SIGX001 · No mount function#

Dev message

No mount function provided and no default mount function set.

Suggestion

Either pass a mount function to app.mount(), or import a platform package (e.g., @sigx/runtime-dom) that sets the default.

What happened#

app.mount() needs a renderer to turn your component tree into something a platform can display. SignalX's core is renderer-agnostic, so it ships no mount function of its own — a platform package supplies one.

Importing a platform package registers its mount function as the default. That import is usually implicit: the sigx umbrella pulls in @sigx/runtime-dom for you, which is why web apps never see this error. It shows up when you're on core alone, or on a platform whose package hasn't been imported.

Fix it#

Import a platform package so it can install the default:

TypeScript 
import { createApp } from '@sigx/runtime-core';
import '@sigx/runtime-dom';   // registers the DOM mount function

createApp(App).mount('#app');

On the web, importing from the sigx umbrella does this for you:

TypeScript 
import { createApp } from 'sigx';

createApp(App).mount('#app');

Or pass a mount function explicitly — this is the path a custom renderer takes:

TypeScript 
createApp(App).mount(myMountFunction);