@projectsophon/snarkjs-helpers

This package contains simple TypeScript types for working with SnarkJS, plus utilities to convert from SnarkJS outputs to smart contract call data.

Installation

You can install this package using npm or yarn by running:

npm install --save @projectsophon/snarkjs-helpers

yarn add @projectsophon/snarkjs-helpers

When using this in a plugin, you might want to load it with skypack

import * as snarkjsHelpers from 'http://cdn.skypack.dev/@projectsophon/snarkjs-helpers'

Table of contents

Type Aliases

• ContractCallArgs
• SnarkJSProof
• SnarkJSProofAndSignals

Functions

• buildContractCallArgs
• mockProof

Type Aliases

ContractCallArgs

Ƭ ContractCallArgs: [[string, string], [[string, string], [string, string]], [string, string], string[]]

Type representing the shape that can be passed into smart contract functions that require zkSNARK verification.

---

SnarkJSProof

Ƭ SnarkJSProof: Object

A zkSNARK proof (without signals) generated by SnarkJS fullProve

Type declaration

Name	Type
pi_a	[string, string, string]
pi_b	[[string, string], [string, string], [string, string]]
pi_c	[string, string, string]

---

SnarkJSProofAndSignals

Ƭ SnarkJSProofAndSignals: Object

A zkSNARK proof and corresponding public signals generated by SnarkJS fullProve

Type declaration

Name	Type
proof	SnarkJSProof
publicSignals	string[]

Functions

buildContractCallArgs

▸ buildContractCallArgs(snarkProof, publicSignals): ContractCallArgs

Function for converting the output of SnarkJS fullProve into a shape that can be passed into smart contract functions which perform zk proof verification.

Parameters

Name	Type	Description
snarkProof	SnarkJSProof	the SNARK proof
publicSignals	string[]	the circuit's public signals (i.e. output signals and public input signals)

Returns

ContractCallArgs

The input data in a shape that is suitable to use as smart contract call data

---

mockProof

▸ mockProof(publicSignals?): SnarkJSProofAndSignals

Function to generate mock proof and signal data in the shape SnarkJS would return.

Only useful if you are using a mock hash and ZK proofs are disabled

Parameters

Name	Type	Default value	Description
publicSignals	string[]	[]	the circuit's public signals (i.e. output signals and public input signals)

Returns

SnarkJSProofAndSignals

A mock proof and public signals in the shape of SnarkJS output