Update App Store Metadata with the App Store Connect API

Each row comes from Apple's attribute lists: app store version localizations carry locale, description, keywords, marketing URL, promotional text, support URL and What's New; app info localizations carry locale, name, subtitle and the privacy fields.

Apple says the API can automate certain tasks in App Store Connect. Keys are role-based, and the Account Holder must request API access in App Store Connect before anyone can create one. Use the narrowest role that can edit metadata, and keep the private key out of source control.

1. Export the current state. Read the existing localizations for the editable version and save them as files. This is your rollback.
2. Prepare changes in files, one per locale. Keep them in version control so diffs are visible.
3. Validate before sending. Check name and subtitle at 30 characters, promotional text at 170, description and What's New at 4,000, and the keyword field at 100 bytes. The keyword field counts bytes, so a Japanese list holds about a third as many characters. Use the metadata limits tool or your own script.
4. Diff against the export. Review every changed locale. Check every locale code against the locale code reference so each change lands on the language you intend.
5. Send to an editable version only. Apple says other attributes than promotional text need the app in an editable state. If no version is editable, you need to create the next version first.
6. Check the result. After a write, Apple says changes can take up to 24 hours to appear on the App Store. Read the data back through the API rather than relying on the storefront.
7. Submit for review yourself. Writing metadata does not submit anything. Submission is a separate action you take when the draft is correct.

A hypothetical habit tracker, Streakly, has English and German localizations and wants to change the German keyword field. The new value is "Gewohnheiten,Tagesplaner,Routine,Ziele", which is 38 characters and 38 bytes, safely under 100. The change touches one attribute of one localization. The script diffs it against the export, shows one changed field, sends one request and reads it back. Nothing else is modified.

If the new value had been Japanese, the same check would run on bytes, not on characters.

• It does not research keywords or decide what to write.
• It does not make a change visible to everyone immediately.
• Apple's attribute lists above name the fields; media such as screenshots have their own resources, and Apple notes that older screenshot and preview relationships are deprecated in favor of its asset library.

LocalASO works without an Apple account by reading the public listing. If you add an App Store Connect key with the App Manager role, it can show your real keyword field and all localizations, and upload listing text to App Store Connect as a draft after you review an old-versus-new diff. It only writes to an editable version or creates the next one, and it never submits an app for review, touches builds or deletes anything. You submit from App Store Connect. Setup is in the App Store Connect docs.