Inspiration
We wanted to replace expensive lawyers and trust banks with Bitcoin native code. Inspired by the Sovereignty theme of bitcoin++, we built a "Trustless Trust" where you rely on math and block height, not third-party custodians. "Trust code, not lawyers."
What it does
OpBits is a Bitcoin trust fund protocol powered by nLockTime.
Visual Dashboard: Tracks locked assets and remaining time (block height).
Trustless Mechanism: Uses pre-signed transactions that are valid only after a future date.
Hybrid Custody: Users can self-custody the pre-signed JSON files or delegate storage to OpBits.
One-Click Claim: Beneficiaries broadcast the transaction instantly when the time-lock expires.
How we built it
Core: Rust and BDK (Bitcoin Dev Kit) for wallet logic and signing.
Protocol: Pure Bitcoin L1 nLockTime (no sidechains/tokens).
Frontend: A reactive web interface for interacting with raw hex data.build with Nextjs.
What we learned
How to use bdk-cli.
What's next for OpBits Decentralized Storage: Publishing pre-signed transaction blobs to Nostr or IPFS.
Hardware Wallets: Adding HWI support for signing directly from cold storage.