Free local-first desktop copilot

Desktop AI interview and meeting copilot.

ExtraBrain follows live interviews and meetings on your Mac with transcription, screen-aware context, and answers from on-device Gemma or the AI provider you choose. Free and local-first, with privacy controls you can see.

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Free for Mac · macOS 14+ · Apple Silicon & Intel · Pro from $9.99/mo

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Local Parakeet transcription On-device Gemma AI Bring OpenAI, Anthropic, Claude, or Codex

Live session

System design interview · live

14:02

ExtraBrain · live transcript Listening · 14:02

14:02:10Host Design a rate limiter for a public API with regional spikes and abusive bursts.

14:02:18You Should limits be per user, per IP, or per endpoint?

14:02:24Host Start with per-user and per-endpoint limits. We care about burst traffic and graceful fallback.

Answer · 2 sources · 0.6s

Start with token buckets at the edge for burst tolerance, then coordinate counters through Redis or another distributed store. Call out fail-open vs fail-closed.

transcript · 14:02:10 transcript · 14:02:24

Saved facts

Rate limiter · public API

Burst traffic: edge token buckets

Tradeoff: fail-open vs fail-closed

Session memory

Live context

Transcript-aware answers, saved facts, and follow-ups while the call is still active.

Built for high-stakes live thinking. Free, local-first desktop AI interview and meeting copilot.

Compatibility

Works invisibly across the interview and meeting platforms people actually use.

ExtraBrain is designed to stay hidden from screen sharing and screen recording on major video call tools and coding interview environments, while remaining available on your own Mac. Always follow the rules of the interview, employer, school, meeting, or platform.

What the interviewer sees

The shared editor, without the ExtraBrain window.

What you see on your Mac

The same screen, plus a private ExtraBrain window designed to stay hidden from screen sharing.

Zoom

Google Meet

Microsoft Teams

Cisco Webex

Amazon Chime

Lark / Feishu

Slack Huddles

Discord

HackerRank

CoderPad

Codility

CodeSignal

Built for live coding interviews, LeetCode-style prompts, system design rounds, behavioral interviews, product interviews, data and ML interviews, consulting cases, lectures, and research calls.

Overview

An invisible AI copilot for interviews, meetings, lectures, and research.

ExtraBrain turns live audio, transcript text, screenshots, and selected context into organized prompts, answer structures, and session memory while keeping provider choice, costs, and privacy boundaries visible.

From download to live support in three steps.

Keep the setup path simple: install the Mac app, choose local or cloud transcription, choose on-device AI or provider access, and rehearse once before a real interview, meeting, or lecture.

Start the Mac app

Download the latest release, open ExtraBrain before the interview or meeting, and confirm microphone, transcription, and provider settings.

Choose Gemma-powered AI or providers you control

Use on-device AI powered by Gemma, or connect OpenAI, Anthropic, custom OpenAI-compatible endpoints, Claude Subscription, or Codex Subscription modes.

Follow the live signal

Use transcript-aware prompts for coding interviews, system design rounds, product meetings, lectures, and research calls.

Live interview and meeting context

Capture transcripts, prompts, screenshots, constraints, and follow-up questions while the call is still moving.
Interview answers with structure

Turn coding, system design, and behavioral prompts into clarifying questions, baselines, tradeoffs, and follow-up points.

End Ask Screenshot

Assistant Chat

Find the k-th largest element in the array

Use a min-heap of size k.

Push each value into the heap.
If heap size exceeds k, pop the smallest.
After processing everything, the heap top is the k-th largest.

Follow-ups

New Topic

Heap-based top-k selection

Confidence: 91% Analyze

ExplainAsk clarifying questionWhat should I say?Recap Manage

Ask anything, or type / for actions...

Leave with useful context

Generate summaries, action items, edge cases, unresolved risks, and post-answer feedback before the session context fades.

Local-first by design

Keep transcripts, prompts, screenshots, and notes on your Mac in a fully local setup, or explicitly send selected content to external providers when you choose them.

Sessions

Top-k coding interview

May 27, 5:04 PM 18m 40s

Overview Insights0 Analyses1 Entries57 Facts6

ConstraintThe problem is to find the k-th largest element in the array.

active confidence: 97%05:10:41 PM

ConstraintThe example mentions the eighth largest element.

active confidence: 97%05:10:41 PM

How it works

Try ExtraBrain right here.

Click Start to run a 1-minute practice interview and see what ExtraBrain does while you talk.

ExtraBrain FileEditViewWindow Tue 10:42

rate_limiter.py — interview-prep

Explorer ▾ interview-preprate_limiter.pytest_limiter.pynotes.md

rate_limiter.py test_limiter.py

1import time
2
3class TokenBucket:
4    """Per-key token bucket: allows bursts, enforces an average rate."""
5
6    def __init__(self, rate: float, capacity: int):
7        self.rate = rate
8        self.capacity = capacity
9        self.buckets: dict[str, tuple] = {}
10
11    def allow(self, key: str) -> bool:
12        now = time.monotonic()
13        tokens, last = self.buckets.get(key, (self.capacity, now))
14        tokens = min(self.capacity, tokens + (now - last) * self.rate)
15        if tokens < 1:
16            self.buckets[key] = (tokens, now)
17            return False
18        self.buckets[key] = (tokens - 1, now)
19        return True
20
21# TODO: shard buckets by key across Redis for multi-region

mainPython 3.12Ln 14, Col 9

Ready to help

Start a session to begin.

Use cases

Designed for moments where context moves faster than notes.

Use ExtraBrain as a private thinking layer during high-pressure live work: interviews, meetings, customer calls, lectures, and research conversations.

Candidate

Summarize the coding prompt, list edge cases, and outline a clean baseline before I start.

Who it's for

Engineers
Students

Coding interview guide

System design

Turn these requirements into components, tradeoffs, and follow-up questions.

Who it's for

Engineers

System design guide

Meeting lead

Extract decisions, risks, owners, and follow-ups from this call.

Who it's for

PMs
Founders

Meeting assistant guide

Customer research

Highlight customer pain points and quotes I can use in roadmap notes.

Who it's for

Research teams
PMs
Founders

Meeting copilot guide

Lecture mode

Convert this explanation into concepts, examples, and review questions.

Who it's for

Students

AI note taker guide

Trust and control

Local-first control belongs in the main product story.

ExtraBrain can keep requests on your device when you use Gemma-powered on-device AI and local Parakeet transcription. Privacy still depends on your selected setup, including what you send to optional model and transcription providers.

Where your session data goes Stays on your Mac Sent only if you choose it

Capture
Microphone and system audio Recorded by the desktop app, not a meeting bot

Screenshots you take Only the regions you capture
Transcription
NVIDIA Parakeet Runs locally on your Mac

Deepgram Optional, with your own key
AI answers
Gemma on-device Macs with 16 GB of RAM or more

OpenAI, Anthropic, Claude, Codex Or a custom endpoint, billed to your account
History
Transcripts, notes, saved facts Stored on your Mac until you delete them

Read the full data-flow page

You choose what to capture

ExtraBrain is a desktop app, not a meeting bot joining the room. Keep session scope, prompts, and outputs in your control.

Your model choice stays yours

The app does not force a single hosted AI vendor. Use on-device AI powered by Gemma, or connect the provider subscriptions, accounts, or API keys you trust.

Use it within the rules

Interview and workplace policies vary. ExtraBrain should support your thinking, notes, and preparation without misrepresenting your skills.

ExtraBrain should support your thinking, notes, and preparation. You are still responsible for following interview, workplace, and platform policies.

Interview policy reminder

Pricing structure

Free to start. Pro from $9.99/month, $99/year, or $179 lifetime.

Free core access, on-device AI powered by Gemma, BYO provider subscriptions or API keys, Pro workflow tools, and enterprise support by contact.

Free

Core desktop app, live workflow support, on-device AI powered by Gemma, and BYO provider setup.

Always free

Download and use the Mac app
Use on-device AI powered by Gemma, or connect OpenAI, Anthropic, Claude, Codex, or compatible provider access
Local-first transcripts, prompts, screenshots, notes, and session context
Local Parakeet transcription and optional Deepgram setup
Help center, setup, privacy, and troubleshooting guides

Download Free

Pro

Advanced controls for repeated interview, meeting, and research workflows, plus 1,000 ExtraBrain AI credits per billing month with eligible monthly and yearly subscriptions. Pick the billing option that fits your timeline.

Monthly

$9.99/mo
Yearly

$99/yr

Yearly Pro access.
Lifetime

$179

Everything in Free
Custom profiles with reusable prompt guidance
Profile-specific workflow controls for analysis behavior
Richer session history across transcripts, notes, screenshots, and saved facts
Post-session summaries for decisions, risks, follow-ups, and review
Premium model and advanced workflow controls
1,000 ExtraBrain AI credits per billing month with eligible monthly and yearly Pro subscriptions
Purchase and activate from Settings → Plan & Billing inside the app

Start Pro for $9.99/mo

Enterprise

Policy, deployment, privacy, and workflow support for teams.

Custom

Team rollout planning
Responsible-use and policy guidance
Security and deployment review
Custom workflow support for team requirements

Talk to us

Comparing with other interview assistants? See how pricing and data handling differ.

FAQ

Common questions about ExtraBrain.

Short answers about pricing, privacy, AI providers, supported platforms, and responsible use.

See all questions

What is ExtraBrain?

ExtraBrain is a free, local-first desktop AI interview and meeting copilot. It provides live transcription, screen-aware context, structured prompts, question generation, on-device AI powered by Gemma, and a desktop window designed for private live workflows. It is available for Mac today, with Windows and Linux planned.

Is ExtraBrain free?

Yes. ExtraBrain is free to download and use. ExtraBrain Pro starts at $9.99/month, with $99/year and a $179 Lifetime option. Eligible monthly and yearly Pro subscriptions include 1,000 ExtraBrain AI credits per billing month. Pro also adds custom profiles, reusable prompt guidance, richer session history, post-session summaries, premium model controls, and advanced workflow tools.

What platforms does ExtraBrain support?

ExtraBrain is available for macOS 14 Sonoma or later, on Apple Silicon Macs such as M1, M2, M3, and M4, and on Intel Macs. Windows and Linux are planned, not current release targets.

Which AI providers does ExtraBrain support?

ExtraBrain supports on-device AI powered by Gemma (on Macs with 16 GB of RAM or more), plus provider access you control: OpenAI, Anthropic, custom OpenAI-compatible endpoints, Claude Subscription, and Codex Subscription modes.

Does ExtraBrain collect user data?

ExtraBrain is designed as a local-first app. With local Gemma 4 and local Parakeet transcription, transcription and AI prompts can stay on your Mac. Content may leave your device only when you choose optional external providers such as cloud model APIs or Deepgram.

Is using ExtraBrain in interviews allowed or considered cheating?

ExtraBrain is a tool, and you are responsible for following the policies of the company, interviewer, school, employer, or platform you are working with. Use it to support thinking, notes, accessibility, and preparation without misrepresenting your skills.

Can interviewers detect ExtraBrain on Zoom, Google Meet, or Microsoft Teams?

ExtraBrain is designed to stay hidden from screen sharing and screen recording on major meeting tools. You should still follow all interview, workplace, school, and platform rules.

Does ExtraBrain join the meeting as a bot?

No. ExtraBrain runs as a desktop app on your Mac rather than joining Zoom, Google Meet, Microsoft Teams, or other calls as another participant.

Ready when the conversation starts

Download the free Mac app before the call starts.

ExtraBrain gives you a private live workspace for interview prompts, meeting notes, structured answers, and session context in a free desktop app you control. Upgrade only if you need Pro workflow features.

Download Free Mac App Open help center