ Constructs for infrastructure specific to a project/generator

      • …
    • Directorycore/ Generic constructs which are reused by constructs in app

      • …
    • index.ts Entry point exporting constructs from app
  • project.json Project build targets and configuration

Note

This project is generated using the ts#project generator and therefore configures the same build targets.

Terraform

• Directorypackages/common/terraform

  • Directorysrc

    • Directoryapp/ Terraform modules for infrastructure specific to a project/generator

      • …
    • Directorycore/ Generic modules which are reused by modules in app

      • …
  • project.json Project build targets and configuration

Note

This project is generated using the terraform#project generator and therefore configures the same build targets.

For deploying your MCP Server, the following files are generated:

CDK

• Directorypackages/common/constructs/src

  • Directoryapp

    • Directorymcp-servers

      • Directory<project-name>

        • <project-name>.ts CDK construct for deploying your MCP Server
        • Dockerfile Passthrough docker file used by the CDK construct
  • Directorycore

    • Directoryagent-core

      • runtime.ts Generic CDK construct for deploying to Bedrock AgentCore Runtime

Terraform

• Directorypackages/common/terraform/src

  • Directoryapp

    • Directorymcp-servers

      • Directory<project-name>

        • <project-name>.tf Module for deploying your MCP Server
  • Directorycore

    • Directoryagent-core

      • runtime.tf Generic module for deploying to Bedrock AgentCore Runtime

Working with Your MCP Server

Adding Tools

Tools are functions that the AI assistant can call to perform actions. You can add new tools in the server.ts file:

server.tool("toolName", "tool description",
  { param1: z.string(), param2: z.number() }, // Input schema using Zod
  async ({ param1, param2 }) => {
    // Tool implementation
    return {
      content: [{ type: "text", text: "Result" }]
    };
  }
);

Caution

The MCP SDK only supports Zod v3 at present. To allow for Zod v4 to be used in other generators, the dependency on Zod v3 is installed as zod-v3. For MCP tool schemas, you will need to import Zod as follows:

import { z } from 'zod-v3';

Once this issue with the MCP SDK is resolved, you can remove the additional zod-v3 dependency and just import from zod.

Adding Resources

Resources provide context to the AI assistant. You can add static resources from files or dynamic resources:

const exampleContext = 'some context to return';

server.resource('resource-name', 'example://resource', async (uri) => ({
  contents: [{ uri: uri.href, text: exampleContext }],
}));

// Dynamic resource
server.resource('dynamic-resource', 'dynamic://resource', async (uri) => {
  const data = await fetchSomeData();
  return {
    contents: [{ uri: uri.href, text: data }],
  };
});

Configuring with AI Assistants

Configuration Files

Most AI assistants that support MCP use a similar configuration approach. You’ll need to create or update a configuration file with your MCP server details:

{
  "mcpServers": {
    "your-mcp-server": {
      "command": "npx",
      "args": ["tsx", "/path/to/your-mcp-server/stdio.ts"]
    }
  }
}

Caution

If you receive an error such as ENOENT npx when connecting to your server, you might need to specify the full path to npx, which you can obtain by running which npx in your terminal.

Hot Reload

While developing your MCP server, you may wish to configure the --watch flag so that the AI assistant always sees the latest versions of tools/resources:

{
  "mcpServers": {
    "your-mcp-server": {
      "command": "npx",
      "args": ["tsx", "--watch", "/path/to/your-mcp-server/stdio.ts"]
    }
  }
}

Note

If you add new tools or resources you may need to refresh your MCP server in the AI assistant.

Assistant-Specific Configuration

Please refer to the following documentation for configuring MCP with specific AI Assistants:

• Amazon Q Developer
• Cline
• Cursor
• Claude Code
• Roo Code

Tip

Some AI Assistants, such as Amazon Q Developer, allow you to specify workspace level MCP server configuration, which is particularly useful for defining the relevant MCP servers for a particular project.

Running Your MCP Server

Inspector

The generator configures a target named <your-server-name>-inspect, which starts the MCP Inspector with the configuration to connect to your MCP server using STDIO transport.

pnpm

pnpm nx run your-project:your-server-name-inspect

yarn

yarn nx run your-project:your-server-name-inspect

npm

npx nx run your-project:your-server-name-inspect

bun

bunx nx run your-project:your-server-name-inspect

This will start the inspector at http://localhost:6274. Get started by clicking on the “Connect” button.

STDIO

The easiest way to test and use an MCP server is by using the inspector or configuring it with an AI assistant (as above).

You can however run your server with STDIO transport directly using the <your-server-name>-serve-stdio target.

pnpm

pnpm nx run your-project:your-server-name-serve-stdio

yarn

yarn nx run your-project:your-server-name-serve-stdio

npm

npx nx run your-project:your-server-name-serve-stdio

bun

bunx nx run your-project:your-server-name-serve-stdio

This command uses tsx --watch to automatically restart the server when files change.

Streamable HTTP

If you would like to run your MCP server locally using Streamable HTTP transport, you can use the <your-server-name>-serve-http target.

pnpm

pnpm nx run your-project:your-server-name-serve-http

yarn

yarn nx run your-project:your-server-name-serve-http

npm

npx nx run your-project:your-server-name-serve-http

bun

bunx nx run your-project:your-server-name-serve-http

This command uses tsx --watch to automatically restart the server when files change.

Deploying Your MCP Server to Bedrock AgentCore Runtime

Infrastructure as Code

If you selected BedrockAgentCoreRuntime for computeType, the relevant CDK or Terraform infrastructure is generated which you can use to deploy your MCP server to Amazon Bedrock AgentCore Runtime.

CDK

A CDK construct is generated for your, named based on the name you chose when running the generator, or <ProjectName>McpServer by default.

You can use this CDK construct in a CDK application:

import { MyProjectMcpServer } from ':my-scope/common-constructs';

export class ExampleStack extends Stack {
  constructor(scope: Construct, id: string) {
    // Add the MCP server to your stack
    new MyProjectMcpServer(this, 'MyProjectMcpServer');
  }
}

Terraform

A Terraform module is generated for you, named based on the name you chose when running the generator, or <ProjectName>-mcp-server by default.

You can use this terraform module in a Terraform project:

# MCP Server
module "my_project_mcp_server" {
  # Relative path to the generated module in the common/terraform project
  source = "../../common/terraform/src/app/mcp-servers/my-project-mcp-server"
}

Caution

Docker is required to build and deploy your MCP server. Make sure you have installed and launched Docker to avoid errors such as:

ERROR: Cannot connect to the Docker daemon at unix://path/to/docker.sock.

Authentication

IAM

By default, your MCP server will be secured using IAM authentication, simply deploy it without any arguments:

CDK

import { MyProjectMcpServer } from ':my-scope/common-constructs';

export class ExampleStack extends Stack {
  constructor(scope: Construct, id: string) {
    new MyProjectMcpServer(this, 'MyProjectMcpServer');
  }
}

You can grant access to invoke your MCP on Bedrock AgentCore Runtime using the grantInvoke method. For example you may wish for an agent generated with the py#strands-agent generator to call your MCP server:

import { MyProjectAgent, MyProjectMcpServer } from ':my-scope/common-constructs';

export class ExampleStack extends Stack {
  constructor(scope: Construct, id: string) {
    const agent = new MyProjectAgent(this, 'MyProjectAgent');
    const mcpServer = new MyProjectMcpServer(this, 'MyProjectMcpServer');

    mcpServer.agentCoreRuntime.grantInvoke(agent.agentCoreRuntime);
  }
}

Terraform

# MCP Server
module "my_project_mcp_server" {
  # Relative path to the generated module in the common/terraform project
  source = "../../common/terraform/src/app/mcp-servers/my-project-mcp-server"
}

To grant access to invoke your agent, you will need to add a policy such as the following, referencing the module.my_project_mcp_server.agent_core_runtime_arn output:

{
  Effect = "Allow"
  Action = [
    "bedrock-agentcore:InvokeAgentRuntime"
  ]
  Resource = [
    module.my_project_mcp_server.agent_core_runtime_arn,
    "${module.my_project_mcp_server.agent_core_runtime_arn}/*"
  ]
}

Cognito JWT Authentication

The below demonstrates how to configure Cognito authentication for your agent.

CDK

To configure JWT authentication, you can pass the authorizerConfiguration property to your MCP server construct. Here is an example which configures a Cognito user pool and client to secure the MCP server:

import { MyProjectMcpServer } from ':my-scope/common-constructs';

export class ExampleStack extends Stack {
  constructor(scope: Construct, id: string) {
    const userPool = new UserPool(this, 'UserPool');
    const client = userPool.addClient('Client', {
      authFlows: {
        userPassword: true,
      },
    });

    new MyProjectMcpServer(this, 'MyProjectMcpServer', {
      authorizerConfiguration: {
        customJWTAuthorizer: {
          discoveryUrl: `https://cognito-idp.${Stack.of(userPool).region}.amazonaws.com/${userPool.userPoolId}/.well-known/openid-configuration`,
          allowedClients: [client.userPoolClientId],
        },
      },
    });
  }
}

Terraform

To configure JWT authentication, you can edit your MCP Server module to configure the customJWTAuthorizer variable as follows:

packages/common/terraform/src/app/mcp-servers/my-project-mcp-server/my-project-mcp-server.tf

data "aws_region" "current" {}

locals {
  aws_region = data.aws_region.current.name

  # Replace with your user pool and client ids or expose as variables
  user_pool_id = "xxx"
  user_pool_client_ids = ["yyy"]
}

module "agent_core_runtime" {
  source = "../../../core/agent-core"
  agent_runtime_name = "MyProjectMcpServer"
  docker_image_tag = "my-scope-my-project-agent:latest"
  server_protocol = "MCP"
  customJWTAuthorizer = {
    discoveryUrl = "https://cognito-idp.${local.aws_region}.amazonaws.com/${local.user_pool_id}/.well-known/openid-configuration",
    allowedClients = local.user_pool_client_ids
  }
  env = var.env
  additional_iam_policy_statements = var.additional_iam_policy_statements
  tags = var.tags
}

Bundle Target

In order to build your MCP server for Bedrock AgentCore Runtime, a <your-mcp-server>-bundle target is added to your project, which:

• Bundles your MCP server into a single JavaScript file with esbuild, using http.ts as the entrypoint for a Streamable HTTP MCP server.
• Builds a docker image from the Dockerfile which runs this bundled server on port 8000, as per the MCP protocol contract

Tip

The docker image is built using a tag (for example my-scope-my-project-mcp-server:latest), which the CDK construct’s Dockerfile inherits from, allowing for your Dockerfile to be co-located with your MCP server project.

Observability

Your MCP server is automatically configured with observability using the AWS Distro for Open Telemetry (ADOT), by configuring auto-instrumentation in your Dockerfile.

You can find traces in the CloudWatch AWS Console, by selecting “GenAI Observability” in the menu. Note that for traces to be populated you will need to enable Transaction Search.

For more details, refer to the AgentCore documentation on observability.