How to code with Codex on mobile: a complete 15-minute tutorial
Learn to use the built-in Codex function of ChatGPT mobile version in 15 minutes to write code, connect to the warehouse, and deploy online anytime and anywhere
Beginner · 15 min · May 15, 2026
Tutorial Objectives
Learn to use the built-in Codex function of ChatGPT mobile version in 15 minutes to write code anytime and anywhere. This article is a complete step-by-step tutorial, from installation to completion of the first project.
What will you build?
- Remote Coding Environment: Open ChatGPT on your mobile phone and start the Codex terminal directly
- Code Warehouse Connection: Connect Codex to GitHub warehouse and edit in real time on mobile phone
- Project Deployment: Use Codex to complete a small web application and deploy it online
Preparation list
- ChatGPT account (the free version is enough, supports the basic functions of Codex)
- Smartphone (iOS or Android, install ChatGPT official app)
- GitHub account (optional, used for warehouse synchronization) -Basic programming concepts (not required, novices can also follow along)
Overall architecture
The tutorial is divided into 4 modules. If you follow the sequence, you can start from scratch and complete a real coding project with your mobile phone in 15 minutes.
| Module | Input | Output | Estimated time |
|---|---|---|---|
| 1. Install and start Codex | ChatGPT account + mobile phone | Codex terminal interface | 3 minutes |
| 2. Create your first project | Codex terminal | A runnable Python script | 4 minutes |
| 3. GitHub synchronization | GitHub account | Push code to remote warehouse | 4 minutes |
| 4. Deployment and online | Codex terminal + free cloud service | Publicly accessible URL | 4 minutes |
Step 1: Install and start Codex
Open the ChatGPT mobile app and make sure you've upgraded to the latest version (check the iOS App Store or Google Play store for updates).
There are two ways to start Codex:
| Method | Operation | Description |
|---|---|---|
| Conversation start | Enter "Start Codex" in the chat input box | The most direct, suitable for quick tasks |
| Menu startup | Click "..." at the bottom for more menus → Select Codex | More complete functions, suitable for long-term projects |
Upon startup, ChatGPT automatically creates a Codex session. You'll see a terminal-style interface with input boxes at the bottom. This is your mobile development environment.
Tip: Codex is also available in the free version of ChatGPT. All you need to do is log in to your ChatGPT account. The paid version (Plus/Pro) offers faster models and higher usage limits.
Step 2: Create your first project
Enter a natural language command into the Codex terminal to describe the code you want to build. There is no need to remember the specific command syntax.
For example, enter:
创建一个 Python Flask Web 应用，提供一个简单的 REST API
，包含一个 /hello 端点返回 JSON 格式的问候信息Codex 会自动串联规划、编写和执行代码。你会看到它：
- 创建项目目录结构
- 安装必要的依赖（如 Flask）
- 编写代码文件
- 运行并展示结果
关键操作技巧
| 操作 | 在手机上的方式 | 说明 |
|---|---|---|
| 输入指令 | 语音输入或键盘打字 | 语音输入速度更快，适合描述需求 |
| 查看代码 | 上下滑动屏幕 | Codex 会以文件树形式展示 |
| 修改代码 | 说出要修改的内容 | "把 /hello 改成 /greet" |
| 运行测试 | 输入 "运行测试" | Codex 自动执行并返回结果 |
对于需要复杂模型能力的项目，升级到 ChatGPT Plus 可以获得 GPT-4 级别的代码生成质量。
第 3 步：连接 GitHub 仓库
Codex 支持远程连接 GitHub 仓库。在手机上操作的方式：
/github connect <你的仓库URL>
Codex 会自动处理认证流程。连接成功后，你可以：
- 浏览仓库文件树
- 直接编辑代码（Codex 会自动探测文件类型）
- 提交并推送更改（
/github commit -m "Update instructions"）
提示：对于个人项目，也可以用
/github init创建一个新的仓库，Codex 会全程引导。
第 4 步：部署到云端
项目完成后，Codex 可以一键部署。输入：
帮我把这个应用部署到云端，免费可用
Codex 会自动选择适合的云服务平台（如 Render、Fly.io 或 Railway），完成部署配置，最后返回一个公网可访问的 URL。
如果想在本地机器上继续开发，Codex 也支持远程连接模式。在桌面端安装 Codex CLI 后，通过同一个 ChatGPT 账户可以无缝切换设备和会话。
常见问题排查（FAQ）
Q1：Codex 在手机上写代码，键盘太小不方便怎么办？
使用语音输入功能。ChatGPT 的语音转文字质量很高，你可以用口语描述需求，Codex 会将其转化为代码逻辑。很多用户发现语音输入反而比打字更快。
Q2：手机上的 Codex 和桌面版有什么不同？
核心能力相同：都能编写、阅读和修改代码。桌面版更适合长时间、高强度的开发工作；移动版适合快速修复、查看代码、跟进项目进展。两者通过同一个 ChatGPT 账号同步上下文。
Q3：免费版 Codex 有使用限制吗？
免费版有每日使用次数限制，但对于日常的小项目修复和代码查询完全够用。Plus 用户（$20/月）获得更高的使用额度和 GPT-4 模型的优先访问。
SEO+GEO：FAQ 结构满足 AI 问答引擎的提取偏好，同时覆盖了"Codex 免费版限制"、"手机写代码"等长尾搜索词。
工具词条（触发工具悬浮卡）
正文中自然出现的工具名，平台侧会匹配已维护 tools 库生成 hover-card：
OpenAI、ChatGPT、Codex、Flask、GitHub
Reference video/material
Internal link guidance
- Someone has successfully practiced it: a real case of an independent developer using AI coding tools to automate workflow and earning $5,000 per month: 独立开发者用n8n+OpenClaw搭建自动化工作流，月入5000美元的实战案例
- Want to learn about more advanced automation processes? Paired with n8n + OpenAI 搭建 AI 销售开发代表系统, the results of mobile coding can be automated into a complete business system
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