> ## Documentation Index
> Fetch the complete documentation index at: https://base-a060aa97-docs-cobalt-200ms-native-blocks.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Overview

> Cobalt introduces canonical 200ms blocks, improves the B20 token standard, and introduces dynamic node upgrades.

|         | Status   | Date           |
| ------- | -------- | -------------- |
| Sepolia | Planning | September 2026 |
| Mainnet | Planning | September 2026 |

## Features

<AccordionGroup>
  <Accordion title="Dynamic Upgrades">
    **Base** · RPC

    Dynamic Upgrades introduces an Ethereum smart contract that stores upgrade timestamps for Base nodes, allowing nodes to query the contract and apply changes live. This change will be rolled out in metrics-only mode for Cobalt as data is collected to validate that the upgrades work smoothly.
  </Accordion>

  <Accordion title="200ms Native Blocks">
    **Base** · Blocks

    Cobalt replaces Flashblocks with [complete canonical blocks every 200ms](/upgrades/cobalt/200ms-blocks). Each block has its own hash, state root, receipts, and finality lifecycle, giving applications sub-second updates through standard block and RPC streams.
  </Accordion>

  <Accordion title="B20 Improvements">
    **Base** · Precompile

    Cobalt brings improvements to the B20 token standard: pay transaction fees in B20s, schedule multiplier updates, transfer blocked simplification, and new Union and Intersect policies.
  </Accordion>
</AccordionGroup>