Case Studies PromptVault: a prompt library across AI chats
PromptVault: a prompt library across AI chats
TL;DR Good prompts get lost in chat history. PromptVault saves and organises your prompts and drops them into ChatGPT, Claude, and Gemini on demand. The work is making one extension behave consistently across three different chat interfaces.
If you use AI assistants seriously, you develop prompts that just work: the ones that get the format right, set the tone, or frame a task cleanly. Then you lose them in the chat history. PromptVault is my fix for that, a library that follows you across ChatGPT, Claude, and Gemini.
The problem
A good prompt is an asset. You tune it over several tries until it reliably does what you want. Then the conversation scrolls away and the prompt goes with it. Next time you either rewrite it from memory or dig through old chats.
On top of that, people do not stick to one assistant. You might draft in one tool, code in another, and research in a third. A prompt library trapped inside a single tool does not help.
The approach
Two goals shaped it.
- Keep the good prompts. Save, name, and organise prompts so the ones you rely on are one click away.
- Work everywhere you chat. Support the major assistants so the library is useful no matter which one you open.
The interesting constraint is that each chat tool has its own interface. Making one extension insert a prompt cleanly into three different, changing UIs is most of the real work.
What shipped
PromptVault lets you save prompts, organise them, and drop them into ChatGPT, Claude, or Gemini when you need them. Your library lives in the browser, on your machine, and travels with you across the tools rather than being stuck in one.
What I learned building it
The lesson was that other people's interfaces are moving targets. A selector that works today can break when a chat app ships a redesign, so the extension has to be resilient and easy to update rather than clever and brittle. Building against UIs you do not control is a lesson in keeping the integration points few and simple.
PromptVault is one of several browser tools I have built. The full set is in the Chrome extensions section of the site.
FAQ
Why keep a prompt library?
The prompts you refine are worth reusing, but they get buried in scrollback across different tools. A library keeps your best ones in one place, so you paste a proven prompt instead of rewriting it from memory each time.
Does it work across different AI tools?
Yes, that is the point. It targets ChatGPT, Claude, and Gemini so your library follows you regardless of which assistant you are using that day, rather than being locked to one.
Where are the prompts stored?
They live in the browser's extension storage, on your machine. The library is yours; it is not a shared cloud service collecting your prompts.