streamlitd

Streamlit for D. Write data apps as a plain D function that reruns from top to bottom on every interaction, the way you write them in Python with Streamlit. dub build produces one self-contained binary: the web UI, charts, maps, math rendering and fonts are compiled in, so it runs offline and deploys by copying a file.

import streamlitd;

void app(St st)
{
    st.title("Hello 👋");
    auto name = st.textInput("Your name", "World");
    auto n = st.slider("Times", 1, 10, 3);
    if (st.button("Greet", type: "primary"))
        st.success("Hello " ~ name ~ "!");
}

mixin StreamlitMain!app;

dub run                          # → http://localhost:8501

📚 Documentation: docs/ has the getting started guide, the tutorial and the Python → D cheat sheet.

Screenshots

Sales dashboard from the tutorial: cached CSV, filters, metrics, charts	Every input widget: text, numbers, sliders, selects, dates, colors
DataFrames: sortable, searchable tables with CSV export	Charts: line, bar, area, scatter and any Vega-Lite spec
Data editor: edit, add and delete rows	Plotly figures with selection events
Chat UI and multipage navigation (dark mode)	Dialogs, fragments and partial reruns
LaTeX (KaTeX) and syntax-highlighted code	Maps (Leaflet, configurable tiles)
Layout: columns, tabs, expanders, containers, popovers	Login: password users and OIDC single sign-on
Themed controls: searchable selects, calendar, time list and color picker (no native browser pop-ups)	Design × scheme: win95 × paper

8 design styles × 8 color schemes × light/dark (theming): streamlit, terminal, retro, win95, XP, brutalist, material and glass, each usable with any color scheme:

terminal × solarized, dark	win95 × paper

Features

• Streamlit's programming model: reruns, widget state, st.session, callbacks, forms, st.rerun/st.stop, cacheData/cacheResource, multipage st.navigation, query params.
• About 70 elements and widgets:
  • text, markdown (with :color[...] and $math$), alerts, metrics, JSON, progress, spinner, toast
  • all input widgets, file upload and download, chat input and messages
  • pills, segmented control, feedback
• Layout: sidebar, columns, tabs, expanders, containers, popovers, st.empty, dialogs, status containers, fragments with runEvery auto-refresh.
• Data: a DataFrame type (structs, CSV, JSON; filter, sort, groupBy), interactive tables, a data editor, Vega-Lite charts, Plotly, maps, images, audio, video.
• Theming: 8 design styles (terminal, retro, win95, XP, brutalist, material, glass, streamlit) × 8 color schemes × light/dark, custom colors and fonts (Streamlit-compatible [theme] keys), and a viewer appearance menu.
• Production:
  • worker threads, so CPU-heavy sessions don't block other users
  • config.toml and secrets.toml (existing .streamlit/ files work)
  • base URL path for reverse proxies, origin checks, session limits
  • Docker image, health endpoint
• Auth: sign-up with automatic password hashing (the first account is admin), invites or approval, roles (st.user.hasRole, st.requireRole), a ready-made admin panel (st.userAdmin()), account page, login throttling, CLI user commands; plus users in secrets.toml and OIDC (Google, Entra ID, Keycloak, …): Authentication.
• App shell and business UI beyond Streamlit: top navigation with sections, breadcrumbs, a header bar, user menu, footer and banners; menu buttons, pagination, cards, stepper, timeline, tags, tree select, date ranges and more: Layout, More elements.
• Custom components compatible with Streamlit's component protocol.
• Extensible: add your own color schemes, design styles and native widgets, in D or in config.toml: Extending.
• JSON API endpoints next to the UI (FastAPI-style typed REST interfaces via vibe.d), on the same port and login, with an optional generated OpenAPI document and Swagger UI at /docs: API endpoints.
• Testing: headless AppTest for unit tests; Playwright end-to-end tests.
• Branding: streamlitd's own favicon by default; set yours per app ([server] favicon, --favicon) or per page (st.setPageConfig(icon:) with an emoji, URL or image file; multipage apps show the page icon).

Documentation

Getting started	install, first app, project layout
Tutorial	build a dashboard step by step
Core concepts	reruns, state, callbacks, forms, fragments, caching, threads
Layout & navigation · Data & charts · Theming	guides
Configuration · Deployment (Docker, nginx, systemd) · Authentication	running in production
Custom components · Extending · JSON API endpoints · Testing	extending and testing
Porting from Python · Cheat sheet · API reference	reference
Troubleshooting · Architecture	FAQ and internals

Requirements

• dub and a D compiler. Tested with LDC 1.36 and DMD 2.114.
• OpenSSL 3 and zlib at runtime, as with every vibe.d app.

Repository layout

source/streamlitd/   the library (server, session, St API, DataFrame, charts, auth, ...)
assets/              frontend: index.html, app.js, style.css, vendor/ (bundled JS libraries)
examples/            runnable apps: hello, widgets, data, multipage, themes, prod, fragments, extras, auth, tutorial, api, custom
docs/                documentation and screenshots
tests/unit/          headless AppTest suites (dub test)
tests/e2e/           Playwright end-to-end tests and the screenshot script
tools/               asset list, API docs and doc-snippet generators/checkers

Tests

./run-tests.sh      # D unit tests + Playwright e2e tests + compile every doc snippet

License

MIT. Bundled third-party libraries are listed in assets/vendor/licenses.