> ## Documentation Index > Fetch the complete documentation index at: https://docs.stackone.com/llms.txt > Use this file to discover all available pages before exploring further. # Connect PubMed with API Key – StackOne Hub > Link a PubMed account in the StackOne Hub using API Key. End-user guide to authorize the integration and start using PubMed actions.

Create your NCBI API key

The NCBI E-utilities API that powers this connector works without any credentials at a rate of 3 requests/second per IP address. Adding an NCBI API key is optional and raises that limit to 10 requests/second. Follow the steps below to generate a key from your NCBI account and add it in StackOne Hub.

Open the NCBI account login page and sign in. NCBI does not use a password of its own — pick one of the third-party login methods on the Log in screen:

  • eRA Commons
  • Google Account
  • ORCiD
  • Login.gov
  • Microsoft
  • NIH Account
  • NCBI Account
  • If you do not yet have an NCBI account, use more login options or Sign up to create one first.
NCBI Log in screen showing the available third-party login methods

Once signed in, click Account Settings in the top navigation bar (you can also open it directly at the NCBI Account Settings page). The NCBI Account Settings page opens.

NCBI Account Settings page with the Account Settings navigation item highlighted

Scroll down to the API Key Management section and click Create API Key. NCBI generates a single key for your account.

  • The section confirms: *E-utils users are allowed 3 requests/second without an API key. Create an API key to increase your e-utils limit to 10 requests/second.*
  • Only one API Key per user. Replacing or deleting will inactivate the current key.
  • The key is used by passing it as the `api_key=API_key` request parameter — StackOne does this for you automatically.
API Key Management section of NCBI Account Settings with the Create API Key button highlighted

After you click Create API Key, the message API key successfully created. appears and your key is shown in the API Key row. Copy that value and paste it into the API Key field in StackOne Hub.

  • API Key — the NCBI key you just generated. Copy the value shown in the API Key row and paste it into the API Key field in StackOne Hub. It is required for this connection.
  • Contact Email — optional. Enter the maintainer email address NCBI should use to contact you before throttling heavy usage, in the Contact Email field in StackOne Hub.
  • Your key stays available in API Key Management — return here any time to copy it again, use Replace API key to rotate it, or Remove API key to delete it.
API Key Management section after key creation, with the generated key redacted and the Copy your API key location highlighted

Linking the Account from the Hub

Use one of the three Linking Account Methods to access the Hub. Fill out the following fields using details from your provider:
  • API Key
  • Contact Email (Optional)
  • Click Connect
  • If applicable, the provider will redirect you to a sign-in or authorization page. Complete the provider's authorization flow.
  • Once authorization is successful, you will see a confirmation popup

If the account linking is successful, you will see the newly linked account in your Accounts page.