chemvas

Chemvas — 2D chemical structure drawing canvas

English · 한국어

Chemvas is a lightweight PyQt6 app for drawing 2D chemical structures and reaction schemes — ACS 1996 defaults, ChemDraw-compatible shortcuts, and publication-ready figure export. Draw fast, export exactly.

Chemvas — a C–P bond cleavage reaction scheme (KOtBu / THF) drawn on the canvas

Statement of need

Sketching a scheme for a lab notebook or paper should not require a commercial suite — and automating edits should not mean trusting an LLM with your drawing. Chemvas keeps the interactive canvas small and fast, and exposes headless CLI contracts for rendering, inspection, editing, and calculation handoff: document edits bind to the exact source hash and unsupported input fails closed. Agents propose, validation decides.

Quickstart

pip install chemvas              # core (PyQt6 included)
pip install "chemvas[rdkit]"     # + SMILES import, formula/weight, calculation handoff, 3D
chemvas

Pick a tool from the toolbar and click/drag on the canvas. Type a SMILES string and press Insert to preview and place it (RDKit). Open examples/template2.chemvas via File ▸ Open to explore the document shown above.

What it does

Capability	Use it for	Details
Drawing	bonds, rings, arrows, lines, brackets, atom labels — with ChemDraw-compatible shortcuts	REFERENCE
Figure export	plain SVG / PDF / PNG / TIFF, outlined glyphs, deterministic physical sizing	REFERENCE
Chemistry I/O	SMILES import, `.mol` interchange, 2D→3D `.xyz`, Molecule Info (RDKit)	REFERENCE
Agent CLI	headless compose / layout-check / render / inspect / hash-gated Graph Patch, no Qt window	AGENT_CLI
Calculation handoff	elementary steps, reviewed precomplexes, one `machine.json` per step (RDKit)	AGENT_CLI

Documents are .chemvas files (JSON, version 7 contract) with autosave and crash recovery; everything except the marked (RDKit) features runs without RDKit.

Development, testing, and full docs

make check runs the whole local gate — lint, formatting, mypy, the file-isolated headless test suite, and the machine.json conformance check. Read CONTRIBUTING.md before moving code: the architecture boundaries are enforced by tests.
Docs index: REFERENCE · AGENT_CLI · ARCHITECTURE · CHANGELOG · RELEASING
Known gaps (SDF interchange, one-file binaries, multi-molecule 3D export) → roadmap

License

MIT License

Download files

Download the file for your platform. If you're not sure which to choose, learn more about installing packages.

Source Distribution

chemvas-0.8.0.tar.gz (595.3 kB view details)

Uploaded Sep 7, 2026 Source

Built Distribution

If you're not sure about the file name format, learn more about wheel file names.

The dropdown lists show the available interpreters, ABIs, and platforms. Enable javascript to be able to filter the list of wheel files.

chemvas-0.8.0-py3-none-any.whl (752.8 kB view details)

Uploaded Sep 7, 2026 Python 3

File details

Details for the file chemvas-0.8.0.tar.gz.

File metadata

Download URL: chemvas-0.8.0.tar.gz
Upload date: Sep 7, 2026
Size: 595.3 kB
Tags: Source
Uploaded using Trusted Publishing? Yes
Uploaded via: twine/7.0.0 CPython/3.13.14

File hashes

Hashes for chemvas-0.8.0.tar.gz
Algorithm	Hash digest
SHA256	`777559564c936d840eacb7ed1569fd8b17425801b78c252ce6dd26c78148c5c0`
MD5	`a3aaf0f8109eb407ccee452c62396e68`
BLAKE2b-256	`cf3bb7946ccf4d3007e8542f4d35ff73821de2a70c63498baf1da0104c1fe881`

See more details on using hashes here.

Provenance

The following attestation bundles were made for chemvas-0.8.0.tar.gz:

Publisher: release.yml on dhsohn/Chemvas

Attestations: Values shown here reflect the state when the release was signed and may no longer be current.

Statement:
- Statement type: https://in-toto.io/Statement/v1
- Predicate type: https://docs.pypi.org/attestations/publish/v1
- Subject name: chemvas-0.8.0.tar.gz
- Subject digest: 777559564c936d840eacb7ed1569fd8b17425801b78c252ce6dd26c78148c5c0
- Sigstore transparency entry: 2747707754
- Sigstore integration time: Sep 7, 2026
Source repository:
- Permalink: dhsohn/Chemvas@943e2825acae93c1cb070c512d7593c973de21eb
- Branch / Tag: refs/tags/v0.8.0
- Owner: https://github.com/dhsohn
- Access: public
Publication detail:
- Token Issuer: https://token.actions.githubusercontent.com
- Runner Environment: github-hosted
- Publication workflow: release.yml@943e2825acae93c1cb070c512d7593c973de21eb
- Trigger Event: push