0x Protocol Definition

0x Protocol supplies open-source infrastructure that lets users exchange Ethereum-based digital assets directly from their own wallets, removing intermediaries and custodial risk. Running on the Ethereum blockchain, the framework gives developers the tools to build decentralized exchanges (DEXs), NFT marketplaces, and other DeFi applications while keeping every component open source and permissionless.

How it works: off-chain speed, on-chain security

0x combines off-chain order relay with on-chain settlement:

1. Order creation – A trader defines the tokens to swap, the exchange rate, and conditions such as expiration.
   
2. Cryptographic signing – The order receives a digital signature that proves authenticity without exposing private keys.
   
3. Off-chain matching – Relayers broadcast the signed order and match counterparties without ever touching user funds.
   
4. On-chain settlement – After a match, a smart contract verifies balances, signatures, and conditions, then finalizes the swap in a single atomic transaction.
   
5. Direct wallet transfer – Tokens move straight from one wallet to another, eliminating counterparty risk.
   
6. Relayer fees – Relayers earn ETH or other tokens for each successful match.

What makes 0x stand out?

• Gas efficiency – Off-chain order books defer gas costs until settlement, unlike fully on-chain exchanges that charge fees at every step.
  
• Flexibility and modularity – Developers can tailor the protocol to DEXs, NFT marketplaces, or institutional trading desks.
  
• Interoperability – Support extends to all Ethereum token standards, including ERC-20 and ERC-721.
  
• Liquidity aggregation – Relayers draw liquidity from multiple sources, reducing slippage and improving prices.

The role of ZRX

ZRX, the native token, underpins protocol governance and staking. Holders vote on upgrades and stake tokens within the governance system, aligning user incentives with the long-term health of the network.