> ## Documentation Index
> Fetch the complete documentation index at: https://base-a060aa97-youssefea-hide-floating-assistant-bar.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Precompiles

> Specification of precompiled contracts on Base, including native EVM implementations available at predefined addresses.

## Overview

[Precompiled contracts](/specifications/reference/glossary#precompiled-contract-precompile) exist on Base at
predefined addresses. They are similar to predeploys but are implemented as native code in the EVM as opposed to
bytecode. Precompiles are used for computationally expensive operations, that would be cost prohibitive to implement
in Solidity. Where possible predeploys are preferred, as precompiles must be implemented in every execution client.

Base contains the [standard Ethereum precompiles](https://www.evm.codes/precompiled) as well as Base-specific precompiles. The table below
lists P256VERIFY, including its introduction version and current gas cost. B20's singleton precompiles are documented
separately in the B20 section.

| Name | Address | Introduced | Gas Cost |
| - | - | - | - |
| P256VERIFY | 0x0000000000000000000000000000000000000100 | Fjord | 6,900 (updated in Azul) |

## P256VERIFY

The `P256VERIFY` precompile performs signature verification for the secp256r1 elliptic curve. This curve has widespread
adoption. It's used by Passkeys, Apple Secure Enclave and many other systems.

It is specified as part of [RIP-7212](https://github.com/ethereum/RIPs/blob/master/RIPS/rip-7212.md) and was added to
the Base protocol in the Fjord release with a gas cost of 3,450.

With the [Azul hardfork](/upgrades/azul/exec-engine#secp256r1-precompile-gas-cost), the gas cost was updated to **6,900** to match [EIP-7951](https://eips.ethereum.org/EIPS/eip-7951) and maintain strict equivalence with L1 precompile pricing.

Address: `0x0000000000000000000000000000000000000100`

## Standard Ethereum Precompile Modifications (Azul)

The [Azul hardfork](/upgrades/azul/exec-engine) introduced changes to two standard Ethereum precompiles:

### MODEXP (Address `0x05`)

* **[EIP-7823](https://eips.ethereum.org/EIPS/eip-7823)** — input fields are capped at 1,024 bytes each. Calls with larger inputs are rejected.
* **[EIP-7883](https://eips.ethereum.org/EIPS/eip-7883)** — minimum gas cost raised from 200 to 500; the general cost formula is tripled.

These changes apply from the Azul activation timestamp and match Ethereum L1 behavior.

## B20

B20 is Base's native token standard for programmable assets. Its shared token logic runs as precompiles in the Base node
rather than as per-token Solidity code. B20 assets expose an ERC-20-compatible interface with additional roles, policies,
and supply controls.

Each B20 asset has its own address, created through the Factory; the addresses below are shared system entry points,
not token addresses.

| Precompile | Address | Purpose |
| - | - | - |
| Factory (`B20_FACTORY_ADDRESS`) | `0xB20f000000000000000000000000000000000000` | Creates and looks up B20 tokens. |
| Policy Registry (`POLICY_REGISTRY_ADDRESS`) | `0x8453000000000000000000000000000000000002` | Stores policies and answers authorization checks for B20 policy scopes. |
| Activation Registry (`ACTIVATION_REGISTRY_ADDRESS`) | `0x8453000000000000000000000000000000000001` | Controls which B20 variants or features are active on a given chain. |

For an overview of B20's design and capabilities, see the [B20 introduction](/specifications/b20/introduction). See
[B20 constants](/specifications/b20/reference/constants#precompile-addresses) for the canonical address list.