datamol

A simpler Python interface for RDKit, a chemistry toolkit used to read, compare, describe, and manipulate molecules.

In plain words
What is it for?
Use it to convert and standardize molecular files, calculate descriptors and fingerprints, generate 3D shapes, cluster compounds, analyze fragments, and process batches.
Why use it?
It reduces the amount of chemistry-specific code needed for common drug-discovery tasks while keeping RDKit molecule objects compatible with other tools.

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/synthetic-sciences/openscience/datamol
Any agent
npx skills add synthetic-sciences/openscience --skill datamol
Clone the repo
git clone --depth 1 https://github.com/synthetic-sciences/openscience

Made for: Claude Code, Codex.

Per session 67 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 5,181 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 $0.00067 $0.05181
Opus 5 $0.00034 $0.02590
Sonnet 5 $0.00013 $0.01036
Haiku 4.5 $0.00007 $0.00518

Measured 2d ago against content hash a375b76fbc65, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

datamol 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 2d 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.

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

8 near-identical copies found in the catalogue:

  • datamol — 95% identical, 7 lines differ
  • datamol — 94% identical, 7 lines differ
  • datamol — 94% identical, 7 lines differ
  • datamol — 92% identical, 11 lines differ
  • datamol — 88% identical, 10 lines differ
  • datamol — 84% identical, 64 lines differ
  • datamol — 84% identical, 64 lines differ
  • datamol — 84% identical, 64 lines differ
backend/cli/skills/chemistry/datamol/SKILL.md · 710 lines

How it starts

The opening of the file, as written. The whole thing — 710 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Datamol Cheminformatics Skill

Overview

Datamol is a Python library that provides a lightweight, Pythonic abstraction layer over RDKit for molecular cheminformatics. Simplify complex molecular operations with sensible defaults, efficient parallelization, and modern I/O capabilities. All molecular objects are native rdkit.Chem.Mol instances, ensuring full compatibility with the RDKit ecosystem.

Key capabilities:

  • Molecular format conversion (SMILES, SELFIES, InChI)
  • Structure standardization and sanitization
  • Molecular descriptors and fingerprints
  • 3D conformer generation and analysis
  • Clustering and diversity selection
  • Scaffold and fragment analysis
  • Chemical reaction application
  • Visualization and alignment
  • Batch processing with parallelization
  • Cloud storage support via fsspec

Installation and Setup

Guide users to install datamol:

uv pip install datamol

Import convention:

import datamol as dm

Core Workflows

1. Basic Molecule Handling

Creating molecules from SMILES:

import datamol as dm

# Single molecule
mol = dm.to_mol("CCO")  # Ethanol

# From list of SMILES
smiles_list = ["CCO", "c1ccccc1", "CC(=O)O"]
mols = [dm.to_mol(smi) for smi in smiles_list]

# Error handling
mol = dm.to_mol("invalid_smiles")  # Returns None
if mol is None:
    print("Failed to parse SMILES")

Converting molecules to SMILES:

# Canonical SMILES
smiles = dm.to_smiles(mol)

# Isomeric SMILES (includes stereochemistry)
smiles = dm.to_smiles(mol, isomeric=True)

# Other formats
inchi = dm.to_inchi(mol)
inchikey = dm.to_inchikey(mol)
selfies = dm.to_selfies(mol)

Standardization and sanitization (always recommend for user-provided molecules):

# Sanitize molecule
mol = dm.sanitize_mol(mol)

# Full standardization (recommended for datasets)
mol = dm.standardize_mol(
    mol,
    disconnect_metals=True,
    normalize=True,
    reionize=True
)

# For SMILES strings directly
clean_smiles = dm.standardize_smiles(smiles)

Read the full file on GitHub · 710 lines

Files

What ships with it

6 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. 2d ago First seen · 710 lines · 67 tokens per session scan A a375b76fbc65

Subscribe to this mod's changes

datamol is a skill published in the GitHub repository synthetic-sciences/openscience (3,385 stars, last pushed today), licensed Apache-2.0. It adds 67 tokens to every session and 5,181 once invoked, about $0.0003 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.

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