tools.ts•3.42 kB
import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
import { z } from "zod";
import { ToolResult } from "./types.js";
// Zod schemas for parameter validation
const GreetSchema = z.object({
name: z.string().min(1, "Name is required"),
});
const EchoSchema = z.object({
message: z.string().min(1, "Message is required"),
times: z.number().int().positive().optional().default(1),
});
export function registerTools(server: McpServer): void {
// Simple hello tool with no parameters
server.tool(
"hello",
{},
async (): Promise<ToolResult> => {
return {
content: [
{
type: "text",
text: "Hello from the Simple MCP Server! This demonstrates a basic tool with no parameters."
}
]
};
}
);
// Greet tool with name parameter
server.tool(
"greet",
{
name: {
type: "string",
description: "The name of the person to greet",
},
},
async (params): Promise<ToolResult> => {
try {
const { name } = GreetSchema.parse(params);
return {
content: [
{
type: "text",
text: `Hello, ${name}! Nice to meet you. This demonstrates parameter validation with Zod.`
}
]
};
} catch (error) {
if (error instanceof z.ZodError) {
const errorMessage = error.errors.map(err =>
`${err.path.join('.')}: ${err.message}`
).join(', ');
return {
content: [
{
type: "text",
text: `Validation error: ${errorMessage}`
}
]
};
}
return {
content: [
{
type: "text",
text: `Error: ${error instanceof Error ? error.message : String(error)}`
}
]
};
}
}
);
// Echo tool with message and optional repetition
server.tool(
"echo",
{
message: {
type: "string",
description: "The message to echo back",
},
times: {
type: "number",
description: "Number of times to repeat the message (default: 1)",
minimum: 1,
maximum: 10,
},
},
async (params): Promise<ToolResult> => {
try {
const { message, times } = EchoSchema.parse(params);
const repeatedMessage = Array(times).fill(message).join('\n');
return {
content: [
{
type: "text",
text: `Echoing your message ${times} time(s):\n\n${repeatedMessage}`
}
]
};
} catch (error) {
if (error instanceof z.ZodError) {
const errorMessage = error.errors.map(err =>
`${err.path.join('.')}: ${err.message}`
).join(', ');
return {
content: [
{
type: "text",
text: `Validation error: ${errorMessage}`
}
]
};
}
return {
content: [
{
type: "text",
text: `Error: ${error instanceof Error ? error.message : String(error)}`
}
]
};
}
}
);
console.error("Simple MCP Server: All tools registered successfully");
}