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Show HN: Hover – IDE style hover documentation on any webpage
I thought it would be interesting to have ID style hover docs outside the IDE.
Hover is a Chrome extension that gives you IDE style hover tooltips on any webpage: documentation sites, ChatGPT, Claude, etc.
How it works:
- When a code block comes into view, the extension detects tokens and sends the code to an LLM (via OpenRouter or custom endpoint)
- The LLM generates documentation for tokens worth documenting, which gets cached
- On hover, the cached documentation is displayed instantly
A few things I wanted to get right:
- Website permissions are granular and use Chrome's permission system, so the extension only runs where you allow it
- Custom endpoints let you skip OpenRouter entirely – if you're at a company with its own infra, you can point it at AWS Bedrock, Google AI Studio, or whatever you have
Built with TypeScript, Vite, and the Chrome extension APIs. Coming to the Chrome Web Store soon.
Would love feedback on the onboarding experience and general UX – there were a lot of design decisions I wasn't sure about.
Happy to answer questions about the implementation.
- ramon156 9mo ago> the extension detects tokens and sends the code to an LLM > The LLM generates documentation so, not documentation? Why not write your own engine and detect the official docs? e.g. docs.rs would do this wonderfully
- sampsonj 9mo agoThe LLM approach is simpler and more flexible since it works with every library and language out of the box. Looking up official documentation would require shipping sophisticated parsers for each language, plus a way to map tokens to their corresponding docs. I'd also need to maintain those mappings as libraries evolve and documentation moves. Some ecosystems make this easier (Rust with docs.rs), but others would be much harder (AWS documentation, for example). I also want explanations visible directly in hover hints rather than linking out to external docs. So even with official documentation, I'd need to extract and present the relevant content anyway. Beyond that, the LLM approach adapts to context in ways static docs can't. It generates explanations for code within the documentation you're reading, and it works on code that doesn't compile, like snippets with stubs or incomplete examples. It could be interesting in the future to look into doing some type of hybrid approach where an LLM goes out and searches up the documentation, that way it's a little bit more flexible. But that would also be a bit slower and more costly.
- nativeit 9mo ago> The LLM approach is simpler For whom? The whole reason I want to consult docs is to get the official documentation on a given topic. How could I trust anything it says, and what’s to say any earned trust is durable over time?
- almostgotcaught 9mo ago> For whom? what is the name for this kind of pointless, lazy, selective, quoting that willfully misconstrues what's being quoted? the answer to this question is incredibly clear: for the developer that created this tool. if that makes you unhappy enough to malign them then maybe you should just not use it?
- sampsonj 9mo agolol thank you, I was just going to respond to them. One thing I should mention too is that if it were at all practical to build without using generative AI, someone would have built something similar years ago before LLMs.
- jagged-chisel 9mo agoIf there’s any amount of irony in your comment, I’m missing it - and I apologize for that. That said, people have built this without LLMs years, even decades, ago. But UX has fallen by the wayside for quite some time in the companies that used to build IDEs. Then some fresher devs come along and begin a project without the benefit of experience in a codebase with a given feature … and after some time someone writes a plugin for VSCode to provide documentation tooltips generated by LLM because “there is just no other way it can be done.” We have language servers for most programming languages. Those language servers provide the tokens one needs to use when referencing the documentation. And it would be so much faster than waiting for an LLM to get back to you. TBH, if anyone’s excuse is “an LLM is the only way to implement feature Q,” then they’re definitely in need of some experience in software creation.
- nativeit 9mo agoOh…I guess this isn’t the documentation-surfacing droids I’m looking for. I could see getting actual docs being useful. Spitting out the delusions of an LLM is pretty well covered already, at least in my stack.
- jagged-chisel 9mo agoVery little “engine” required - use an existing language sever, map tokens to URLs, done.
- deleted 9mo ago[deleted]
- kristopolous 9mo agointeresting idea for a 1.0. Using https://context7.com/ https://context7.com/ might be the right next move here. Also look into https://cht.sh/ https://cht.sh/ Remember: incorrect (misleading) documentation is worse than no documentation. What this might be better for is use-cases that don't require extreme precision. Imagine it for learning language or reading sophisticated academic literature. For example, https://archive.org/details/pdfy-TJ7HxrAly-MtUP4B/page/n111/mode/2up https://archive.org/details/pdfy-TJ7HxrAly-MtUP4B/page/n111/... Stuff like that is hard and every tool to make the complicated more legible I'd embrace.
- dmos62 9mo agoThose are great links.
- kristopolous 9mo agocht.sh is a fairly unknown community i think ... it's really great. Try curl cht.sh it's a wiki system.
- sampsonj 9mo agoThank you! I will look into these! Yeah, it could be useful for providing explanations of key terms in papers or something similar.
- deleted 9mo ago[deleted]
- esafak 9mo agoSince these are called "tooltips" you might want to use the term more prominently.
- iLoveOncall 9mo agoGreat idea with a terrible implementation.
- sampsonj 9mo agoCan you elaborate more. It's still early and I would love feedback
- iLoveOncall 9mo agoLLMs get interfaces wrong all the time, they make up methods that don't exist, invent parameters, etc. This needs to be 100% accurate or it is not useful.
- mathfailure 9mo agoIt uses LLM under the hood. This is the bad part.
- onion2k 9mo agoNice idea, but unless it's using up-to-date docs it's likely to introduce a lot of confusion, especially if you're reading docs to find out what changed between versions. You really need to be sending the code and the version of the software that the person reading the page is looking at.
- sampsonj 9mo agoGood point, thank you
- mmmmbbbhb 9mo agoFirefox has built-in link previews with AI. Hold mouse1 on a link.