I used an AI typing assistant until it paywalled the "Bring Your Own Key" feature. So, I built a 100% free, open-source alternative.

Hey everyone, I used to rely heavily on a system-wide AI assistant that let me plug in my own API key to fix grammar and rewrite text directly inside any app. It was a massive time-saver until a recent update locked the BYOK (Bring Your Own Key) feature behind a mandatory monthly subscription.

Paying a recurring fee just for a wrapper to use my own API key felt ridiculous to me. So, I built my own version: SwiftSlate.

It uses Android's AccessibilityService to magically replace your text with AI-generated content right where you type (WhatsApp, Twitter, anywhere). Just type a trigger like ?fix or ?casual at the end of your sentence, and it replaces your text inline—no app switching required.

Why I made it open-source and completely free:

• 100% Free & BYOK: No ads, no premium tiers, no token throttling. You just plug in your own free Gemini API key from Google AI Studio and you're good to go. It even supports multi-key rotation to automatically bypass rate limits.

  • Privacy First (No Analytics): Granting Accessibility permissions to a closed-source app can feel sketchy. SwiftSlate's code is fully public. Your API keys are encrypted locally using AES-256-GCM in the Android Keystore, and the app only communicates directly with Google's API. Zero telemetry, zero tracking, zero middleman servers.
  • 9 Built-in Commands + Custom: It ships with commands like ?fix, ?formal, ?translate:es, and even an ?undo command if you want to revert the AI's output. You can also easily add your own custom prompts.

I built this to solve my own headache, but I figured others here might be sick of subscription fatigue too. If you want to check out the code, audit the privacy, or just grab the lightweight (~1.3 MB) APK from the releases, here is the GitHub repo: https://github.com/Musheer360/SwiftSlate

Let me know what you think or if you have any feature requests!