Installation
Before anything, go to the Sismo Factory and create your app. Once your app is created, make sure to get your appId.
Chose and install the starter of your choice in one unique command line.
npx create-sismo-connect-app@latest
# or
npm create sismo-connect-app@latest
# or
yarn create sismo-connect-app
This command enables to you install one of the available starters:
- 1.
- 3.[Upcoming] onchain: Sismo Connect + Next.js + hardhat + ethers coming very soon, until then, head over the Manual Installation if you want to use Sismo Connect with hardhat
Feel free to check the Sismo Connect Cheatsheet, a great companion when developing an app using Sismo Connect.
This section is intended for developers who have prior experience with incorporating new tools into their existing repositories.
Make a Sismo Connect Request, users will be redirected to their Data Vault to generate a ZK proof and send your front end a Sismo Connect Response.
This response, containing the ZK proof, will be verified on your back end/smart contract.
- 1.Install our React Library
yarn
npm
yarn add @sismo-core/sismo-connect-react
npm install @sismo-core/sismo-connect-react
- 2.Use our React Button to make Sismo Connect Requests
// Next.js https://nextjs.org/docs/getting-started/installation
// in src/page.tsx
"use client";
import {
SismoConnectButton,
AuthType,
SismoConnectResponse,
ClaimType,
} from "@sismo-core/sismo-connect-react";
export default function Home() {
return (
<SismoConnectButton
config={{
appId: "0xf4977993e52606cfd67b7a1cde717069", // replace with your appId
vault: {
// For development purposes insert the Data Sources that you want to impersonate here
// Never use this in production
impersonate: [
// EVM
"leo21.sismo.eth",
"0xA4C94A6091545e40fc9c3E0982AEc8942E282F38",
"0x1b9424ed517f7700e7368e34a9743295a225d889",
"0x82fbed074f62386ed43bb816f748e8817bf46ff7",
"0xc281bd4db5bf94f02a8525dca954db3895685700",
// Github
"github:leo21",
// Twitter
"twitter:leo21_eth",
// Telegram
"telegram:leo21",
],
},
// displayRawResponse: true,
}}
// request proof of Data Sources ownership (e.g EVM, GitHub, twitter or telegram)
auths={[{ authType: AuthType.GITHUB }]}
// request zk proof that Data Source are part of a group
// (e.g NFT ownership, Dao Participation, GitHub commits)
claims={[
// ENS DAO Voters
{ groupId: "0x85c7ee90829de70d0d51f52336ea4722" },
// Gitcoin passport with at least a score of 15
{ groupId: "0x1cde61966decb8600dfd0749bd371f12", value: 15, claimType: ClaimType.GTE }
]}
// request message signature from users.
signature={{ message: "I vote Yes to Privacy" }}
// retrieve the Sismo Connect Reponse from the user's Sismo data vault
onResponse={async (response: SismoConnectResponse) => {
const res = await fetch("/api/verify", {
method: "POST",
body: JSON.stringify(response),
});
console.log(await res.json());
}}
// reponse in bytes to call a contract
// onResponseBytes={async (response: string) => {
// console.log(response);
// }}
/>
);
}
Your back end/smart contract will receive a Sismo Connect Response forwarded from your front end that you must verify.
- 1.Install the Sismo Connect Library
Onchain - Verify in a Smart Contract
Offchain - Verify in a Back End
Foundry (recommended)
Hardhat
Install the Forge dependency:
foundryup
forge install sismo-core/sismo-connect-solidity --no-commit
Add the remapping in
remappings.txt:echo $'sismo-connect-solidity/=lib/sismo-connect-solidity/src/' >> remappings.txt
# install the package
yarn add @sismo-core/sismo-connect-solidity
Import the library
In your Solidity file:
import "@sismo-core/sismo-connect-solidity/contracts/SismoConnectLib.sol";
Install the TypeScript library
yarn
yarn add @sismo-core/sismo-connect-server
- 2.verify Sismo Connect responses sent from your front end
The Sismo Connect configuration and request used in your smart contract/backend must exactly match those from your frontend.
Onchain - Verify in a Smart Contract
Offchain - Verify in a Back End
// in src/Airdrop.sol of a Foundry project - https://book.getfoundry.sh/getting-started/first-steps
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.20;
import "sismo-connect-solidity/SismoConnectLib.sol";
// This is a sample contract that shows how to use the SismoConnect library
contract Airdrop is SismoConnect {
event ResponseVerified(SismoConnectVerifiedResult result);
constructor()
SismoConnect(
buildConfig({
// replace with your appId from the Sismo factory https://factory.sismo.io/
// should match the appId used to generate the response in your frontend
appId: 0xf4977993e52606cfd67b7a1cde717069,
// For development purposes insert when using proofs that contains impersonation
// Never use this in production
isImpersonationMode: true
})
)
{}
function verifySismoConnectResponse(bytes memory response) public {
// build the auth and claim requests that should match the response
AuthRequest[] memory auths = new AuthRequest[](1);
auths[0] = buildAuth({authType: AuthType.GITHUB});
ClaimRequest[] memory claims = new ClaimRequest[](2);
// ENS DAO Voters
claims[0] = buildClaim({groupId: 0x85c7ee90829de70d0d51f52336ea4722});
// Gitcoin passport with at least a score of 15
claims[1] = buildClaim({
groupId: 0x1cde61966decb8600dfd0749bd371f12,
value: 15,
claimType: ClaimType.GTE
});
// verify the response regarding our original request
SismoConnectVerifiedResult memory result = verify({
responseBytes: response,
auths: auths,
claims: claims,
signature: buildSignature({message: "I vote Yes to Privacy"})
});
emit ResponseVerified(result);
}
}
Create an API route to receive the Sismo Connect response and verify it.
// Next.js API route support: https://nextjs.org/docs/api-routes/introduction
// in src/app/api/verify/route.ts
import {
AuthType,
ClaimType,
SismoConnect,
SismoConnectVerifiedResult,
} from "@sismo-core/sismo-connect-server";
import { NextResponse } from "next/server";
const sismoConnect = SismoConnect({
config: {
appId: "0xf4977993e52606cfd67b7a1cde717069",
vault: {
// For development purposes insert the Data Sources that you want to impersonate here
// Never use this in production
impersonate: [
// EVM
"leo21.sismo.eth",
"0xa4c94a6091545e40fc9c3e0982aec8942e282f38",
// Github
"github:leo21",
// Twitter
"twitter:leo21_eth",
// Telegram
"telegram:leo21",
],
},
},
});
// this is the API route that is called by the SismoConnectButton
export async function POST(req: Request) {
const sismoConnectResponse = await req.json();
try {
// verify the sismo connect response that corresponds to the request
const result: SismoConnectVerifiedResult = await sismoConnect.verify(sismoConnectResponse, {
auths: [{ authType: AuthType.GITHUB }],
claims: [
// ENS DAO Voters
{ groupId: "0x85c7ee90829de70d0d51f52336ea4722" },
// Gitcoin passport with at least a score of 15
{ groupId: "0x1cde61966decb8600dfd0749bd371f12", value: 15, claimType: ClaimType.GTE },
],
// verify signature from users.
signature: { message: "I vote Yes to Privacy" },
});
return NextResponse.json(result, { status: 200 });
} catch (e: any) {
console.error(e);
return NextResponse.json(e.message, { status: 500 });
}
}
If you are using Nextjs, you will need to add this config in the
next.config.js file to be able to verify the proof. You can find more information here./** @type {import('next').NextConfig} */
const nextConfig = {
experimental: {
serverComponentsExternalPackages: ["@sismo-core/sismo-connect-server"],
},
}
module.exports = nextConfig