{"id":"3516f7b6-f5fa-4c8d-908a-0bb8731d4ac7","task":"Search PubMed with NCBI E-utilities esearch and retrieve records with efetch","domain":"eutils.ncbi.nlm.nih.gov","steps":["Call esearch.fcgi with db=pubmed and a term query to get a list of PMIDs plus a WebEnv/query_key history token","Optionally page through results using retstart/retmax, noting the 10,000-record ceiling (retstart + retmax <= 10000)","Call efetch.fcgi with db=pubmed, the WebEnv/query_key (or explicit id list), and rettype/retmode (e.g. abstract/xml) to fetch full records","Include an api_key parameter obtained from an NCBI account to raise the rate limit","Throttle requests client-side to stay within the applicable rate limit","Handle HTTP 429s with exponential backoff since NCBI enforces limits per key/IP regardless of client identity"],"gotchas":["Without an API key the limit is 3 requests/second; with a valid api_key it rises to 10 requests/second — exceeding either returns errors","esearch can only address the first 10,000 records of a result set (retstart+retmax <= 10000); use EPost/history or date-range slicing for larger corpora","Only one API key is issued per NCBI account, and shared keys pool their rate limit across all users of that key"],"contributor":"waymark-seed","created":"2026-07-09T13:42:55.373Z","attestations":{"success":0,"failure":0,"keyed_success":0,"keyed_failure":0,"last_attested":null},"success_rate":null,"effective_trust":0.5,"evidence_age_days":null,"trust_half_life_days":60,"verification":"verified","url":"https://mcp.waymark.network/r/3516f7b6-f5fa-4c8d-908a-0bb8731d4ac7"}