frequently asked questions about Arch

Arch is a bridgeless execution platform that enhances Bitcoin’s capabilities by enabling fast, secure, and fully-verifiable “smart contracts.” In the Arch ecosystem, "smart contracts" are called programs. For more information on our programs refer to our developer documents.

The Arch architecture has three core components:

• A specialized Arch VM handling state changes and complex off-chain computations
• A decentralized Proof-of-Stake Verifier Network that incentivizes validators to provide infrastructure and security through the (upcoming) Arch token.
• A novel FROST + ROAST multisig architecture that creates the framework for conditional execution necessary for enabling programmability without removing assets from the Bitcoin base layer.

This architecture enables role-dependent trust assumptions for users, including some use cases that are fully trustless and others that place trust in our one decentralized verifier network.

Arch adds bridgeless programmability to Bitcoin. 

• It improves UX because users can invoke smart contracts directly from their wallet through UTXOs, something nobody else can say.
• It improves liquidity,  because assets are never bridged, which allows them to remain interoperable with other assets on the base layer, and are able to tap into the full 1T+ liquidity of Bitcoin.
• It improves security compared to other Bitcoin-based programmability options: spot swaps from DeFi market takers are completely trustless, while other actions require only placing trust in its decentralized verifier network.

When you do place trust in Arch, you only place it in Arch. When using an L2 or metaprotocol like Stacks, you place trust in both Stacks AND whichever bridge you use — when you execute the contract and both when you bridge in and out of the protocol.

With Arch,  you no longer are forced to place trust in bridges, which makes it by far the safest and simplest way to access smart contracts with the full liquidity of Bitcoin.

On Bitcoin L2s + metaprotocols, it takes two steps to access smart contracts:

The Arch architecture has three core components:

• Bridge your assets into their ecosystem
• Sign smart contracts through multisigs

Instead, users and dApps can directly invoke smart contracts by sending UTXOs to Arch (through an RPC) with instructions on how they are to be used and delegated authority that gives the network the ability to enact the smart contract if certain conditions are met.

At no point does the user ever have to bridge assets in order to invoke smart contracts on Bitcoin through Arch.

By eliminating bridging, Arch users can access smart contracts in a way that is simpler, more secure, and, critically, more liquid — unlike other options, Arch is able to maintain the deep liquidity of Bitcoin, since assets are settled on the base layer and maintain communication with other assets on Bitcoin.

With Arch, developers can build dApps that can tap into the full liquidity of Bitcoin while providing a far simpler and more secure user experience than bridge-based alternatives.

This includes creating sophisticated smart contracts, deploying decentralized finance (DeFi) protocols, minting and trading non-fungible tokens (NFTs), and constructing decentralized autonomous organizations (DAOs). 

Arch enables seamless integration of these functionalities on the base layer, offering smart contract programmability that is either completely trustless or as trust-minimized as possible, depending on what users do on the platform.