chemvas

Chemvas — Draw interactively. Automate safely. Export exactly.

English · 한국어

Chemvas is an open-source desktop canvas for chemical structures and reaction schemes. Draw on the desktop, export publication-ready SVG, PDF, PNG or TIFF at real column widths, and drive the same documents from scripts.

A benzyl alcohol oxidation scheme exported directly from Chemvas

Open the editable drawing · Get the SVG · Follow the walkthrough

Install

Requires Python 3.12+. The optional RDKit backend adds SMILES insertion:

pip install "chemvas[rdkit]"
chemvas

pip install chemvas skips RDKit; drawing and export still work. Local Windows builds: packaging notes.

Your first reaction scheme

Chemvas walkthrough: insert structures, label an arrow, align the scheme, and export SVG

Choose Ring, type OCc1ccccc1 in its SMILES field, click Insert, then click the canvas. Hover the oxygen, press Enter, label it OH.
Insert O=Cc1ccccc1 to the right. Choose Arrow, drag between the two structures, then double-click the arrow to label it.
Edit ▸ Select All, then Edit ▸ Align ▸ Middle.
Save as .chemvas. File ▸ Export Figure… → Plain SVG, Fit 2-column (174 mm).

The step-by-step guide has the label text and the downloadable files. The drawing is an exercise, not an experimental result.

Scripts

With the downloaded first-scheme.chemvas:

chemvas inspect-document first-scheme.chemvas
chemvas check-layout first-scheme.chemvas
chemvas render-document first-scheme.chemvas --output first-scheme.pdf --width-mm 174

Rendering writes a new file and never touches the source. Composition, Graph Patch, scheme layout and their limits: document CLI guide · scheme layout · publication recipe.

Documentation

Drawing tools and shortcuts · Chemistry I/O · Image objects · Limits and roadmap
Calculation handoff (RDKit): elementary steps and reviewed precomplexes, one machine.json per step.
Documents are editable .chemvas JSON files (version 7). More examples
Contributing · Architecture · Changelog · Releasing · MIT License

Something got in your way? Open an issue.

Download files

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

Source Distribution

chemvas-0.12.0.tar.gz (655.0 kB view details)

Uploaded Sep 11, 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-0.12.0-py3-none-any.whl (820.4 kB view details)

Uploaded Sep 11, 2026 Python 3

File details

Details for the file chemvas-0.12.0.tar.gz.

File metadata

Download URL: chemvas-0.12.0.tar.gz
Upload date: Sep 11, 2026
Size: 655.0 kB
Tags: Source
Uploaded using Trusted Publishing? Yes
Uploaded via: twine/7.0.0 CPython/3.13.14

File hashes

Hashes for chemvas-0.12.0.tar.gz
Algorithm	Hash digest
SHA256	`ad889f6a7b2cd00a4115f023b4437050082a43e8374f2b1da4414eee5e19ab60`
MD5	`7dc5a80bcba3b87a63aac9a35674da63`
BLAKE2b-256	`00759a09199f6c18b6eeb3ded63fbf22b7a930137c2c22ed3b14413d290429db`

See more details on using hashes here.

Provenance

The following attestation bundles were made for chemvas-0.12.0.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-0.12.0.tar.gz
- Subject digest: ad889f6a7b2cd00a4115f023b4437050082a43e8374f2b1da4414eee5e19ab60
- Sigstore transparency entry: 2789964040
- Sigstore integration time: Sep 11, 2026
Source repository:
- Permalink: dhsohn/Chemvas@b94963b5215ffcd504e021265aec170a20aafecf
- Branch / Tag: refs/tags/v0.12.0
- Owner: https://github.com/dhsohn
- Access: public
Publication detail:
- Token Issuer: https://token.actions.githubusercontent.com
- Runner Environment: github-hosted
- Publication workflow: release.yml@b94963b5215ffcd504e021265aec170a20aafecf
- Trigger Event: push