molfeat

molfeat is a skill for Claude Code from dralkh/iktinah. It costs 47 tokens per session (4,083 once invoked), scanned B, original, MIT.

A Python library that converts chemical structures, such as SMILES strings or RDKit molecules, into numerical representations for machine learning. These representations include fingerprints, descriptors, and pretrained-model embeddings.

In plain words
What is it for?
Prepare molecular data for QSAR property prediction, virtual screening, similarity searches, and other molecular machine-learning workflows.
Why use it?
Machine-learning models cannot work directly with most chemical structures. It provides consistent ways to turn molecules into features for comparison, prediction, and screening.

Skill for Claude Code

Written for Claude Code: allowed-tools in frontmatter.

Good fit Prepare molecular data for QSAR property prediction, virtual screening, similarity searches, and other molecular machine-learning workflows.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/dralkh/iktinah/molfeat
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.

Any agent
npx skills add dralkh/iktinah --skill molfeat
Clone the repo
git clone --depth 1 https://github.com/dralkh/iktinah

Made for: Claude Code.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for molfeat

README.md
[![agentmods](https://agentmods.dev/badge/skills/dralkh/iktinah/molfeat/github.svg)](https://agentmods.dev/skills/dralkh/iktinah/molfeat)
Your own site
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Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for molfeat

Your own site · 80×15
<a href="https://agentmods.dev/skills/dralkh/iktinah/molfeat"><img src="https://agentmods.dev/badge/skills/dralkh/iktinah/molfeat.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 47 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 4,083 The whole file, excluding the scripts and references it only reads on demand.
Security scan B 1 finding. A grade says what 26 rules found in the file — not that it is safe.
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 5.1 $0.00047 $0.04083
Opus 5 $0.00023 $0.02041
Sonnet 5 $0.00009 $0.00817
Haiku 4.5 $0.00005 $0.00408

Measured 6d ago against content hash 3d3f41c769c0, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade B, and why

molfeat scanned grade B 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 6d ago.

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.

Unrestricted tool accessmediumExcessive agency

A wildcard tool grant or "run any command" leaves no least-privilege boundary at all.

Prefer molfeat's built-in pretrained-model cache when possible. For custom embedding caches, use NumPy arrays instead of pickle (pickle can execute arbitrary code when loading untrusted files):
Origin

Copies of this mod

1 near-identical copy found in the catalogue:

  • molfeat — 100% identical, 4 lines differ
skills/molfeat/SKILL.md · 522 lines

How it starts

The opening of the file, as written. The whole thing — 522 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Molfeat - Molecular Featurization Hub

Overview

Molfeat is a comprehensive Python library for molecular featurization that unifies 100+ pre-trained embeddings and hand-crafted featurizers. Convert chemical structures (SMILES strings or RDKit molecules) into numerical representations for machine learning tasks including QSAR modeling, virtual screening, similarity searching, and deep learning applications. Features fast parallel processing, scikit-learn compatible transformers, and built-in caching.

Version note: Examples target molfeat 0.11.0 (PyPI stable, May 2025). Requires Python 3.9–3.10 (requires-python caps below 3.11). Depends on datamol ≥0.8.0 and PyTorch ≥1.13. Since 0.8.7, prefer datamol Mol objects over raw rdkit.Chem.Mol. Since 0.10.1, fingerprint calculators use RDKit's rdFingerprintGenerator API internally. Since 0.11.0, pretrained models load in memory and base models are set to PyTorch evaluation mode automatically.

When to Use This Skill

This skill should be used when working with:

  • Molecular machine learning: Building QSAR/QSPR models, property prediction
  • Virtual screening: Ranking compound libraries for biological activity
  • Similarity searching: Finding structurally similar molecules
  • Chemical space analysis: Clustering, visualization, dimensionality reduction
  • Deep learning: Training neural networks on molecular data
  • Featurization pipelines: Converting SMILES to ML-ready representations
  • Cheminformatics: Any task requiring molecular feature extraction

Installation

Use a Python 3.9 or 3.10 environment (molfeat does not install on 3.11+ as of 0.11.0):

uv pip install "molfeat==0.11.0"

# With all pip-installable optional dependencies
uv pip install "molfeat[all]==0.11.0"

Optional dependency extras (PyPI):

  • molfeat[dgl] — GNN models (GIN variants); upstream recommends dgl<=2.0 (graphbolt issues in newer DGL)
  • molfeat[graphormer] — Graphormer models
  • molfeat[transformer] — ChemBERTa, ChemGPT, MolT5
  • molfeat[fcd] — FCD descriptors
  • molfeat[pyg] — PyTorch Geometric featurizers
  • molfeat[viz] — NGLView visualization widgets

Read the full file on GitHub · 522 lines

Files

What ships with it

3 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. 6d ago First seen · 522 lines · 47 tokens per session scan B 3d3f41c769c0

Subscribe to this mod's changes

molfeat is a skill published in the GitHub repository dralkh/iktinah (77 stars, last pushed 2mo ago), licensed MIT. It adds 47 tokens to every session and 4,083 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it B with 1 finding (unrestricted tool access). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.

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