How to run your own AI prompts on selected text in any Mac app
Stop pasting into a chat window. Here's how to save your own AI prompts and run them on whatever text you've highlighted, in Mail, Slack, Notes, your IDE, anywhere, with one keyboard shortcut on macOS.
Most people use AI by copying text out of what they're doing, pasting it into a chat window, typing the same instruction they typed yesterday, then copying the answer back. It works, but it's four steps of friction around a one-second transformation, and you retype the instruction every single time.
The better model: save the instruction once, then run it on whatever you've selected, in place. That's what Khint Agentsdo on macOS. Here's how to set it up.
Step 1: Turn an instruction into an Action
An Action is a saved prompt. In Agents, create one and write what you want it to do, for example:
Rewrite the selected text to be clear and direct.
Keep my meaning and my voice. Cut filler and hedging.
Return only the rewritten text, nothing else.Not sure how to phrase it? Type a short description and hit Generate: Khint drafts the prompt for you. Already have a prompt that's almost right? Improve refines it in place. Either way, you end up with a reusable Action you never have to retype.
Step 2: Run it on a selection
- Highlight the textIn any app (an email draft, a Slack message, a doc, a code comment), select the text you want to act on.
- Press Cmd+Shift+KThe palette opens over the current app. Your Actions are listed and searchable.
- Pick the ActionChoose it (or pin your favorites to the top). Claude runs your prompt on the selected text.
- It pastes backThe result lands in the original app, using the same paste path you'd use by hand, no window to copy out of.
Step 3: Organize with Packs, scale with Chains
Once you have a few Actions, group them into a Pack, a bundle you can switch between (a writing Pack, a dev Pack, a support Pack). The palette shows the active Pack's Actions, so the list stays short and relevant.
When one prompt isn't enough, a Chain runs up to five steps in series, for example summarize → translate → format as bullets. A step can even be an integration write, like creating a Jira issue or a Linear ticket from the running text.
Prompts worth saving as Actions
- Rewrite for clarity / shorten / change tone (formal ↔ friendly).
- Translate to a specific language, preserving formatting.
- Turn rough notes into a structured ticket or a summary.
- Extract action items or decisions from a wall of text.
- Explain or document a selected code snippet.
The point isn't any single prompt. It's that the ones you use daily stop being something you retype and become a shortcut. Try it free: 10 actions a day, no card.
Common questions
Which apps does this work in?
Any app where you can select text and paste: Mail, Slack, Notes, Google Docs, your browser, your IDE, and so on. Khint works on the selection and pastes the result back using the standard system paste path, so it isn't tied to specific integrations.
Can I write my own prompts, or only use presets?
Your own. Actions are your prompts. You can write them from scratch, generate a draft from a short description, or improve an existing one. Presets exist as optional starter packs, but the core idea is that you author what you run.
Does Khint see everything on my screen?
No. It only sees the text you select when you trigger an Action, optionally enriched with your active Memory session's compact summary, if you have one running. There's no background capture of your screen, keystrokes, or other apps.
What model runs my prompts?
Actions run on a fast Claude model (Haiku) by default, so results come back in a second or two. You can also bring your own Anthropic API key if you prefer to use your own account.