Starter
A calculator server that covers every NitroStack primitive
The Starter template is a minimal project for learning the core concepts: one calculator module with a tool, a resource, a prompt, and a widget, and no authentication or database to get in the way.
What's included
Tools
calculate for arithmetic, plus convert_temperature.
Resource
calculator://operations lists the available operations.
Prompt
calculator_help returns usage instructions.
Widget
calculator-result renders the result of a calculation.
Create the project
Scaffold the template in your language:
npx @nitrostack/cli init my-calculator --template typescript-starter
cd my-calculator
npm run devThe dev server runs the MCP server over STDIO and the widget dev server at http://localhost:3001. Open the project in NitroStudio to try it.
nitrostack-py init my-server --template python-starterCalculator server with @widget("calculator-result"), ConfigModule, and a health check. No OAuth. To test in MCP Inspector, use HTTP + stateless with auth off at http://localhost:3000/mcp.
Project structure
The files that matter:
src/
├── modules/calculator/
│ ├── calculator.module.ts # Module definition
│ ├── calculator.tools.ts # @Tool methods
│ ├── calculator.resources.ts # @Resource methods
│ └── calculator.prompts.ts # @Prompt methods
├── health/system.health.ts # Health check
├── widgets/app/calculator-result # Result widget
├── app.module.ts # Root module
└── index.ts # Bootstrapmain.py # McpApplicationFactory.create(AppModule)
app_module.py # Root @module
modules/calculator/ # Controller + service
widgets/out/calculator-result.html # Widget
health/system_health.py # Health checkThe calculate tool
The tool validates its input with a schema, returns a result, and attaches the calculator-result widget. examples gives clients a preview of the widget before the tool runs.
@Tool({
name: 'calculate',
description: 'Perform basic arithmetic calculations',
inputSchema: z.object({
operation: z.enum(['add', 'subtract', 'multiply', 'divide']),
a: z.number(),
b: z.number(),
}),
examples: {
request: { operation: 'add', a: 5, b: 3 },
response: { result: 8, expression: '5 + 3 = 8' },
},
})
@Widget('calculator-result')
async calculate(input: any, ctx: ExecutionContext) {
// ...
}Try it
Ask your AI client things like these:
| Ask | What happens |
|---|---|
| "What's 12 times 8?" | The model calls calculate and the widget shows 12 × 8 = 96. |
| "How do I use the calculator?" | The client uses the calculator_help prompt. |
| "What operations are available?" | The client reads the calculator://operations resource. |
To grow the template, add operations to the enum in calculator.tools.ts, or add a feature module with npx @nitrostack/cli generate module converter.