Pyodide

@cfasim-ui/pyodide runs Python code in the browser using Pyodide Web Workers.

useModel

A Vue composable that loads a Python module and returns a run function for calling module functions, and a useOutputs hook for reactive structured model outputs.

import { ref, watch } from "vue";
import { useModel } from "@cfasim-ui/pyodide";

const n = ref(5);
const { run, result, error, loading } = useModel<number>("my_module");

watch(n, (val) => run("double", { n: val }), { immediate: true });

Parameters

Param	Type	Description
moduleName	string	Python module to load (from wheel)

Returns

Property	Type	Description
run	(fn: string, context?: Record<string, unknown>) => Promise	Call a function on the module. Context keys become Python globals.
result	Ref<T>	Return value from the last call
error	Ref<string>	Error message if the call failed
loading	Ref<boolean>	true while loading module or running a call
useOutputs	(fn, params) => { outputs, error, loading }	Reactive hook for structured ModelOutput results

useOutputs

Returned from useModel. Watches a reactive params object and calls the model function whenever params change. The model function should return a dict via the cfasim_model package's model_outputs() helper.

import { reactive } from "vue";
import { useModel } from "@cfasim-ui/pyodide";

const params = reactive({ steps: 100, rate: 0.5 });
const { useOutputs } = useModel("my_module");
const { outputs, loading } = useOutputs("simulate", params);

// outputs.value?.series.column("time")   → Float64Array
// outputs.value?.series.column("values") → Float64Array

Parameters

Param	Type	Description
fn	string	Python function to call
params	MaybeRef<Record<string, unknown>>	Reactive params (deep-watched)

Returns

Property	Type	Description
outputs	Ref<Record<string, ModelOutput>>	Named output tables from the model
error	Ref<string>	Error message if the call failed
loading	Ref<boolean>	true while running

ModelOutput

A columnar data structure for model results. Each column is a typed array (Float64Array, Int32Array, Uint32Array, or Uint8Array).

import { ModelOutput, modelOutputToCSV } from "@cfasim-ui/shared";

output.column("time"); // Float64Array
output.names; // ["time", "infections", "status"]
output.label("status", 0); // "S" (enum label)
modelOutputToCSV(output); // CSV string

Column types

Type	TypedArray	Description
f64	Float64Array	64-bit floats
i32	Int32Array	32-bit signed integers
u32	Uint32Array	32-bit unsigned integers
bool	Uint8Array	Booleans (0/1)
enum	Uint32Array	Integer indices with string labels

Lower-level API

For more control, use the worker API directly:

import { asyncRunPython, loadModule } from "@cfasim-ui/pyodide";

await loadModule("my_module");
const { result, error } = await asyncRunPython(
  "import my_module\nmy_module.run()",
);

asyncRunPython

Executes a Python script string on a Pyodide Web Worker.

function asyncRunPython(
  script: string,
  context?: Record<string, unknown>,
  worker?: "baseline" | "intervention",
): Promise<{ result?: unknown; error?: string }>;

loadModule

Installs a Python wheel on all workers. The module name is looked up in wheels.json served from the app's public directory.

function loadModule(
  moduleName: string,
): Promise<{ result?: unknown; error?: string }>;

loadModuleOnWorker

Same as loadModule but targets a specific worker.

function loadModuleOnWorker(
  moduleName: string,
  worker: "baseline" | "intervention",
): Promise<{ result?: unknown; error?: string }>;