Shielded SDK

The Mersennet JavaScript SDK (@prime-chain/sdk) ships a shielded surface for wallets and apps that connect to a chain with the ZK privacy hard fork activated. It covers client-side proving, note scanning, balance/position/order reconstruction, selective-disclosure reads, and migration.

All shielded crypto runs client-side. The node is never asked to decrypt your data; it only verifies proofs and gates authorized reads. See Privacy on Mersennet for the conceptual model.

Install

npm install @prime-chain/sdk
# or, from a checkout:
npm install /path/to/prime-chain/sdk

Modules at a glance

Area	Exports
Shielded client	ShieldedClient, ViewingKeyHelpers, createOwnerViewingMaterial, createMockNoteDecryptor
Note scanning	scanGrantedNotes, parseEncryptedNotePayload, parseShieldedNotePlaintext
Reconstruction	reconstructPortfolio, scanAndReconstructBalances, defaultNullifierDeriver
Positions & orders	reconstructPositions, reconstructOpenOrders
Client-side proving	NoirWasmProver
Migration	planMigration, confirmMigration, deriveMigrationNote, matchesMigrationNote, defaultNoteCommitment

Client-side proving (NoirWasmProver)

Shielded transactions require a Noir proof generated in the wallet, so keys never leave the device. NoirWasmProver wraps a proving backend that the wallet injects (built on @noir-lang/noir_js + @aztec/bb.js).

import { NoirWasmProver } from '@prime-chain/sdk';

const prover = new NoirWasmProver({ backend });   // backend: NoirProvingBackend
const proof = await prover.prove('OrderPlace', inputs); // NoirCircuitName + NoirInputValue map

Relevant types: NoirCircuitName, NoirInputValue, NoirProvingBackend, NoirWasmProverOptions.

Note scanning & balance reconstruction

Rebuild private balances locally from encrypted notes (see Note scanning):

import { scanAndReconstructBalances } from '@prime-chain/sdk';

const portfolio = await scanAndReconstructBalances({
  encryptedNotes,   // from prime_viewNotes / prime_getShieldedNotes
  viewingMaterial,  // owner or grantee material
  spentNullifiers,  // from the chain's nullifier set
});
// portfolio.balances → per-asset totals with spent notes excluded

Lower-level building blocks are also exported: scanGrantedNotes (decrypt authorized notes), defaultNullifierDeriver (derive nullifiers), and reconstructPortfolio (sum unspent notes).

Types: Note, EncryptedNote, GrantedDecryptedNote, GrantedNoteScanOptions, GrantedNoteScanResult, GrantedViewingMaterial, ShieldedBalance, ViewingKey, PortfolioNote, ReconstructedPortfolio, NullifierDeriver, BalanceReconstructionResult.

Positions & open orders

import { reconstructPositions, reconstructOpenOrders } from '@prime-chain/sdk';

const positions = reconstructPositions({ orders, fills /* local records */ });
const openOrders = reconstructOpenOrders({ orders });

Types: OrderSide, OrderRecord, FillRecord, OpenOrder, ReconstructedPosition, ReconstructTradingOptions.

Selective disclosure

A grantee uses the same reconstruction primitives, but over the data a viewing grant authorizes. Fetch authorized notes/records via the grant-gated RPC methods (prime_viewNotes, prime_viewBalances, prime_viewPositions, prime_viewOrders) and run reconstructPortfolio / reconstructPositions / reconstructOpenOrders client-side.

Migration

Drive transparent → shielded migration with a plan-then-confirm flow (see Migration):

import { planMigration, confirmMigration } from '@prime-chain/sdk';

const plan = planMigration({ amount, asset, ownerPubKey });
// ... submit via prime_submitShield ...
const result = confirmMigration({ plan, onChainCommitment });

Types: MigrationNote, MigrationNoteParams, MigrationPlan, MigrationConfirmation, NoteCommitmentHasher.

See also

• Shielded JSON-RPC reference — the methods these helpers call.
• JavaScript SDK — the transparent (eth_* / prime_* / primeorders_*) surface.