Ncbi Sequence Fetch

Pulls genetic sequences directly from NCBI's databases into your workspace. You'll need uv installed, and while it works without an API key, you really want one to bump the rate limit from 3 to 10 requests per second. The skill handles credentials properly and notifies you about NCBI's terms on first use. Solid choice if you're doing bioinformatics work and tired of manually downloading FASTA files through the web interface. From Google DeepMind's science skills collection, which passed most security audits though Snyk flagged a warning worth checking.

skills.sh installs: 2.3K
GitHub stars: 3.4K
last updated: Aug 21, 2026

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Install

$ npx -y skills add google-deepmind/science-skills --skill ncbi-sequence-fetch --agent claude-code

Installs into .claude/skills of the current project.

Files

NCBI Sequence Fetch

Prerequisites

uv: Read the uv skill and follow its Setup instructions to ensure uv is installed and on PATH.
User Notification: If .licenses/ncbi_sequence_fetch_LICENSE.txt does not already exist in the workspace root directory then (1) prominently notify the user to check the terms at https://www.ncbi.nlm.nih.gov/ and https://www.ncbi.nlm.nih.gov/home/about/policies/, then (2) create the file recording the notification text and timestamp.
.env file: Make sure the .env file exists in your home directory. Create one if it does not exist.
NCBI_API_KEY (optional): Raises the NCBI rate limit from 3 to 10 requests/second. The skill works without it, but a key is recommended if the user plans many queries or encounters a 429 error. You can register for a key for free at https://www.ncbi.nlm.nih.gov/account/settings/. You MUST use the safe credentials protocol in the credentials skill to check for and request this key if this skill looks relevant to the user's request.