synkit

A Python toolkit for studying chemical reactions as graphs, where atoms are points and bonds are connections.

In plain words
What is it for?
Use it to convert reaction SMILES into graphs, check atom mappings, extract reaction rules, analyze reaction networks, and explore synthesis routes.
Why use it?
It helps organize, compare, validate, and analyze reaction data in a structured form.

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/kdevos12/alkyl/synkit
Any agent
npx skills add Kdevos12/ALKYL --skill synkit
Clone the repo
git clone --depth 1 https://github.com/Kdevos12/ALKYL

Made for: Claude Code, Codex.

Per session 56 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,085 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 $0.00056 $0.01085
Opus 5 $0.00028 $0.00543
Sonnet 5 $0.00011 $0.00217
Haiku 4.5 $0.00006 $0.00109

Measured 2d ago against content hash d2e40169e0d7, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

synkit 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.

skills/synkit/SKILL.md · 104 lines

How it starts

The opening of the file, as written. The whole thing — 104 lines — stays where its author put it; the contents beside it link to each section on GitHub.

SynKit

Graph-based Python toolkit for reaction informatics: ITS graph construction, canonicalization, AAM validation, DPO rule extraction, CRN analysis, and synthesis planning.

Paper: doi:10.1021/acs.jcim.5c02123 | JCIM 2025

When to Use This Skill

  • Converting reaction SMILES → ITS graphs (NetworkX) → DPO rules (GML)
  • Validating or comparing atom-to-atom mappings (AAMValidator)
  • Canonicalizing reaction SMILES (CanonRSMI) or ITS graphs (GraphCanonicaliser)
  • Clustering reactions by structural similarity (WL graph hash)
  • Extracting and composing reaction rules (DPO formalism)
  • Analyzing chemical reaction networks (Feinberg deficiency theory, Petri nets)
  • Detecting autocatalysis, siphons, traps in reaction networks
  • Planning synthetic routes via rule composition (SynReactor)
  • Building reaction databases or curating USPTO/ChEMBL reaction data

Core Concept: ITS Graph

The Imaginary Transition State (ITS) graph merges reactant and product graphs into a single labeled multigraph:

  • Nodes: atoms with attributes (symbol, charge, radical, hybridization, H count)
  • Edges: bonds with attributes (bond type, change flag: formed / broken / unchanged)

ITS ≡ CGR (Condensed Graph of Reaction) — same structure, different naming tradition.

Quick Start

from synkit.IO import load_reaction_smiles
from synkit.Graph import ITSConstruction
from synkit.Chem import CanonRSMI, AAMValidator

# 1. Parse reaction SMILES → ITS graph (NetworkX)
rxn_smiles = "[CH3:1][OH:2].[Na:3][H:4]>>[CH3:1][O:2][Na:3].[H:4][H:5]"
its = ITSConstruction.from_reaction_smiles(rxn_smiles)

# 2. Canonicalize the reaction SMILES
canon = CanonRSMI(rxn_smiles).canonicalize()

# 3. Validate atom-atom mapping
valid = AAMValidator(rxn_smiles).is_valid()

Router — What to Read

Task Reference
Load reactions, format conversion (SMILES ↔ ITS ↔ GML), data I/O references/io-conversion.md
Canonicalization (CanonRSMI), AAM validation, Reaction class references/chem-standardization.md
ITS construction, MTG, graph canonicalization, WL hashing, subgraph search references/graph-its.md
DPO rules, GML format, rule composition, SynReactor forward/retro references/rule-dpo.md
CRN building, Feinberg deficiency theory, Petri nets, autocatalysis references/crn-analysis.md
Synthesis planning, route construction, pathway analysis references/synthesis-planning.md

Read the full file on GitHub · 104 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 · 104 lines · 0 tokens per session scan A d2e40169e0d7

Subscribe to this mod's changes

synkit is a skill published in the GitHub repository Kdevos12/ALKYL (6 stars, last pushed 5mo ago), licensed MIT. It adds 56 tokens to every session and 1,085 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 2026-08-31.

Related

Other skills, from other repositories

add-tool

Scaffold a new MCP tool definition. Use when the user asks to add a tool, create a new tool, or implement a new capability for the server.

cyanheads/pubchem-mcp-server · 35 tokens

api-errors

McpError constructor, JsonRpcErrorCode reference, and error handling patterns for @cyanheads/mcp-ts-core. Use when looking up error codes, understanding where errors should be thrown vs. caught, or using ErrorHandler.tryCatch in services.

cyanheads/pubchem-mcp-server · 54 tokens

field-test

Exercise tools, resources, and prompts against a live HTTP server via MCP JSON-RPC over curl. Starts the server, surfaces the catalog, runs real and adversarial inputs, and produces a tight report with concrete findings and numbered follow-up options. Use after adding or modifying definitions, or when the user asks to…

cyanheads/pubchem-mcp-server · 76 tokens

tool-defs-analysis

Read-only audit of MCP definition language across an existing surface — tools, resources, prompts, server instructions. Walks every definition file and checks 16 categories the LLM reads to decide whether and how to call: voice & tense, internal leaks, audience leaks, defaults, recovery hints, field descriptions…

cyanheads/pubchem-mcp-server · 177 tokens

add-service

Scaffold a new service integration. Use when the user asks to add a service, integrate an external API, or create a reusable domain module with its own initialization and state.

cyanheads/pubchem-mcp-server · 38 tokens

add-app-tool

Scaffold an MCP App tool + UI resource pair. Use when the user asks to add a tool with interactive UI, create an MCP App, or build a visual/interactive tool.

cyanheads/pubchem-mcp-server · 41 tokens