captcha.md

Quick start

The Solve3 Captcha Node Module is designed to offer captcha protection for your smart contracts, effectively guarding against bot interference. Here's a step-by-step guide to help you integrate this module into your projects frontend.

Installation

Begin by installing the @solve3/captcha package using npm or yarn. Open your terminal and run:

npm install @solve3/captcha
# or
yarn add @solve3/captcha

Now, let's dive into the implementation:

Initialization

First, you need to initialize the Solve3 Captcha module by importing it and creating an instance of it. This step should be done at the beginning of your code.

import { Solve3 } from "@solve3/captcha";

const solve3 = new Solve3();

Event handling

The Solve3 Captcha module emits a "success" event when the user successfully completes the captcha challenge. You can listen for this event and define what should happen when the event is triggered.

solve3.on("success", async (proof) => {
  // This is where you can send the transaction using the proof.
  // Example: sendTransaction(proof);
});

Handshake

Before sending a transaction, you'll need a message (handshake) to sign. This message typically includes the user's wallet address, the destination contract, and the network ID (chain ID).

const messageToSign = await solve3.init({
  account: walletAddress,
  destination: destinationContract,
  network: chainId,
});

Sign message

You need to sign the message with the user's wallet. This can be done using a signing function provided by your Ethereum library (e.g., ethers.js or web3.js). Make sure you have the user's wallet set up and available.

const signature = await signMessage(messageToSign);

Open captcha

Finally, open the Solve3 Captcha challenge, passing the previously obtained signature. This will display the captcha challenge to the user.

await solve3.open(signature);

Full Example

using React.js and wagmi

This React.js example initializes the Solve3 Captcha module, gets the message to sign, signs the message using wagmi, and opens the captcha challenge when the `Set Message`` button is clicked. Make sure to replace the placeholders with your actual values and Ethereum provider.

import { useState } from "react";
import { useAccount, useSignMessage, useContractWrite } from "wagmi";
import { abi } from "./abi";
import { Solve3 } from "@solve3/captcha";

const Message = () => {
  const yourContract: `0x${string}` = "0xYourContractAddress";

  const { signMessageAsync } = useSignMessage();
  const { address } = useAccount();
  const [message, setMessage] = useState<string>("");

  const { writeAsync } = useContractWrite({
    address: yourContract,
    abi: abi,
    functionName: "setMessage",
  });

  const solve3 = new Solve3();

  solve3.on("success", async (proof: string) => {
    // function sig: setMessage(string memory message, bytes memory proof)
    await writeAsync({ args: [message, proof] });
  });

  const onClickHandler = async () => {
    const messageToSign: string = await solve3.init({
      account: address as string,
      destination: yourContract,
      network: 5,
    });

    const signature = await signMessageAsync({ message: messageToSign });
    await solve3.open(signature);
  };

  return (
    <div>
      ...
      <h3>New Message:</h3>
      <input
        type="text"
        value={message}
        onChange={(e) => setMessage(e.target.value)}
      />
      <button onClick={onClickHandler}>Set Message</button>
      ...
    </div>
  );
};

export default Message;