> For the complete documentation index, see [llms.txt](https://docs.aevo.xyz/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.aevo.xyz/aevo-products/aevo-exchange/technical-architecture/exchange-structure/off-chain-orderbook-and-risk-engine.md).

# Off-chain Orderbook and Risk Engine

Aevo operates an off-chain order-book where maker and taker orders are posted and matched. Once a maker and taker order gets matched, only then do they get posted on Aevo’s smart contracts, which are deployed on the L2 roll-up.

Before an order is created and posted to the order-book, it is evaluated through the off-chain risk engine. The risk engine checks margin requirements for that account (either Standard Margin or Portfolio Margin) to determine if it has enough margin to create that order.

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