Using Persistent Storage in Custom Apps

What is Persistent Storage?

Custom Apps can store data that persists between sessions using a server-side key-value store, ctx.dataContainer. Unlike client-side JavaScript variables (which reset on reload), values in the data container survive across page loads.

How it works

Storage lives in the app’s server API (Lua). The Vue client calls a server handler with window.rpc; the handler reads or writes ctx.dataContainer.

Server API (serverApi.lua):

exports = {}

function exports.saveCount(input)
  ctx.dataContainer.put("counter", input.count)
  return { status = "ok" }
end

function exports.loadCount()
  return { status = "ok", result = ctx.dataContainer.get("counter") }
end

Client (Script):

// save
await window.rpc('saveCount', { count: 5 });

// read
const r = await window.rpc('loadCount');
const count = r.result;   // nil/undefined if never set

API (server-side, custom apps)

Function	What it does
ctx.dataContainer.put(key, value)	Store a value (string, number, or table)
ctx.dataContainer.get(key)	Retrieve a value (nil if not set)
ctx.dataContainer.delete(key)	Remove a value

ctx.dataContainer is custom-app-only. Tenant Scripts don’t have it; integration scripts use ctx.integration.containers* instead.

Notes

• Store structured data as a table; use ctx.json.encode / ctx.json.decode if you need an explicit string form.
• Keep related data under one key and update it together to minimize round-trips.
• The data container is scoped to the app.