> ## Documentation Index
> Fetch the complete documentation index at: https://docs.chainstack.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Chainstack updates: November 6, 2026

> Base's Denim upgrade activated on Base Mainnet: 200 ms blocks replace 2-second blocks, and Flashblocks are retired. Move to newHeads, logs, and latest.

**Base**. Base's Denim upgrade activated on Base Mainnet on Nov 5, 2026, at 18:00 UTC: Base now produces a canonical block every 200 ms instead of every 2 seconds, and Flashblocks are retired. Replace Flashblocks subscriptions and `pending`-tag reads with `newHeads`, `logs`, and `latest`, and check any limit or logic that counts blocks. See [Base Denim: 200 ms blocks](https://docs.chainstack.com/docs/base-denim-200ms-blocks.md) and [Stream real-time transactions on Base](https://docs.chainstack.com/docs/base-streaming-transactions.md).