0x Protocol (ZRX)

Overview

0x Protocol is a set of tools for exchanging digital assets through blockchain applications. It began as an open protocol for peer-to-peer trades on Ethereum. Today, the broader 0x platform also offers application programming interfaces, or APIs, that let wallets and other apps find swap routes and prepare transactions across several networks. Its token, ZRX, was created for the protocol’s governance and earlier staking system. (github.com)

A useful way to picture 0x is as exchange infrastructure. A wallet can use 0x to offer swaps inside its own app, while the person trading keeps control of the tokens in their wallet until the signed transaction settles. The name “0x” can refer to the original protocol or the wider collection of trading tools built around it. That distinction matters when looking at ZRX: growth in 0x’s APIs does not, by itself, describe a new use for the token. (docs.0x.org)

History & Team

From Ethereum orders to trading APIs

Will Warren and Amir Bandeali co-founded the project in 2016. Its early design addressed a simple problem: people needed a common way to share token-trading orders without recording every proposed trade on Ethereum. The resulting protocol allowed orders to be created and shared off-chain, then settled through smart contracts when someone accepted them. ZRX launched in 2017, and later versions added features such as staking, more sources of liquidity, and support for NFT orders. (assets-cms.kraken.com)

0x Labs became the main developer of the protocol and built products around it, including the Matcha trading app and Swap API. In April 2022, it announced a $70 million Series B funding round led by Greylock. Participants included Pantera Capital, Jump Crypto, Coinbase, OpenSea, Sound Ventures, Brevan Howard, and others. This company funding was separate from the original ZRX token sale. (beta.0x.org)

A major technical change followed in 2024, when 0x introduced the Settler contracts used by its newer swap systems. Its earlier Exchange Proxy contract was effectively deprecated. That shift also changed the practical role of the older ZRX governance system. (help.0x.org)

Technology & How It Works

Orders, routes, and settlement

In a traditional 0x order, a maker states what they are willing to trade and signs the terms digitally. A taker accepts the offer. The smart contract checks the signature and trade conditions before moving the assets. Because orders can be shared off-chain, every unfilled offer does not need its own blockchain transaction. The completed exchange still settles on-chain. Earlier protocol versions supported trades involving ERC-20 tokens and NFT standards such as ERC-721 and ERC-1155. (0x.org)

Modern 0x swaps can draw on more than individual orders. The Swap API checks sources such as decentralized exchange pools and professional market makers, then prepares a route for an app to present to its user. A route may split a swap between sources. The user approves the transaction in a wallet, and settlement takes place through smart contracts. In API v2, token permissions and swap execution are handled by separate contracts, including AllowanceHolder or Permit2 for permissions and 0x Settler for execution. (docs.0x.org)

More than one network

0x’s EVM Swap API supports Ethereum and networks including Base, Arbitrum, Polygon, and BNB Smart Chain. Separate products cover Solana swaps and trades that cross between networks. For a cross-chain trade, the API finds a route, prepares a transaction, and tracks delivery through a bridge provider. The Gasless API offers another option: it lets an app arrange a swap without requiring the user to hold the network’s native token for an upfront gas payment. The cost is handled through the trade or sponsored by the app. (docs.0x.org)

Tokenomics & Utility

Supply and original distribution

ZRX is an Ethereum ERC-20 token with a fixed total supply of one billion tokens. Half was allocated to participants in the 2017 token sale. The other half was allocated among the team, advisers, early supporters, and an ecosystem fund. This is the original distribution plan, rather than a description of who holds the tokens today. (assets-cms.kraken.com)

How ZRX has been used

ZRX holders historically used the token to take part in decisions about protocol changes. A later staking design let holders delegate ZRX to market-maker pools, which could receive a share of liquidity rewards. These features formed part of the protocol’s earlier incentive system. (github.com)

That history differs from the current governance position. Following the move to Settler, 0x describes protocol governance as dormant. Its support materials address how holders of previously staked ZRX can withdraw it. Meanwhile, today’s API quotes can show applicable swap, app, and cross-chain fees in their own fee fields. The original staking model should therefore be understood as a historical part of ZRX’s utility, rather than an assumed reward from using a current 0x-powered app. (help.0x.org)

Ecosystem & Use Cases

Trading inside other apps

The clearest use case for 0x is adding token exchange to an existing product. A wallet can put a swap button beside a user’s holdings. A portfolio app can offer a trade without building its own routing system. Matcha uses 0x technology in a trading-focused interface, while 0x also identifies integrations with products such as Coinbase Wallet, Phantom, MetaMask, and Zerion. (docs.0x.org)

For developers, the APIs reduce the work involved in connecting to many trading sources one by one. A single quote request can draw from pools and market makers. Gasless tools can make a swap simpler for users moving between networks, while cross-chain tools bring route discovery, transaction preparation, and tracking into one integration. These products serve different jobs, even when an app combines them in one experience. (help.0x.org)

The earlier 0x Protocol also provided order types for NFT exchanges. Its NFT order design supported trades between ERC-20 tokens and ERC-721 or ERC-1155 assets. This shows how a shared settlement standard can be used for digital collectibles as well as ordinary fungible tokens. (0x.org)

Advantages & Challenges

What the design makes possible

0x gives builders a flexible way to add exchanges to wallets and other apps. Gathering quotes from multiple sources helps an app look beyond a single trading pool. Keeping order sharing off-chain in the original design reduced the need to put unfilled offers on Ethereum. On-chain settlement, in turn, lets the parties complete a trade according to the signed terms. For wallet users, the non-custodial design means assets stay under their control until the transaction they approve moves them. (0x.org)

Where complexity remains

A good route still depends on the sources available for the particular tokens and network. Some token pairs have fewer useful routes than others. Network fees and confirmation times also remain part of on-chain trading, even when an app makes the steps easier to follow. Cross-chain swaps add a bridge provider and a second network to the process. For developers, supporting different networks, token permissions, and transaction results requires careful integration. (help.0x.org)

There is also a distinction between the success of 0x’s trading tools and ZRX’s current function. The APIs continue to develop, while ZRX governance is dormant. Both facts are needed to understand the project’s present shape. (docs.0x.org)

Where to Buy & Wallets

ZRX is available on Coinbase and Kraken. Exchange access and purchase methods depend on location and account eligibility. After a purchase, holders can keep ZRX in an exchange account or transfer it to a wallet that supports Ethereum ERC-20 tokens. (coinbase.com)

MetaMask can display ERC-20 tokens held at an Ethereum address, including tokens added manually when needed. Trezor lists support for ZRX on Ethereum through its hardware wallets and Trezor Suite. Because 0x’s trading tools operate on several chains while the original ZRX token is an Ethereum asset, the selected withdrawal network matters when moving tokens from an exchange to a wallet. (support.metamask.io)

Regulatory & Compliance

Rules for a token, an exchange service, and the assets available through that service can involve different questions. In the United States, one concrete event in 0x’s history concerns its Matcha app: in September 2023, the Commodity Futures Trading Commission settled charges with ZeroEx Inc. over access to certain third-party leveraged tokens. The order required a $200,000 civil penalty and a halt to the conduct covered by the charges. It illustrates why the kinds of assets offered through a trading interface matter to compliance. (cftc.gov)

In the European Union, the Markets in Crypto-Assets framework sets authorization requirements for businesses providing covered crypto-asset services. In the United Kingdom, businesses carrying out certain crypto services must meet registration requirements, and marketing cryptoassets to UK consumers is subject to financial-promotion rules. These frameworks chiefly address the activities of service providers rather than giving a blanket approval to every asset available through them. (esma.europa.eu)

ZRX’s halal or Shariah-compliance status calls for a review of the token’s rights, how its issuance proceeds were used, and the transactions in which it is used. Malaysia’s Securities Commission Shariah Advisory Council permits qualifying digital-asset investment and trading within its regulated framework, while setting conditions for assessing individual digital tokens. Its resolution is limited to assets within that framework; it does not establish a ZRX-specific ruling. For 0x, the range of assets and trade types available through an app is relevant alongside the token’s own design. (sc.com.my)

Future Outlook

0x’s development is focused on making exchange functions easier to add across networks. Its Cross-Chain API became generally available in June 2026, and its developer documentation records continued additions to swap routing and network support. These efforts address a lasting challenge for blockchain apps: tokens and trading sources are spread across different systems. (0x.org)

For ZRX, the central open question is different. The token has a defined supply and a history of governance and staking utility, but 0x currently describes governance as dormant. A future return of token-holder decision-making would require a change from that position. Until then, the clearest way to understand the ecosystem is to consider the active trading products and the token’s present role separately. (assets-cms.kraken.com)

Summary

0x began as an Ethereum protocol for sharing orders off-chain and settling trades on-chain. It has grown into a set of tools that helps apps offer swaps across networks. ZRX remains the token tied to the project’s original governance and staking design, although governance is currently dormant. Together, the protocol’s history and its newer APIs make 0x an example of how shared infrastructure can place token trading inside many kinds of blockchain applications. (0x.org)