Architecture

DA Builder's architecture consists of several key components that work together to aggregate and execute transactions efficiently. Below is an example showing how a rollup would setup an account with DA Builder and submit blob transactions to their inbox through DA Builder to save on costs:

System Architecture

Component Responsibilities

User's EOA with EIP-7702 Proposer Code:

• Contains the deployed proposer contract code (e.g., TrustlessProposer)

• Validates signatures and executes authorized transactions

• Signs transactions to be submitted to DA Builder

DA Builder Service:

• Accepts transaction submissions from users

• Validates EIP-7702 setup and account funding

• Collects multiple user transactions

• Creates aggregated EIP-4844 blob transactions

• Manages transaction ordering and batching

• Returns transaction IDs for tracking

ProposerMulticall Contract:

• Executes the aggregated transaction on-chain

• Calls each user's proposer contract in sequence

GasTank Contract:

• Stores user deposits to cover their respective transaction fees

• Provides balance tracking and allows for trustless withdrawals

L2 Rollup Inbox:

• Receives the actual user transaction

• Processes it according to L2 protocol rules

• Updates L2 state based on transaction execution