# Architecture Overview Shell's main smart contract is [the Ocean](/how-shell-works/the-ocean-accounting-hub.md), a simpler and more efficient home for composing DeFi operations. It is three things in one: a shared multi-token ledger, a standardized accounting framework for DeFi primitives, and a smarter system for composing primitives. The first primitive on Shell was [Proteus](/how-shell-works/proteus-amm-engine.md), a tool that can precisely implement any trading strategy, allowing concentrated liquidity with fungible LP tokens, as well as bonding curves that can evolve over time. As an AMM engine, it allows financial engineers to design custom AMMs without ever writing a line of Solidity code. The Proteus AMM Engine owes its flexibility to the fact that it was designed as a [Shell-native primitive](/getting-started/integrations/shell-native-primitives.md). In other words, the first set of AMMs released using Proteus were also the very first primitives on Shell. Although the Ocean is the main hub, Proteus is a major component of Shell Protocol because of its role in creating fungible LP tokens, which are fundamental building blocks not only in many DeFi applications, but also the future of money. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://wiki.shellprotocol.io/how-shell-works/architecture-overview.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.