How Base is built

Ten preconfirmations per 2‑second block.

Base Mainnet seals a block every 2 seconds. Inside it, the sequencer streams ten Flashblocks: each one preconfirms the transactions so far, so an app can show a result before the block is sealed.

Base's devnet already runs 200 ms native blocks.

On Vibenet every 200 ms slice is a full block with its own number, hash and receipts. Denim targets the same on Mainnet in November 2026. Until then, Mainnet's 200 ms steps are Flashblocks, not blocks.

A token standard in the node, not in bytecode.

B20 tokens are created by a precompile that runs inside the Base node. There is no contract code to read, so the way to ask is a call to the factory itself.

• Factory0xB20f000000000000000000000000000000000000
• Activation registry0x8453000000000000000000000000000000000001
• Policy registry0x8453000000000000000000000000000000000002

Smart accounts the chain itself understands.

Experimental, and only on Vibenet for now. An account registers who may sign for it, and the chain checks that rule itself.

• Batched calls that succeed or revert together.
• An optional gas payer, so an app can sponsor its users.
• No bundler, relay or separate mempool.

import {  newSmartAccount8130, sendCalls8130, estimateGas8130,  encodeWalletCalls, waitForTransactionReceipt8130, allPhasesSucceeded,} from "viem/experimental/eip8130";

We used it to check the Lab's snippets against real Base state.

It runs a chain of calls, as any address, on top of current state, and returns every result without committing anything. Our scripts first type-check each snippet against the real packages, then simulate it on Mainnet from an address that really holds the tokens.

• verify-earn-snippet.mjsA Morpho vault deposit from a real USDC holder
• verify-trade-snippet.mjsApprove then swap on Uniswap, against the pool’s own Quoter
• verify-pay-snippet.mjsA USDC transfer, before any wallet is involved
• verify-shell-recipes.mjsEvery write recipe in the Shell

Two snippets can't be run this way, because running them would move money: the x402 paywall and the Base Pay checkout. Those are type-checked only.

Three shipped this year. One is next.

1. AzulMainnet · May 28, 2026

   Base's first independent upgrade, on its own node stack.

2. BerylMainnet · Jun 25, 2026

   B20 tokens in the node. Faster withdrawals.

3. CobaltMainnet · Sep 30, 2026

   Validity transactions. More B20 policies.

4. DenimMainnet · Nov 2026Target · may change

   Native 200 ms blocks replace Flashblocks.