SubletSafe
Inspiration
Every UC Davis student knows the summer sublease panic — you're stuck in a lease you can't afford to keep, posting on Facebook groups with blurry photos and crossing your fingers someone responds. There's no verification, no transparency, and no real reason for anyone to take over your lease. We wanted to fix that with something that actually makes subletters want to say yes.
What It Does
SubletSafe is a sublease marketplace built for UC Davis students. Tenants upload their lease PDF, and Claude AI instantly summarizes it in plain English — key terms, rules, fees, and anything to watch out for. Tenants also offer a monthly rent incentive locked in a Solana escrow wallet, so subletters can verify the money is real before committing. Listings show the discounted rent upfront, and both parties confirm the handoff inside the app to release the funds.
How We Built It
We built a Python + FastAPI backend that handles lease PDF processing, Claude API calls for AI summaries, Firebase Firestore for listing storage, and a Solana devnet escrow wallet for incentive locking. The frontend is React with TanStack Router and Clerk for authentication. The backend and frontend communicate over a REST API with CORS enabled for cross-device development.
Challenges We Ran Into
Figuring out the right Solana integration was the biggest challenge — building a full Anchor smart contract in 24 hours wasn't realistic, so we designed around a backend-controlled escrow wallet that demonstrates the concept with real devnet SOL. We also ran into issues with Firebase Firestore setup, PDF binary decoding, and coordinating backend and frontend across two laptops on the same WiFi.
Accomplishments That We're Proud Of
We're proud that the entire flow actually works end-to-end — a real PDF goes in, Claude reads it and returns a structured plain-English summary, the listing hits Firebase, and the Solana Explorer shows a real wallet with real devnet SOL. The SOL-to-dollar conversion updates live as you fill out the form. It's not a mockup — it's a working product.
What We Learned
We learned how to integrate the Anthropic Claude API for document understanding, how Solana devnet wallets work, and how to coordinate a split frontend/backend architecture under time pressure. We also learned that the hardest part of a sublease isn't finding someone — it's giving them a reason to trust you.
What's Next for SubletSafe
- Full Solana smart contract escrow using Anchor so funds are truly trustless
- Phantom wallet integration so tenants deposit directly from their own wallet
- DocuSign API integration to trigger automatic fund release when the countersigned lease is uploaded
- UC Davis SSO verification through .ucdavis.edu email to ensure both parties are real Aggies
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