cobrapy

A Python library for studying how chemical reactions and nutrients flow through a cell using constraint-based metabolic models, including genome-scale models.

In plain words
What is it for?
Use it for flux-balance analysis, flux-range analysis, gene or reaction knockout studies, growth-medium design, metabolic engineering, model repair, and SBML or JSON model files.
Why use it?
It lets researchers test possible metabolic behaviour computationally when direct experiments are costly or difficult. Constraints represent limits such as available nutrients or reaction capacity.

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

Made for: Claude Code, Codex.

Per session 38 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 3,589 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. 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 $0.00038 $0.03589
Opus 5 $0.00019 $0.01795
Sonnet 5 $0.00008 $0.00718
Haiku 4.5 $0.00004 $0.00359

Measured yesterday against content hash bb99605b1a4e, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

cobrapy scanned grade A with 0 findings 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.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

Origin

Copies of this mod

3 near-identical copies found in the catalogue:

  • cobrapy — 100% identical, 4 lines differ
  • cobrapy — 100% identical, 0 lines differ
  • cobrapy — 100% identical, 4 lines differ
skills/cobrapy/SKILL.md · 497 lines

How it starts

The opening of the file, as written. The whole thing — 497 lines — stays where its author put it; the contents beside it link to each section on GitHub.

COBRApy - Constraint-Based Reconstruction and Analysis

Overview

COBRApy is a Python library for constraint-based reconstruction and analysis (COBRA) of metabolic models, essential for systems biology research. Work with genome-scale metabolic models, perform computational simulations of cellular metabolism, conduct metabolic engineering analyses, and predict phenotypic behaviors.

Version note: Examples target cobra 0.31.1 on PyPI (import cobra). Docs: cobrapy.readthedocs.io. Repo: opencobra/cobrapy.

When to Use This Skill

Use this skill when:

  • Loading, building, or exporting genome-scale metabolic models (SBML, JSON, YAML)
  • Running FBA, pFBA, FVA, or flux sampling on COBRA models
  • Performing gene or reaction knockout screens and production envelope analysis
  • Designing or optimizing growth media and exchange constraints
  • Gap-filling infeasible models or validating model consistency

Installation

uv pip install "cobra==0.31.1"

MATLAB model I/O (optional):

uv pip install "cobra[array]==0.31.1"

COBRApy uses optlang for solvers. GLPK installs automatically via swiglpk. For large MILPs/QPs, cobra 0.29+ adds a hybrid solver (HIGHS/OSQP); model.solver = "osqp" now routes through hybrid and may error on plain LPs in a future release—prefer model.solver = "hybrid" when available.

Core Capabilities

COBRApy provides comprehensive tools organized into several key areas:

1. Model Management

Load existing models from repositories or files:

from cobra.io import load_model

# Bundled locally (no network): textbook, iJO1366, salmonella
model = load_model("textbook")      # alias for e_coli_core (95 reactions)
model = load_model("e_coli_core")   # same core E. coli model
model = load_model("iJO1366")       # genome-scale E. coli (bundled)
model = load_model("salmonella")    # Salmonella iYS1720 (bundled)

# Remote (BiGG / BioModels; requires network, cached after first fetch)
model = load_model("iML1515")       # E. coli genome-scale on BiGG

# Load from files
from cobra.io import read_sbml_model, load_json_model, load_yaml_model
model = read_sbml_model("path/to/model.xml")
model = load_json_model("path/to/model.json")
model = load_yaml_model("path/to/model.yml")

Read the full file on GitHub · 497 lines

Files

What ships with it

2 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 · 497 lines · 38 tokens per session scan A bb99605b1a4e

Subscribe to this mod's changes

cobrapy is a skill published in the GitHub repository K-Dense-AI/scientific-agent-skills (40,390 stars, last pushed yesterday), licensed MIT. It adds 38 tokens to every session and 3,589 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

Related

Other skills, from other repositories

discovery-toolbox

A routed repertoire of 90 scientific thinking operators for biological research agents - visual reasoning, detectability and information budgets, search reframing, causal identification, competing explanations, observation and selection processes, pipeline artifact diagnosis, effort allocation, and confirmation…

dekan-aleksandr/biodiscovery-skills · 122 tokens

alphafold-pocket-evaluator

Parses AlphaFold2 PDB files, computes per-residue pLDDT confidence scores, and evaluates Solvent Accessible Surface Area (SASA) of active site pockets.

YuliaNuzhnenko/bioinformatics-agent-skills · 43 tokens

pydeseq2-bulk-rna

Automated negative binomial differential gene expression analysis, log2 fold-change calculation, p-value adjustment (FDR), and Volcano plot generation.

YuliaNuzhnenko/bioinformatics-agent-skills · 38 tokens

scanpy-sc-analyzer

Autonomous single-cell RNA-seq quality control filtering, Harmony batch-effect correction, Leiden clustering, UMAP visualization, and marker gene annotation.

YuliaNuzhnenko/bioinformatics-agent-skills · 34 tokens

card-amr-profiler

Scans bacterial genome assemblies against CARD (Comprehensive Antibiotic Resistance Database) and ResFinder to map drug-class resistance heatmaps.

YuliaNuzhnenko/bioinformatics-agent-skills · 32 tokens

diffdock-virtual-screener

Runs DiffDock generative diffusion models for blind protein-ligand docking against AlphaFold structures and ranks candidates by confidence scores.

YuliaNuzhnenko/bioinformatics-agent-skills · 33 tokens