Compaki

Marketplaces for communities, where every sale also funds a shared purpose.

Built for the Pura Vida Ideathon, organized by the Blockchain Acceleration Foundation (BAF). Compaki is a working prototype on Stellar testnet that uses demo money: compaki.vercel.app.

What Compaki is

Producers who already sell together, such as a farmers' market, a cooperative or a craft fair, have no simple way to sell online as a group. Someone has to coordinate the orders, work out each person's share, set money aside for shared goals and explain who received what.

Compaki lets any organizer launch a marketplace for their community in a few minutes. Several sellers list their products in it, and every payment is split automatically, in the same transaction, between:

• the seller;
• the organizer;
• a community fund;
• Compaki, which charges a fixed 2%.

The organizer chooses what the community fund does:

Mode	What happens to the community share
Classic	It goes straight, with every sale, to the community fund wallet the organizer names.
Community Rewards	It accumulates for a period (monthly to yearly; every 10 minutes on testnet, for demos), then returns to that period's buyers and sellers in proportion to what each one bought and sold, like a cooperative's dividend.
Fundraising	It accumulates until a target is reached, then pays fixed public recipients, such as a school or shared equipment, round after round.

Who benefits

• Organizers get a storefront for their community with the split, the fund and its rules handled for them, and receive their share directly.
• Sellers see what they will earn per unit before publishing, and are paid at the moment of each sale, not days later.
• Buyers sign in with email or Google, with no crypto wallet to install. In rewards marketplaces they get part of the fund back.
• Communities get a fund that grows with every sale, with rules and recipients anyone can check, instead of a spreadsheet someone has to explain.

Why it matters

• The rules run with the payment. A Soroban smart contract applies the split and the fund's rules in the same transaction as the purchase. Nobody has to divide the money afterwards.
• Anyone can verify it. Every receipt links to its transaction on Stellar Expert, and the community page shows the fund, its periods or rounds, and who received what.
• The fund pays for itself. It is financed by a share of real sales, not by donations or a speculative token. Under the deployed contract code, nobody, including the organizer or Compaki, can withdraw it or change a running period's rules.
• It feels like a normal store. Sign-in with Google or email, prices in dollars, and one signature per payment.

Stellar ecosystem tools used

Tool	What Compaki uses it for
Soroban	One smart contract for every marketplace: the atomic split of each payment, the rewards treasury with its periods and claims, fundraising rounds, and in-place upgrades. Contract README
Stellar Asset Contract	Lets the contract move CPKUSD, the demo payment asset.
Scaffold Stellar	Builds and optimizes the contract, and generates the typed TypeScript client the API uses to call it. CI checks the client matches the contract.
Stellar SDK, RPC and Horizon	The API prepares, simulates and submits transactions, and manages accounts and trustlines. API README
Cavos	Email and Google sign-in with an embedded Stellar wallet. Users sign their own launches, purchases and claims; Compaki never holds that key.
Stellar Wallets Kit	Sign-in and signing with existing wallets such as Freighter, xBull, Albedo and Lobstr.
SEP-10	Standard Stellar web authentication for wallet sign-in, also open to other Stellar clients. Details
SEP-1	stellar.toml publishing Compaki's signing key, auth endpoint and the demo asset, marked as a test asset.
Stellar Expert	Public verification of every receipt, fund and contract.
Friendbot	Funds testnet accounts and the payers for deploys.

Status and limits

• Testnet only. Payments use CPKUSD, a demo asset Compaki issued on Stellar testnet. It is not Circle's USDC and has no value.
• Upgradeable contract. Its admin can replace the code, which is a trust trade-off; the guarantees hold for the deployed version.
• Per-item checkout. Each product payment is atomic; a cart of several items is settled as one payment per item.
• Not yet validated with users. Interviews and a first community pilot are the next step.

Details: contract guarantees and sign-in and wallets.

Repository

Part	What it is
contracts/marketplace	Soroban contract (Rust): split, rewards, fundraising, 44 tests.
apps/api	Hono + Prisma API: the only part that talks to Stellar; sign-in, scheduler, deploy scripts.
apps/web	Next.js app for buyers, sellers and organizers, in English and Spanish.

To run it locally, start with the API, then the web app. GitHub Actions builds and tests all three parts on every push.

Before and during the ideathon

Before: a Next.js frontend and Hono API, a Soroban contract with a three-way split, the launch wizard, products, cart and checkout, receipts linked to Stellar Expert, dashboards, custodial testnet accounts and 9 contract tests.

During the ideathon (October 24–25, 2026; see the git history):

• Contract: the three community modes; distributions anyone can trigger, with next-period rules scheduled by the organizer; sellers who register themselves; the fixed 2% fee; in-place upgrades; 9 → 44 tests, including strict authorization and mutation testing.
• Stellar ecosystem: Cavos and Stellar Wallets Kit sign-in, with users signing their own transactions; the organizer's own wallet as the on-chain operator; SEP-1 and SEP-10; Scaffold Stellar with a generated client; fee bumps for today's testnet fees.
• Product: rewards and fundraising dashboards, the public community page, the member rewards page, "My marketplaces", seller earnings preview, order fulfilment and tracking, no overselling or double charges, a redesign with dark mode, and English and Spanish throughout.
• Security: every account now signs with its own wallet (no server-held keys or passwords); a fix for account takeover in seller registration; signed, expiring Secure session cookies; CI for the contract, API and web.