@solose-ts/como-circulo

This library contains tooling to compile, execute and prove circom circuits from js/ts code.

The final goal of the library is to facilitate the development of secure and valid circuits.

Installing

# pnpm
pnpm add @solose-ts/como-circulo

# yarn
yarn add @solose-ts/como-circulo

# npm
npm add @solose-ts/como-circulo

# bun
bun add @solose-ts/como-circulo

[!WARNING] At the moment the cjs build is not tested. In order to make everything work we recommend import it as a module.

How to use it.

The main abstraction provided is the CircomCompiler which is basically a wrapper around circom cli.

The compiler can be used to compile inline snippets or circom files:

import { CircomCompiler } from '@solose-ts/como-circulo';
import * as path from 'node:path';

const compiler = new CircomCompiler();

const circuit1 = await compiler.compileStr(`
    pragma circom 2.2.2;
    template AbsoluteTruth {
        42 === 42;
    }
    component main = AbsoluteTruth();
`);

const circuit2 = await compiler.compileFile(path.join('path', 'to', 'your', 'source-code.circom'));

Circuits can be executed to generate a witness:

const witness = await circuit.witness({});

Witness generation accept input signals. The format of the signals is not type safe. The right format needs to be sent to avoid having a runtime error.

const circuit3 = await compiler.compileStr(`
    pragma circom 2.2.2;
    template EnsureAreEqual {
        input signal left;
        input signal right;
        left === right;
    }
    component main = EnsureAreEqual();
`);

const rightWitness = await circuit3.witness({ left: '10', right: '10' }); // Ok!

await circuit3.witness({ doesNotExist: 11 }); // Will fail with `CircomRuntimeError`;

Once the witness was calculated it can be used to calculate a proof:

const proof = await witness.proveGroth16();
console.log(proof);
// {
//   proof: <circom-groth-16-json-prof>,
//   publicSignals: ['signal1', 'signal2', ...]
// }

Lastly the proof can be verified.

const isValid = await circuit.groth16Verify(proof);
console.log(isValid); // `true` or `false`

Options

The object CircomCompiler can be initialized with the following parameters:

export type CircomCompilerOpts = {
  compilerPath?: string;
  outDir?: string;
  cwd?: string;
  ptauPath?: string;
  libraryRoots?: string[];
};

compilerPath

This the location of the circom binary. By default it assumes that it's in the path, so it uses circom with no absolute or relative path. If circom is not in the path or a particular version has to be used, this the place to set the path of the correct binary.

outDir

This is the directory where intermediary files are going to be stored. By default, it's a temporary directory.

cwd

Current working directory for commands executed by the compiler.

ptauPath?

Location of a prepared ceremony file. If the ptau path is not present the witness and prove steps cannot be calculated (will throw with appropriate error);

libraryRoots

This is the -l option on circom cli. The most ergonomic way to use the inline snippets to add your circuit root here. Then your templates can be included in your snippets.