An account marked as writable in an instruction's account metas, allowing the program to modify its data or lamport balance. Non-writable accounts are read-only. The runtime enforces that programs can only modify writable accounts. Writable accounts also affect scheduling—transactions sharing writable accounts cannot run in parallel.
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An account marked as writable in an instruction's account metas, allowing the program to modify its data or lamport balance. Non-writable accounts are read-only. The runtime enforces that programs can only modify writable accounts. Writable accounts also affect scheduling—transactions sharing writable accounts cannot run in parallel.
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Accounts, instructions, PDAs, transactions, and execution flow.
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Writable Account (writable) Category: Programming Model Definition: An account marked as writable in an instruction's account metas, allowing the program to modify its data or lamport balance. Non-writable accounts are read-only. The runtime enforces that programs can only modify writable accounts. Writable accounts also affect scheduling—transactions sharing writable accounts cannot run in parallel. Related: Account, Transaction
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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.
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.
The byte array stored in an account that holds program-specific state. Data is typically serialized using Borsh and must be explicitly allocated at account creation. The maximum data size is 10MB. Programs are responsible for defining and managing their own data layout, including discriminators for type identification.
A temporary account used during Solana program deployment to hold the program's ELF binary before it is written to the program data account. The deployer creates a buffer account, uploads the compiled SBF binary in chunks via the Upgradeable BPF Loader's Write instruction, and then issues a Deploy or Upgrade instruction that copies the buffer contents to the final program data account. Buffer accounts can be closed after deployment to reclaim rent.
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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.
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.