> For the complete documentation index, see [llms.txt](https://docs.cartesi.io/llms.txt)

---
title: Architecture
tags: [maintain, sdk, off-chain, architecture, low-level developer]
---

What follows is a summary of the architecture and the components that are involved in running a Cartesi Compute Application, meaning some dApp that makes use of our SDK. It is convenient to start with the description of the typical ingredients involved in a decentralized application. Namely, the blockchain node and the client software.

As with any decentralized application, users are expected to have access to a _blockchain node_. This could be a local Ethereum node (like [geth](https://geth.ethereum.org/), [parity](https://www.parity.io/) or a remote one such as [Infura](https://infura.io/).
On the blockchain, the application logic is written in a set of _dApp Smart Contracts_.
Moreover, the off-chain logic is executed on the _Client Software_, either through the internet browser (using [web3](https://web3js.readthedocs.io/en/v1.2.9/)) or by installing a native client. These are the typical ingredients of a decentralized application.

For an application that uses the Cartesi Compute SDK, one also needs the Cartesi Compute Infrastructure, which is composed of an on-chain and an off-chain component, as described below.

## Cartesi Compute on-chain

The on-chain component of Cartesi Compute is a set of smart contracts developed by Cartesi.
For convenience, the dApp developer interacts with a single one of these contracts, named "CartesiCompute".
The API to interact with the Cartesi Compute smart contract is described [here](../compute/instantiate.md).

## Cartesi Compute off-chain

The off-chain component of Cartesi Compute is called the Cartesi Compute Node, which plays a very similar role to the blockchain node.
More precisely, in the same way that a blockchain node allows clients to interact with the first layer, a Cartesi Compute Node allows clients to interact with Cartesi.

It is expected that all validator parties (claimer and challengers) have a Cartesi Compute Node working on their behalves.
In Section [Topologies](../compute/topologies.md), we discuss alternatives to this setup.

These nodes will guarantee that their interests will be enforced on the blockchain by:

- automatically running computations;
- submitting results;
- verifying claims;
- challenging and punishing misbehavior.

All these tasks are performed automatically, with no intervention from the dApp users or even the dApp Client Software.

![Cartesi Compute Architecture](/img/compute-architecture.png)

This gives a complete picture of the software components involved in running a Cartesi Compute powered dApp: The _Blockchain Node_, the _dApp Client Software_, the _dApp Smart Contracts_ and the _Cartesi Compute Node_, see the above picture.