Skip to main content

​
What is Umbra?

Umbra adds a privacy layer on top of standard Solana SPL and Token-2022 tokens. It lets you:
  • Shield balances — move tokens from a public Associated Token Account (ATA) into an EncryptedTokenAccount (ETA) where the balance is hidden from everyone except authorized viewers.
  • Transfer anonymously — write a Stealth Pool Note into a shared mixer tree, then burn it from any wallet with no on-chain linkage to the sender.
  • Control who sees what — grant selective viewing access to auditors or compliance systems without exposing your full history.
Everything runs on Solana using a combination of on-chain programs and Arcium multi-party computation (MPC) for the confidential arithmetic.
You do not need to understand MPC or zero-knowledge proofs to use Umbra. The SDK handles all cryptographic operations for you.

​
Key terms

The SDK and these docs use this vocabulary throughout:
  • ATA — AssociatedTokenAccount. A standard SPL Associated Token Account holding plaintext tokens.
  • ETA — EncryptedTokenAccount. An Umbra-managed account whose balance is encrypted. Two modes: MXE-only (Arcium decrypts) and Shared (the user can also decrypt locally).
  • Stealth Pool Note — a leaf in the shared mixer tree. On-chain it is a commitment in the Indexed Merkle Tree; the SDK surfaces it as a “note”.
  • Burn — consuming a note: it reveals the note’s nullifier on-chain and credits the destination balance.
The on-chain instruction is burn_* and the relayer endpoint is /v1/claims — the wire protocol uses these lower-level nouns, and a handful of TS aliases bridge them so the relayer client plugs into the burner factories unchanged. You should not need to touch any of that as an SDK consumer.

​
Core Concepts at a Glance

Encrypted Balances

Shield any SPL or Token-2022 token balance in an EncryptedTokenAccount. Only you — and anyone you explicitly grant access to — can see the amount.

Stealth Pool

Break the on-chain link between sender and recipient using a shared Merkle tree of Stealth Pool Notes and zero-knowledge burn proofs.

SDK

One TypeScript package, @umbra-privacy/sdk. The ZK prover, indexer client, and relayer client all ship as subpath modules — no separate @umbra-privacy/web-zk-prover package.

Indexer API

A read-only REST API for Stealth Pool Note records and Merkle proofs — used internally by the SDK and available for direct integration.

​
How It Fits Into Your Stack

Umbra is designed to slot into an existing Solana application. You bring your wallet adapter; Umbra handles the rest. 
Your App
  └── Wallet (Phantom, Solflare, etc.)
        └── Umbra SDK (@umbra-privacy/sdk)
              ├── Solana RPC     — sends and confirms transactions
              ├── Arcium MPC     — performs confidential computation off-chain
              ├── Umbra Indexer  — indexes Stealth Pool Notes + Merkle proofs
              ├── Umbra Relayer  — submits burn transactions for the user
              └── ZK prover      — Groth16 (snarkjs), runs in a Web Worker

​
Program IDs

The Umbra on-chain program is deployed at different addresses per network:
  • Mainnet: UMBRAD2ishebJTcgCLkTkNUx1v3GyoAgpTRPeWoLykh
  • Devnet: DSuKkyqGVGgo4QtPABfxKJKygUDACbUhirnuv63mEpAJ
The SDK resolves the correct program address automatically based on the network parameter.

​
Supported Networks

  • mainnet — Production. wSOL, USDC, USDT, UMBRA, CASH, ZINC.
  • devnet — Development and integration testing. wSOL only.
  • localnet — Local validator. wSOL only.

​
Next Steps

Quickstart

Install the SDK and run your first deposit + burn in under 5 minutes.

How Umbra Works

Understand the privacy model before you start building.