Built at Flow 2023 Hackathon: https://devfolio.co/projects/linklock-2686

Demo video: https://www.youtube.com/watch?v=JEI0IIuT77s

Notice: We can’t demonstrate the usage of mainnet .find or FlowNS domains as our project is connected to testnet (it must be, because our contracts are deployed there). So if you can’t find a valid testnet domain name, try using your account address, or see this example account: https://supportify.vercel.app/0xde4a0b425de4053e.

What's it about?

Flow ecosystem lacks community tools and infrastructure. If you want to create a membership program with your own set of requirements for members (e.g. must pay a certain price, must own X and Y NFTs, must join our Discord server,...) it's currently not possible to do that without building your own solution from scratch.

LinkLock tries to solve that problem, by enabling communities and individuals to create membership programs (in form of membership NFTs), define a set of membership requirements (which can be extended by implementing your own smart contract "plugin"), and distribute them to their audience/users. We also support membership content gating/authorization functionality out of the box.

Usage

Usage of various packages available in this monorepo. Note that this is not yet available to install from NPM.

Note: This is not a stable version, but instead an MVP. The APIs could change.

JavaScript client

Initialization

import { MembershipService } from "@membership/client";

const membershipService = new MembershipService({
  network: "testnet",
});

Creating memberships

Before distributing your memberships to your users, you first need to create a membership program.

const membership = await membershipService.createMembership({
  name: "My membership",
  description: "This is my first membership.",
  // Number of memberships that can be claimed by users.
  maxSupply: "2",
  // Expiration in days
  expirationInterval: "1000000",
  thumbnail: "https://example.com/my-thumbnail.png",
  requirement: {
    // Price in fungible tokens used in requirement contract
    price: "1.0",
    // Contract that implements Flow token requirement.
    // (requires use to pay certain FLOW amount to become a member)
    contractName: "FlowRequirement",
    // Deployment address of requirement contract.
    // (this is the testnet address of FlowRequirement contract)
    contractAddress: "0x358daba93d60587b",
  },
});

// ID of the membership (aka. membership definition ID)
console.log(membership.id)

Authorization with Passport.js

We created a Passport.js authentication strategy to allow easy membership checks on the backend.

import { MembershipStrategy, buildAuthHandlerUrl } from "@membership/passport";

// The membership NFT ID 
const membershipDefinitionId = "6";
// The address of account that created a membership
const adminAddress = "0xde4a0b425de4053e";
// Points to the below endpoint (on local development instance)
const callbackUrl = `http://localhost:3004/callback`;

const membershipStrategy = new MembershipStrategy({
  network: "testnet",
  membershipDefinitionId,
  adminAddress,
});

passport.use(membershipStrategy);

// ...

// Redirect user to membership validation page,
// where users can prove they own a valid membership.
app.get("/login", (req, res) => {
  res.redirect(
    buildAuthHandlerUrl({
      adminAddress,
      membershipDefinitionId,
      callbackUrl,
    })
  );
});

// After user sucessfully completes the membership validation,
// it will be redirected back to this callback endpoint
// where our plugin will do the rest (verify the user signature).
app.get(
  "/callback",
  passport.authenticate(membershipStrategy.name, { failureRedirect: "/login" }),
  function (req, res) {
    res.send("You are a valid member!")
  }
);