0x

Cryptocurrency

API for querying token and pool stats across various liquidity pools

DEX liquidity aggregator — quote token swaps across 100+ liquidity pools.

No AuthHTTPSCORS

Auth

No Auth

HTTPS

Yes

CORS

Yes

API URL

https://0x.org/api

Common Use Cases

•Build financial dashboards with real-time market data
•Create currency conversion tools for e-commerce
•Develop trading analysis and portfolio tracking apps

Integration Guide

Review the API Documentation

Visit the official 0x documentation to understand available endpoints, request formats, and response structures. Familiarize yourself with the API's rate limits and usage policies before integration.

No Authentication Required

Good news — 0x does not require any authentication. You can start making API requests directly without registering for an API key or setting up OAuth credentials.

Use HTTPS for Secure Requests

0x supports HTTPS, ensuring encrypted communication. Always use HTTPS endpoints in production to protect data in transit and comply with modern web security standards.

CORS Enabled — Direct Browser Access

0x has CORS enabled, meaning you can make requests directly from the browser. This is ideal for frontend-only applications built with React, Vue, or vanilla JavaScript.

Implement and Test

Write your API integration code, start with a simple test request to verify connectivity. Implement proper error handling for network failures, rate limits, and invalid responses. Monitor your API usage to stay within any limits.

Code Examples

JavaScript / Fetch API:

javascript

// JavaScript example
fetch("https://0x.org/api")
  .then(response => {
    if (!response.ok) {
      throw new Error(`HTTP error! status: ${response.status}`);
    }
    return response.json();
  })
  .then(data => {
    console.log("API response:", data);
  })
  .catch(error => {
    console.error("Error fetching from 0x:", error);
  });

Python / Requests:

python

# Python example
import requests

response = requests.get("https://0x.org/api")

if response.status_code == 200:
    data = response.json()
    print("API response:", data)
else:
    print(f"Error: {response.status_code}")

Frequently Asked Questions

Is 0x free to use?

Yes, 0x is listed as a free public API. However, some free APIs may have usage limits or rate restrictions. Check the official documentation for details on any quotas or fair use policies.

Do I need an API key for 0x?

No, 0x does not require authentication. You can start using the API immediately without registering or obtaining any credentials. This makes it perfect for quick prototyping and demos.

Can I use 0x in a browser-based application?

Yes, 0x supports CORS, so you can make requests directly from the browser. This makes it suitable for frontend applications built with React, Vue, Angular, or vanilla JavaScript.

What category does 0x belong to?

0x is categorized under Cryptocurrency. You can browse more APIs in the same category to find similar services and alternatives for your project.

Is 0x secure?

Yes, 0x supports HTTPS, which encrypts all data transmitted between your application and the API server. Always use HTTPS endpoints in production environments.

Editor's Notes & Deep Dive

Key Features

→GET /swap/v1/quote?sellToken=ETH&buyToken=USDC&sellAmount=1 returns a signed swap quote
→GET /permit2/quote supports EIP-712 gasless approvals via Permit2
→Aggregates Uniswap, Sushi, Curve, Balancer, and many more in one call

Rate Limits & Quotas

Free tier: 100 req/min per IP on api.0x.org. Higher limits require a 0x API key.

Known Issues & Pitfalls

!Quotes are point-in-time — gas and prices move fast; submit the transaction within ~30 seconds
!The free RPC has no SLA; for production use a paid key or self-host the 0x mesh
!Some token pairs return no quote if no pool has enough liquidity

How It Compares

The leading free DEX aggregator API. 1inch has wider coverage but requires an API key and OAuth flow; Paraswap is similar but with stricter rate limits.

Sample Response

json

{
  "chainId": 1,
  "price": "3245.12",
  "guaranteedPrice": "3240.00",
  "to": "0x88ad0951...",
  "data": "0x...",
  "value": "0",
  "gas": "180000",
  "sellToken": "ETH",
  "buyToken": "USDC"
}

Pro Tips

✓Always verify the guaranteedPrice — that's the worst-case execution price with slippage

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