Search PubMed biomedical literature database. Returns articles matching your query with metadata, abstracts, and citations. Supports Boolean operators (AND, OR, NOT), MeSH terms, and field tags like [Title], [Author]. Use format="compact" for quick overviews when browsing, "detailed" for in-depth analysis. Use days_back to limit to recent publications.

Retrieve complete metadata for specific PubMed articles by PMID. Accepts a single PMID or array of PMIDs (up to 20). Returns full article records including abstract, authors, journal, DOI, MeSH terms. Use when you have specific PMIDs from a previous search or citation and need the full record.

Extract specific structured sections from a PubMed article. Use when you need only certain aspects (author details, structured abstract, keywords, DOI) rather than the full record. More token-efficient than get_details for targeted extraction.

Find articles related to a given PubMed article. Discovers similar papers or review articles to build a comprehensive literature picture. Use after identifying a key paper to expand your search in relevant directions.

View cache statistics or perform maintenance. Use action="stats" to check hit rates and storage usage. Use action="clean" to remove expired entries, or action="clear" to wipe a specific cache layer.