agent-bazaar

    #[account(        mut,        seeds = [b"agent", agent.service.as_bytes()],        bump = agent.bump,        has_one = owner,        close = owner,    )]    pub agent: Account<'info, Agent>,     #[account(mut)]    pub owner: Signer<'info>,} #[derive(Accounts)]#[instruction(nonce: u64, amount: u64)]pub struct OpenEscrow<'info> {    pub agent: Account<'info, Agent>,     #[account(        init,        payer = client,        space = 8 + Escrow::LEN,        seeds = [            b"escrow",

1. Line 375 seeds = [b"agent", agent.service.as_bytes()],: Declares the PDA seeds. Anchor re-derives the address and rejects the account if it doesn't match.
2. Line 376 bump = agent.bump,: Uses the bump seed, the extra byte that pushes the derived address off the ed25519 curve.
3. Line 377 has_one = owner,: Checks that a stored pubkey field matches the passed account.
4. Line 378 close = owner,: Closes the account at the end of the instruction and refunds its lamports.
5. Line 383 pub owner: Signer<'info>,: Requires this account to have signed the transaction.
6. Line 392 init,: Creates and pays for a new account. Space and payer must be specified.

   // ─── Senders (firman + envían + esperan confirmación) ───────   async sendAndConfirm(    instructions: TransactionInstruction[],    payer: Keypair,    extraSigners: Keypair[] = [],  ): Promise<string> {    const { blockhash, lastValidBlockHeight } = await this.connection.getLatestBlockhash('confirmed');    const message = new TransactionMessage({      payerKey: payer.publicKey,      recentBlockhash: blockhash,      instructions,    }).compileToV0Message();    const tx = new VersionedTransaction(message);    tx.sign([payer, ...extraSigners]);    const sig = await this.connection.sendTransaction(tx, { skipPreflight: false, maxRetries: 3 });    await this.connection.confirmTransaction(      { signature: sig, blockhash, lastValidBlockHeight },      'confirmed',    );    return sig;  }

1. Line 189 const { blockhash, lastValidBlockHeight } = await this.connection.getLatestBlockhash('conf: Fetches a recent blockhash. Transactions expire if it gets too old.
2. Line 197 const sig = await this.connection.sendTransaction(tx, { skipPreflight: false, maxRetries: : Submits the signed transaction to the cluster.

    return this.keypair.publicKey();  }   // ─── helpers de invocación ─────────────────────────────────   /** Método que cambia estado: prepara (simula + footprint + auth), firma, envía y espera. */  private async invoke(method: string, args: xdr.ScVal[]): Promise<string> {    const source = await this.server.getAccount(this.keypair.publicKey());    const tx = new TransactionBuilder(source, {      fee: BASE_FEE,      networkPassphrase: this.networkPassphrase,    })      .addOperation(this.contract.call(method, ...args))      .setTimeout(30)      .build();     const prepared = await this.server.prepareTransaction(tx);    prepared.sign(this.keypair);     const sent = await this.server.sendTransaction(prepared);    if (sent.status === 'ERROR') {      throw new Error(        `[${this.label}] ${method} rechazada: ${JSON.stringify(sent.errorResult)}`,      );

1. Line 91 private async invoke(method: string, args: xdr.ScVal[]): Promise<string> {: Makes a cross-program invocation into another program.
2. Line 104 const sent = await this.server.sendTransaction(prepared);: Submits the signed transaction to the cluster.