Backend maintainer guide

What it does

The backend is a FastAPI app with one endpoint: POST /generate.

It receives a values dict from the UI, writes it to a temp file, runs helm template, and returns the rendered manifests (or an error string from stderr).

In production it also serves the compiled React frontend as static files.

Running locally

cd ui/backend
pip install -r requirements.txt
uvicorn main:app --port 8000 --reload

The React dev server (npm run dev in ui/frontend, or npm start in ui/docs) proxies /generate to http://localhost:8000 automatically — no extra config needed.

Endpoint

POST /generate

Request body:

Field	Type	Default	Description
values	object	—	The values dict (same content as values.yaml, parsed to JSON)
release_name	string	my-app	Helm release name
oci_chart_ref	string	oci://ghcr.io/my-github-repo/helm/base-chart	OCI chart reference
oci_chart_version	string	1.0.0	Chart version

Success response: { "manifests": "<yaml string>" }

Error response: { "error": "<helm stderr>" }

Requirements

• helm must be installed and in $PATH
• For private OCI registries, run helm registry login <registry> first

Production build

cd ui/frontend
npm run build          # outputs to ui/frontend/dist/

cd ui/backend
uvicorn main:app --port 8000   # serves React + /generate on port 8000

Adding a new endpoint

Add a route in main.py before the static-files mount at the bottom:

@app.get("/health")
async def health():
    return {"status": "ok"}

The app.mount("/", ...) line must stay last — it acts as a catch-all for the React frontend.