Sonarr / Radarr login and "API Key Rejected"
Your Sonarr/Radarr page asks for a login you never set, or a companion app says "API Key Rejected" when connecting.
Each Sonarr/Radarr instance has its own API key, created by the app itself the first time it starts. The key only changes when an app is reinstalled with delete config or a workflow deploys a fresh copy — anything still holding the old key then gets rejected. The other common cause: the login gate on the app's web address can block outside integrations before they ever reach the app, which also shows up as "API Key Rejected".
Get the current credentials from the dashboard, then update anything that connects to the app:
Go to Apps → My Apps and click the app. The detail view shows its access details, including the login when the app has one.
In Sonarr/Radarr: Settings → General → Security → API Key. Copy it fresh from here — don't reuse a key you saved earlier.
Paste the current key into the companion app or integration that complained, and use the app's address exactly as shown on its card — no /api on the end, and no username or password inside the URL. Save, then retry. Still rejected with the right key? The login gate in front of the app may be blocking the integration — contact support and we'll open it up.
If you installed the TV & Movies Autopilot workflow, it wires Sonarr, Radarr and Prowlarr together for you — including keys. Your existing login is kept if you set one earlier.
Forgot the app's login?
Check the app's card first: Apps → My Apps → open the app → Login tab — it shows the username and password whenever SonicBit manages one (including logins the Autopilot workflow set). A plain reinstall won't reset a login: the login lives in the app's config, which survives reinstalls along with your settings. To truly start fresh, choose Uninstall & delete config and install again — just know that clears the app's settings and library configuration too. If in doubt, contact support instead.