---
title: "How Signet Works"
url: "/updates/how-signet-works/index.md"
date: "2025-04-30"
description: "The three pieces that make cross-chain execution feel like one chain"
---
Cross-chain is usually complicated. Bridges, relayers, waiting periods, partial failures. Signet makes it simple: transactions either complete on both chains in the same block, or they don't happen at all.

Three mechanisms make this work.

## 1. Synchronized Blocks

Every Signet block corresponds to exactly one Ethereum block. Same timestamp. Same finality. If Ethereum reorgs, Signet reorgs. If Ethereum finalizes, Signet finalizes.

No pre-confirmations. No optimistic settlement. No challenge period.

> **Deep dive**: [Synchronous Finality](/updates/synchronous-finality/index.md)

## 2. Conditional Transactions

Signet transactions can require outcomes on Ethereum. "Execute this swap only if I receive 1 ETH on L1." The protocol enforces the condition—if the L1 side doesn't happen, the Signet side reverts automatically.

No partial fills. No abandoned assets. No gas wasted.

> **Deep dive**: [Application Controlled Execution](/updates/application-controlled-execution/index.md)

## 3. Competitive Fillers

Who provides the L1 side of Signet's cross-chain swaps? Market participants called Fillers. They compete to fulfill your orders — the best price wins. Instead of extracting value from your transactions, Fillers use them in cross-chain bundles where both sides profit.

Same actors, different incentives.

> **Deep dive**: [The Filler Economy](/updates/the-filler-economy/index.md)

## One Mental Model

Users get instant cross-chain execution. Applications get atomic guarantees without bridge infrastructure. Developers get a single mental model instead of async complexity.

| I want to... | Start here |
|--------------|------------|
| Build an app with cross-chain execution | [Solidity Examples](/updates/contracts-that-read-the-future/index.md) |
| Implement order creation and filling | [Building with Orders](/updates/building-with-orders/index.md) |
| Become a block builder | [Block Building Without Auctions](/updates/block-building-without-auctions/index.md) |
| Test on the public testnet | [Introducing Parmigiana](/updates/introducing-parmigiana/index.md) |

Questions? [Get in touch](https://t.me/anthspezzano).