# Chemthermo Change Loop > Use when implementing or reviewing changes in this Chemical-Thermodynamics repository. Apply the repo contract by reading .agents/brain/brain.md first, preserving SI-unit and public-API invariants, shipping thin vertical slices with a runnable golden path, running CI-equivalent quality gates (ruff format, ruff format --check, ruff check, pyright, pytest), verifying editable and non-editable install smoke checks, and updating ADR/brain docs when architecture or public API changes. - Skill: `tomevault-io/chemthermo-change-loop` (Agent Skill, multi-file: 2 files) - Install (CLI): `npx skillmds@latest add tomevault-io/chemthermo-change-loop` - Raw SKILL.md: https://api.skillmd.com/api/skills/tomevault-io/chemthermo-change-loop/raw - Safety review: pending (external: skill-scanner PASS, skillspector PASS) - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: Integrations & APIs - Author: tomevault-io (https://skillmd.com/u/tomevault-io) - Updated: 2026-09-17 - Page: https://skillmd.com/skills/tomevault-io/chemthermo-change-loop --- # Chemthermo Change Loop ## Inputs - User request and acceptance criteria - Files expected to change - Whether public API or architecture boundaries are affected - Local environment status (Python 3.11+, editable install) ## Workflow 1. Establish scope and constraints. - Read `README.md` and `.agents/brain/brain.md` before structural edits. - If the change is architectural or API-facing, read relevant ADRs in `.agents/brain/adr/`. - Confirm scope policy remains consistent across docs: VLLE and PC-SAFT are in scope, and no thermodynamic capability class is categorically out of scope. 2. Classify the change. - Treat edits touching `src/chemthermo/__init__.py`, `src/chemthermo/eos/__init__.py`, or `src/chemthermo/vlle/__init__.py` as public API-sensitive. - Treat changes to solver/model internals as invariant-sensitive (SI units, composition validation, deterministic flash behavior). - Treat notebook edits as hygiene-sensitive (strip outputs, keep runnable narrative). 3. Implement a thin vertical slice. - Prefer the smallest end-to-end usable increment over scaffold-only work. - Declare the slice explicitly before implementation: "After this change, user can X by running Y." - Keep interfaces and behavior coherent across code, tests, and examples. - Avoid opportunistic refactors unrelated to the requested change. 4. Validate in escalating order. - Run focused tests for touched modules first. - Run canonical bootstrap, CI gates, and golden path from `.agents/dev-contract.md`. - Run installability checks from `.agents/dev-contract.md` (`pip install -e ".[dev]"` path and `pip install .` smoke via `tools/smoke_install.py`). - Use the cheap-check subset in `.agents/dev-contract.md` during iteration, then run full CI gates before finalizing. - If validation extras are installed, run optional reference checks under `tests/validation/`. 5. Update docs and decision records. - Update README/examples/notebooks docs when user-visible behavior changes. - Update `.agents/brain/steering-brief.md` when architecture context changes. - Add or update an ADR for public API or architectural decisions. 6. Report outcomes clearly. - Summarize what changed, what was validated, and any known risks. - Include thin-slice evidence from `.agents/dev-contract.md` (slice declaration, golden path, focused tests, CI checks, install smoke). - If any checks were skipped, state exactly which checks and why. ## Mandatory completion checklist (hard gate) - Slice declaration is present: "After this change, user can X by running Y." - At least one golden-path command/test was run and outcome reported. - Focused tests for touched behavior were run and outcomes reported. - CI-equivalent checks were run and outcomes reported. - Editable and non-editable install smoke checks were run and outcomes reported. - User-visible behavior changes include docs updates in the same slice. ## Notebook-specific checklist - Keep notebooks in `notebooks/` runnable top-to-bottom. - Preserve concise markdown context for each code block. - Ensure outputs are stripped before commit (nbstripout workflow). - Keep supporting utilities in `notebooks/_nb_utils.py` or regular modules when reuse is needed. ## Guardrails - Do not invent thermodynamic constants, component data, or external-reference results. - Do not loosen CI or invariant checks unless explicitly requested. - Keep commits small and logically grouped. - Keep the working tree clean at handoff. --- > Converted and distributed by [TomeVault](https://tomevault.io/claim/ahmadalkadri) — claim your Tome and manage your conversions.