Looking for guidance on Gmail extension development
I want to create a Chrome extension that works with Gmail. I need help understanding what’s possible and what the recommended approaches are.
Features I’m considering:
- Auto-adding PGP encryption to outgoing messages
- Custom toolbar buttons with special functions
- Intercepting the send action to show confirmation dialogs
- Modifying the compose window interface
Current approach
I’ve started working on this but I’m using fragile CSS selectors that might break when Gmail updates:
// manifest.json content script config
{
"matches": ["https://mail.google.com/*"],
"css": ["styles.css"],
"js": ["jquery.min.js", "extension.js"]
}
// extension.js - adding custom button
var buttonElement = $("div.T-I.T-I-KE.L3");
var customBtn = buttonElement.clone();
customBtn.attr("title", "Custom Action");
customBtn.click(function() {
$("body").append("<div class='my-modal'>Custom content here</div>");
});
buttonElement.after(customBtn);
Main concerns
- Gmail’s obfuscated class names change frequently
- No official API for deep Gmail integration
- Extensions break when Google updates Gmail’s structure
I’ve seen successful extensions like Boomerang and WiseStamp, so I know it’s possible. I’m looking for:
- Reliable methods to interact with Gmail’s interface
- Strategies to handle Gmail UI changes
- Community resources or documentation
- Alternative approaches to brittle CSS selectors
Any advice on stable techniques for Gmail extension development would be appreciated.
I’ve been building Gmail extensions for three years and learned the hard way that reliability is everything. Don’t rely purely on DOM manipulation - use Gmail’s keyboard shortcuts as triggers instead. You can intercept key combos and hook into Gmail’s native actions.
For compose window stuff, wait for specific DOM events rather than targeting classes directly. The contenteditable elements have more consistent attributes you can actually rely on.
Always build fallback detection. When your main selectors break (and they will), you need backup methods to find elements. I use a small utility that tries multiple approaches in sequence until something works.
The most stable setup I’ve found? Combine MutationObserver with event delegation on container elements that Gmail rarely touches. When they restructure the UI, your extension degrades gracefully instead of dying completely.
gmail extensions are tricky but totally doable. skip the css classes - they break constantly. use data attributes or aria labels instead since they’re way more stable. you’ll also want mutation observers to catch when gmail loads new content dynamically. inboxsdk was perfect for this but google killed it off. your best bet now is prob the gmail api with oauth - much safer for integrations.
Gmail extensions need a totally different approach than regular web dev. I wasted months chasing Gmail’s constantly changing selectors before I figured out the real trick - stop fighting Gmail and work with it instead. Forget hunting for specific buttons or UI elements. Monitor Gmail’s internal state through their global variables. Gmail exposes certain window objects that stay way more consistent than DOM elements. Hook into these to catch compose events, email loads, and interface changes. For your PGP encryption, skip the UI level and intercept at the network level. Gmail’s send requests follow predictable patterns that don’t break like their interface does. You can modify the request payload before it goes out. Here’s what saved me tons of headaches: build a compatibility layer. When Gmail updates inevitably break your extension, the layer detects changes and tries mapping new selectors to your existing functions. Buys you time for proper fixes without users getting stuck with broken stuff. Extensions like Boomerang probably do the same thing - multiple detection methods and tons of compatibility testing across Gmail’s different interfaces.