GET /esearch.fcgi

nih.gov:ncbi-gene-api

Summary: Search Gene database
Operation ID: searchGenes
Auth: none
Description

Searches the Gene database and returns a list of matching gene IDs.

Parameters (9)

WebEnv (string, query, optional)

Web environment string for history server

db (string, query, required, default: gene)

Database to search

Constraints: {'enum': ['gene']}

query_key (string, query, optional)

Query key for history server

retmax (integer, query, optional, default: 20)

Maximum number of results to return

retmode (string, query, optional, default: json)

Return mode

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

retstart (integer, query, optional, default: 0)

Start position for returned results

sort (string, query, optional)

Sort order

Constraints: {'enum': ['date', 'relevance']}

term (string, query, required)

Search query (e.g., 'BRCA1', 'human[orgn] AND kinase')

usehistory (string, query, optional, default: n)

Store results on history server

Constraints: {'enum': ['y', 'n']}

Examples (3)

TitleTypeURLAction
Basic gene search for BRCA1 curl https://www.ncbi.nlm.nih.gov/gene/esearch.fcgi?db=gene&term=BRCA1&retmode=json
Search with pagination limit curl https://www.ncbi.nlm.nih.gov/gene/esearch.fcgi?db=gene&term=TP53&retmax=10&retstart=0&retmode=json
Complex boolean query with organism filter curl https://www.ncbi.nlm.nih.gov/gene/esearch.fcgi?db=gene&term=cancer+AND+human%5BOrganism%5D&retmax=5&retmode=json&sort=relevance

Probe History

Latency

Status Codes

TimeStatusLatencySize
2026-03-23 10:48:55.292788 404 482ms
2026-03-23 10:29:49.530875 404 466ms
2026-03-23 09:26:39.605743 404 443ms