Build a GitHub MCP Server 實戰 — 自動化管理 Issue / PR / Repo

2026-05-12 · MCP 實戰 · Eric Cheung

前言：AI 直接操控 GitHub 嘅威力

快速結論（TL;DR）

• 呢個 GitHub MCP Server 用 @modelcontextprotocol/sdk 加 Octokit 建立，支援 8 個 Tools：Issues（create/read/list/update）、PR（create/read/merge）同 Repo（get）。
• GitHub Token 要揀 Fine-grained tokens，設定 Issues 同 Pull requests 嘅 Read/Write 權限，再存入 .env。
• 用 StdioServerTransport 起 server，透過 ListToolsRequestSchema 同 CallToolRequestSchema 處理工具清單同呼叫。
• 註冊到 Claude Code 只需喺 .claude 設定 mcpServers 指向 server 檔案，之後就可以用自然語言操控 GitHub。
• GitHub API 有 500+ endpoints，你可以繼續擴展 search code、create release、manage actions 等工具，由開發者變成 DevEx Automation Engineer。

想像下：對住 Claude Code 講一句「幫我 create 一個 PR，將 login page refactor 去用 Tailwind，assign 俾 @design-team」，10 秒後 PR 已經出咗。今日我哋就實現呢個夢想 — 建立一個 GitHub MCP Server，令 Claude Code 直接操控 GitHub。

呢個 MCP Server 會支援 8 個 Tools：管理 Issues（create/read/list/update）、管理 Pull Requests（create/read/merge）、管理 Repositories（get info/search）。全部經自然語言操控。

Part 1：Project Setup

安裝依賴

mkdir github-mcp-server && cd github-mcp-server
npm init -y
npm install @modelcontextprotocol/sdk @octokit/rest dotenv

獲取 GitHub Token

• ① 上 GitHub → Settings → Developer settings → Personal access tokens → Fine-grained tokens
• ② Generate new token → 設定 repo 權限：Issues (Read/Write)、Pull requests (Read/Write)、Metadata (Read)
• ③ 複製 token → 存入 .env：GITHUB_TOKEN=ghp_xxxxxxxxxxxx

完整 Server 架構

import { Server } from "@modelcontextprotocol/sdk/server/index.js";
import { StdioServerTransport } from "@modelcontextprotocol/sdk/server/stdio.js";
import {
  ListToolsRequestSchema,
  CallToolRequestSchema,
} from "@modelcontextprotocol/sdk/types.js";
import { Octokit } from "@octokit/rest";
import "dotenv/config";

const octokit = new Octokit({ auth: process.env.GITHUB_TOKEN });

const server = new Server({ name: "github-mcp", version: "1.0.0" },
  { capabilities: { tools: {} } });

Part 2：定義 8 個 GitHub Tools

Tool 清單

server.setRequestHandler(ListToolsRequestSchema, async () => ({
  tools: [
    // === Issues ===
    { name: "github_create_issue",
      description: "Create a new GitHub issue",
      inputSchema: {
        type: "object",
        properties: {
          owner: { type: "string", description: "Repo owner" },
          repo: { type: "string", description: "Repo name" },
          title: { type: "string", description: "Issue title" },
          body: { type: "string", description: "Issue description" },
          labels: { type: "array", items: { type: "string" } },
          assignees: { type: "array", items: { type: "string" } },
        }, required: ["owner", "repo", "title"],
      },
    },
    { name: "github_list_issues",
      description: "List issues in a repository",
      inputSchema: {
        type: "object",
        properties: {
          owner: { type: "string" },
          repo: { type: "string" },
          state: { type: "string", enum: ["open", "closed", "all"] },
          labels: { type: "string" },
        }, required: ["owner", "repo"],
      },
    },
    { name: "github_get_issue",
      description: "Get a specific issue by number",
      inputSchema: {
        type: "object",
        properties: {
          owner: { type: "string" },
          repo: { type: "string" },
          issue_number: { type: "number" },
        }, required: ["owner", "repo", "issue_number"],
      },
    },
    { name: "github_update_issue",
      description: "Update an existing issue",
      inputSchema: {
        type: "object",
        properties: {
          owner: { type: "string" },
          repo: { type: "string" },
          issue_number: { type: "number" },
          title: { type: "string" },
          body: { type: "string" },
          state: { type: "string", enum: ["open", "closed"] },
          labels: { type: "array", items: { type: "string" } },
        }, required: ["owner", "repo", "issue_number"],
      },
    },
    // === Pull Requests ===
    { name: "github_create_pr",
      description: "Create a new pull request",
      inputSchema: {
        type: "object",
        properties: {
          owner: { type: "string" },
          repo: { type: "string" },
          title: { type: "string" },
          head: { type: "string", description: "Source branch" },
          base: { type: "string", description: "Target branch" },
          body: { type: "string" },
        }, required: ["owner", "repo", "title", "head", "base"],
      },
    },
    { name: "github_list_prs",
      description: "List pull requests",
      inputSchema: {
        type: "object",
        properties: {
          owner: { type: "string" },
          repo: { type: "string" },
          state: { type: "string", enum: ["open", "closed", "all"] },
        }, required: ["owner", "repo"],
      },
    },
    { name: "github_merge_pr",
      description: "Merge a pull request",
      inputSchema: {
        type: "object",
        properties: {
          owner: { type: "string" },
          repo: { type: "string" },
          pull_number: { type: "number" },
          merge_method: {
            type: "string",
            enum: ["merge", "squash", "rebase"],
          },
        }, required: ["owner", "repo", "pull_number"],
      },
    },
    // === Repo ===
    { name: "github_get_repo",
      description: "Get repository information",
      inputSchema: {
        type: "object",
        properties: {
          owner: { type: "string" },
          repo: { type: "string" },
        }, required: ["owner", "repo"],
      },
    },
  ],
}));

Part 3：實作 Tool Handlers

Handle Tool Calls

server.setRequestHandler(CallToolRequestSchema, async (req) => {
  const { name, arguments: args } = req.params;

  switch (name) {
    case "github_create_issue": {
      const { data } = await octokit.issues.create({
        owner: args.owner,
        repo: args.repo,
        title: args.title,
        body: args.body,
        labels: args.labels,
        assignees: args.assignees,
      });
      return { content: [{ type: "text",
        text: `✅ Issue #${data.number} created: ${data.html_url}` }] };
    }

    case "github_list_issues": {
      const { data } = await octokit.issues.listForRepo({
        owner: args.owner, repo: args.repo,
        state: args.state || "open",
        labels: args.labels,
      });
      const summary = data.map(i =>
        `#${i.number} [${i.state}] ${i.title}`).join("\n");
      return { content: [{ type: "text", text: summary }] };
    }

    case "github_create_pr": {
      const { data } = await octokit.pulls.create({
        owner: args.owner, repo: args.repo,
        title: args.title,
        head: args.head, base: args.base,
        body: args.body,
      });
      return { content: [{ type: "text",
        text: `✅ PR #${data.number} created: ${data.html_url}` }] };
    }

    case "github_merge_pr": {
      const { data } = await octokit.pulls.merge({
        owner: args.owner, repo: args.repo,
        pull_number: args.pull_number,
        merge_method: args.merge_method || "merge",
      });
      return { content: [{ type: "text",
        text: `✅ PR merged: ${data.message}` }] };
    }

    case "github_get_repo": {
      const { data } = await octokit.repos.get({
        owner: args.owner, repo: args.repo,
      });
      return { content: [{ type: "text",
        text: `${data.full_name}\n⭐ ${data.stargazers_count}` +
             `\n🍴 ${data.forks_count}\n${data.description}` }] };
    }

    default:
      throw new Error(`Unknown tool: ${name}`);
  }
});

Part 4：註冊到 Claude Code

Claude Code MCP Config

{
  "mcpServers": {
    "github": {
      "command": "node",
      "args": ["./github-mcp-server/index.js"],
      "env": {
        "GITHUB_TOKEN": "$GITHUB_TOKEN"
      }
    }
  }
}

實際使用：自然語言操控 GitHub

• "幫我 create 一個 issue: Fix login page responsive layout, label: bug, assign: @eric" → AI 自動 call github_create_issue
• "Show me all open PRs in ericcheung621-ckw/eric-cheung-portfolio" → AI 自動 call github_list_prs
• "Merge PR #42 with squash" → AI 自動 call github_merge_pr
• "What's the current status of my main repo?" → AI 自動 call github_get_repo

Part 5：進階擴展 — 由 8 個 Tool 到無限可能

掌握咗基礎之後，你可以繼續擴展更多功能：

• github_search_code — 用 GitHub Code Search API 搜尋全 repo code
• github_create_release — 自動 generate release notes + create release
• github_get_diff — 比較兩個 commit/branch 嘅 diff
• github_create_webhook — 管理 repo webhooks
• github_manage_actions — Trigger / cancel / list CI runs

GitHub API 有 500+ endpoints — 你嘅 MCP Server 只需要 expose 你真正需要用到嘅功能。關鍵係令 AI 可以用自然語言操控，而唔係每次都記 API endpoint 名。

總結：由開發者到 DevEx Automation Engineer

建立 GitHub MCP Server 唔單止係學 MCP 開發技巧，更加係一個思維轉變：由「人用 Git + GitHub UI」到「AI 自動化 GitHub 操作」。當你的 CI/CD pipeline 有咗 AI 直接操控 GitHub 嘅能力，成個開發流程就會大幅加速。

Written by Eric Cheung · Learn One AI Thing Every Day · Day 4: Build a GitHub MCP Server