Web applet and the web contract

Local Flask applet

webapp/ is a single-page Flask + Plotly UI over the runtime, for local exploration only:

pip install -e ".[web]"
./run.sh            # then open http://127.0.0.1:5000

Showcase tables mode: pick a planet, scenario, number of transits and R; get the spectrum with one noisy realization, the template S/N, transit light curves and the slicersim readout diagnostics. Custom planet mode: prefill from a showcase preset, edit the star, planet and atmosphere, run the parametric model; a Derived table reports \(g\), \(H\), \(\mu\) and its source, the temperature clamp, the Vega→AB conversion, the readout used and any residual saturation.

The web contract

Every UI, including the public page on the Lazuli simulators site, drives the model through two small modules so defaults, ranges and messages live in one place:

lazuli_exo.forms.parse() takes the raw form/query strings and returns typed values, fatal errors (missing magnitude, non-positive radius) and non-fatal warnings (a value was replaced or clamped; the run proceeds). Blank mu means chemistry, blank log_p_cloud means clear, blank log_a_haze means no haze.
lazuli_exo.forms.to_params() maps the values onto lazuli_exo.simulate(); lazuli_exo.forms.from_preset() prefills from a showcase planet and scenario.
lazuli_exo.report.summary() turns the resulting SimulatedSpectrum into plain JSON: the arrays to plot, result scalars, derived rows (label, value, css class) and the caveat strings.

The Flask endpoints /api/presets, /api/preset and /api/simulate are a dozen lines each on top of these. Notebook 7. A custom planet, end to end walks through the same path in Python.