| name | streamlit |
| description | Build a CEDA Streamlit app the house way — src/ layout with a frontend/ page tree, st.navigation multipage wiring, npuls logo/branding, and uv+Docker packaging. Use when creating a new Streamlit app, adding a page, or structuring the frontend of a CEDA tool. |
streamlit
CEDA Streamlit apps follow a shared shape. Start from streamlit-template-app
for a new app; match the target repo's existing structure when extending one.
When this applies
This is a knowledge skill — it loads (explicitly via /streamlit, or
automatically) when you create a new Streamlit app, add a page, or structure the
frontend of a CEDA tool. It is reference/convention.
Project layout
src/
├── main.py # entrypoint: page config, navigation, logo
├── frontend/ # pages grouped by subdirectory
│ ├── Overview/Home.py # (or Home/Home.py)
│ ├── Files/...
│ └── Modules/...
├── backend/ # non-UI logic (file handling, processing)
├── config/ # config.yaml + helpers
└── assets/ # npuls_logo.png etc.
Two multipage patterns (match the repo)
- Auto-discovery (
streamlit-template-app): config/screen_scanner.py
provides get_screens() + group_pages_by_subdirectory(); main.py calls
st.navigation(grouped_pages). Add a page = drop a .py in a frontend/
subdir; no wiring needed.
- Explicit (
1cijferho): main.py declares each page with
st.Page("frontend/<Group>/<Page>.py", icon="…", title="…") and passes the
list to st.navigation([...]). Add a page = add a .py and a st.Page
line.
main.py essentials
st.set_page_config(page_title="CEDA …", page_icon=":material/edit:")
pg = st.navigation(pages)
st.logo("src/assets/npuls_logo.png")
pg.run()
Global CSS is applied once in main.py and shared across pages. For NPULS
house style, see the npuls-huisstijl skill.
Auth (optional, SRAM)
Apps gate access with OIDC via SRAM when OIDC_PROVIDER is set — wrap the app
in require_authentication(). See /sram-oidc. Auth is disabled cleanly when
the env vars are absent, so local dev needs no login.
Packaging & run
- Deps via uv (
pyproject.toml + uv.lock); run uv run streamlit run src/main.py.
- Container + local dev: see /docker. Deploy on SDP: see /sdp-onboard,
/surf-sdp-helm-flux (Streamlit URL pattern
https://<app>.<env>.sdp.surf.nl,
health probe /healthz, ingress port 8501).
Important
- Match the repo's multipage pattern (auto-discovery vs explicit
st.Page);
don't mix them.
- Streamlit UI can't be meaningfully unit-tested headless — run the app and click
through the golden path before calling a UI change done; say so if you can't.
- Auth is opt-in: no
OIDC_PROVIDER → app runs open (fine for local dev).
See /sram-oidc. Packaging/deploy: /docker, /sdp-onboard.
- Applies to cedanl repos.
