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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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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Accounts, instructions, PDAs, transactions, and execution flow.
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Versioned Transaction (versioned-transaction) Category: Programming Model Definition: 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. Aliases: v0 Transaction Related: Transaction, Address Lookup Table (ALT)
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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.
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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 hard upper limit of 1,400,000 compute units that a single Solana transaction can consume. This cap applies regardless of the SetComputeUnitLimit instruction value — no transaction can request more than 1.4M CU. The default per-instruction budget is 200,000 CU, but multi-instruction transactions share the overall 1.4M cap. Transactions exceeding their CU limit fail with a ComputeBudgetExceeded error.
The simulateTransaction RPC method that dry-runs a transaction against a specified bank state without submitting it to the network or consuming fees. Simulation returns the execution result including logs, compute units consumed, return data, and any error. Developers use simulation to estimate CU usage, debug program errors, and verify transaction correctness before sending. Simulation does not require valid signatures.
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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.
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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.