PWA Support
Make your web app installable.
What it adds
A manifest, icons, and a service worker so users can install the app and it survives a flaky connection.
What your agent is told to do
4
What your agent is told to do
4-
1
Add a web app manifest with a name, icons at every required size, theme colour, and display mode.
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2
Register a service worker that caches the app shell and static assets.
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3
Provide an offline fallback page rather than the browser's dinosaur.
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Be deliberate about what you cache. Caching API responses without a strategy will show users stale data.
Edge cases it handles
5
Edge cases it handles
5- A service worker will serve a STALE app forever if you don't handle updates — implement a skipWaiting/refresh prompt.
- Never cache authenticated API responses in a shared cache — that's a cross-user data leak on shared devices.
- Cached assets must be invalidated on deploy, or users run last week's JavaScript against this week's API.
- The install prompt must not be shown immediately on first visit.
- Signing out must clear caches containing user data.
Definition of done
8
Definition of done
8- The app is installable with a valid manifest and icons.
- A service worker caches the shell and static assets.
- An offline fallback exists.
- Deploys invalidate stale caches and prompt an update.
- No authenticated data is cached in a shared cache.
- Signing out clears user-specific caches.
- The feature matches the existing design system.
- No existing functionality is broken.
Related features
SEO Setup
SEO Setup
Make your app findable — titles, meta, Open Graph, sitemap, robots.
What it does
The baseline SEO and social-preview setup every public app should have, and most skip.
How it works
- 1 Give every public page a unique, descriptive title and meta description. Find the app's layout and add a mechanism for each page to set them.
- 2 Add Open Graph and Twitter Card tags so shared links render a preview instead of a bare URL.
- 3 Generate a sitemap.xml covering every public, indexable page, and a robots.txt pointing at it.
Copy the prompt
No account needed
Add this feature to my app:
https://addthisfeature.com/x/seo-setup
Design Token Linter
Design Token Linter
Find the hardcoded colours, spacings, and radii that drifted away from the token set.
What it does
A check over the app's styles and markup that reports raw colour, spacing, typography, radius, and shadow values where an approved token exists.
How it works
- 1 Read the app's existing token definitions as the source of truth for the check, so adding a token to the design system automatically widens what the linter recognises without a second list to maintain.
- 2 Scan every place a value can be written: stylesheets, style objects, inline style attributes, utility class strings, and component props that take a raw value.
- 3 Report the nearest matching token alongside each finding, with the difference, so a developer sees that a 15px gap is one pixel from an existing step and can decide rather than re-derive.
Copy the prompt
No account needed
Add this feature to my app:
https://addthisfeature.com/x/design-token-linter
Multi-Model Routing
Multi-Model Routing
Send each AI request to the right model using rules you can read and test.
What it does
A deterministic routing layer that picks a model per request from task type, context size, latency budget, and data sensitivity.
How it works
- 1 Express routing as explicit, ordered rules over inputs the app can measure: task type, estimated context size, latency budget, and the sensitivity classification of the data involved. A rule set that can be read line by line can be reviewed and tested.
- 2 Make routing deterministic. The same inputs must always produce the same route, so a bad output can be reproduced and a rule change can be evaluated. Randomised or load-based selection turns every incident into guesswork.
- 3 Classify data before routing and refuse to route restricted content to any destination not approved for it. This check is a hard block, not a preference, and it must run before the request is assembled.
Copy the prompt
No account needed
Add this feature to my app:
https://addthisfeature.com/x/multi-model-routing
How it works
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1
Copy the link
Grab the Markdown instruction URL for this feature.
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2
Give it to your AI
Paste it into Claude Code, Cursor, v0, Lovable — whatever you build with.
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3
It inspects, then implements
Your agent reads your existing app first, then adds the feature to fit it.
Works with your stack
These instructions are written to adapt. They tell the agent to detect your framework, match your existing design system, and reuse what you already have — rather than assuming a particular stack.
Need it tighter than that? Customize the feature and tell it exactly what you're running.