Web of Sciences Expanded API Throttle Limits

Web Services Throttling limits:

The following limits are placed on WoS Web Services APIs by default in order to maintain consistently working APIs for all customers. Throttling Limits:

1. Session ends after 4 hours of inactivity
2. Sessions per 5 minutes = 30

• 30 authentication requests in 5 minutes
• Solution if error occurs – Reuse session (SID) for multiple query requests

3. Requests per second = 25

• 25 simultaneous requests can be sent per second
• Solution if error occurs – Limit simultaneous requests to 25 per second

4. Queries per session limit = 2,500

• 2,500 queries can be requested in one (1) session
• Solution if error occurs– Periodically close the session (send close session request) before reaching 2,500 queries. Then send the authenticate request to open a new session (SID)

5. Records per request and references per request = 100

• 100 records or references can be downloaded at one time with one request
• Solution if error occurs– Iterate the requests for downloads to 100 records/references per request. For example, request 1 for records 1 – 100, request 2 for records 101 – 200, request 3 for records 201 – 300, and so on until the entire set is downloaded