Local Program Development

Summary #

• To develop onchain programs locally, you need the Solana CLI, Rust, and (optional, but recommended) Anchor.
• You can use anchor init to create a new blank Anchor project.
• anchor test runs your tests and also builds your code.

Lesson #

There's no formal lesson here! Let's get hands-on by installing the Solana CLI tools, the Rust SDK, and Anchor, and create a test program to verify that everything is set up correctly.

Lab #

Extra steps for Windows users #

First, install Windows Terminal from the Microsoft store.

Next, install Windows Subsystem for Linux (WSL). WSL provides a Linux environment that launches instantly when needed without slowing down your computer.

Open Windows Terminal, start an 'Ubuntu' session and proceed with the rest of these steps.

Download Rust #

First, install Rust by following the instructions:

curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh

Download the Solana CLI tools #

Next, download the Solana CLI tools:

sh -c "$(curl -sSfL https://release.anza.xyz/stable/install)"

After installation, solana -V should display solana-cli 1.18.x (where x can be any number).

Running the Solana Test Validator #

The Solana Test Validator is a local emulator for the Solana blockchain. It provides developers with a private and controlled environment to build and test Solana programs without needing to connect to a public testnet or mainnet.

To start the Solana Test Validator, run the following command:

solana-test-validator

When running solana-test-validator, you should see output indicating that the validator is working correctly. Below is an example of what the output should look like:

$ solana-test-validator
--faucet-sol argument ignored, ledger already exists
Ledger location: test-ledger
Log: test-ledger/validator.log
⠴ Initializing...
Waiting for fees to stabilize 1...
Identity: J8yKZJa5NtcmCQqmBRC6Fe8X6AECo8Vc3d7L3dF9JPiM
Genesis Hash: FTPnCMDzTEthZxE6DvHbsWWv83F2hFe1GFvpVFBMUoys
Version: 1.18.22
Shred Version: 49491
Gossip Address: 127.0.0.1:1024
TPU Address: 127.0.0.1:1027
JSON RPC URL: http://127.0.0.1:8899
WebSocket PubSub URL: ws://127.0.0.1:8900
⠄ 00:00:25 | Processed Slot: 114 | Confirmed Slot: 114 | Finalized Slot: 82 | Full Snapshot Slot: - | Incremental Snapshot Slot: - | Transactions: 111 | ◎499.999445000

If you see this output, it means the Solana test validator is running correctly. You should cancel the process by pressing CTRL + C, as you'll need to run the anchor test command next.

For more detailed information, you can refer to the Solana Test Validator guide.

Download Anchor #

Finally, download Anchor:

cargo install --git https://github.com/coral-xyz/anchor avm --locked --force
avm install latest
avm use latest

After installation, anchor -V should display anchor-cli 0.30.1. For more detailed information on Anchor, refer to The Anchor Book.

Verify your Anchor Installation #

Create a temporary project with the default contents using Anchor and ensure it compiles and runs:

anchor init temp-project
cd temp-project
anchor test

The anchor test command should complete without errors or warnings. If you encounter issues, we’ll address them below:

Error: package 'solana-program v1.18.12' cannot be built because it requires rustc 1.75.0 or newer #

Run cargo add solana-program@"=1.18.x", where x matches your version of solana-cli. Then re-run anchor test.

Error: Unable to read keypair file #

Add a keypair to .config/solana/id.json. You can either copy a keypair from an .env file (just the array of numbers) into a file or use the command solana-keygen new --no-bip39-passphrase to create a new keypair file. Then re-run anchor test.

Error: Your configured rpc port: 8899 is already in use #

If you are running solana-test-validator, you may encounter the error Error: Your configured rpc port: 8899 is already in use when running anchor test. To resolve this, stop the solana-test-validator before running anchor test.

All done? #

Ensure anchor test completes successfully - with no warnings and no errors - before continuing.