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

# Overview

> Azul is Base's first independent network upgrade. It focuses on increasing security and decentralization, accelerating the path to 1 gigagas/s, and improving developer experience.

Azul is Base's first independent network upgrade. It focuses on increasing security and decentralization, accelerating the path to 1 gigagas/s, and improving developer experience.

|         | Status | Date           |
| ------- | ------ | -------------- |
| Sepolia | Live   | April 20, 2026 |
| Mainnet | Live   | May 28, 2026   |

[Documentation](/base-chain/specs/upgrades/azul/exec-engine)

## Features

<AccordionGroup>
  <Accordion title="EIP-7823: Upper-Bound MODEXP" icon="code">
    **EIP** · Execution

    Caps MODEXP precompile inputs to a maximum of 1024 bytes per field. Calls with larger inputs are rejected.
  </Accordion>

  <Accordion title="EIP-7825: Transaction Gas Limit Cap" icon="code">
    **EIP** · Execution

    Introduces a protocol-level maximum gas limit of 16,777,216 (2^24) per transaction. Transactions above this cap are rejected during validation, and Base adopts the same cap as L1 to maximize Ethereum equivalence.
  </Accordion>

  <Accordion title="EIP-7883: MODEXP Gas Cost Increase" icon="code">
    **EIP** · Execution

    Raises the MODEXP precompile minimum gas cost from 200 to 500 and triples the general cost calculation.
  </Accordion>

  <Accordion title="EIP-7939: CLZ Opcode" icon="code">
    **EIP** · Execution

    Adds a new CLZ opcode that counts the number of leading zero bits in a 256-bit word, returning 256 if the input is zero.
  </Accordion>

  <Accordion title="EIP-7951: secp256r1 Precompile" icon="code">
    **EIP** · Execution

    Specifies the secp256r1 precompile at address 0×100. From Azul, the gas cost increases to 6,900 to match the L1 gas cost specified in EIP-7951.
  </Accordion>

  <Accordion title="EIP-7642: eth/69" icon="code">
    **EIP** · Networking

    Updates the Ethereum wire protocol to version 69, removing legacy fields from the Status message and simplifying the handshake.
  </Accordion>

  <Accordion title="Remove Account Balances & Receipts" icon="code">
    **Base** · Networking

    Simplifies the FlashblocksMetadata payload by removing new\_account\_balances and receipts from the Flashblocks WebSocket format.
  </Accordion>

  <Accordion title="Use basev0 protocol ID for discv5" icon="code">
    **Base** · Networking

    Updates execution-layer discovery to use basev0 as the protocol ID so Base nodes can find each other more quickly, especially on smaller networks like Sepolia.
  </Accordion>

  <Accordion title="EIP-7910: eth_config RPC Method" icon="code">
    **EIP** · RPC

    Introduces the eth\_config JSON-RPC method, which returns chain configuration parameters such as fork activation timestamps.
  </Accordion>

  <Accordion title="Engine API Usage" icon="code">
    **Base** · RPC

    At and after Azul activation, block production and import use the following Engine API methods: engine\_forkchoiceUpdatedV3 for starting block builds and forkchoice synchronization, engine\_getPayloadV5 for retrieving built payloads.
  </Accordion>

  <Accordion title="Multiproofs" icon="code">
    **Base** · Proofs

    Proof System introduces a multi-proof system for L2 checkpoints, where AggregateVerifier can verify one or two proofs for the same proposal before withdrawals rely on it.
  </Accordion>
</AccordionGroup>