Program Derived Addresses (PDAs)
A PDA is an address derived from a program ID plus a list of seeds, deliberately chosen so that it has no private key. Only the deriving program can sign for it (via invo…
Learn by example
Each lesson explains one concept, then walks through real excerpts from projects in the stack, pinned to a commit.
Cross-Program Invocations (CPIs)
A CPI is one program calling an instruction on another program, such as the Token Program or System Program. The caller passes the accounts the callee needs. When a PDA m…
SPL Tokens: mints, accounts and transfers
Fungible tokens on Solana are accounts owned by the Token Program. A mint account defines supply and decimals, and a token account holds a balance of one mint for one own…
Token-2022 (Token Extensions)
Token-2022 is a separate token program with the same core layout as the original Token Program, plus optional extensions configured when the mint is created: transfer fee…
Escrow patterns
An escrow holds assets in a program-controlled account, usually a token account whose authority is a PDA, until agreed conditions are met. The usual lifecycle is make (de…
NFTs with Metaplex
Most Solana NFTs follow Metaplex standards. Token Metadata attaches a metadata account to a supply-1 mint, and Metaplex Core is a newer single-account asset standard. Cod…
Building and sending transactions from a client
A transaction bundles instructions, a recent blockhash and signatures. Clients fetch a recent blockhash, add instructions (often including compute-budget instructions for…
Anchor account constraints
In Anchor, the #[derive(Accounts)] struct is where most security lives. Constraints such as init, mut, has_one, seeds/bump, constraint = ... and close are checked before …