Check Deployment

Before sending transactions, the client verifies the on-chain program is deployed.

Verification Flow

1. Check Program Keypair

The client looks for the program keypair at ./target/deploy/program-keypair.json. This file is generated during cargo build-bpf. If not found, the client exits with an error.

2. Retrieve Program Account

The program account is retrieved using the pubkey from the keypair. The client checks two things:

• The account exists on-chain
• The account is executable

3. Handle Upgradable vs BPF Loader

This check alone is not sufficient for programs owned by the upgradable BPF loader (BPFLoaderUpgradeab1e11111111111111111111111). When a program is closed via solana program close, the program data account is wiped, but the program account still reports as executable.

The client handles this by also checking for the program data account where actual bytecodes are stored:

The blue line (BPF Loader) does not allow closing a deployed program. The red underline (Upgradeable BPF Loader) — we query the program data account; if it’s empty, the program was closed even though the program account says executable.