CityLightAI

        let registry_key = r.key();        let commitment = hashv(&[registry_key.as_ref(), &sequence.to_le_bytes(), &evidence_hash, &previous]).to_bytes();        let receipt = &mut ctx.accounts.receipt;        receipt.registry = registry_key;        receipt.publisher = ctx.accounts.publisher.key();        receipt.sequence = sequence;        receipt.evidence_hash = evidence_hash;        receipt.previous = previous;        receipt.commitment = commitment;        receipt.slot = Clock::get()?.slot;        r.next_sequence = sequence.checked_add(1).ok_or(AuditError::Overflow)?;        r.last_commitment = commitment;        Ok(())    }} #[derive(Accounts)]#[instruction(run_id: [u8;16])]pub struct RegisterRun<'info> {    #[account(mut)]    pub authority: Signer<'info>,    #[account(init, payer=authority, space=8+32+32+16+32+32+8+32,        seeds=[b"run", authority.key().as_ref(), run_id.as_ref()], bump)]    pub registry: Account<'info, RunRegistry>,

1. Line 34 receipt.slot = Clock::get()?.slot;: Reads on-chain time from the Clock sysvar.
2. Line 35 r.next_sequence = sequence.checked_add(1).ok_or(AuditError::Overflow)?;: Uses checked arithmetic so overflow fails instead of wrapping.
3. Line 45 pub authority: Signer<'info>,: Requires this account to have signed the transaction.
4. Line 46 #[account(init, payer=authority, space=8+32+32+16+32+32+8+32,: Creates and pays for a new account. Space and payer must be specified.
5. Line 47 seeds=[b"run", authority.key().as_ref(), run_id.as_ref()], bump)]: Declares the PDA seeds. Anchor re-derives the address and rejects the account if it doesn't match.
6. Line 47 seeds=[b"run", authority.key().as_ref(), run_id.as_ref()], bump)]: Uses the bump seed, the extra byte that pushes the derived address off the ed25519 curve.

const receiptAddress=(id:PublicKey,registry:PublicKey,sequence:number)=>PublicKey.findProgramAddressSync([Buffer.from('receipt'),registry.toBuffer(),u64(sequence)],id)[0];async function readAccount(address:PublicKey,disc:string,id:PublicKey){ const account=await connection.getAccountInfo(address,'finalized');if(!account)throw Error(`Account not found: ${address}`); if(!account.owner.equals(id)||!account.data.subarray(0,8).equals(discriminator('account',disc)))throw Error('Invalid account owner/discriminator'); return account.data;}async function send(id:PublicKey,data:Buffer,keys:any[],payer:Keypair){ const tx=new Transaction().add(new TransactionInstruction({programId:id,data,keys})); return sendAndConfirmTransaction(connection,tx,[payer],{commitment:'finalized',preflightCommitment:'confirmed',maxRetries:5});}export async function verifyBundle(bundle:any,hash:string){return sha(canonical(bundle)).toString('hex')===hash;}async function verify(){ const local=JSON.parse(readFileSync(`${runs}/latest.json`,'utf8')); const chain=JSON.parse(readFileSync(`${runs}/chain.json`,'utf8')); if(chain.run_id!==local.metadata.run_id)throw Error('Displayed run does not match published run'); const id=program();if(chain.program_id!==id.toBase58())throw Error('Unexpected program ID'); const registry=new PublicKey(chain.registry);const authority=new PublicKey(chain.authority); const config=JSON.parse(readFileSync(programFile,'utf8')); if(authority.toBase58()!==config.operator_authority)throw Error('Untrusted operator authority'); if(!registry.equals(registryAddress(id,authority,local.metadata.run_id)))throw Error('Registry PDA mismatch'); const state=await readAccount(registry,'RunRegistry',id); if(state.length!==192)throw Error('Registry length mismatch'); if(!new PublicKey(state.subarray(8,40)).equals(authority))throw Error('Authority mismatch'); const publisher=new PublicKey(state.subarray(40,72));

1. Line 25 const receiptAddress=(id:PublicKey,registry:PublicKey,sequence:number)=>PublicKey.findProg: Derives a PDA from seeds and the program ID and returns the address with its canonical bump.
2. Line 33 return sendAndConfirmTransaction(connection,tx,[payer],{commitment:'finalized',preflightCo: Submits the signed transaction to the cluster.