My plant

A plant design kept as plain files in git: P&IDs in DEXPI 2.0.1 (the open P&ID exchange standard) in pid/, engineering lists as YAML, decisions and progress as Markdown. Edited by people and by coding agents (Claude Code), checked by cheme-as-code.

New to ChemE-as-Code? cheme-as-code.org explains the idea in plain language, the documentation describes the commands and files, and the Process Atlas is a library of chemical processes built with the same tools. ChemE-as-Code is research software in active development: research output, not engineering advice.

What is where

Path	Contents
plant.yaml	name, stage, sheets
pid/	P&ID sheets (DEXPI 2.0.1 XML)
process/design-basis.yaml	capacity, feeds, products, utilities, site
process/materials.yaml, process/flowsheet.yaml	components, blocks and streams: the source of the block flow and process flow diagrams (BFD, PFD) in process/*.xml
equipment/equipment-list.yaml, piping/line-list.yaml, control/instrument-list.yaml	lists, consistent with the P&IDs
control/cause-effect.yaml	interlocks and trips (cause and effect)
piping/special-items.yaml (optional)	tagged piping components: safety valves, silencers, rupture discs (skill lists-sync)
safety/	HAZOP studies (safety/hazop/<id>/study.yaml) and the risk matrix they rate against; safety/README.md says how
layout/, electrical/, estimate/, lca/	3D layout, electrical, cost estimate and life cycle assessment; each folder's README.md says what goes there
checks/checks.yaml	engineering-step gates (checks that must pass before a stage is signed off); checks/status.json their result at the last sign-off
reviews/	review records
runs/	one record per design session, written by cheme runs record (runs/README.md); never edited
DESIGN.md, PROGRESS.md, STAGES.md	decisions, change log, stage definitions
scripts/	scripts that generate sheets (see generator: in plant.yaml)
.claude/skills/	skills: the instructions an AI agent follows when it works here

How this repository works

• This repository holds your plant: drawings, lists, decisions. It does not hold the tools.
• The tools come from cheme-as-code, installed once on your computer (uv tool install git+https://github.com/ChemE-as-Code/core.git). Every check, drawing and generated file is made by the cheme command, so you need it to work here. The continuous integration (CI) in .github/workflows/ installs it too.
• The skills in .claude/skills/ are copies of the ones in cheme-as-code, so that Claude Code finds them here. After upgrading (uv tool upgrade cheme-as-code), run cheme skills update to refresh them; cheme skills status shows which are out of date. A skill you changed here is kept.

Quick start

uv tool install git+https://github.com/ChemE-as-Code/core.git   # once: the cheme command
cheme git-setup                 # once per clone: readable P&ID diffs + pre-commit hook
cheme validate                  # after every change

To look at the plant in a browser (P&IDs, streams, 3D layout), install the Viewer extra with uv tool install 'cheme-as-code[serve] @ git+https://github.com/ChemE-as-Code/core.git', run cheme serve here, and see the Viewer documentation.

More commands

cheme status                    # where the plant stands: sheets, findings, gates, sign-offs
cheme fmt                       # canonical XML, stable ids
cheme render [--png] [--crop]   # build/<sheet>[_crop-X0-Y0-X1-Y1].svg (or .png)
cheme render --png --tiles auto # build/<sheet>_tile-A1.png ... to read the whole sheet
cheme show <id or tag>          # where an object and its drawing are in the file
cheme diff main [--list]        # build/diff.html, or one line per changed plant item
cheme check                     # engineering-step gates (--write only at sign-off)
cheme runs list                 # the record of each design session in runs/
cheme process build             # BFD and PFD from process/*.yaml
cheme process streams           # stream table with provenance, block balances

Licence

The ChemE-as-Code tools, including the skill copies in .claude/skills/ and the scripts in scripts/ that cheme init wrote, are licensed under AGPL-3.0-or-later (see .claude/skills/NOTICE.md and cheme-as-code.org/licence). Your plant data and models (P&IDs, YAML, reports, generated drawings and results) are yours, and you can license them however you choose. Running the tools does not put AGPL on what they produce.