Every request to the CoinMarketCap Pro API requires a valid API key. This guide covers how to get a key, how to pass it with your requests, and how usage credits are tracked.
Acquiring an API Key
All HTTP requests made against the CoinMarketCap Pro API must be validated with an API Key. If you don't have an API Key yet visit the API Developer Portal to register for one.
Using Your API Key
You may use any server side programming language that can make HTTP requests to target the CoinMarketCap Pro API. Pro API requests should target domain https://pro-api.coinmarketcap.com.
This page covers API key authentication for the Pro API. Other access models documented elsewhere in this site, such as x402, may use different authentication or payment flows.
You can supply your API Key in REST API calls in one of two ways:
- Preferred method: Via a custom header named
X-CMC_PRO_API_KEY - Convenience method: Via a query string parameter named
CMC_PRO_API_KEY
Security Warning: It's important to secure your API Key against public access. The custom header option is strongly recommended over the querystring option for passing your API Key in a production environment.
API Key Usage Credits
Most API plans include a daily and monthly limit or "hard cap" to the number of data calls that can be made. This usage is tracked as API "call credits" which are incremented 1:1 against successful (HTTP Status 200) data calls made with your key with these exceptions:
- Account management endpoints, usage stats endpoints, and error responses are not included in this limit.
- Paginated endpoints: List-based endpoints track an additional call credit for every 100 data points returned (rounded up) beyond our 100 data point defaults. Our lightweight
/mapendpoints are not included in this limit and always count as 1 credit. See individual endpoint documentation for more details. - Bundled API calls: Many endpoints support resource and currency conversion bundling. Bundled resources are also tracked as 1 call credit for every 100 resources returned (rounded up). Optional currency conversion bundling using the
convertparameter also increment an additional API call credit for every conversion requested beyond the first.
You can visit the Developer Portal to view live stats on your API Key usage and limits including the number of credits used for each call. You can also find call credit usage in the JSON response for each API call. See the status object for details. You may also use the /key/info endpoint to quickly review your usage and when daily/monthly credits reset directly from the API.
Note: "day" and "month" credit usage periods are defined relative to your API subscription. For example, if your monthly subscription started on the 5th at 5:30am, this billing anchor is also when your monthly credits refresh each month. The free Basic tier resets each day at UTC midnight and each calendar month at UTC midnight.