OneShot: Reloaded

About the Project

RapBattle is an on-chain protocol on Aptos that lets players mint “Rapper” NFTs, stake them to train away vices, and then battle head-to-head with on-chain bets using a custom fungible token (CRED).

Core ideas:

• Rapper NFTs (Token V2 / Objects): One-click mint from the Rappers collection. Each token has logical stats (tracked in a resource table) that affect battle outcomes.
• Staking (“Streets”): Stake a Rapper to the protocol to gradually remove vices and earn CRED per full day staked.
• Battles: Two players match equal CRED bets; the protocol computes outcome from the Rapper stats; the winner receives the prize pool, and the winner’s Rapper accrues a win.
• Credibility Token (CRED): Simple Coin<CRED> with module-owned mint/burn capabilities; used for staking rewards and battle wagers.

This repo targets Aptos CLI 7.7.0 and the current mainnet revisions of aptos-framework and aptos-token-objects. It is designed to compile and run with a single unit test out of the box.

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Actors

Actors:

• Module Owner (@battle_addr):

  • Publishes modules and owns the CRED mint/burn capabilities.
  • Can call mint_rapper (enforced: only @battle_addr as signer).
  • Centralization risk: can mint arbitrary CRED and Rapper NFTs.

• Player / Holder (any address):

  • Receives/mints Rapper NFTs (via module owner).
  • Stakes Rapper NFTs in streets to improve stats and earn CRED.
  • Uses CRED to place battle wagers.

• Defender / Challenger (players in rap_battle):

  • Defender takes the stage first with a bet; Challenger matches the bet to initiate a battle.
  • The winner receives the CRED prize pool and the win is recorded on the winning Rapper.

Centralization and limitations:

• Mint authority: @battle_addr controls the CRED supply and the minting of new Rappers.
• Custody during battles/staking: The protocol custodies NFTs at @battle_addr during staking and battles. The code updates an internal ownership registry (resource table). Actual object transfers out from @battle_addr require its signer; the sample battle flow updates records and deposits prize tokens but does not physically transfer the NFTs post-battle.
• RNG: Battle randomness is derived from timestamp::now_seconds().

Scope (contracts)

├── sources
│   └── cred_token.move
│   └── one_shot.move
│   └── streets.move
│   └── rap_battle.move

Key design notes for auditors:

• Stats storage: Instead of per-token property maps, Rapper stats are recorded in a RapperStats resource (two Tables) under @battle_addr. Access outside one_shot happens only through public(friend) helpers.
• Friends: streets and rap_battle are declared friend of one_shot to call those helpers; they do not read/write RapperStats fields directly.
• Coins: CRED follows standard aptos_framework::coin patterns. No copy/drop on Coin<T>; merging and extract_all are used correctly.

Compatibilities

Compatibilities:

• Blockchains:

  • Aptos (devnet/testnet/mainnet) using Aptos CLI 7.7.0.

• Token standards / packages:

  • Aptos Token V2 / TokenObjects for NFTs (collection + token creation via ConstructorRef → Object).
  • Aptos Framework coin for fungible CRED.

• Addresses / Config:

  • aptos_token_v2 = "0x4" (official Token V2 address).
  • Dependencies pinned to mainnet revs (see Move.toml).

Setup

Prereqs

• Aptos CLI 7.7.0
• Rust toolchain (transitively required by CLI)

Build & Test

Clone and run:

# from repo root
aptos move clean
aptos move test --dev

Expected result:

• Builds the AptosFramework, AptosTokenObjects, and this package.
• Runs tests/one_shot_tests.move which mints a Rapper and verifies balance via the one_shot::balance_of view. Test should pass.

Project Layout & Notes

• Move.toml pins:

  • AptosFramework and AptosTokenObjects (subdir aptos-move/framework/aptos-token-objects) at rev = "mainnet".
  • aptos_token_v2 address at 0x4.

• Module initialization:

  • Functions literally named init_module are private per Move rules.
  • one_shot::mint_rapper lazy-initializes the collection/tables during tests or first use.

• Commands you might use while auditing:

  aptos move compile --dev
  aptos move test --dev
  aptos move prove --dev  # if you want to run the Move Prover (additional setup required)

Known Issues

None reported!