Umbra examples

Reference applications for Umbra — a privacy protocol for Solana that shields SPL / Token-2022 balances using Arcium MPC and zero-knowledge proofs. Everything here is built on the public TypeScript SDK, @umbra-privacy/sdk (5.0.0-rc.9, protocol V18).

What's here

• private-payments-nextjs/ — a full private-payments Next.js app (mainnet-beta by default; one env switch to devnet). Wallet-only signer, the SDK's standard browser store adapters (createShardedUtxoDataStore + createShardedNullifierStore), and the five private-payment steps as one tab each:

  1. Register — Umbra registration (3-step, idempotent) + key-consistency restore.
  2. Deposit — public ATA → your EncryptedTokenAccount (ETA), via MPC.
  3. Transfer — write a Stealth Pool Note from your ETA (receiver- or self-claimable).
  4. Claim — scan + burn notes addressed to you (→ ETA or ATA).
  5. Withdraw — ETA → your public ATA (unshield), via MPC.

  See private-payments-nextjs/README.md for the full walkthrough and architecture.

• compliance-auditor/ — a headless (no-UI) selective-disclosure example: derive the scoped viewing-key hierarchy (Master → Mint → Monthly → Daily) and issue / query / revoke an on-chain X25519 re-encryption grant to an auditor. A framework-agnostic core (src/core/) + a thin Node CLI demo — drop the core into a CLI, React, or mobile app unchanged. See compliance-auditor/README.md.

Run the app

cd private-payments-nextjs
pnpm install
pnpm dev              # http://localhost:3000

Connect a Solana wallet set to devnet, fund it from the faucet, then walk tabs 1 → 5.

Versions

Built on @umbra-privacy/sdk@5.0.0-rc.6, which pins @umbra-privacy/umbra-codama@3.0.0-rc.6. No package-manager overrides or dist patches are needed — the earlier rc.3/rc.4 codama PDA bug (ConstraintSeeds 2006) and columnar scan() bug are both fixed in rc.6. Just pnpm install.

Links

• Docs: https://sdk.umbraprivacy.com/
• Supported tokens: https://sdk.umbraprivacy.com/supported-tokens
• SDK on npm: https://www.npmjs.com/package/@umbra-privacy/sdk