Under the hood · Jul 3, 2026
When we built the hand-off feature, we assumed most AI tools would support some way of pre-filling a prompt through the URL. It's such an obvious integration point. We were wrong.
Out of the nineteen tools currently in our directory, only four have a reliable, documented-or-stable query parameter that fills the input box on page load: ChatGPT, Claude, Perplexity, and Suno. A few others have parameters that half-work, work only for logged-in users, or worked last quarter and silently broke. We don't ship those, because a hand-off that fails is worse than no hand-off.
The pattern among tools that do support it is interesting: they're all products that win when the friction of starting is low. Search-style tools especially. Perplexity treats a URL query the same way a search engine does, which makes sense given what it is.
For everything else, we settled on the clipboard approach: we copy your prompt automatically and open the tool, so you're one paste away. It's not as slick, and we're honest about that in the interface. But it's dependable, and dependable beats clever.
We re-test these links roughly monthly, because they break without announcement. When Suno changed its create-page URL structure earlier this year, our hand-off silently failed for about a week before we caught it. That incident is why the interface now tells you explicitly which behavior to expect from each tool, so nothing feels like a bug when it's actually a limitation.
If you build with these deep-links yourself, one practical tip: always URL-encode the prompt, and test with prompts containing ampersands and question marks. Those two characters account for basically every breakage we've seen.