chembl

chembl is a skill for Claude Code from K-Dense-AI/drug-discovery-agent-skills. It costs 134 tokens per session (2,480 once invoked), scanned A, original, MIT.

A connection to ChEMBL, a database of published measurements showing how chemical compounds affect biological targets.

In plain words
What is it for?
Use it to look up compounds, targets, tests, mechanisms, drug uses, warnings, and measured activity for building screening or QSAR datasets.
Why use it?
It helps you find existing compounds and judge their activity while avoiding raw records that may be duplicated, unreliable, or unsuitable for modelling.

Skill for Claude Code

Written for Claude Code: allowed-tools in frontmatter. Also seen: built for openclaw.

Good fit Use it to look up compounds, targets, tests, mechanisms, drug uses, warnings, and measured activity for building screening or QSAR datasets.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/k-dense-ai/drug-discovery-agent-skills/chembl
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 K-Dense-AI/drug-discovery-agent-skills --skill chembl
Clone the repo
git clone --depth 1 https://github.com/K-Dense-AI/drug-discovery-agent-skills

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 chembl

README.md
[![agentmods](https://agentmods.dev/badge/skills/k-dense-ai/drug-discovery-agent-skills/chembl/github.svg)](https://agentmods.dev/skills/k-dense-ai/drug-discovery-agent-skills/chembl)
Your own site
<a href="https://agentmods.dev/skills/k-dense-ai/drug-discovery-agent-skills/chembl"><img src="https://agentmods.dev/badge/skills/k-dense-ai/drug-discovery-agent-skills/chembl/github.svg" alt="Measured on agentmods" height="20"></a>

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 chembl

Your own site · 80×15
<a href="https://agentmods.dev/skills/k-dense-ai/drug-discovery-agent-skills/chembl"><img src="https://agentmods.dev/badge/skills/k-dense-ai/drug-discovery-agent-skills/chembl.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 134 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,480 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 1 finding. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
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 $0.00134 $0.02480
Opus 5 $0.00067 $0.01240
Sonnet 5 $0.00027 $0.00496
Haiku 4.5 $0.00013 $0.00248

Measured 13d ago against content hash 9f48130f57f5, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade A, and why

chembl 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 13d ago.

The scan reads SKILL.md. This mod also ships 4 executable files (scripts/_common.py, scripts/chembl_query.py, scripts/compound_lookup.py, …), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

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.

the wrong molecule. The script encodes for you; a hand-written `curl` will not.
skills/chembl/SKILL.md · 172 lines

How it starts

The opening of the file, as written. The whole thing — 172 lines — stays where its author put it; the contents beside it link to each section on GitHub.

ChEMBL

ChEMBL is the curated database of measured bioactivity from the medicinal-chemistry literature — about 24.5 million activity values over 2.9 million compounds and 18,500 targets. It is where you find out what has already been made against a target, how potent it was, and how much of that is trustworthy.

Base URL: https://www.ebi.ac.uk/chembl/api/data — REST, no key. Docs: interactive schema · ChEMBL home Checked against: ChEMBL_37, released 2026-05-01.

Read references/api-reference.md before writing a request by hand, references/data-curation.md before modelling anything you pull, and references/entity-fields.md when you need to know what a field means or what type it really is.

The one thing to get right

Raw ChEMBL rows are not a dataset. activity.json?target_chembl_id=CHEMBL203 returns everything ever published against that id: censored > values, rows ChEMBL itself flags as wrong, assays whose target assignment is a guess, mutant-protein assays, and the same compound measured eight times across four papers. Modelling that directly is the most common way to produce a QSAR model that scores well and predicts nothing.

target_activities.py applies the curation and prints the attrition:

python skills/chembl/scripts/target_activities.py --uniprot P00533 \
    --standard-type Ki --min-confidence 8 --out egfr_ki.tsv
# resolved P00533 -> CHEMBL203 (Epidermal growth factor receptor, SINGLE PROTEIN); 15 other ChEMBL target(s) share this component
# CHEMBL203 Ki assay_type=B: 538 activity rows
# fetching confidence scores for 78 assays
# input rows: 538
# dropped 23: potential_duplicate flag
# kept rows: 515
# warning: 78 molecule(s) have replicate pChEMBL values spanning >= 1.0 log units -- review before modelling
# wrote 321 rows to egfr_ki.tsv

Read the full file on GitHub · 172 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. 13d ago First seen · 172 lines · 134 tokens per session scan A 9f48130f57f5

Subscribe to this mod's changes

chembl is a skill published in the GitHub repository K-Dense-AI/drug-discovery-agent-skills (28 stars, last pushed 5d ago), licensed MIT. It adds 134 tokens to every session and 2,480 once invoked, about $0.0007 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.