❄️ SubZero — Autonomous Web3 Subscription Protocol on Massa Blockchain

SubZero is an autonomous recurring payments protocol built on the Massa blockchain, enabling creators and dApps to define self-executing subscription plans without requiring manual renewals or Web2 intermediaries.

🚀 Built for WaveHack · Powered by Massa + Bearby Wallet

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⚡ Why SubZero?

• 🔁 Truly Recurring: No need for reminders or approvals — payments just happen on-chain.
• 🧾 Plan-as-a-Contract: Every plan is securely tracked and stored on-chain.
• 👥 Creator-first: Creators deploy subscription plans with pricing, frequency, and accepted tokens.
• 🔐 No Custody, No Risk: User funds are never held by third parties.

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🔗 Live Demo

👉 https://subzero-app.vercel.app/ 🎥Watch Demo on YouTube

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🛠️ Tech Stack

Layer	Tech
Smart Layer	Massa AssemblyScript (SDK)
Wallet/Web3	Bearby Wallet + @hicaru/bearby.js
Frontend	Next.js 14 + App Router
UI Framework	ShadCN + TailwindCSS
Dev Tools	massa-sc-runtime + asbuild
Storage	Massa SC Persistent Storage

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🧠 How It Works

1. Creator logs in using Bearby wallet.
2. Creator creates plan with:
   • Plan ID (UUID)
   • Name, Description
   • Token accepted, Amount, Frequency (e.g. monthly)
3. Plan is stored via Massa SC Storage.
4. Subscriber connects wallet → subscribes to the plan.
5. Protocol automatically triggers payment at each interval.
6. Revenue is routed to the creator’s address.

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🧩 Smart Contract Overview

• createPlan(planId, name, token, amount, freq, createdAt)
• getPlansByCreator(creatorAddress)
• subscribeToPlan(planId) (coming soon)
• charge(planId) (executed automatically or by keeper)

Stored as:

// Stored per plan
Storage.set("plan:" + planId, JSON.stringify({ ... }))

// Creator registry
Storage.set("creatorPlan:{creator}:{index}", planId)
Storage.set("creatorPlanCount:{creator}", count)

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📂 Project Structure

subzero/
├── app/                     # Next.js App Router
│   ├── layout.tsx
│   └── page.tsx
├── components/             # Reusable UI
│   └── creator/
├── lib/
│   └── massa/              # massa & bearby interaction
│       ├── callCreatePlan.ts
│       └── getCreatorPlans.ts
├── contracts/
│   └── main.ts             # Massa AssemblyScript contract
├── public/
├── scripts/
├── README.md
└── package.json

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⚙️ Massa Integration

Bearby Contract Call:

import { web3 } from "@hicaru/bearby.js";
import { Args } from "@massalabs/massa-web3";

const args = new Args()
  .addString(planId)
  .addString(planName)
  .addString(token)
  .addString(amount)
  .addString(frequency)
  .addString(createdAt);

const txHash = await web3.contract.call({
  fee: 10_000_000,
  maxGas: 100_000_000,
  coins: 0,
  targetAddress: "<DeployedContractAddress>",
  functionName: "createPlan",
  unsafeParameters: args.serialize()
});

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Run Locally

# 1. Clone and install
pnpm install

# 2. Connect Bearby wallet in browser

# 3. Deploy contract using Station or manually with Massa CLI

# 4. Start frontend
pnpm dev

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📦 Smart Contract: main.ts

export function createPlan(...) {
  const creator = Context.caller().toString();

  Storage.set("plan:" + planId, planJson);

  const countKey = "creatorPlanCount:" + creator;
  const indexKey = "creatorPlan:" + creator + ":" + count;

  Storage.set(indexKey, planId);
  Storage.set(countKey, (count + 1).toString());

  generateEvent("PlanCreated:" + planId);
}

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🌱 Future Improvements

• Subscriber-side dashboard
• Auto-charging mechanism via keepers
• Token gating and NFT perks
• Refund and cancel logic
• Marketplace of top creators

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👨‍💻 Author

• Name: Manan
• Role: Fullstack + Smart Contract Dev
• Project: Built for WaveHack · Phase 2
• Stack: Massa + Bearby + Next.js