# MCP TypeScript Template
A TypeScript template for building remote Model Context Protocol (MCP) servers with modern tooling and best practices while leveraging the [MCP TypeScript SDK](https://github.com/modelcontextprotocol/typescript-sdk).
## Features
This template provides:
- **TypeScript 7** - Native compiler with strict configuration; TypeScript 6 remains available as `tsc6`
- **Effect** - Typed configuration, validation, logging, error handling, and async workflows
- **Vite+** - Build, test, lint, and format through the `vp` CLI (Vite, Vitest, Oxlint, and Oxfmt). npm script names stay the same
- **Express** - Fast, unopinionated web framework for HTTP server
- **Oxlint anti-slop rules** - Vendored custom plugins in `tools/oxlint/anti-slop`, loaded by Vite+
- **Docker** - Containerization support
- **Example Tools** - `echo` and `elicit_echo` tools demonstrating tool implementation, structured output, annotations, and MCP elicitation
- **Example Agent Skill** - `example-server` published through the MCP Skills extension (`skills/list`, `skills/get`, and `resources/read`)
## Getting Started
The easiest way to get started is using `degit`:
1. **Create a new project from this template**
```bash
npx degit nickytonline/mcp-typescript-template my-mcp-server
cd my-mcp-server
```
2. **Install dependencies**
```bash
npm install
```
3. **Build the project**
```bash
npm run build
```
4. **Start the server**
```bash
npm start
```
The server will be available at `http://localhost:3000` for MCP connections.
### Alternative: Using GitHub Template
You can also click the "Use this template" button on GitHub to create a new repository, then clone it:
```bash
git clone <your-repo-url>
cd my-mcp-server
npm install
```
## Development
Node.js 24.11 or newer. Vite+ does not run on earlier Node 24 releases. `npm start` still runs `node dist/index.js`, and the bundle target stays Node 24.
[mise](https://mise.jdx.dev/) users get that runtime from `mise.toml` (`node = "24"`). Vite+ does not read `mise.toml`. The project-local `vp` binary uses the Node already on PATH; a global `vp` install is not required.
### Type checking
`npm run typecheck` uses the TypeScript 7 compiler. The `typescript` package remains an npm alias for the TypeScript 6 compatibility package and is available as `tsc6` when needed.
### Watch mode for development (with hot reloading)
```bash
npm run dev
```
### Build the project
```bash
npm run build
```
### Linting
- Lint the project
```bash
npm run lint
```
- Fix all auto-fixable lint errors
```bash
npm run lint:fix
```
### Formatting
- Format files in the project
```bash
npm run format
```
- Check formatting
```bash
npm run format:check
```
## Testing Your MCP Server
You can test your MCP server using the [MCP Inspector](https://github.com/modelcontextprotocol/inspector):
```bash
npx @modelcontextprotocol/inspector
```
This will launch a web interface that allows you to:
- Connect to your MCP server
- Test your tools interactively
- View request/response messages
- Debug your MCP implementation
Make sure your server is running (using `npm start` or `npm run dev`) before connecting with the inspector.
## Available Tools
The template includes two example tools:
### echo
Echoes back the provided message - a simple example to demonstrate MCP tool implementation.
**Parameters:**
- `message` (string) - The message to echo back
### elicit_echo
Demonstrates [MCP elicitation](https://modelcontextprotocol.io/specification/2025-06-18/client/elicitation): the tool takes no input, asks the connected client to prompt the user for a message, then echoes it back. Handles all three elicitation outcomes (accept, decline, cancel) and errors when the client doesn't support elicitation.
Both tools declare an `outputSchema` and return `structuredContent` alongside the text result, and carry `annotations` (`readOnlyHint`, `idempotentHint`, `openWorldHint`) describing their safety profile.
## Agent skill
The template bundles an [example Agent Skill](skills/example-server/SKILL.md) that tells a client how to use `echo` and `elicit_echo`, and how to replace that guidance. On protocol revision `2026-07-28` or later, `server/discover` advertises `io.modelcontextprotocol/skills`. Clients that support the extension call `skills/list` or `skills/get` for `skill://example-server/SKILL.md`, then read the same bytes with `resources/read`. The listing includes a file manifest with SHA-256 digests and byte sizes, plus `ttlMs` and `cacheScope` freshness hints. Directory reads are left unimplemented.
Add another skill by creating `skills/<name>/SKILL.md` whose frontmatter `name` matches `<name>`. The server publishes valid, non-hidden skill directories under `skills/`. Coding skills in `.agents/skills/` stay local to this repository and are separate from the skills the running server publishes.
A digest match checks that fetched bytes match the server's manifest. Reading a resource returns those bytes; the host decides whether to verify, approve, and load the skill. See [docs/AGENT_SKILLS.md](docs/AGENT_SKILLS.md).
## Customizing Your MCP Server
1. **Update package.json** - Change `name`, `version`, description, and keywords. The MCP server name and version are read from `name` and `version` unless `SERVER_NAME` or `SERVER_VERSION` is set
2. **Modify src/tools.ts** - Replace the `echo` / `elicit_echo` tools with your custom tools
3. **Replace skills/example-server** - Add your own `skills/<name>/SKILL.md` and remove the example once it no longer describes the server. Delete every skill directory, leaving `skills/` in place, to publish none
4. **Add your logic** - Create additional TypeScript files for your business logic
5. **Update README** - Document your specific MCP server functionality
## Docker
Build and run using Docker:
- Build the Docker image
```bash
docker build -t my-mcp-server .
```
- Run the container
```bash
docker run -p 3000:3000 my-mcp-server
```
### Docker Compose
A `docker-compose.yml` is included with a health check pre-configured:
```bash
docker compose up --build
```
## Project Structure
```
mcp-typescript-template/
โโโ src/
โ โโโ app.ts # Express app and MCP Node adapter wiring
โ โโโ app.test.ts # HTTP boundary integration tests
โ โโโ index.ts # Effect startup and shutdown
โ โโโ tools.ts # Tool registration (registerTools) and logic
โ โโโ tools.test.ts # Integration tests (in-memory client/server)
โ โโโ skills.ts # Bundled Agent Skills and MCP Skills extension
โ โโโ skills.test.ts # Skill discovery, manifest, and resource tests
โ โโโ config.ts # Env var loading and validation (Effect Config)
โ โโโ logger.ts # Effect structured logging
โ โโโ lib/
โ โโโ utils.ts # MCP response helpers
โ โโโ mcp-schema.ts # Effect Schema โ MCP Standard Schema adapter
โ โโโ utils.test.ts # Unit tests
โ โโโ mcp-schema.test.ts # Schema adapter and dialect tests
โโโ skills/
โ โโโ example-server/SKILL.md # Example Agent Skill published by the server
โโโ docs/AGENT_SKILLS.md # Discovery, security, packaging, and compatibility
โโโ dist/ # Built output (generated)
โโโ tsconfig.json # TypeScript configuration
โโโ vite.config.ts # Vite+ build, lint, and format configuration
โโโ mise.toml # Node 24 pin for mise
โโโ Dockerfile # Docker configuration
โโโ package.json # Dependencies and scripts
```
## Architecture
This template follows a simple architecture:
- **HTTP Transport** - Uses Express with `createMcpHandler` (`@modelcontextprotocol/server`) for remote MCP connections
- **Stateless** - Per the MCP 2026-07-28 spec: no session handshake or session ID; the app creates a fresh server per request and supports older clients through the SDK fallback
- **Tool Registration** - `registerTools(server)` in `src/tools.ts` is the single source of truth for tool wiring; `getServer()` and the tests both use it
- **Agent Skills** - `registerSkills(server)` in `src/skills.ts` publishes `skills/` through MCP resources and the `io.modelcontextprotocol/skills` extension
- **Typed I/O** - Effect Schema `inputSchema`/`outputSchema` values adapted to MCP Standard Schema, plus `structuredContent` for typed results
- **JSON Schema Dialects** - The adapter supports both MCP-requested `draft-07` and `draft-2020-12` output
- **Error Handling** - Genuine tool execution failures return `isError: true` via `createErrorResult` rather than being thrown; protocol, transport, and capability failures (e.g. an unsupported elicitation) can still reject the client call
- **Health Check** - `GET /health` is a plain liveness endpoint (used by the Docker health check); `GET /mcp` is routed to the MCP handler itself
## Example: Adding a New Tool
Add the registration inside `registerTools()` in `src/tools.ts`. See the `create-mcp-tool` skill (`.agents/skills/create-mcp-tool`) for the full walkthrough.
```typescript
import type {
CallToolResult,
ServerContext,
} from "@modelcontextprotocol/server";
import { Effect, Schema } from "effect";
import { toMcpSchema } from "./lib/mcp-schema.ts";
import { createTextResult, runMcpEffect } from "./lib/utils.ts";
server.registerTool(
"my_tool",
{
title: "My Custom Tool",
description: "Description of what this tool does",
inputSchema: toMcpSchema(
Schema.Struct({
param1: Schema.String,
param2: Schema.optional(Schema.Number),
}),
),
outputSchema: toMcpSchema(Schema.Struct({ output: Schema.String })),
annotations: { readOnlyHint: true, openWorldHint: false },
},
(args, ctx) => runMcpEffect(myTool(args, ctx)),
);
function myTool(
args: { param1: string; param2?: number },
_ctx: ServerContext,
): Effect.Effect<CallToolResult> {
return Effect.succeed(createTextResult({ output: args.param1 }));
}
```
Keep the tool workflow in `Effect` and use `runMcpEffect()` only where it crosses back into the MCP SDK callback API. For asynchronous work, use `Effect.tryPromise`; for independent parallel work, use `Effect.all` with explicit concurrency.
## Why Express?
This template uses Express for the HTTP server, which provides:
- **MCP SDK Compatibility** - Full compatibility with `@modelcontextprotocol/server`'s `createMcpHandler`, adapted to Node/Express via `@modelcontextprotocol/node`'s `toNodeHandler`
- **Mature & Stable** - Battle-tested HTTP server with extensive ecosystem
- **TypeScript Support** - Excellent TypeScript support with comprehensive type definitions
- **Middleware Ecosystem** - Rich ecosystem of middleware for common tasks
- **Documentation** - Comprehensive documentation and community support
- **Reliability** - Proven reliability for production applications
## Repository Guidelines
Contributors should review `AGENTS.md` for project structure, coding standards, and pull request expectations before opening changes.