Atomicity
Every change a command makes is applied together or not at all. Commands run against an overlay of committed state; a business rejection leaves all records unchanged and still keeps its place in the order.
StateVec · Built for core business transactions
A verifiable business engine
for core transactions
Run business rules as deterministic plugins, with ACID transactions, replication and verifiable recovery.
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ACID for core business transactions
A business transaction rarely changes just one record. A transfer may debit an account, credit another, charge a fee and consume a limit. StateVec keeps these changes in one ACID transaction: every related update succeeds together, or none takes effect.
Your plugin defines the data model and the rules that accept or reject each command. The engine provides atomic updates, serializable execution and durable recovery across the cluster. Both execution modes share this foundation; Verify mode adds replica execution checks before commit.
Consistency
Requests are checked against the typed data model before execution, and deterministic rules give every replica the same result from the same input. Verify mode confirms replica agreement before commit; declarative business-invariant checks are in development.
Isolation
Commands execute one at a time in a single global order fixed by the log. Each command sees every earlier committed command and none of the later ones, giving serializable isolation.
Durability
A command commits only after a quorum of voters has persisted it with the required disk syncs. After a crash, a node restores a selected checkpoint and replays the committed log.
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Business scenarios
Build applications where balances, positions, limits or inventory must stay in agreement. StateVec fits well-defined business rules, bounded core state and short, deterministic operations that can be replayed during recovery.
FINANCIAL CORE
Core financial transactions
Build spot and margin trading for exchanges and brokers, with application-defined order checks and position rules. Validate available funds and update order, position and balance records in the same command.
Orders, positions and funds move together as one atomic business transaction.
ACCOUNTING
Ledgers, balances and settlement
Post debits and credits, update balances and advance settlement state in one ACID transaction. Define explicit rejection rules for insufficient funds or invalid account transitions.
Handlers keep debits and credits balanced, with no one-sided entries. External settlement uses an integration protocol.
BILLING & LIMITS
Real-time billing, limits and credits
Process usage events, apply pricing rules, check available limits and deduct credits in one transaction. Interpret historical inputs under the rule version that applied when they were processed.
Use request identity in the business rules so a retry cannot charge the same usage twice.
RESERVATION
Ticketing and inventory management
Reserve, confirm and release seats or inventory through explicit commands. Keep available quantities and order status in agreement, with expiry driven by time inputs recorded in transaction order.
Plugin rules prevent the same seat or inventory unit from being assigned to two confirmed orders.
Keep plugins short and deterministic. External calls, long computations and analytics run outside the core. Writes require an available quorum.
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Explore the engine in depth
StateVec overview
Understand the transaction core: business plugins, ACID execution, replication and recovery.
Read the overview →Plugin contract in 5 minutes
Define records and commands, write deterministic handlers, and test business refusals with the Bank example.
Read the guide →StateVec, SpacetimeDB and Aeron Cluster
Compare their transaction models, developer responsibilities, replication and execution verification.
Read the comparison →Controlled evolution and auditable history
Explore plugin upgrades, historical audit views and business-invariant checks.
Read the article →