Authentication

An API key is a unique string (value) that you include in your HTTP requests that identifies you to NCBI servers. API keys offer enhanced levels of access to NCBI APIs. Any IP address posting more than three requests per second to Datasets without an API key will receive an error message. Including an API key, an IP address can post up to ten requests per second. If you expect your usage to exceed ten requests/second, please contact us and we can negotiate a higher rate limit.

You can obtain an API key from the Settings page of your NCBI account (to create an account, visit https://account.ncbi.nlm.nih.gov/signup/ ). After creating the key, include it in each request by assigning it to the api_key parameter.