Preconfirmation Gateway

A Rust-based preconfirmation gateway that enables Ethereum validators to issue commitments for transaction inclusion. The gateway implements the Commitments API specification and integrates with the Constraints API for relay communication, providing near-instant preconfirmation responses to users while ensuring compliance with Ethereum's block construction requirements.

Getting Started

Prerequisites

• Rust (latest stable version)
• Cargo
• Taskfile
• PostgreSQL 15+ (for database operations)

Database Setup

The gateway requires PostgreSQL for storing commitments, delegations, and slot metadata.

Option 1: Using Docker (Recommended)

# Start PostgreSQL using docker-compose
docker-compose up -d postgres

# Set database URL
export DATABASE_URL=postgresql://postgres:postgres@localhost:5432/preconfirmation_gateway

Option 2: Local PostgreSQL Installation

# Install PostgreSQL (macOS example)
brew install postgresql@15

# Start PostgreSQL
brew services start postgresql@15

# Create database
createdb preconfirmation_gateway

# Set database URL
export DATABASE_URL=postgresql://postgres:postgres@localhost:5432/preconfirmation_gateway

Running Database Migrations

The gateway uses SQLx for database migrations. Migrations are automatically run on startup, but you can also run them manually:

# Install sqlx-cli (one-time setup)
cargo install sqlx-cli --no-default-features --features postgres

# Run migrations
sqlx migrate run

# Check migration status
sqlx migrate info

Note: The DATABASE_URL environment variable must be set before running the gateway or migrations. You can also configure it in config.toml.

Building

task build

Running

task run

This starts the RPC server on 127.0.0.1 with a random port and demonstrates client connectivity.

Development

Code Formatting

task format

Linting

task lint

Testing

task test

Architecture

The preconfirmation gateway implements a comprehensive system for Ethereum transaction preconfirmations:

Core Features

• Commitments API: Implements 4 JSON-RPC methods (commitmentRequest, commitmentResult, slots, fee)
• Validator Integration: Issues commitments on behalf of Ethereum proposers
• Constraint Management: Creates and disseminates constraints to builders via relay integration
• Gas Pricing: Dynamic pricing using rETH gas oracle with configurable pricing curves
• First-Come-First-Serve: Ensures fair commitment dispensing with near-instant response times

Technical Implementation

• PostgreSQL Integration: Persistent storage for commitments, delegations, and slot metadata
• BLS/ECDSA Cryptography: Secure signature verification and commitment signing
• Slot Timing Management: 8-second constraint submission windows with automated scheduling
• Relay Communication: Integration with Constraints API for builder coordination

Dependencies

Core Runtime

• jsonrpsee: JSON-RPC 2.0 server implementation
• tokio: Async runtime with multi-threading support
• deadpool-postgres: Async PostgreSQL connection pooling
• tracing: Structured logging and diagnostics

Specifications

This project implements the following Ethereum preconfirmation specifications:

• Commitments API
• Constraints API
• Gateway Specification