Rate Limits

Last updated: June 18, 2026

What are the 0x API rate limits?

Rate limits cap how many requests your API key can make in a given window. They keep the API fast and reliable for everyone by preventing any single integration from overwhelming the system.

The limits

The Standard plan allows approximately 5 requests per second (RPS), shared across all 0x API endpoints. The Custom plan supports higher throughput. If you need more than 5 RPS, see "How to upgrade your plan" or contact the team about a Custom plan.

How the limit is calculated

A few details that matter when you're optimizing your request setup:

  • The 5 RPS is counted across all endpoints combined, not per endpoint.

  • It applies to a fixed one-second window. The API allows up to 5 calls anywhere within that window.

  • Opening a streaming (SSE) connection — for example, to the cross-chain quotes stream — counts as one request. Individual events delivered over an open stream do not count against your limit. However, each new connection, including any reconnection, counts as a new request.

What happens when you exceed the limit

Requests over your limit are rejected. The request isn't processed — you'll need to retry it.

To handle this cleanly in production, you could:

  • Implement exponential backoff rather than retrying immediately in a tight loop. Immediate retries usually compound the problem.

  • Queue and pace outbound requests so you stay under your window rather than bursting.

  • Avoid polling for quotes you don't intend to act on. The APIs are optimized for trading; consistently requesting quotes without submitting trades will hit limits faster on the Standard plan, risking your account to be blocked.

Checking your usage

You can view your current usage and limits anytime on the 0x Dashboard.

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