ExtraBrain - local-first desktop copilot for live calls

Hi HN, I’m the maker of ExtraBrain.

I built it because I kept running into the same problem in high-pressure live conversations: the call moves faster than my notes. By the time I’ve captured the prompt, constraints, edge cases, or action items, the conversation has already shifted.

ExtraBrain is a Mac desktop app that gives you a private live workspace during interviews, meetings, lectures, and research calls. It can transcribe the session, keep track of context, help structure answers or follow-ups, and turn the session into notes afterward.

A few things I cared about while building it:

It’s local-first: transcripts, screenshots, prompts, and notes can stay on your Mac. It supports local transcription / local models where installed and compatible. You can bring your own OpenAI, Anthropic, Claude, Codex, or compatible provider access. It does not join your meeting as a bot. The free version is usable; Pro adds workflow/history/profile features. I know the interview-assistant category is sensitive. My intent is not to help people misrepresent their skills. I’m trying to build a tool for live thinking, accessibility, note-taking, preparation, and post-session review. People should still follow the rules of their interview, school, workplace, or platform.

I’d especially love feedback on:

whether the local-first/privacy model is clear enough whether the setup feels too heavy for a normal Mac user what responsible-use boundaries you’d expect from a tool like this whether “meeting copilot” or “interview copilot” better explains the product

Mac version is available now: https://extrabrain.app

Happy to answer questions, and genuinely curious where HN thinks this kind of tool should draw the line.