Instrument

One engineering desk: Library, Studio, Review, and Project.

Open a finished model, or write your own. Units stay on the quantity. Method, assumptions, and limits sit in the same frame.

This is not two products. Caliper and Gauge are retired names for the same desk.

Shared look: packages/ui (@instrument/ui). Units: packages/units (@instrument/units). Formula: packages/formula.

Instrument is a preliminary screening desk, not a design approval, sealed calculation, or code-compliance tool. Verify every output against the geometry, loading, material, and specifications that apply to the actual project.

Features

• Finished library models across fundamentals, mechanics, fluids, thermal, electrical, quality, automation, manufacturing, and applied systems
• Studio to author a unit-aware calculator with method attached
• SI-canonical arithmetic with declared display units
• Command palette (⌘K / Ctrl+K)
• Project snapshots and review records (no account required)
• Engineering review: checklists, weighted trade study, FMEA arithmetic
• Optional account (email + password) to sync work across devices
• Dark and light themes

Requirements

• Node.js 22+ (see .nvmrc)
• npm 10.x — corepack enable once and you get it automatically

npm refuses to install under npm 11 here, by way of engine-strict in .npmrc. npm 10 and 11 disagree about which entries a lockfile must carry, and one written by npm 11 failed npm ci in CI with a missing-package error that did not reproduce on the machine that wrote it.

Two weaker mechanisms were tried first. A preinstall guard cannot work: npm writes the lockfile before lifecycle scripts run, so it reports a mismatch already on disk. Leaving it as a convention does not work either — with the check removed, a single npm install under npm 11 stripped the entry again.

Deployment installs opt out (installCommand in vercel.json). Nothing that only runs npm ci can corrupt a lockfile, so the guard buys nothing there, and it failed the Vercel build while it applied.

Quick start

git clone https://github.com/meetpatelc/instrument.git
cd instrument
corepack enable
npm install
npm run dev

The app listens on port 8080. Open http://localhost:8080.

Calculators and local saves work without signing in. Copy .env.example to .env.local only if you need Postgres or other overrides.

Scripts

Command	Purpose
npm run dev	Development server
npm run build	Production frontend build
npm run db:migrate	Apply SQL migrations when DATABASE_URL is set
npm run typecheck	TypeScript (tsc --noEmit)
npm run lint	ESLint
npm run format	Prettier
npm test	Node test runner

Pushing

npm install points git at .githooks/, and pre-push runs the same five commands as CI's required Check job — typecheck, lint, test, build, brand-check — taking about a minute. A push that CI would reject stops here instead, before Vercel starts building a deploy from it. Skip it with git push --no-verify when you have a reason.

This is deliberately not a required status check on GitHub. Requiring one forces every change through a pull request, since a commit that has just been pushed has no status yet, and on a repo with one committer that is a review with no reviewer. main instead blocks the two things a local hook cannot catch — force pushes and deletion — and those apply to administrators too.

Layout

src/routes/          Pages (library, studio, review, project, account)
src/lib/             Catalog, documents, units, desk
src/studio/          Studio evaluator, ISO 286, authoring
src/components/      Shell, calculator workspace, diagrams
packages/ui          Shared Instrument UI kit
packages/units       Canonical SI inventory
packages/formula     Expression evaluator
migrations/          Auth + desk schema

Engineering posture

• Units stay attached to every quantity.
• Assumptions are visible before a result is trusted.
• Sources and method notes remain one step away.
• A screening result is never a certification.

See About & limits in the app for what Instrument is and is not designed to support.

License

MIT