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Authority-Based State Derivation

What is Authority-Based State Derivation?​

All game state and player state accounts in Shrimp Farm are tied to an authority key.
This means every piece of on-chain data is derived using the authority's public key as a seed.

The authority key acts as a unique identifier that creates isolated game instances.
Different authority keys = completely separate games with their own state.

This design started as a necessity for our Anchor tests, but turned into a clean architectural pattern.

Why We Built It This Way​

Testing Requirements​

The local Solana validator used by anchor test doesn't support resetting state between tests.
Without authority-based derivation, all tests would share the same game state—causing interference.

Our solution: generate a fresh authority keypair for each test, creating isolated game instances.

Show the test setup
tests/shrimp.ts
beforeEach(async () => {
  await new Promise(r => setTimeout(r, 1000)); // prevent validator crashes
  
  /* fresh game for every test */
  authority = Keypair.generate();
  gameStateAccount = utils.findGameDataAcc(authority.publicKey);
  
  playerAccount = await utils.findPlayerDataAcc(
    wallet.publicKey, 
    authority.publicKey
  );
  
  refAccount = Keypair.generate();
  refStateAccount = await utils.findPlayerDataAcc(
    refAccount.publicKey, 
    authority.publicKey
  );
});

Clean Architecture​

Authority-based derivation creates predictable, collision-free account addresses.
Every account type follows the same pattern: [specific_seeds, authority_key].

How Accounts Are Derived​

All Program Derived Addresses (PDAs) include the authority key as the final seed:

Game State: ["shrimp", authority]
Player State: [player_pubkey, "shrimp", authority]
Contract Data: ["contractdata", authority]

Show the derivation utilities
utils.ts
const findPlayerDataAcc = (player: PublicKey, authority: PublicKey) => {
  const [playerDataAcc, _] = PublicKey.findProgramAddressSync(
    [player.toBuffer(), Buffer.from("shrimp"), authority.toBuffer()],
    SHRIMP_PROGRAM_ID
  );    
  return playerDataAcc;
};

const findGameDataAcc = (authority: PublicKey) => {
  const [gameDataAcc] = PublicKey.findProgramAddressSync(
    [Buffer.from("shrimp"), authority.toBuffer()],
    SHRIMP_PROGRAM_ID
  );
  return gameDataAcc;
};

const findContractDataAcc = (authority: PublicKey) => {
  const [contractDataAcc] = PublicKey.findProgramAddressSync(
    [Buffer.from("contractdata"), authority.toBuffer()],
    SHRIMP_PROGRAM_ID
  );
  return contractDataAcc;
};

Authority-Only Functions​

The authority key also controls several admin functions that only work during initialization or in test environments:

set_market - Manually adjust market state (test env only)
end_premarket - Force pre-market to end early (test env only)
testnet_bonus - Toggle 1% bonus for specific accounts
set_collection - Set NFT collection (called once at deployment)

These functions verify the signer matches the stored authority before executing.