The maximum serialized size of a Solana transaction: 1,232 bytes, matching the IPv6 minimum MTU to ensure single-packet transmission. This limit constrains the number of accounts, instructions, and data per transaction. Address lookup tables (v0 transactions) help fit more accounts within this limit.
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The maximum serialized size of a Solana transaction: 1,232 bytes, matching the IPv6 minimum MTU to ensure single-packet transmission. This limit constrains the number of accounts, instructions, and data per transaction. Address lookup tables (v0 transactions) help fit more accounts within this limit.
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Transaction Size Limit (transaction-size) Category: Programming Model Definition: The maximum serialized size of a Solana transaction: 1,232 bytes, matching the IPv6 minimum MTU to ensure single-packet transmission. This limit constrains the number of accounts, instructions, and data per transaction. Address lookup tables (v0 transactions) help fit more accounts within this limit. Related: Transaction, Address Lookup Table (ALT), Versioned Transaction
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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.
An on-chain account that stores up to 256 pubkeys, enabling v0 transactions to reference accounts by 1-byte index instead of full 32-byte pubkeys. ALTs dramatically reduce transaction size when interacting with many accounts (e.g., DEX routing). ALTs must be created and populated in advance; entries become active after a slot delay.
A transaction format introduced with v0 that supports address lookup tables. Legacy transactions include all pubkeys inline (limited to ~35 accounts); v0 transactions reference ALTs to include up to 256 accounts while staying within the 1,232-byte limit. The version byte (0) precedes the message.
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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.
The first signature in a transaction, which uniquely identifies it on the network. Since each transaction has a unique combination of signers and a recent blockhash, the first signer's Ed25519 signature over the transaction message serves as a globally unique identifier. Transaction IDs are displayed as Base58-encoded 64-byte strings and used for lookups via getTransaction and getSignatureStatuses.
The limited lifespan of a Solana transaction determined by its referenced blockhash. A transaction's blockhash must correspond to a block within the last 150 slots (~60-90 seconds) or the transaction is rejected as expired. This mechanism prevents replay attacks and bounds the time validators must track transaction deduplication. Durable nonces bypass mortality for use cases requiring long-lived transactions.
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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.
An on-chain account that stores up to 256 pubkeys, enabling v0 transactions to reference accounts by 1-byte index instead of full 32-byte pubkeys. ALTs dramatically reduce transaction size when interacting with many accounts (e.g., DEX routing). ALTs must be created and populated in advance; entries become active after a slot delay.
A transaction format introduced with v0 that supports address lookup tables. Legacy transactions include all pubkeys inline (limited to ~35 accounts); v0 transactions reference ALTs to include up to 256 accounts while staying within the 1,232-byte limit. The version byte (0) precedes the message.
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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.