CashSwap
Decentralized P2P In-Person Crypto-to-Cash Exchange Platform
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About
The problem it solves We noticed a critical "last-mile" problem in cryptocurrency adoption in Indonesia. Small local businesses are open to accept cryptocurrency, but converting those tokens into Rupiah for daily expenses causes a lot of friction. Their suppliers, landlords, and utilities still insist on cash (or digital rupiah), so crypto remains an impractical payment option. A similar gap once slowed adoption of e-wallets like GoPay and OVO. They solved it by leveraging their network of rideshare driver to accomodate easy and fast e-wallet topups. We are bringing that same playbook to crypto. CashSwap connect merchants who need rupiah with nearby users looking to buy crypto, secured using an escrow system and the trust of in-person transaction. Here's how it works: 1. Businesses can list their tokens on CashSwap, with a specified location and fee; 2. Local users can browse through the listing and send offers with their preferred fee; 3. Once an offer is accepted, the assets are secured in an escrow; and 4. Both parties meet at the agreed location, the buyer hands over cash, the seller confirms, and the crypto is released from escrow. This allows an easy and fast access for merchants to exchange their digital assets to cash, while local users can profit from the fees.
How it's made
Challenges we ran into We spent a lot of time designing a secure, in-person exchange flow that protects both parties while keeping third-party dependence to a minimum. We take inspiration from pre-existing escrow flows from companies like Binance, LocalBitcoin, etc. We experimented with several approaches and testing edge cases such as “what if the token-holder runs away after receiving the cash?”. And finally, we settled on a two-step handshake: 1. The seller signs a message proving control of the wallet that will fund the trade; 2. The buyer verifies that signature in real time. Once both sides are satisfied, they complete the cash hand-off and mark the escrow as completed. To cover the remaining corner cases, the escrow contract includes: - Automatic time-outs. If either party becomes unresponsive, the other can safely claim their funds when the time-out expires; - Dispute management. In the future, a third party arbiter can be added to resolve disagreements on-chain. This design still isn’t bullet-proof, but the combination of a live signature check, deterministic fallbacks, and an optional arbiter greatly reduces the risk of loss for everyone involved.