Building in public. Follow along on X

For indie hackers and hackathon teams

Who paid what.
Who owns what.

One shared ledger for side projects with a partner. Split the bills, track the domain, hand it over clean.

Free sheet today No card needed MCP & API
Two founders sharing one project, split 50/50 yourproject.com 50 50 Matt Partner $

How it works, in 12 seconds

to: yourproject@inbox.whoownswhat.xyz

Fwd: Your Supabase Pro receipt

Amount: 25.00 · Card ending 4417

AI is reading the receipt

Supabase Pro · monthly · paid by Matt+25.00

The problem

+ You bought the domain

+ Vercel Pro on your card

+ Notion, Slack and Claude on your card

+ Recovery email: your personal Gmail

+ 6 months of "I'll pay you back"

= one awkward breakup away from a mess

There's an easier way.

An IOU receipt of unsplit project costs IOU domain12.00 vercel20.00 notion10.00 claude20.00 slack8.75 who pays????

Features

Everything a two-person project needs. Nothing it doesn't.

Forward the invoice. Done.

Every project gets its own inbox. AI reads who paid and how much.

to: yourproject@inbox.whoownswhat.xyz

Vercel Pro · monthly20.00

Settle up in one tap

Like Splitwise, but for your project's tools. Pay back with the app you already use.

RevolutPayPalWise

See who really owns it

Domain, GitHub, Vercel, Stripe. Owner, payer, backup admin and recovery email, in one list.

DomainMattno backupGitHubMattPartner

Get pinged before it breaks

Expiring domains, dead cards, a single admin. You hear about it first.

yourproject.com expires in 12 daysCard on Vercel billing has expired

Hand it over clean

Someone leaves, or you sell? Get a step-by-step transfer list for every asset.

[x] GitHub org owner added[x] Vercel billing card moved[ ] Domain auth code sent

A one-page founder deal

Shares, who keeps what, what happens if someone leaves. Plain words, signed by both.

Matt 50% · Partner 50%Signed 2/2
48-hour stopwatch 48h

HACKATHON MODE

48 hours with strangers? Decide the ending up front.

When the weekend ends, the team votes: archive it, or transfer everything to whoever keeps building. See the hackathon kit.

ENDS SUN 18:00

Archive1 vote
Transfer to Ana3 votes

MCP · CLI · APIReal project plan

Skip the dashboard. Talk to your ledger.

Connect WhoOwnsWhat.xyz to Claude, ChatGPT or Cursor. Log costs, check balances and fix ownership from the chat you already have open.

  • Set up a whole project from one prompt
  • "I paid for X" and it's logged and split
  • Hackathon tip: one command connects the whole team

$ npx whoownswhat mcp add --project yourproject

ClaudeClaude CodeChatGPTCursorREST API

In development. See what's planned.

your AI chat whoownswhat connected

Just paid 25 for Supabase Pro for the project.

whoownswhat_add_cost whoownswhat_balance

Logged: Supabase Pro, 25.00, paid by you. Partner now owes you 23.50. Send them the Revolut link?

Who can renew the domain if I get hit by a bus?

whoownswhat_assets

Only you, and recovery goes to your personal Gmail. Want me to add Partner as a backup admin?

WHY I BUILT THIS

Matt @mwarcholinski

I started a project with a co-founder. I bought the domain, Notion, Slack, Claude and Vercel Pro. All on my card, all on my accounts.

We trust each other. But on paper, he owns nothing. And I've been paying every month without a clean way to split it.

So I'm building the tool I wanted on day one.

Pricing

Cheaper than one awkward conversation

Side project

$0

  • 1 project, 2 people
  • Cost split and settle-up links
  • Ownership list
  • Hackathon mode
Join the waitlist

WhoOwnsWhat.xyz is in development. Prices may change before launch, and nothing is charged during early access.

Questions

When can I use it?

We're building it now. Join the waitlist for early access. The free Google Sheet works today.

Do you hold our money?

No. Money moves straight between you, through Revolut, PayPal or Wise. We only keep the score.

Do you store our passwords?

Never. We track who controls each account, not the logins themselves.

Can I use it from Claude or ChatGPT?

That's the plan for the Real project tier: connect the MCP server once and your AI can log costs, read balances and check ownership. Read more.

Is the founder agreement legally binding?

It's a plain-language starting point so you agree early. For anything big, show it to a lawyer. See the free template.

I'm not a developer. Is this for me?

Yes. If you can forward an email and click "connect", you're set.

Start the project right.

Settle who owns what on day one, not on the day someone leaves. Join the waitlist for early access.

One email when early access opens, plus rare build updates. Unsubscribe anytime. See our privacy policy.

Can't wait? Copy the free Google Sheet.