An account that has provided a valid Ed25519 signature in the current transaction. The runtime enforces the is_signer flag on instruction account metas—if an instruction declares an account as a signer, the transaction must include its signature. Missing signer checks are a common vulnerability in Solana programs.
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An account that has provided a valid Ed25519 signature in the current transaction. The runtime enforces the is_signer flag on instruction account metas—if an instruction declares an account as a signer, the transaction must include its signature. Missing signer checks are a common vulnerability in Solana programs.
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Accounts, instructions, PDAs, transactions, and execution flow.
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Signer (signer) Category: Programming Model Definition: An account that has provided a valid Ed25519 signature in the current transaction. The runtime enforces the is_signer flag on instruction account metas—if an instruction declares an account as a signer, the transaction must include its signature. Missing signer checks are a common vulnerability in Solana programs. Related: Authority, Keypair, Transaction
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A pubkey with administrative privileges over a resource—such as the mint authority (can mint tokens), freeze authority (can freeze accounts), upgrade authority (can upgrade a program), or the signer authorized to perform operations on a PDA-controlled account. Authority is a convention, not a runtime concept.
A pair of a 32-byte Ed25519 private key and its corresponding 32-byte public key. Keypairs are used to sign transactions and derive account addresses. They are stored as 64-byte arrays (private + public concatenated) in JSON files by the Solana CLI. The private key should never be shared or exposed.
An atomic unit of execution containing one or more instructions, a recent blockhash, and one or more signatures. All instructions in a transaction execute sequentially and atomically—if any instruction fails, the entire transaction reverts. Transactions have a 1,232-byte size limit (matching IPv6 MTU) and a default 200,000 CU budget.
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Byte arrays used as inputs to derive a Program Derived Address. Seeds can be any combination of static strings, user pubkeys, mint addresses, or other identifiers (each seed max 32 bytes, up to 16 seeds). For example, seeds=[b'vault', user.key()] derives a unique vault PDA for each user.
A 64-byte Ed25519 digital signature over a transaction's message. Each signer in a transaction produces one signature. The first signature (from the fee payer) also serves as the unique transaction ID. Signature verification is parallelized in the TPU's sigverify stage using GPU acceleration.
The native token of the Solana blockchain, used for paying transaction fees, staking, and rent. 1 SOL equals 1 billion lamports. SOL has an inflationary supply schedule starting at 8% annually, decreasing by 15% per year, with a long-term floor of 1.5%. Transaction base fees (5,000 lamports) are partially burned.
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A pubkey with administrative privileges over a resource—such as the mint authority (can mint tokens), freeze authority (can freeze accounts), upgrade authority (can upgrade a program), or the signer authorized to perform operations on a PDA-controlled account. Authority is a convention, not a runtime concept.
A pair of a 32-byte Ed25519 private key and its corresponding 32-byte public key. Keypairs are used to sign transactions and derive account addresses. They are stored as 64-byte arrays (private + public concatenated) in JSON files by the Solana CLI. The private key should never be shared or exposed.
An atomic unit of execution containing one or more instructions, a recent blockhash, and one or more signatures. All instructions in a transaction execute sequentially and atomically—if any instruction fails, the entire transaction reverts. Transactions have a 1,232-byte size limit (matching IPv6 MTU) and a default 200,000 CU budget.
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The fundamental data storage unit on Solana. Every piece of state is stored in an account identified by a 32-byte public key. Accounts hold a lamport balance, an owner program, a data byte array (up to 10MB), and an executable flag. Only the owning program can modify an account's data, but anyone can credit lamports to it.
Executable code deployed on-chain, equivalent to a smart contract on other blockchains. Programs are stateless—they store no data themselves but read/write data in separate accounts they own. Programs are compiled to SBF bytecode and loaded via the BPF Loader. Every program has a unique Program ID (its account's public key).
A single operation within a transaction that invokes a program. An instruction specifies: (1) the program ID to call, (2) an array of account metas (pubkey, is_signer, is_writable), and (3) an opaque data byte array. Programs decode the instruction data to determine which operation to perform.
An atomic unit of execution containing one or more instructions, a recent blockhash, and one or more signatures. All instructions in a transaction execute sequentially and atomically—if any instruction fails, the entire transaction reverts. Transactions have a 1,232-byte size limit (matching IPv6 MTU) and a default 200,000 CU budget.