GET /einfo.fcgi

NCBI API key for higher rate limits (optional but recommended for heavy usage)

Database name. If omitted, returns list of all valid Entrez databases.

Constraints: {'enum': ['pubmed', 'protein', 'nuccore', 'ipg', 'nucleotide', 'structure', 'genome', 'annotinfo', 'assembly', 'bioproject', 'biosample', 'blastdbinfo', 'books', 'cdd', 'clinvar', 'gap', 'gapplus', 'grasp', 'dbvar', 'gene', 'gds', 'geoprofiles', 'medgen', 'mesh', 'nlmcatalog', 'omim', 'orgtrack', 'pmc', 'proteinclusters', 'pcassay', 'protfam', 'pccompound', 'pcsubstance', 'seqannot', 'snp', 'sra', 'taxonomy', 'biocollections', 'gtr']}

Return mode. Use 'json' for JSON output, 'xml' for XML output.

Constraints: {'enum': ['xml', 'json']}