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Interep groups

In this section, we will learn how to integrate the Interep groups in your application.

Interep allows users to join groups based on certain parameters. Each group has a provider and a name, and it can be used by users to anonymously perform tasks that require them to prove, for example, that they have a certain reputation on Twitter.

caution

Before going any further, if you are not familiar with Semaphore, read the official documentation.

OAuth tokens​

If you want to allow a user to join a OAuth provider group (i.e. Twitter, Github or Reddit) directly from your app without going through the Interep app, you will need to create a OAuth authentication system to generate a valid access token in order to calculate the users' reputation and to add their identity commitment to an Interep group.

caution

With POAP you can skip the first two steps. As we will see later, it is sufficient to sign the identity commitment with Metamask and send the signature and the address of the Ethereum account used to sign. The flow of the Email and Telegram providers cannot currently be onboarded.

User's reputation​

Once you have generated a valid OAuth token and you are able to obtain the user's account data you can calculate their reputation with @interep/reputation.

import { calculateReputation, OAuthProvider } from "@interep/reputation"

// 'getGithubUserByToken' is an example function.
const { id, plan, followers, receivedStars } = await getGithubUserByToken(token)

const reputation = calculateReputation(OAuthProvider.GITHUB, {
    proPlan: plan.name === "pro",
    followers,
    receivedStars
})

console.log(reputation) // gold

Semaphore identity​

In order for a user to join a group they must create their own Semaphore identity with @interep/identity.

  1. Get the Ethereum account signer from Metamask:
import detectEthereumProvider from "@metamask/detect-provider"
import { ethers } from "ethers"

const ethereumProvider = await detectEthereumProvider()
const provider = new ethers.providers.Web3Provider(ethereumProvider)
const signer = provider.getSigner()
  1. Create the Semaphore identity and the identity commitment:
import createIdentity from "@interep/identity"

const sign = (message) => signer.signMessage(message)

const identity = await createIdentity(sign, "<provider>")
const identityCommitment = identity.genIdentityCommitment().toString()
caution

While the identity commitment can be public, the Semaphore identity must remain private, as it contains the parameters necessary to create Semaphore proofs.

New members​

You can now add a member to a OAuth group by using a OAuth token and the correct user's reputation:

await api.addMember({
    provider: "github",
    name: reputation,
    identityCommitment,
    authenticationHeader: `token ${token}`
})

Or you can add a member to a Web3 group by using the user Ethereum address and the signature of their identity commitment:

const userSignature = await signer.signMessage(identityCommitment)
const userAddress = await signer.getAddress()

await api.addMember({
    provider: "poap",
    name: "devcon4",
    identityCommitment,
    userAddress,
    userSignature
})
tip

The POST methods of the Interep APIs are restricted to a list of domains defined in a whitelist. If you want to add your app domain please contact us or open a pull request. You can find the configuration file here.