Arcane.preferences.set()

This focused page is derived from the mechanically checked full member inventory.

Syntax

Arcane.preferences.set(key, value)

Parameters

key; JSON-compatible value up to 131,072 encoded bytes

Return value

Promise<{key, value, bytes, totalBytes, maximumBytes}>

Description

Atomically writes one preference under the 1 MiB total quota. Requires preferences.write.

Overview

Atomically creates or replaces one app-scoped preference. The complete value is validated before mutation, and the resolved receipt returns the JSON-normalized value that was actually persisted.

Input, result, and errors

Requires preferences.write. Keys and values use the storage key, JSON, 128 KiB per-value, and 1 MiB total-envelope limits. The promise resolves to {key,value,bytes,totalBytes,maximumBytes}. Invalid JSON-compatible data or a quota overflow rejects without replacing the prior preference document.

Example

async function saveDensity(density) {
    if (!['compact', 'comfortable'].includes(density)) {
        throw new TypeError('Unsupported density');
    }
    return Arcane.preferences.set('layout.density', density);
}

await saveDensity('compact');

Reference group

Filesystem, storage, preferences, and appearance