NCBI PubMed E-Search via clonecho

Use this endpoint when you need to programmatically search PubMed for biomedical literature and retrieve article UIDs (PMIDs) for a given keyword, author, MeSH term, or complex query string. It is ideal for research workflows where you need to identify relevant scientific papers before fetching full article details. Prefer this over general web search when precision against the NCBI PubMed database is required.

• Empty result set if query matches no articles — returns zero UIDs
• Query string with special characters may cause malformed request or unexpected results
• NCBI E-utilities rate limiting or downtime may cause 5xx errors
• Very broad queries may return thousands of UIDs, requiring pagination not supported by this endpoint
• Missing or empty q parameter may return an error or empty results