Works in every app
Triple-fallback text detection via macOS Accessibility APIs. Native apps, browsers, Electron — if you can select text, Contexter can act on it.
Native macOS · Free · Bring your own key
AI text actions,
everywhere on your Mac.
Select text in any app. A floating popup appears with AI-powered actions — fix grammar, translate, summarize, adjust tone. One click, done.
macOS 15.6 or later · Apple Silicon & Intel · ~12 MB
contexter — demo
Features
Everything you need. Nothing you don't.
Six providers, your choice
Bring your own keys for OpenAI, Anthropic, Gemini, DeepSeek, Groq, or Mistral. Pick a different model per command. No markup, no lock-in.
Unlimited custom commands
11 built-in actions, plus your own prompts, icons, shortcuts, and app-scoping rules. Translation only in Mail. Code review only in Xcode.
Privacy by default
Direct API calls from your Mac to your provider. No intermediary server. No telemetry. No analytics. Your keys stay on your machine.
Native & lightweight
Pure Swift and SwiftUI. Zero external dependencies. No Electron. Respects system appearance, responds instantly, sips resources.
Three ways to invoke
Floating popup on selection. Global keyboard shortcuts from anywhere. Native macOS Services menu. However you work, Contexter fits.
BYOK
Your keys. Your choice. Zero lock-in.
Connect any combination of six providers. Assign a different one per command. Pay the provider directly at their rates.
OpenAI
GPT-4o, reasoning
Anthropic
Claude, long context
Gemini
Google, multimodal
DeepSeek
Cost-effective
Groq
Ultra-fast
Mistral
EU hosting
Ready out of the box
11 built-in commands. Infinite custom ones.
Start with curated actions. Then build your own — with prompts, icons, shortcuts, and per-app scoping.
✦ Fix Grammar ✦ Translate to English ✦ Summarize ✦ Simplify ✦ Make Professional ✦ Empathetic Rewrite ✦ Extract Action Items ✦ Shorten for Social ✦ Plain Language ✦ Answer Quiz ✦ Draft Reply + unlimited custom
Why not just use ChatGPT?
Chat apps are tabs. Contexter is a tool.
| Capability | Chat apps | Browser extensions | Contexter |
|---|---|---|---|
| Works in every macOS app | — | — | ✓ |
| Inline text replacement | — | some | ✓ |
| Custom commands with prompts | — | limited | ✓ |
| Per-command provider choice | — | — | ✓ |
| App-scoped commands | — | — | ✓ |
| No intermediary server | — | — | ✓ |
| Native macOS performance | varies | — | ✓ |
Privacy
Your text never touches our servers.
Because there are none. Contexter makes direct API calls from your Mac to your chosen provider. No proxy. No user tracking. No cookies. Self-hosted aggregate analytics only — your text and keys never leave your Mac.
✓ Open source ✓ BYOK ✓ Zero dependencies ✓ No account required
FAQ
Questions, answered.
Why does Contexter need Accessibility permission?
To read the text you select in other apps, macOS requires Accessibility access. Contexter only reads selected text when you trigger a command — it never logs, stores, or transmits anything you don't explicitly act on.
Is it really free?
Yes. Contexter is free to download and use. You only pay your AI provider directly for API usage at their published rates — no markup, no subscription, no account.
Why bring my own API key?
Three reasons: privacy (your text goes to your provider, not ours), cost control (you pay metered rates instead of a flat subscription), and flexibility (switch or mix providers anytime).
Which macOS versions are supported?
macOS 15.6 (Sequoia) or later. Works on both Apple Silicon and Intel Macs.
Does it work in Electron apps like Slack, VS Code, and Notion?
Yes. The triple-fallback detection (Accessibility API → mouse position → clipboard) handles native apps, browsers, and Electron without app-specific integrations.
Can I use my own prompts?
Absolutely. Create unlimited custom commands with your own prompts, SF Symbols icons, keyboard shortcuts, output modes, and per-app scoping rules.
Where are my API keys stored?
Locally, in the macOS keychain. They never leave your machine and are never transmitted anywhere except directly to the provider when you run a command.
Stop copy-pasting.
Start shipping.
Contexter brings AI text processing to every app on your Mac. Select, click, done.
Download Contexter for macOS
Free · Bring your own key · Setup takes 2 minutes
macOS 15.6 or later. Requires an API key from OpenAI, Anthropic, Gemini, DeepSeek, Groq, or Mistral.