Meet NucleusYour virtual co-founder.

Your virtual co-founder for

Talk through your idea out loud. Nucleus stress-tests it, finds real users for you to interview, and turns what you learn into a plan you can actually build from.

It's free to get started!

The co-founder that pushes back.

You talk, Nucleus listens, then it stress-tests your idea, tracks your assumptions, lines up real people for you to interview, and turns what you learn into a plan you can hand straight to your build tool of choice. It remembers everything about your startup, so no session ever starts from zero.

Most AI tools just tell you what you want to hear: ask if your idea is good and they'll say yes, every time. That false confidence is why so many AI-built products launch to zero users. Nucleus grounds every next step in real evidence: customer conversations, market numbers, and your own validated assumptions.

Built for the founder who already has the idea, and the AI tools to build it. Nucleus brings the missing piece: a co-founder who keeps every step grounded in real evidence, not just enthusiasm.

Watch a session with Nucleus unfold

Ideation

Product philosophies guide every conversation you have with Nucleus.

  1. 01

    One idea at a time

    Splitting focus across ideas is the fastest way to finish none of them. Nucleus keeps you locked on one at a time.

  2. 02

    Always talk to potential users

    Nucleus surfaces people from your LinkedIn network worth talking to, so validation never stalls for lack of a lead.

  3. 03

    Set a clear assumption and rank by risk

    Nucleus sharpens vague hunches into testable assumptions, then ranks them by what matters most to get right first.

  4. 04

    Break products into features and prioritize

    Nucleus turns a broad idea into scoped features and phases, so you ship the smallest valuable slice first.

  5. 05

    Launch early, get feedback, experiment fast

    Nucleus writes a build-ready plan sharp enough to hand straight to your vibe-coding tool of choice.

  6. 06

    Distribution makes or breaks consumer products

    Nucleus pushes you to nail distribution before you go deep on the build, so you never ship into silence.

Pricing

Starter

Free

Get a feel for Nucleus, no card required.

  • 30 minutes of voice conversation
  • Brainstorming with Nucleus

No credit card needed

Most popular
Growth

$20/month

Launch offer

Your co-founder available 24/7 on voice and text.

  • Everything in Starter, plus:
  • 5x more conversation time
  • Turn a raw idea into a sharp, testable assumption
  • Get matched with real users worth interviewing, sourced from your own network
  • Walk out of every customer chat with a clear script review of what you actually heard
  • Competitor analysis and market trend tracking
  • Data-grounded market sizing for your idea
  • Ship a product plan reviewed from every angle you'd have missed alone
  • See your momentum session to session, so you always know the next move

Cancel anytime. No lock-in.

Founder+

$50/month

Launch offer

For founders moving fast on more than one front.

  • Everything in Growth, plus:
  • 20x more conversation time
  • Proactive research that keeps working even when you're not talking to Nucleus

Cancel anytime. No lock-in.

Frequently Asked

1. What is Nucleus?⌄

A voice-first co-founder that stress-tests your ideas, keeps your startup memory (ideas, assumptions, customer chats, product plan) in one place, and pushes back instead of flattering you.

2. Is Nucleus for me?⌄

Yes, if you've got an idea and the AI tools to build it, and you want a co-founder who keeps you grounded in real evidence as you go. Aspiring founders, solo builders, and anyone chasing a side project with real business potential all fit.

3. Is there a free version?⌄

Yes. Starter gives you 30 minutes of voice conversation for idea brainstorming, no card required. Growth ($20/mo) and Founder+ ($50/mo) unlock full validation, research, and planning tools.

4. Will Nucleus build my product?⌄

No. Nucleus is a strategic co-founder. It helps you validate and scope what to build; you (or your own tools) handle the code.

5. Is everything I build here mine?⌄

Yes. Every idea, assumption, product plan, and customer chat you create in Nucleus is saved securely under your account and is yours to keep: bring it up any time ("show me my artifacts") and download any of it as a PDF, individually or all at once. That includes the research Nucleus does on its own between conversations — ask "what have you found?" any time to see the full history.