biopython

A collection of Python tools for working with biological data such as DNA, RNA, proteins, and molecular structures. It also reads common biology file formats and connects to databases such as NCBI.

In plain words
What is it for?
Use it to manipulate sequences, read or write FASTA and GenBank files, run or parse BLAST searches, align sequences, analyze protein structures, and build evolutionary trees.
Why use it?
It avoids writing separate low-level code for common biology data tasks and lets scripts combine file handling, database searches, and analysis.

Skill for Claude CodeCodex

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/k-dense-ai/scientific-agent-skills/biopython
Any agent
npx skills add K-Dense-AI/scientific-agent-skills --skill biopython
Clone the repo
git clone --depth 1 https://github.com/K-Dense-AI/scientific-agent-skills

Made for: Claude Code, Codex.

Per session 76 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 3,960 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 1 finding. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00076 $0.03960
Opus 5 $0.00038 $0.01980
Sonnet 5 $0.00015 $0.00792
Haiku 4.5 $0.00008 $0.00396

Measured yesterday against content hash 81eab1bd7db6, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

biopython scanned grade A with 1 finding against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured yesterday.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

from urllib.error import HTTPError
Origin

Copies of this mod

8 near-identical copies found in the catalogue:

skills/biopython/SKILL.md · 473 lines

How it starts

The opening of the file, as written. The whole thing — 473 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Biopython: Computational Molecular Biology in Python

Overview

Biopython is a comprehensive set of freely available Python tools for biological computation. It provides functionality for sequence manipulation, file I/O, database access, structural bioinformatics, phylogenetics, and many other bioinformatics tasks. The current version is Biopython 1.87 (released 30 March 2026). It supports Python 3.10-3.14 and PyPy3.10, and requires NumPy. Biopython 1.87 also addresses CVE-2025-68463 in Bio.Entrez.Parser when parsing untrusted files, so prefer 1.87+ for workflows that parse externally supplied Entrez XML.

When to Use This Skill

Use this skill when:

  • Working with biological sequences (DNA, RNA, or protein)
  • Reading, writing, or converting biological file formats (FASTA, GenBank, FASTQ, PDB, mmCIF, etc.)
  • Accessing NCBI databases (GenBank, PubMed, Protein, Gene, etc.) via Entrez
  • Running BLAST searches or parsing BLAST results
  • Performing sequence alignments (pairwise or multiple sequence alignments)
  • Analyzing protein structures from PDB files
  • Creating, manipulating, or visualizing phylogenetic trees
  • Finding sequence motifs or analyzing motif patterns
  • Calculating sequence statistics (GC content, molecular weight, melting temperature, etc.)
  • Performing structural bioinformatics tasks
  • Working with population genetics data
  • Any other computational molecular biology task

Core Capabilities

Biopython is organized into modular sub-packages, each addressing specific bioinformatics domains:

  1. Sequence Handling - Bio.Seq and Bio.SeqIO for sequence manipulation and file I/O
  2. Alignment Analysis - Bio.Align and Bio.AlignIO for pairwise and multiple sequence alignments
  3. Database Access - Bio.Entrez for programmatic access to NCBI databases
  4. BLAST Operations - Bio.Blast for running and parsing BLAST searches
  5. Structural Bioinformatics - Bio.PDB for working with 3D protein structures
  6. Phylogenetics - Bio.Phylo for phylogenetic tree manipulation and visualization
  7. Advanced Features - Motifs, population genetics, sequence utilities, and more

Read the full file on GitHub · 473 lines

Files

What ships with it

7 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. yesterday First seen · 473 lines · 76 tokens per session scan A 81eab1bd7db6

Subscribe to this mod's changes

biopython is a skill published in the GitHub repository K-Dense-AI/scientific-agent-skills (40,390 stars, last pushed yesterday), licensed MIT. It adds 76 tokens to every session and 3,960 once invoked, about $0.0004 per session on Opus 5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

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