How to define prompt templates in an MCP server

1// TypeScript
2import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
3import { z } from "zod";
4
5const server = new McpServer({ name: "prompt-server", version: "1.0.0" });
6
7server.registerPrompt("review-code", {
8  description: "Generate a code review for the given code snippet",
9  argsSchema: {
10    code: z.string().describe("The code to review"),
11    language: z.string().default("typescript").describe("Programming language"),
12  },
13}, ({ code, language }) => ({
14  messages: [{
15    role: "user",
16    content: {
17      type: "text",
18      text: `Review this ${language} code for bugs, security issues, and style improvements:\n\n\`\`\`${language}\n${code}\n\`\`\`\n\nProvide specific line-by-line feedback.`,
19    },
20  }],
21}));

1// TypeScript
2server.registerPrompt("debug-error", {
3  description: "Help debug an error with structured analysis",
4  argsSchema: {
5    error: z.string().describe("The error message or stack trace"),
6    context: z.string().optional().describe("Additional context about when the error occurs"),
7  },
8}, ({ error, context }) => ({
9  messages: [
10    {
11      role: "user",
12      content: {
13        type: "text",
14        text: `I need help debugging this error:\n\n${error}${context ? `\n\nContext: ${context}` : ""}\n\nPlease analyze:\n1. What is the root cause?\n2. What are the likely fixes?\n3. How can I prevent this in the future?`,
15      },
16    },
17  ],
18}));

1// TypeScript
2server.registerPrompt("analyze-with-schema", {
3  description: "Analyze code against the project schema",
4  argsSchema: {
5    code: z.string().describe("Code to analyze"),
6  },
7}, ({ code }) => ({
8  messages: [
9    {
10      role: "user",
11      content: {
12        type: "resource",
13        resource: {
14          uri: "db://schema",
15          text: "(Schema will be loaded from resource)",
16          mimeType: "text/plain",
17        },
18      },
19    },
20    {
21      role: "user",
22      content: {
23        type: "text",
24        text: `Given the database schema above, review this code for correctness:\n\n${code}`,
25      },
26    },
27  ],
28}));

1# Python
2from mcp.server.fastmcp import FastMCP
3
4mcp = FastMCP("prompt-server")
5
6@mcp.prompt()
7async def review_code(code: str, language: str = "python") -> str:
8    """Generate a code review for the given code snippet."""
9    return f"""Review this {language} code for bugs, security issues, and style:
10
11```{language}
12{code}
13```
14
15Provide specific, actionable feedback."""
16
17@mcp.prompt()
18async def generate_tests(code: str, framework: str = "pytest") -> str:
19    """Generate unit tests for the given code."""
20    return f"""Write comprehensive {framework} tests for this code:
21
22```python
23{code}
24```
25
26Cover edge cases, error conditions, and happy paths."""

1# Start your server for testing
2npx tsc && node dist/index.js
3
4# In another terminal, use the Inspector
5npx @modelcontextprotocol/inspector