Owner: @Thomas Lavaur

Reviewers: 🟢@Mehmet 🟢@Marcin Pawlowski 🟨@Daniel Sanchez Quiros 🟨@Gusto Bacvinka 🟢@Youngjoon Lee 🟢@Daniel Kashepava 🟢@David Rusu

Revisions History

• Removed notions of Sovereignty and Rollups and used Zones for simplicity.
• Removed Nomos from specifications and DSTs.
• Added bridging and decentralized sequencing for channels. |

Introduction

Mantle is a foundational element of Bedrock, designed to provide a minimal and efficient execution layer that connects together Bedrock Services in order to provide the necessary functionality for Zones. It can be viewed as the system call interface of Bedrock, exposing a safe and constrained set of Operations to interact with lower-level Bedrock services, similar to syscalls in an operating system.

Mantle Transactions provide Operations for Zones and blockchain Services to interact with Bedrock. For example, a Zone sequencer posting an update to Bedrock, or a node operator declaring its participation in the Blend Network, would be done through the corresponding Operations within a Mantle Transaction.

Mantle manages assets using a note-based ledger that follows an UTXO model. Each Mantle Transaction includes a Ledger Transaction, and any excess balance serves as the fee payment.

Overview

Mantle Transaction

The features of the Logos Blockchain are exposed through Mantle Transactions. Each transaction can contain zero or more Operations and one Ledger Transaction. Mantle Transactions enable users to execute multiple Operations atomically. The Ledger Transaction serves two purposes: it pays the transaction fee and allows users to issue transfers.

Mantle Operations

Logos Blockchain features are exposed through Mantle Operations, which can be combined and executed together in a single Mantle Transaction atomically. These Operations enable functions such as on-chain data posting, Cross-Zone interactions, SDP interaction, and leader reward claims.

Mantle Ledger

The Mantle Ledger enables asset transfers using a transparent UTXO model. While a Ledger Transaction can consume more tokens than it creates, the Mantle Transaction excess balance must exactly pay for the fees.

Transaction Fees

Mantle Transaction fees are derived from a gas model. The Logos Blockchain has two different gas markets, accounting for permanent data storage, and execution costs. Each Operation and Ledger Transaction has an associated Execution Gas cost. Users can specify their gas prices in their Mantle Transactions to incentivize the network to include their transaction.

Mantle Transaction

Mantle Transactions form the core of Mantle, enabling users to combine multiple Operations to access different functions. Each transaction contains zero or more Operations plus a Ledger Transaction. The system executes all Operations atomically, while using the Mantle Transaction's excess balance—calculated as the difference between the consumed and created value— as the fee payment.