Solana - RareSkills

Cross Program Invocation In Anchor Cross Program Invocation (CPI) is Solana’s terminology for a program calling the public function of another program. We’ve already done CPI before when we sent a transfer SOL transaction to the system program. Here is the relevant snippet by way of reminder: pub fn send_sol(ctx: Context<SendSol>, amount: u64) -> Result<()> […]

Reading Another Anchor Program’s Account Data On Chain In Solidity, reading another contract’s storage requires calling a view function or the storage variable being public. In Solana, an off-chain client can read a storage account directly. This tutorial shows how an on-chain Solana program can read the data in an account it does not own. […]

[derive(Accounts)] in Anchor: different kinds of accounts #[derive(Accounts)] in Solana Anchor is an attribute-like macro for structs that holds references to all the accounts the function will access during its execution. In Solana, every account the transaction will access must be specified in advance One reason Solana is so fast is that it executes transactions […]

Modifying accounts using different signers In our Solana tutorials thus far, we’ve only had one account initialize and write to the account. In practice, this is very restrictive. For example, if user Alice is transferring points to Bob, Alice must be able to write to an account initialized by user Bob. In this tutorial we […]

Deleting and Closing Accounts and Programs in Solana In the Anchor framework for Solana, close is the opposite of init (initializing an account in Anchor) — it reduces the lamport balance to zero, sending the lamports to a target address, and changes the owner of the account to be the system program. Here is an […]

PDA (Program Derived Address) vs Keypair Account in Solana A program derived address (PDA) is an account whose address is derived from the address of the program that created it and the seeds passed in to the init transaction. Up until this point, we’ve only used PDAs. It is also possible to create an account […]

Owner vs Authority in Solana Newcomers to Solana are frequently confused by the distinction between an “owner” and an “authority.” This article attempts to clear up the confusion as succinctly as possible. Owner vs Authority Only programs can write data to accounts — specifically, only to accounts they own. A program cannot write data to […]

Multicall in Solana: Batching Transactions and Transaction Size Limit Solana has multicall built in In Ethereum, we use the multicall pattern if we want to batch multiple transactions together atomically. If one fails, the rest fails. Solana has this built into the runtime, so we don’t need to implement a multicall. In the example below, […]

Init_if_needed in Anchor and the Reinitialization Attack In previous tutorials, we’ve had to initialize an account in a separate transaction before we can write data to it. We may wish to be able to initialize an account and write data to it in one transaction to simplify things for the user. Anchor provides a handy […]