---
title: "Base Schedules Denim Upgrade for Mainnet Activation on Nov. 5"
description: "The deployment will bring 200-millisecond block times to Base while removing Flashblocks subscriptions and pending-state access."
url: https://basisdesk.news/news/base-denim-upgrade-mainnet-activation-november-5
published: 2026-10-29T20:48:57.382Z
modified: 2026-10-29T20:48:57.382Z
section: Tech & Protocols
author: Basis Desk Newsroom (AI-generated, source-verified)
sentiment: neutral
tickers: [ETH]
tags: [Base, Layer 2, Upgrades, Denim, Infrastructure]
license: Quote with attribution to Basis Desk (basisdesk.news). Not financial advice.
---

# Base Schedules Denim Upgrade for Mainnet Activation on Nov. 5

The deployment will bring 200-millisecond block times to Base while removing Flashblocks subscriptions and pending-state access.

## At a glance

- **What happened:** Base scheduled the activation of its Denim upgrade on mainnet for Nov. 5, introducing 200ms blocks.
- **Why it matters:** Flashblocks subscriptions and pending-state access will be removed, requiring developers and indexers to change integrations.
- **Who is affected:** Developers and indexers operating applications or infrastructure on Base.
- **Takes effect:** Nov. 5
- **What's next:** Mainnet deployment of the Denim upgrade on Nov. 5.
- **Status:** announced
- **Primary source:** [Base Sets November 5 for Denim's 200ms Mainnet Blocks](https://thedefiant.io/news/blockchains/base-sets-november-5-for-denim-s-200ms-mainnet-blocks) — thedefiant.io

## Key points

- Base has scheduled its Denim upgrade for mainnet launch on Nov. 5.
- The Denim upgrade brings 200-millisecond block times to the layer-2 network.
- Flashblocks subscriptions and pending-state access will be removed, requiring developer integration updates.

## Editorial remark

- **Context:** Base has set an activation date for its Denim release to transition the network to 200-millisecond blocks.
- **Impact:** Developers and indexers must update software integrations to account for the deprecation of Flashblocks subscriptions and pending-state access.
- **Watch:** Mainnet activation of the Denim upgrade scheduled for Nov. 5.

Layer-2 network Base has scheduled its Denim upgrade to activate on mainnet on Nov. 5 [1]. The upgrade will introduce 200-millisecond block times to the network [1]. At the time of writing, Ethereum ($ETH) traded at $2,302, down 2.0% over the prior 24 hours.

The deployment will alter how external infrastructure reads data from the network [1]. Under the Denim upgrade, Flashblocks subscriptions and pending-state access will disappear, requiring developers and indexers to change their integrations ahead of the rollout [1]. 

## Developer and Indexer Impact

The planned removal of pending-state access and Flashblocks subscriptions shifts the integration architecture for data providers operating on Base [1]. Developers and indexing services relying on legacy endpoints will need to adjust their applications to maintain operational compatibility once Denim activates on Nov. 5 [1].

Related development across the broader ecosystem includes network parameter adjustments, such as when [Solana Cuts Target Slot Times to 250ms Ahead of 200ms Target](https://basisdesk.news/news/solana-slot-time-reduction-250ms-epoch-1052) during its ongoing performance improvements. For Base, the transition to 200ms block times alongside the deprecation of pending-state feeds marks a significant structural update for client and tooling teams [1].

## Sources

1. [Base Sets November 5 for Denim's 200ms Mainnet Blocks](https://thedefiant.io/news/blockchains/base-sets-november-5-for-denim-s-200ms-mainnet-blocks) — thedefiant.io, 2026-10-29

---
Basis Desk Newsroom · AI-generated, source-verified · https://basisdesk.news/about/how-we-use-ai