Prover

The Prover handles ZK proof generation for transfers and unshields.

createProver

Create a new prover instance.

import { createProver } from '@zkprivacy/sdk';

const prover = await createProver(config: ProverConfig): Promise<Prover>

ProverConfig

Property	Type	Required	Description
transferCircuit	CircuitSource	Yes	Transfer circuit JSON
unshieldCircuit	CircuitSource	Yes	Unshield circuit JSON

CircuitSource

Can be:

• string - URL to fetch the circuit JSON
• object - Already-parsed circuit JSON

Examples

// Browser: fetch from URLs
const prover = await createProver({
  transferCircuit: '/circuits/transfer.json',
  unshieldCircuit: '/circuits/unshield.json',
});

// Node.js: pass parsed JSON
import { readFileSync } from 'fs';

const prover = await createProver({
  transferCircuit: JSON.parse(readFileSync('circuits/transfer.json', 'utf-8')),
  unshieldCircuit: JSON.parse(readFileSync('circuits/unshield.json', 'utf-8')),
});

---

setGlobalProver

Set the global prover instance used by PrivacyClient.

import { setGlobalProver } from '@zkprivacy/sdk';

setGlobalProver(prover: Prover): void

Example

const prover = await createProver({ ... });
setGlobalProver(prover);

// PrivacyClient will use this prover automatically
const client = new PrivacyClient({ ... });

---

Prover Class

isReady

Check if prover is initialized.

prover.isReady(): boolean

generateTransferProof

Generate a proof for a transfer.

await prover.generateTransferProof(params: TransferParams): Promise<ProofResult>

INFO

You typically don't call this directly. Use client.transfer() instead.

generateUnshieldProof

Generate a proof for an unshield.

await prover.generateUnshieldProof(params: UnshieldParams): Promise<ProofResult>

---

Types

ProofResult

interface ProofResult {
  proof: Uint8Array;
  publicInputs: bigint[];
}

TransferParams

interface TransferParams {
  // Input notes
  inputs: {
    note: Note;
    leafIndex: number;
    siblings: bigint[][];
  }[];
  
  // Output notes
  outputs: {
    npk: bigint;
    amount: bigint;
    random: bigint;
  }[];
  
  // Keys
  spendingKey: bigint;
  nullifyingKey: bigint;
  
  // Merkle root
  merkleRoot: bigint;
  
  // Token
  tokenId: bigint;
}

---

Performance

Circuit	Browser	Node.js
Transfer	30-60s	15-30s
Unshield	20-40s	10-20s

Optimization Tips

1. Reuse prover instance - Don't recreate for each proof
2. Initialize early - Load prover at app startup
3. Show progress - 30-60s is a long wait for users
4. Consider relayer - Offload proving to server if needed

---

Circuit Files

Circuit files are ~500KB each and contain:

{
  "noir_version": "1.0.0-beta.17",
  "hash": 12345678,
  "abi": { ... },
  "bytecode": "H4sIAAAA..."
}

Host them on your server or CDN. The SDK fetches them once and caches.