您的第一个“Hello World”扩展
创建一个最小化的“Hello World”扩展，涵盖清单文件、基本结构以及如何将其加载到浏览器中
您的第一个“Hello World”扩展 是 CoddyKit 上的免费 Browser Extensions Development (Chrome & Edge) 课时。 这是第 3 节课，共 4 节。 你可以在下方免费阅读本课时的完整内容 — 然后在浏览器中使用内置代码编辑器和全天候 AI 导师进行实践。 这是 Browser Extensions Development (Chrome & Edge) 学习路径的一部分，你的进度在网页和 CoddyKit 应用中同步。 Browser Extensions Development (Chrome & Edge) 课程共包含 4 节课。
本课时的部分内容尚未翻译，以英文显示。
Your First Extension: Hello World
Time to build your first extension — a classic Hello World popup that greets you when you click its toolbar icon. The core Manifest V3 shape.
Core Extension Components
Every extension needs a few key files: manifest.json (the blueprint), popup.html (the popup content), and an icon. We'll build them step by step.
Manifest.json: The Blueprint
The manifest.json is the most important file — JSON metadata like name, version, and permissions, in the structure Manifest V3 expects.
Essential Manifest Fields
Start your manifest with three required fields: manifest_version 3, a name, and a version. The snippet below shows the minimal shape.
{ "manifest_version": 3,
"name": "Hello World Extension",
"version": "1.0"
}Adding Description & Icons
Add a description and an icons map so users understand and recognize your extension. Provide several sizes like 16, 48, and 128 pixels.
{ "manifest_version": 3,
"name": "Hello World Extension",
"version": "1.0",
"description": "A simple 'Hello World' extension for CoddyKit.",
"icons": {
"16": "icon16.png",
"48": "icon48.png",
"128": "icon128.png"
}
}Defining the Popup with 'action'
The action field defines the toolbar button: default_popup points to your popup HTML, and default_icon sets the toolbar image.
{ "manifest_version": 3,
"name": "Hello World Extension",
"version": "1.0",
"description": "A simple 'Hello World' extension for CoddyKit.",
"icons": { "16": "icon16.png" },
"action": {
"default_popup": "popup.html",
"default_icon": { "16": "icon16.png" }
}
}Creating popup.html
Create popup.html — a plain HTML file holding your Hello World message. Keep it small and light, since it shows in a tiny popup window.
<!DOCTYPE html>
<html>
<head>
<title>Hello World Popup</title>
<style>
body { font-family: sans-serif; padding: 15px; width: 150px; }
h1 { font-size: 1.2em; color: #333; margin: 0; }
</style>
</head>
<body>
<h1>Hello, CoddyKit!</h1>
</body>
</html>Your Extension's Folder Structure
Your folder should now hold manifest.json, popup.html, and the icons, all directly inside — a clean layout the browser can load correctly.
Loading Your Extension (Chrome)
Load it in Chrome or Edge: open chrome://extensions, flip on Developer mode, click Load unpacked, and pick your folder. It joins the list!
Test Your New Extension!
Spot your extension's icon in the toolbar and click it — a popup appears reading "Hello, CoddyKit!" from your popup.html. First extension done!
Quick Check: Manifest V3
Which field is absolutely essential to declare the manifest format version in manifest.json for a Manifest V3 extension?
Recap: Your First Extension
You built and loaded a real extension: a manifest with key fields, an action popup, a popup.html, all run via Developer mode. Keep tinkering!
常见问题解答
「您的第一个“Hello World”扩展」课时是免费的吗？
是的 — 「您的第一个“Hello World”扩展」的完整文本可在网页上免费阅读。要进行交互式练习（内置代码编辑器和全天候 AI 导师）并解锁 Browser Extensions Development (Chrome & Edge) 课程的其余内容，请升级到 CoddyKit PRO。 Browser Extensions Development (Chrome & Edge) 课程共包含 4 节课。
「您的第一个“Hello World”扩展」这节课中我会学到什么？
创建一个最小化的“Hello World”扩展，涵盖清单文件、基本结构以及如何将其加载到浏览器中 你通过在浏览器中直接运行的动手代码来练习 Browser Extensions Development (Chrome & Edge)，全天候 AI 导师会在你学习这节课的过程中回答你的问题。
学习 Browser Extensions Development (Chrome & Edge) 需要有经验吗？
无需任何先前经验。CoddyKit 上的 Browser Extensions Development (Chrome & Edge) 课程适合初学者到高级学习者，你可以从这里开始或从头开始，按照自己的节奏学习。 这是第 3 节课，共 4 节。
「您的第一个“Hello World”扩展」课时需要多长时间？
大多数 CoddyKit 课程大约需要 5–10 分钟。每节课都很精短且互动，所以你能稳步进步，并在网页和应用中从离开的地方继续。
我能在这节 Browser Extensions Development (Chrome & Edge) 课中编写并运行代码吗？
能。每节 Browser Extensions Development (Chrome & Edge) 课都包含内置代码编辑器，你可以在浏览器中直接编写并运行真实代码，并获得即时 AI 反馈 — 无需本地设置。