Why this exists
Every embedded wallet SDK I evaluated forced an unhappy tradeoff: custodial models held keys on a server (regulatory exposure, single point of failure) or seed-phrase models pushed the entire UX problem onto the user. The third option — MPC — was locked behind enterprise contracts. I wanted a wallet layer that was open, non-custodial by default, and didn't require a user to write a 12-word phrase on paper.
What Rabit does
Rabit splits the user's private key into three Shamir shares: one on-device, one in a provider-side encrypted vault, one held by a recovery service. Any two reconstruct the key. No single party — including the integrator — can spend.
The monorepo:
@rabit/core— share splitting, key reconstruction, message signing primitives@rabit/react— provider, hooks (useWallet,useTransaction,useRecovery)@rabit/evmand@rabit/solana— chain adapters@rabit/connectors— RainbowKit / wagmi interop so existing dApps adopt incrementally@rabit/smart-accounts— ERC-4337 abstraction wrapper@rabit/onramp— fiat → crypto via Transak / MoonPay@rabit/ui,@rabit/keys,@rabit/types— supporting packagescreate-rabit-app—npx create-rabit-appscaffolder
Design decisions
Why Shamir, not MPC? MPC requires multi-round signing protocols; Shamir reconstructs the key in a single round. For consumer wallets the constant-factor latency matters more than MPC's marginal theoretical advantage.
Why a monorepo with 11 packages? Each chain adapter, each connector, each onramp is a separate package so teams install only what they need. The full SDK is ~50KB gzipped if you pull everything; ~12KB if you stick to EVM-only.
Why MIT? OpenZeppelin, ethers, viem, and wagmi are all MIT-licensed. The wallet layer shouldn't be the place teams hit a license boundary.
What's in the public repo
CONTRIBUTING, SECURITY (including disclosure policy), Code of Conduct, full Changesets release flow with automated CHANGELOG generation, semver-aware version bumping. Anyone shipping a wallet SDK can fork the architecture.