Connect a Mastodon-Compatible Client App

Overview

Connect a Mastodon-compatible client app so a user can work with their Joomla actor outside the administrator backend. This gives the actor a mobile or client-driven workflow while keeping the identity on your own site.

You typically need this when a user wants to test client-app compatibility or manage their actor through an external app that speaks the expected protocol. This is a Pro feature. After you complete the flow, the client app should show the Joomla actor as a connected account and be able to perform the supported authenticated actions.

Before you begin

OAuth/C2S endpoints require the Pro tier.
The Joomla user must already have a local actor.
Your site base URL must be publicly reachable by the client app.
Use a Mastodon-compatible client app that allows adding an account on a custom server or instance URL.

Steps

Open your Mastodon-compatible client app.
Choose Add account, Log in to another instance, or the equivalent action.
Enter your Joomla site base URL as the server or instance address.
- Server or instance URL - Use the public base URL of your Joomla site. The app must be able to reach this address externally for OAuth and actor discovery.
Continue into the browser-based OAuth sign-in flow.
Sign in with the Joomla user account that owns the local actor.
Review the requested access and approve the authorization.
Return to the client app and confirm the account is connected.

Check your result

The actor appears as a connected account in the client app.
OAuth token exchange succeeds.
Authenticated actions such as outbox posting or media upload are available.

Troubleshooting

The client app cannot connect to the site

Likely cause: The site is not on the Pro tier, the public base URL is wrong, or the site is not reachable from the client app.
Solution: Confirm the license tier first, then verify the site’s public base URL and external reachability.

Likely cause: The Joomla user authenticated successfully, but there is no local actor provisioned for that user.
Solution: Create or resave the Joomla user so a local actor exists, then repeat the client-app connection flow.

The account connects, but expected actions are missing

Likely cause: The client app expects capabilities beyond the currently supported authenticated actions.
Solution: Verify the app against the supported action list below rather than assuming full Mastodon parity.

Supported authenticated actions

OAuth token exchange
Authenticated outbox posting
Authenticated media upload