Move Smart Contract Product Requirement Documents (PRDs)

Purpose: Provide five well‑scoped product ideas—each with a detailed PRD and on‑chain design—for developers who want to master the Move language on Aptos and Sui. These documents are intended as build guides, learning road‑maps, and reference specs.

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Table of Contents

1. FlowStream – Continuous Payment Streaming Protocol
2. Rentable – NFT Time‑Bound Rental Marketplace
3. MoveDAO – Modular On‑Chain Governance & Treasury
4. NodeStaker – DePIN Sensor Staking & Reward Module
5. MoveBridge – Cross‑Network Liquidity & Message Bridge

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1. FlowStream – Continuous Payment Streaming Protocol

Suggested GitHub Repo Name

move-flowstream-payments

Vision & Goals

Create an on‑chain protocol that lets users stream fungible tokens (APT, SUI, or any Move‑based asset) to recipients in real‑time, unlocking use‑cases such as payroll, subscriptions, and grant disbursement. Emphasize efficient resource handling and time‑based calculations.

Personas & Use Cases

Persona	Need	Example
Indie developer	Pay SaaS hosting per second	0.01 APT/hr stream
DAO treasurer	Continuous payroll	Pay contributors
Investor	Vest seed tokens linearly	1‑yr cliffless vesting

Functional Requirements

1. CreateStream: Sender defines token, rate_per_second, start_time, end_time, recipient.
2. WithdrawStreamed: Recipient may pull accrued amount at any time.
3. CancelStream: Sender cancels; remaining balance refunds appropriately.
4. TopUp: Anyone may add funds to an active stream.
5. Pause/Resume (v2).

Smart‑Contract Architecture

Module	Responsibility
flowstream::manager	Entry points, authority checks
flowstream::stream	struct Stream { id, sender, recipient, token, rate, start, end, deposited, withdrawn } stored as a resource under sender’s account
flowstream::utils	Time math, safe division

Key Resources & Capabilities

• Resource Stream – guarantees single writer (sender) via key ability.
• Use event streams: StreamCreated, Withdraw, Cancelled.
• Leverage Aptos Timestamp / Sui Clock oracle modules.

Entry Functions (Public Interfaces)

public entry fun create_stream<Currency>(
    sender: &signer,
    recipient: address,
    rate: u64,
    duration_secs: u64,
    initial_deposit: u64
)

(full signature list continues)

Aptos vs. Sui Divergence

Aspect	Aptos	Sui
Clock	0x1::timestamp seconds‑precision	0x3::clock ms‑precision
Fee model	Gas units, parallel execution	Object‑centric, gas after effects
Storage	Table handles	Object mappings

Invariants & Security

• Total withdrawn ≤ deposited.
• One active stream ID per (sender, nonce).
• Reentrancy safe via Move’s single‑threaded execution.

Gas & Performance Targets

• create_stream ≤ 70k gas.
• withdraw_streamed ≤ 40k gas on median path.

Upgrade Path & Governance

• Owned by DAO; upgrade_cap stored in governance vault.

Testing & Simulation Plan

• Unit tests for edge times.
• Property test: Sum of balances constant.
• Integration: Faucet tokens on devnet, CLI demo script.

Future Extensions

• Stream NFTs (transferable rights).
• Streaming with cliff + linear vest.

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2. Rentable – NFT Time‑Bound Rental Marketplace

Suggested GitHub Repo Name

move-nft-rentable

Vision & Goals

Enable owners to lend NFTs for a fixed period while retaining ultimate ownership, unlocking in‑game asset rentals or paid access passes.

Personas & Use Cases

• Gamer: Rents rare sword for weekend tournament.
• Landlord: Lends metaverse land plot for advertising.

Core Features

1. ListForRent: Specify NFT object, daily price, max duration, collateral (optional).
2. Rent: Renter pays upfront; receives time‑limited usage right (wrapped NFT).
3. Auto‑Return: Contract‐enforced reclaim after expiry.
4. Early Return & Refund: Unused days refunded minus fee.

Smart‑Contract Architecture

Module	Summary
rentable::market	Listing registry, price oracle integration
rentable::wrapper	Mints RentalNFT object with expires_at field
rentable::admin	Pause, fee config

Resources:

• Listing { owner, nft_id, price_per_day, max_duration }
• RentalNFT { original_id, expires_at } – object in Sui world.

Events

Listed, Rented, Returned, ExpiredAutoReturn.

Aptos vs. Sui Notes

• Use object wrapping/unwrapping on Sui for automatic recall.
• On Aptos, represent leases via Table<address, Lease> and withdraw rights via capability token.

Security Considerations

• Prevent double‑wrap.
• Validate metadata immutability.

Testing Matrix

• Time warp tests for expiry.
• Fuzz price calculations.

Extensions

• Revenue‑sharing between lender & creator (royalties).
• Reputation scores for renters.

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3. MoveDAO – Modular On‑Chain Governance & Treasury

Suggested GitHub Repo Name

move-dao-governance-framework

Vision & Goals

Deliver a composable DAO framework (token‑weighted or NFT membership) with proposal modules, timelock, and asset treasury that can govern other Move modules via upgrade capabilities.

Functional Modules

1. Token: Optional governance token mint.
2. Treasury: Holds multi‑asset vault.
3. Governor: Creates & executes proposals.
4. Strategy: Pluggable voting logic (Simple Majority, Quadratic, etc.).

Proposal Lifecycle

Draft → Active → Succeeded → Queued (Timelock) → Executed / Vetoed.

Move Design Highlights

• Each DAO is a resource DAO { id, config, treasury, governor_cap }.
• Delegation map Table<address, u64> for vote power.

Differences Aptos vs. Sui

• Sui’s dynamic fields suit delegation maps.
• Aptos’ multi‑agent txns enable proposal batching.

Security & Auditing Checklist

• Timelock cannot be bypassed.
• Voting period difference between chains.
• Upgrade authority stored inside DAO itself.

Testnets & DevOps

• CLI script to spin‑up a local DAO in 30 seconds.
• End‑to‑end governance flow.

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4. NodeStaker – DePIN Sensor Staking & Reward Module

Suggested GitHub Repo Name

move-depin-node-staker

Vision & Goals

Power decentralized physical network (e.g., air‑quality sensors) by letting node operators stake tokens that unlock data submission rights and earn emission rewards based on data proofs.

Actors & Flows

1. Operator stakes tokens → receives ValidatorCap resource.
2. Submits signed data proof with epoch nonce.
3. Epoch Rewards distributed proportionally to proof quality score.
4. Slashing if invalid data or downtime.

Contract Components

• staking::pool – lock/unlock stake, epoch accounting.
• oracle::submit – verify data signatures.
• rewards::distributor – mint or transfer rewards.

Move‑Specific Tricks

• Use vector of epoch records inside Stake resource.
• Implement slashing via burning stake resource.

Aptos vs. Sui Specifics

• Aptos: Use on‑chain ed25519 verify & event index.
• Sui: Leverage Move events + off‑chain indexer for scoring.

KPIs & Metrics

• Stake TVL, data proofs per day, slash events.

Educational Value

• Practice capability tokens, epoch accounting, burn/mint patterns.

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5. MoveBridge – Cross‑Network Liquidity & Message Bridge

Suggested GitHub Repo Name

move-aptos-sui-bridge

Vision & Goals

Bridge fungible assets and arbitrary messages between Aptos and Sui testnets/mainnets using light‑client verification and relayer network.

Core Mechanics

1. Lock & Mint: Lock tokens on source chain, mint wrapped tokens on destination.
2. Burn & Release: Burn wrapped tokens to unlock originals.
3. Generic Message Passing: Relay bytes payload with proof.

Contract Breakdown

Module	Chain	Function
bridge::vault	both	Escrow & release
bridge::mint	dest	Mint wrapped coin
bridge::lightclient	both	Verify headers & Merkle proofs

Proof System

• Use Merkle Accumulator from Move stdlib.
• Off‑chain relayers supply proof.

Security Model

• 2‑of‑3 multisig of independent relayers initially.
• Upgrade to zk‑proof once prover available.

Testing Plan

• Localnet docker compose for dual chains.
• Stress test with 10k tx batch.

Learning Outcomes

• Cross‑chain data structures, signature verification, Merkle proofs.

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6. MoveETF – On‑Chain Tokenized Index Fund

Suggested GitHub Repo Name

move-etf-index-fund

Vision & Goals

Enable anyone to mint and redeem a single fungible token that represents a diversified basket of underlying Move‑based assets on Aptos or Sui—similar to an ETF. The protocol automatically rebalances holdings according to a chosen index methodology.

Personas & Use Cases

Persona	Need	Example
Retail user	Simple diversified exposure	Buy APT‑DeFi Index token
DAO treasury	Park funds in low‑maintenance index	30% APT, 40% stable, 30% RWA
Portfolio manager	Offer branded index products	Launch "AI Infra Index"

Core Features

1. MintShares: Deposit the precise proportion of each constituent asset to receive ETF shares.
2. RedeemShares: Burn shares to withdraw underlying assets pro‑rata.
3. Rebalance: Anyone can call with new weights; executes swaps via integrated DEX; incentivized via small fee rebate.
4. FeeCollection: Streaming protocol fee (bps per second) flows to manager.
5. Pause / Emergency Exit: Safety switches for extreme events.

Smart‑Contract Architecture

Module	Responsibility
etf::vault	Stores basket reserves, validates mint/redeem
etf::share_token	Implements ETF share as fungible Coin/Sui::coin::Coin
etf::rebalance	Weight oracle, DEX router calls
etf::admin	Set fees, approve new constituents

Key Resources & Types

• Vault { id, constituents: vector<CoinType>, weights: vector<u64>, total_shares }
• struct RebalanceRequest { new_weights, deadline } event‑driven.

Aptos vs. Sui Specific Notes

Aspect	Aptos	Sui
Share token	Standard Coin implementing store + key	Native Sui::coin::Coin<T> object
Rebalance execution	Multi‑agent txn calling aptoswap	Object‑centric DEX call e.g. DeepBook
Storage	On‑chain table of constituent reserves	Individual objects per asset held in vault

Invariants & Security

• Vault reserve balance equals aggregate deposits minus withdrawals.
• No share inflation beyond total_shares.
• Rebalance must conserve total value within slippage tolerance.

Events

Mint, Redeem, RebalanceExecuted, FeesCollected.

Testing & Audit Checklist

• Property test: NAV before = NAV after ± slippage.
• Fuzz mint/redeem with random weights.
• Simulate oracle manipulation attempts.

Gas Targets

• mint_shares ≤ 80k gas.
• rebalance linear in constituents; ≤ 200k gas for 10 assets.

Educational Value

• Practice complex resource accounting, DEX integration, oracle usage, and fee design.

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How to Use These PRDs

1. Pick one project that excites you.
2. Use the Smart‑Contract Architecture section as a coding road‑map.
3. Read the Aptos/Sui notes to understand chain‑specific tweaks.
4. Write unit tests first; reference the Testing Plan.
5. Iterate → Deploy to devnet → Seek feedback.

Happy building & mastering Move! 🚀