An app can only use the folders, AI and URLs its manifest declares. Test what this example is allowed to do, see the errors you get, and learn to check before you call.
It can read all of Documents but only write to Documents/Reports, can't use AI, and can only call Open-Meteo's /v1 API.
Reads use readDir. Writes save and then delete a small test file. Every app also gets its own private folder (its sandboxPath) without asking.
This manifest has "ai": false, so AI is off for this app.
A URL is allowed when it starts with a declared entry. canFetch() checks without sending anything.
Return values and errors show up here, exactly as your code would get them.
Every call this page made. Click one to see its result again.
The helpers this page runs on. Copy them into your app as they are.