A node that participates in the Solana network by validating transactions, voting on blocks, and (when selected as leader) producing new blocks. Validators run the Agave, Firedancer, or Jito client software, require significant hardware (128+ GB RAM, high-core CPU, NVMe SSD), and earn rewards from inflation and transaction fees.
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A node that participates in the Solana network by validating transactions, voting on blocks, and (when selected as leader) producing new blocks. Validators run the Agave, Firedancer, or Jito client software, require significant hardware (128+ GB RAM, high-core CPU, NVMe SSD), and earn rewards from inflation and transaction fees.
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Think of it as the machine and software stack that helps produce blocks, vote on forks, and keep the network alive.
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Consensus, leader rotation, slots, epochs, and the runtime.
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Validator (validator) Category: Core Protocol Definition: A node that participates in the Solana network by validating transactions, voting on blocks, and (when selected as leader) producing new blocks. Validators run the Agave, Firedancer, or Jito client software, require significant hardware (128+ GB RAM, high-core CPU, NVMe SSD), and earn rewards from inflation and transaction fees. Related: Vote Account, Stake, Leader Schedule
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An on-chain account that records a validator's Tower BFT votes and tracks their voting history. Each validator has one vote account that stores the last 32 vote slots with their confirmation counts. The vote account also tracks earned credits used to calculate epoch rewards. Vote transactions constitute ~70-80% of all transactions on Solana.
SOL tokens that are delegated to a validator to increase its voting weight and earn staking rewards. Staking is non-custodial—stakers retain ownership of their SOL. Stake activates/deactivates at epoch boundaries with a warmup/cooldown period. Validators with more stake are assigned more leader slots and have proportionally more influence in consensus.
A deterministic mapping of slots to validators for an entire epoch, computed from stake weights. Validators with more stake are assigned proportionally more leader slots. The schedule is derived using a seed from the previous epoch's randomness, so all validators independently compute the same schedule without coordination.
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The first validator in a Solana cluster that produces the genesis block and bootstraps the initial ledger. The bootstrap validator generates the genesis configuration, creates the initial accounts (mint, vote, stake), and begins producing PoH entries and blocks. Other validators then join the cluster by connecting to the bootstrap validator via gossip and downloading a snapshot.
A modified fork of the Agave validator client maintained by Jito Labs that adds an out-of-protocol block space auction. Jito's modifications include a block engine that accepts transaction bundles with tips, enabling MEV extraction while returning value to stakers. The majority of mainnet-beta stake runs the Jito client.
The vote-optimized transaction ordering component of the Alpenglow consensus protocol. Votor handles off-chain voting and certificate generation, replacing Tower BFT's on-chain vote transactions that currently account for 70-80% of Solana's transaction volume. By moving voting off-chain and using a structured protocol for collecting and aggregating validator votes, Votor enables sub-second finality while freeing on-chain bandwidth for user transactions.
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An on-chain account that records a validator's Tower BFT votes and tracks their voting history. Each validator has one vote account that stores the last 32 vote slots with their confirmation counts. The vote account also tracks earned credits used to calculate epoch rewards. Vote transactions constitute ~70-80% of all transactions on Solana.
SOL tokens that are delegated to a validator to increase its voting weight and earn staking rewards. Staking is non-custodial—stakers retain ownership of their SOL. Stake activates/deactivates at epoch boundaries with a warmup/cooldown period. Validators with more stake are assigned more leader slots and have proportionally more influence in consensus.
A deterministic mapping of slots to validators for an entire epoch, computed from stake weights. Validators with more stake are assigned proportionally more leader slots. The schedule is derived using a seed from the previous epoch's randomness, so all validators independently compute the same schedule without coordination.
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A clock mechanism that cryptographically proves the passage of time between events. PoH uses a sequential SHA-256 hash chain where each output becomes the next input, creating a verifiable ordering of events without requiring consensus. The leader produces ~400,000 hashes per slot (~400ms), and any validator can verify the sequence in parallel, enabling Solana's high throughput by removing the need for validators to agree on time.
Solana's custom BFT consensus algorithm built on top of Proof of History. Tower BFT uses PoH as a clock to reduce communication overhead in traditional PBFT from O(n²) to O(n). Validators vote on forks with exponentially increasing lockout periods—each consecutive vote doubles the lockout, making rollbacks progressively more expensive. A fork is finalized when it reaches supermajority (66.7%+ of stake).
A time window during which a designated leader validator can produce a block. Each slot lasts approximately 400 milliseconds. Slots are numbered sequentially from genesis and grouped into epochs of 432,000 slots (~2-3 days). Not every slot produces a block—a skipped slot means the leader was offline or too slow.
A set of entries produced by a leader during a single slot. A block contains transactions bundled into entries, each with a PoH hash proving ordering. Blocks are broken into shreds for network propagation via Turbine. Maximum block size is limited by compute units (48M CU cap per block) rather than byte size.