ESTELA Exam Builder

Build multiple unique physics exam versions from isomorphic problem banks — export to LaTeX or Word in one click.

ESTELA is a desktop application for physics instructors. It lets you browse a curated bank of isomorphic physics problems, assemble an exam cart, and generate multiple exam versions where every version tests the same concepts but with different problems. Powered by Tauri and supported by NSF Award #2421299 and the Gates Foundation.

⬇ Download for Windows / macOS / Linux

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What are isomorphic problems?

Isomorphic problems share the same physics concept and difficulty level but differ in surface details — different numbers, scenarios, or physical setups — so that any two problems in a bank can be used interchangeably as exam questions without giving an unfair advantage to students who have seen a previous version.

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Features

• Browse & search — Filter problem banks by course, unit, topic, or free-text keyword. Preview individual questions with fully rendered equations (KaTeX).
• Multiple exam versions — Generate up to 10 unique versions from a single cart. Version A gets question 1 from each bank, Version B gets question 2, and so on. Multiple-choice answer order is also shuffled per version.
• Flexible export
  • LaTeX (.tex) using the exam document class
  • Word (.docx) with native OMML equations via bundled Pandoc
  • Browser preview (KaTeX-rendered HTML)
  • Bundle ZIP — all versions + answer keys + figures in one archive
• Answer keys — generated automatically alongside every exam version
• Built-in bank sync — download individual courses directly from within the app; no manual cloning needed
• Light / dark mode

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Download

Pre-built installers are available for all platforms at:

jeebuscrossaint.github.io/estela

Platform	Format
Windows 10/11	.exe installer
macOS Apple Silicon (M1–M4)	.app bundle (zip)
macOS Intel	.app bundle (zip)
Linux	AppImage + .deb

Installers are built automatically by CI on every update. No LaTeX distribution or Python install required — Pandoc is bundled.

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Getting started

1. Get problem banks

Either clone this repository:

git clone https://github.com/jeebuscrossaint/estela.git

Or use the Get Problem Banks panel inside the app to download individual courses directly from the sidebar.

2. Load the repository

Enter the folder path in the Repository field in the sidebar and click Load. All .yaml / .yml problem bank files are scanned recursively.

3. Build your exam

1. Browse by course and topic, or use the search box.
2. Click Preview on any card to see questions with rendered equations.
3. Click + Add to add a bank to the cart.
4. Set an exam title and number of versions.
5. Click an export button to download.

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Repository structure

estela/
├── docs/                         # GitHub Pages site (download page + one-pager)
├── frontend/
│   └── index.html                # Full app UI (HTML + CSS + JS, single file)
├── src-tauri/
│   ├── src/main.rs               # All backend logic (Tauri commands)
│   ├── tauri.conf.json           # App config
│   └── binaries/                 # Bundled Pandoc binary (gitignored, downloaded by CI)
├── PHY I Mechanics/              # Problem bank folders, organized by unit
│   ├── 0_Vector and Math/
│   ├── 1_1D Motion/
│   └── ...
├── Templates/
│   ├── Problem-bank-template.yaml
│   ├── YAML_formatting_prompt.md
│   └── YAML_problem_types.md
└── .github/workflows/build.yml   # CI — builds all platforms, publishes to releases

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Problem bank format

Problem banks are YAML files following the ESTELA schema. See Templates/Problem-bank-template.yaml for the full format. A minimal example:

bank_info:
  title: "Newton's Second Law — Horizontal Surface"
  bank_id: PHY1-F-N2L-091525
  date_created: 09-15-2025
  status: ready
  authors:
    - Your Name

questions:
  - numerical:
      id: q1
      title: Block on a surface
      text: "A <latex>5\\,\\text{kg}</latex> block is pushed with a net force of <latex>20\\,\\text{N}</latex>. Find the acceleration."
      answer:
        value: 4
        tolerance: 0.1

  - multiple_choice:
      id: q2
      title: Direction of friction
      text: "A block slides to the right. Kinetic friction acts..."
      answers:
        - answer: {text: "to the left", correct: true}
        - answer: {text: "to the right", correct: false}
        - answer: {text: "downward", correct: false}

Naming convention: Subject-Unit-Abbreviation-mmddyy.yaml Example: PHY1-F-N2L-091525 = Physics 1 / Forces / Newton's 2nd Law / Sep 15 2025

Supported question types

numerical · multiple_choice · true_false · multiple_answers · essay · formula · fill_in_multiple_blanks · ordering · categorization · hot_spot · file_upload

Note: categorization and hot_spot are Canvas-only and are flagged as unsupported for paper export.

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Creating new problem banks

1. Copy Templates/Problem-bank-template.yaml into the appropriate course/unit folder.
2. Use the AI prompts in Templates/YAML_formatting_prompt.md to generate and format problems.
3. Name the file following the convention above.
4. Load the folder in the app to verify rendering.
5. (Optional) Upload to Canvas via the UCF YAML-to-QTI converter.

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Building from source

Prerequisites:

• Node.js 18+
• Rust toolchain
• Pandoc binary in src-tauri/binaries/ (see below)

Get Pandoc (Windows):

$ver = (Invoke-RestMethod "https://api.github.com/repos/jgm/pandoc/releases/latest").tag_name
Invoke-WebRequest "https://github.com/jgm/pandoc/releases/download/$ver/pandoc-$ver-windows-x86_64.zip" -OutFile pandoc.zip
Expand-Archive pandoc.zip -DestinationPath pandoc-tmp -Force
Copy-Item "pandoc-tmp/pandoc-$ver/pandoc.exe" "src-tauri/binaries/pandoc-x86_64-pc-windows-msvc.exe"

Get Pandoc (macOS/Linux):

# macOS
brew install pandoc
cp "$(brew --prefix)/bin/pandoc" src-tauri/binaries/pandoc-aarch64-apple-darwin  # or x86_64-apple-darwin

# Linux
apt install pandoc   # then copy binary to src-tauri/binaries/pandoc-x86_64-unknown-linux-gnu

Run:

npm install
npm run tauri dev     # development
npm run tauri build   # production build

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Canvas integration

ESTELA exports to LaTeX and Word for print/paper delivery. For Canvas online delivery, upload the QTI zip produced by the UCF YAML-to-QTI converter to a Canvas New Quiz item bank.

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License

CC BY-NC 4.0 — free for educational and non-commercial use.

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Funding & acknowledgements

• NSF Award #2421299 — HSI Implementation and Evaluation Project
• Bill & Melinda Gates Foundation INV-076932
• UCF Department of Physics