Overview
RENTL turns any surface into rentable ad space. Anyone — a person, a venue, or a website — can auction off a spot (a t-shirt, a billboard, a corner of a homepage) to advertisers, with bidding and payouts settled in USDC on Solana. It's a simple idea with a sharp edge: programmable, transparent advertising deals without intermediaries.
To prove the concept on stage, I auctioned ad space on my own t-shirt and walked out as a literal human billboard.
The pitch
RENTL was built as a Colosseum Solana hackathon submission and pitched at Superteam Balkan's Demo Day — Solana Startup Competition in Belgrade:
- 30 teams competing for a $10k prize pool
- 100+ people in the room and 2.3k watching live
- Walked away with a Judge's Honorable Mention
The most valuable part wasn't the recognition — it was hours of detailed, honest feedback from judges including Vidor (Solflare), Stanko (V3V Ventures), Marko (Lucid Drakes) and Ivan (Neon Labs) who stayed long after the event to help every team.
What I built
- On-chain auctions for ad slots, with bids and settlement in USDC on Solana
- Listing flow for physical and digital surfaces, each with its own slot, duration and reserve price
- Wallet-based bidding and transparent, verifiable winner selection
- Creator + advertiser views so both sides can manage listings, bids and active placements
Tech Stack
- Solana + SPL / USDC for payments and settlement
- Anchor (Rust) smart contracts for the auction logic
- Next.js + TypeScript front end with Solana wallet adapter
- Tailwind CSS for the UI
RENTL was built and shipped under competition pressure — two intense weeks of building, mentorship and (very little) sleep with the Superteam Balkan crew. If this is what 18 looks like, I can't wait for what comes next.
Live: rentl.dev