Venue types

An exchange registers with a venue type: a centralized exchange, an AMM DEX, or a hybrid. The type drives the two decisions that separate a DEX venue from a CEX one: how a swap is priced, and how an order settles.

What the type decides

venueBehavior maps a venue type to two flags. usesOrderBook chooses between central-limit-order-book matching and AMM reserve pricing. A centralized exchange and a hybrid both use a book; a pure AMM does not, and its fills come from the pool curve instead. onChainSettlement chooses between the synchronous CEX order lifecycle and the probabilistic on-chain one where a transaction can sit pending, revert, or be re-broadcast with higher gas. Both DEX types settle on-chain.

Venue type	Uses order book	On-chain settlement
Centralized exchange	yes	no
AMM DEX	no	yes
Hybrid DEX	yes	yes

Reading it through a symbol

SymbolRegistry::venueTypeForSymbol resolves a symbol to its exchange's venue type, defaulting to a centralized exchange when the symbol or its exchange is unknown. A component that holds a symbol but not its exchange, an executor deciding how to fill or a connector deciding how to settle, asks the registry and then reads the behavior flags.

Why a flag table

Routing code reads usesOrderBook and onChainSettlement rather than switching on the enum in each place. A new venue type is described once, in the behavior table, and every routing decision picks it up. The pricing model, the lifecycle, and the valuation a venue needs all hang off these two flags rather than off scattered checks for a specific enum value.