The Autocomplete AI extension is an addon for FireFox and forks of it (e.g. Zen Browser). It allows you to double-tap backtick (`) to trigger an AI-powered text completion. It works on all textareas and other text inputs.
It uses the Google Gemini API, with the 2.0-Flash model.
I plan to add support for other LLMs (namely OpenAI/GPT and xAI/Grok) in the future. I also want to add support for custom instructions and options to fine-tune completions. Any other new features you want to see can be suggested in Issues, or feel free to add them yourself with a pull request.