MCP 协议

MCP（Model Context Protocol）是一个开放协议，它规范了应用程序向 LLM 提供上下文的方式。MCP 就像 AI 应用程序的 USB-C 端口一样。正如 USB-C 提供了一种标准化的方式将您的设备连接到各种外围设备和配件一样，MCP 也提供了一种标准化的方式将 AI 模型连接到不同的数据源和工具。

总体架构

MCP 的核心遵循客户端-服务器架构，MCP Hosts可以连接到多个服务器：

MCP Hosts: 应用程序 像 Cursor, IDE 或 AI 工具。 MCP Clients: 客户端是用来在 Hosts 应用程序内维护与 Server 之间 1:1 连接。 MCP Servers: 通过标准化的协议，为 Client 端提供上下文、工具和提示。 Local Data Sources: 本地的文件、数据库和 API。 Remote Services: 外部的文件、数据库和 API。

Function Calling

Function Calling 和MCP（Model Context Protocol）协议都是为了扩展AI模型能力

例子

const server = new Server(
  {
    name: "github-mcp-server",
    version: VERSION,
  },
  {
    capabilities: {
      tools: {},
    },
  }
);

server.setRequestHandler(ListToolsRequestSchema, async () => {
  return {
    tools: [
      {
        name: "search_repositories",
        description: "Search for GitHub repositories",
        inputSchema: zodToJsonSchema(repository.SearchRepositoriesSchema),
      },
      {
        name: "create_issue",
        description: "Create a new issue in a GitHub repository",
        inputSchema: zodToJsonSchema(issues.CreateIssueSchema),
      },
      {
        name: "search_issues",
        description: "Search for issues and pull requests across GitHub repositories",
        inputSchema: zodToJsonSchema(search.SearchIssuesSchema),
      }
    ],
  };
});

server.setRequestHandler(CallToolRequestSchema, async (request) => {
  try {
    if (!request.params.arguments) {
      throw new Error("Arguments are required");
    }

    switch (request.params.name) {
      case "search_repositories": {
        const args = repository.SearchRepositoriesSchema.parse(request.params.arguments);
        const results = await repository.searchRepositories(
          args.query,
          args.page,
          args.perPage
        );
        return {
          content: [{ type: "text", text: JSON.stringify(results, null, 2) }],
        };
      }

      case "create_issue": {
        const args = issues.CreateIssueSchema.parse(request.params.arguments);
        const { owner, repo, ...options } = args;
        const issue = await issues.createIssue(owner, repo, options);
        return {
          content: [{ type: "text", text: JSON.stringify(issue, null, 2) }],
        };
      }

      case "search_issues": {
        const args = search.SearchIssuesSchema.parse(request.params.arguments);
        const results = await search.searchIssues(args);
        return {
          content: [{ type: "text", text: JSON.stringify(results, null, 2) }],
        };
      }

      default:
        throw new Error(`Unknown tool: ${request.params.name}`);
    }
  } catch (error) {}
});

async function runServer() {
  const transport = new StdioServerTransport();
  await server.connect(transport);
  console.error("GitHub MCP Server running on stdio");
}

runServer().catch((error) => {
  console.error("Fatal error in main():", error);
  process.exit(1);
});

export const SearchOptions = z.object({
  q: z.string(),
  order: z.enum(["asc", "desc"]).optional(),
  page: z.number().min(1).optional(),
  per_page: z.number().min(1).max(100).optional(),
});

export const SearchIssuesOptions = SearchOptions.extend({
  sort: z.enum([
    "comments",
    ...
  ]).optional(),
});

export async function searchUsers(params: z.infer<typeof SearchUsersSchema>) {
  return githubRequest(buildUrl("https://api.github.com/search/users", params));
}

export const SearchRepositoriesSchema = z.object({
  query: z.string().describe("Search query (see GitHub search syntax)"),
  page: z.number().optional().describe("Page number for pagination (default: 1)"),
  perPage: z.number().optional().describe("Number of results per page (default: 30, max: 100)"),
});

export async function searchRepositories(
  query: string,
  page: number = 1,
  perPage: number = 30
) {
  const url = new URL("https://api.github.com/search/repositories");
  url.searchParams.append("q", query);
  url.searchParams.append("page", page.toString());
  url.searchParams.append("per_page", perPage.toString());

  const response = await githubRequest(url.toString());
  return GitHubSearchResponseSchema.parse(response);
}

资源

MCP servers

参考链接

mcp introduction

MCP 终极指南