Developer-focused cheminformatics library

Cheminformatics that runs anywhere.

A developer-focused chemistry engine for Python, Rust, browsers, and AI tools. Parse molecules, calculate descriptors, and build chemistry tools.

Install chematic
pip install chematic
cargo add chematic --features "smiles,perception,chem,3d,fp"
npm install @kent-tokyo/chematic
<script type="module">
  import init, { parse_smiles } from "https://cdn.jsdelivr.net/npm/@kent-tokyo/chematic@1.0.12/chematic_wasm.js";

  await init();
  const mol = parse_smiles("CC(=O)Oc1ccccc1C(=O)O"); // aspirin
  console.log(mol.molecular_weight().toFixed(2)); // 180.16
  mol.free();
</script>

† Pure Rust by default. The optional native-inchi feature vendors a C reference library for bit-exact InChI — see Validation.

Try it now

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v1.0.12Python · Rust · WebAssembly · MCPPure Rust by default†Reproducible, versioned validation

At a glance

Current releasev1.0.12Published 2026-09-10
One core, four surfacesPython · RustPython 3.9–3.13 · Rust · WebAssembly · MCP
Validated core100%MW, LogP, TPSA, HBA/HBD, and aromatic ring count match RDKit at 100% on the published corpus.
Browser package1.40 MB1.40 MB gzip · measured from v1.0.12

Where chematic fits

Choose chematic when

  • Browser or WebAssembly deployment matters
  • You need a native Rust integration
  • You want the standard pure-Rust path without a C++ toolchain
  • You're building a small, local-first tool
  • You want one core shared across Python, Rust, and the browser
  • You want local AI-agent integration through MCP

Choose RDKit when

  • You need a mature cheminformatics ecosystem and long production history
  • You need independently established validation for a production workflow
  • You need advanced, well-established 3D, reaction, or plugin compatibility
  • You have an existing RDKit codebase to keep using
  • Compatibility with an existing RDKit workflow is required

Read the validation and RDKit guide →

Contribute

chematic is open source under MIT OR Apache-2.0. Issues, discussions, and pull requests are welcome.