CircomJS is a javascript framework for automating and easing workflow around developing in the Circom DSL.

We would suggest getting started with this gitbook, and you should also checkout our blog post on why we made CircomJS.

The framework operates on a simple circuit.config.js file, which is a configuration file for circomJS.

below is an example of what a circuit.config.json file looks like.

{
  "projectName": "arithmetic",
  "outputDir": "./out",
  "build": {
    "inputDir": "./circuits",
    "circuits": [
      {
        "cID": "mul",
        "fileName": "multiply.circom",
        "compilationMode": "wasm"
      },
      {
        "cID": "add",
        "fileName": "addition.circom",
        "proofType": "plonk",
        "compilationMode": "wasm"
      }
    ]
  }
}

(example circuit.config.json)

You can also take a look at CircomJS starter repository for reference.

CircomJS gives you the following capabilities in Javascript!

const {CircomJS} = require("@zefi/circomjs")

const main = async() => {
    const circomjs = new CircomJS()
    const circuit =  circomjs.getCircuit("mul")

    // it will build the circuit with cID mul
    await circuit.compile()
}

main()

const {CircomJS} = require("@zefi/circomjs")

const main = async() => {
    const circomjs = new CircomJS()
    const circuit =  circomjs.getCircuit("mul")

    // important to await compilation, before running circuit.genProof()
    await circuit.compile()

    const input = {
        x: 3,
        y: 5
    }

    const proof = await circuit.genProof(input);
    console.log("proof verification result ----->",await circuit.verifyProof(proof))
}

main()

const {CircomJS} = require("@zefi/circomjs")

const main = async() => {
    const circomjs = new CircomJS()
    const circuit =  circomjs.getCircuit("mul")

    // important to await compilation, before running circuit.genProof()
    await circuit.compile()

    const input = {
        x: 3,
        y: 5
    }

    const proof = await circuit.genProof(input);
    console.log("proof verification result ----->",await circuit.verifyProof(proof))
}

main()

You can do a lot more than this:

• calculate witness
• calculate total constraints
• check constraints on a generated witness
• automatic download of ideal power of tau file

We are working towards adding new features to the framework, some of which include:

• support for C compilation of circuits { witness generation programs }
• parallel build of ZK Circuits
• integration with Ethersjs to deploy smart contract verifiers
• smart builds: only building circuits when either source code or a dependency of the circuit has changed.
• export solidity smart contract verifier
• export solidity call-data

We at zefi are open to ideas around the project and would love to interact with the community and see contributions comings its way, feel free to join our telegram group and say hi, also feel free to write to us at contact@zefi.io.