molclaw-mol-similarity

molclaw-mol-similarity is a skill for Claude Code, Codex from InternScience/MolClaw. It costs 36 tokens per session (746 once invoked), scanned A, original, MIT.

A chemistry tool that compares a target molecule with candidate molecules using fingerprints, machine-readable summaries of molecular structure.

In plain words
What is it for?
Use it to calculate Tanimoto similarity and shared structural fragments from SMILES strings, with a chosen fingerprint radius and bit count.
Why use it?
It provides a consistent similarity score and shared-fragment count instead of requiring manual structure comparison.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit Use it to calculate Tanimoto similarity and shared structural fragments from SMILES strings, with a chosen fingerprint radius and bit count.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/internscience/molclaw/molclaw-mol-similarity
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 InternScience/MolClaw --skill molclaw-mol-similarity
Clone the repo
git clone --depth 1 https://github.com/InternScience/MolClaw

Made for: Claude Code, Codex.

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 molclaw-mol-similarity

README.md
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Your own site
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Your own site · 80×15
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Per session 36 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 746 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. 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 $0.00036 $0.00746
Opus 5 $0.00018 $0.00373
Sonnet 5 $0.00007 $0.00149
Haiku 4.5 $0.00004 $0.00075

Measured 10d ago against content hash fb4211d36610, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-10, from the pricing page.

Security

Grade A, and why

molclaw-mol-similarity 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 10d 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.

skills/L1_tools/molclaw-mol-similarity/SKILL.md · 83 lines

What it actually says

Molecule Similarity Calculation

Note:

  • Local files are not directly accessible by the server. Please upload them to the server using molclaw-file-transfer before execution.
  • For PDB file inputs, it is recommended to preprocess them using molclaw-pdbfixer before execution.
  • Please refer to skill molclaw-scp-server to complete tool invocation.

Scene 1: Compute the Tanimoto similarities between a target molecule and a list of candidate molecules using Morgan fingerprints. Need to use the tool calculate_morgan_fingerprint_similarity.

The description of tool calculate_morgan_fingerprint_similarity.

Compute the Tanimoto similarities between a target molecule and a list of candidate molecules using Morgan fingerprints.
Args:
    target_smiles (str): SMILES string of the target molecule
    candidate_smiles_list (List[str]): List of candidate molecule SMILES strings
    radius (int): Required Morgan fingerprint radius (commonly 2)
    nBits (int): Required Morgan fingerprint vector bit count (commonly 2048)
Return:
    status (str): success/error
    msg (str): message
    similarities (List[dict]): List of dict, each containing the keys 'smiles' and 'score'.
        --smiles (str): A SMILES string of candidate_smiles_list
        --score (float): Similarity value between the candidate SMILES and the target SMILES

How to use tool calculate_morgan_fingerprint_similarity :

response = await client.session.call_tool(
    "calculate_morgan_fingerprint_similarity",
    arguments={
        "target_smiles": target_smiles,
        "candidate_smiles_list": candidate_smiles_list,
        "radius": radius,
        "nBits": nBits
    }
)
result = client.parse_result(response)
similarities = result["similarities"]

Scene 2: Compute the count of shared structural fragments between a target molecule and a list of candidate molecules using Morgan fingerprints. Need to use the tool calculate_common_fragments.

The description of tool calculate_common_fragments.

Compute the count of shared structural fragments between a target molecule and a list of candidate molecules using Morgan fingerprints.
Args:
    target_smiles (str): SMILES string of the target molecule
    candidate_smiles_list (List[str]): List of candidate molecule SMILES strings
    radius (int): Required Morgan fingerprint radius (commonly 2)
Return:
    status (str): success/error
    msg (str): message
    fragments_info (List[dict]): List of dict, each containing the keys 'smiles' and 'common_fragment_count'.
        --smiles (str): A SMILES string of candidate_smiles_list
        --common_fragment_count (float): Number of structural fragments shared between the candidate SMILES and the target SMILES

How to use tool calculate_common_fragments :

response = await client.session.call_tool(
    "calculate_common_fragments",
    arguments={
        "target_smiles": target_smiles,
        "candidate_smiles_list": candidate_smiles_list,
        "radius": radius
    }
)
result = client.parse_result(response)
fragments_info = result["fragments_info"]
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. 10d ago First seen · 83 lines · 36 tokens per session scan A fb4211d36610

Subscribe to this mod's changes

molclaw-mol-similarity is a skill published in the GitHub repository InternScience/MolClaw (33 stars, last pushed 1mo ago), licensed MIT. It adds 36 tokens to every session and 746 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.

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