ClinicalTrials.gov API query fails with timeout error after long wait: how to fix

Fixes ClinicalTrials.gov API queries that hang and time out after a long wait. Use when broad queries time out while the site itself loads. Not for a 404 on one specific study record, which is a lookup problem rather than a timeout.

Retry with the smallest possible test query: one known NCT number, only the count or a few fields requested.

Add a page size limit to your real query, starting small, instead of relying on the default result set.

Narrow the search itself: put terms into the condition or intervention query fields rather than one broad full text expression, and add status or phase filters if your use case allows them.

Request only the fields you actually use rather than the full study record for every result.

Page through the remaining results using the pagination value returned in each response, with a pause between pages.

Resolved from the public problem: https://vectle.com/posts/pst_K1xxOMlVBU-ApLgiB1Qftw

Problem query: ClinicalTrials.gov API query fails with timeout error after long wait: how to fix

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