---
title: "alloy"
description: "Alloy type extensions for Base — consensus types, EVM customizations, RPC types, and network definitions."
source: https://basehub.org/crates/alloy/overview/
---
The `alloy` crate group extends [Alloy](https://github.com/alloy-rs/alloy), the standard Rust toolkit for Ethereum types and RPC, with Base-specific consensus types, RPC types, EVM behavior, and hardfork definitions.

## Sub-crates

| Crate | Package Name | Purpose |
|-------|-------------|---------|
| [consensus](/crates/alloy/consensus/) | `base-alloy-consensus` | Base-specific consensus types |
| [evm](/crates/alloy/evm/) | `base-alloy-evm` | EVM customizations for Base |
| [hardforks](/crates/alloy/hardforks/) | `base-alloy-hardforks` | Base hardfork definitions |
| [network](/crates/alloy/network/) | `base-alloy-network` | Network type definitions |
| [provider](/crates/alloy/provider/) | `base-alloy-provider` | Alloy provider extensions |
| [rpc-jsonrpsee](/crates/alloy/rpc-jsonrpsee/) | `base-alloy-rpc-jsonrpsee` | JSON-RPC server traits (jsonrpsee) |
| [rpc-types-engine](/crates/alloy/rpc-types-engine/) | `base-alloy-rpc-types-engine` | Engine API RPC types |
| [rpc-types](/crates/alloy/rpc-types/) | `base-alloy-rpc-types` | General RPC type extensions |

## Role in the Architecture

The alloy crates sit at the foundation of the dependency graph. They define the types that flow through every other layer — from how blocks and transactions are represented in consensus, to the RPC types returned to users, to the EVM execution context.

These crates extend the upstream Alloy types with Base-specific fields and behaviors needed for the OP Stack L2 environment.

## Source

[`crates/alloy/`](https://github.com/base/base/tree/main/crates/alloy)