# Private Sprint - Build privacy apps on Starknet

> An 18-day sprint to ship a real privacy application on Starknet mainnet. $5,000 USD paid in STRK, split $2,500 / $1,500 / $1,000 across the top three. Everyone builds in the open, on their own public repository, and every push shows up on the hub while the sprint is running.

## Dates

- **August 14** - registration and hacking opens
- **August 31, 23:59 UTC** - submissions close
- **September 4** - winners announced

## How it works

1. **Apply** - open a pull request against the [strk20-hackathon repository](https://github.com/starkience/strk20-hackathon) with your project, your team's GitHub handles and Telegram usernames, and a description of what you're building. Nothing needs to be deployed. The pull request is an application: we review it, and merging it means we're adding you to the builders group.
2. **Build in public** - work in your own public repository. Every push shows up on the hub, so the rest of the field sees what you ship the day you ship it.

**Registration is the only pull request you ever open.** Everything on the hub is read from your repository and refreshed every 30 minutes: your latest push and how long ago, a sentence describing what changed, lines added and removed, what your project does (from your README), the stack you're using (from `package.json`, `Scarb.toml` and your README), your deployed contracts and which network each is on, your live demo (GitHub Pages, your repository's Website field, or your latest deployment), and your team's avatars. You never open a PR to report progress.
3. **Ship to mainnet** - to win, your app has to run on Starknet mainnet against the live STRK20 pool: at least three mainnet transactions, and a demo anyone can open. Add your Starknet address to your entry once you have one.
4. **Nothing to submit** - whatever your repository shows at August 31, 23:59 UTC is your entry. Your demo, contract addresses, Starknet address and demo video live in a `strk20.json` at the root of your own repository. None of it belongs in a pull request to us: add each piece when you have it and we read it from there. Judges need all four to score you, and the hub shows which are still missing.

## Eligibility

- Anyone can apply, individuals and teams. Applications are reviewed.
- Existing or new projects.
- Public, open-source repositories required.
- Starknet mainnet deployment required.
- One payout address per winning team.

## Judging

A named panel scores every submitted project against four weighted criteria. Nothing on the hub ranks projects by merit - the panel does that, after submissions close.

- **STRK20 integration depth (30%)** - how far into the stack you went: shielded balances, private transfers, anonymizer contracts, the SDK.
- **Working mainnet product (30%)** - it runs, on mainnet, for a real user. Not a prototype behind a login.
- **Innovation (25%)** - something the ecosystem doesn't have yet, or a materially better take on something it does.
- **Documentation & open-source quality (15%)** - a README someone can follow, code someone can build on, a license.

## Prize pool

$5,000 USD paid in STRK: $2,500 for first, $1,500 for second, $1,000 for third. Strong projects may receive continued support after the sprint through technical feedback, ecosystem introductions, and the Starknet Foundation Grants Program.

## Builder resources

- [Starter kit](https://github.com/starkware-libs/starknet-privacy-starter-kit) - clone-and-go template with a working escrow demo wired to the live pool.
- [Documentation](https://strk20-by-example.org/what-is-strk20) - STRK20 by example: the pool, the wallet API, anonymizer contracts, the SDK.
- [Ideas list](https://github.com/starkience/strk20-hackathon/blob/main/IDEAS.md) - inspiration, not bounties. Build one of these or something else entirely.
- [Build on STRK20](https://strk20.starknet.io/build) - pick your integration route: private dapp, privacy wallet, or your own prover.

The STRK20 team is in the Telegram group every day of the sprint for architecture questions, integration help, and infrastructure blockers.