You want your Mastodon account to follow users on a GoToSocial instance and have your posts appear in their federated timeline. GoToSocial is a lightweight ActivityPub server that can communicate with Mastodon, but federation is not automatic. This article explains the exact settings and steps required to establish two-way federation between a Mastodon account and any GoToSocial instance.
Federation relies on both servers implementing the ActivityPub protocol correctly. Mastodon and GoToSocial both support this protocol, but differences in configuration defaults and moderation policies can block communication. You must ensure your Mastodon instance has outbound federation enabled and that the GoToSocial instance is not blocking your server.
This guide covers how to verify federation settings, search for and follow GoToSocial accounts, and troubleshoot common failures like timeouts or empty profiles. After reading, you will be able to connect to any public GoToSocial instance without errors.
Key Takeaways: Federating Mastodon With GoToSocial
- Preferences > Administration > Federation: Check that your instance allows federation with remote servers and that GoToSocial is not in the domain block list.
- Search box with full @username@domain: Paste the complete GoToSocial user address to trigger a remote follow request.
- Server-side domain blocks: If a GoToSocial user appears offline or unreachable, ask the GoToSocial admin to confirm your Mastodon domain is not blocked on their side.
Why Mastodon and GoToSocial Can Fail to Federate
Mastodon and GoToSocial both implement the ActivityPub standard, but they use different software stacks and configuration defaults. Federation fails when one server rejects incoming requests due to domain blocks, rate limits, or missing WebFinger records.
The most common root cause is a domain-level block applied by either server. Mastodon instance administrators can block entire domains through the admin interface. GoToSocial administrators can do the same via the configuration file or the admin API. If your Mastodon domain is blocked on the GoToSocial side, all follow requests and posts will be silently dropped.
WebFinger and Account Discovery
When you search for a GoToSocial user, Mastodon first performs a WebFinger lookup. The GoToSocial instance must return a valid JSON response containing the user’s ActivityPub actor URL. If the GoToSocial instance is behind a reverse proxy that does not forward the .well-known/webfinger path, the lookup fails and Mastodon shows a “User not found” error.
HTTPS and TLS Certificate Requirements
Both Mastodon and GoToSocial require valid TLS certificates for federation. Self-signed certificates or expired certificates cause connection errors. If the GoToSocial instance uses a certificate from a non-standard certificate authority, Mastodon may refuse the connection. Verify that the GoToSocial domain has a valid certificate by visiting https://[gotosocial-domain] in a browser.
Steps to Federate Your Mastodon Account With a GoToSocial Instance
Follow these steps to establish two-way federation between your Mastodon account and a specific GoToSocial instance. Perform each step in the order listed.
- Verify your Mastodon instance allows outbound federation
Log in to your Mastodon account. Open Preferences > Administration > Federation. Confirm that the option “Allow federation with remote servers” is enabled. If you are not an admin, ask your instance admin to check this setting. - Check that the GoToSocial domain is not blocked
In the same Federation page, look at the “Domain blocks” section. If the GoToSocial domain appears in the list, it is blocked. You cannot follow users on blocked domains. Ask your admin to remove the block if you need federation. - Obtain the full GoToSocial user address
Ask the user on GoToSocial for their full handle. The format is@username@gotosocial-domain.example. For example,@alice@social.example.org. Do not omit the@symbols. - Search for the GoToSocial user in Mastodon
Open the Mastodon search box in the top-left corner. Paste the full handle exactly as provided. Press Enter. Mastodon performs a WebFinger lookup. If the user is found, their profile appears in the search results. - Send a follow request
Click the user’s profile in the search results. Click the “Follow” button on their profile page. If the GoToSocial account is private, the user must approve your request. If public, the follow happens immediately. - Confirm the follow appears on both sides
Go back to your Mastodon home feed. Wait up to 30 seconds. The GoToSocial user’s recent public posts should appear in your timeline. Then ask the GoToSocial user to check if your Mastodon account appears in their followers list. - Test posting and visibility
Compose a new public post on Mastodon that mentions the GoToSocial user using@username@gotosocial-domain. Send the post. Ask the GoToSocial user if they received a notification. This confirms two-way federation is working.
If Mastodon Still Has Issues Federating With GoToSocial
Even after following the steps above, federation may fail. Below are the most common failure patterns and their solutions.
“User Not Found” Error When Searching for a GoToSocial Handle
This error means the WebFinger lookup failed. Possible causes and fixes: the GoToSocial instance is down, the domain is misspelled, or the instance does not expose WebFinger. Verify the domain by visiting it in a browser. Check with the GoToSocial admin that the .well-known/webfinger endpoint is accessible from the internet. If the instance uses a subdirectory path like example.com/social, Mastodon cannot discover the user without additional configuration.
Follow Request Never Arrives on the GoToSocial Side
The GoToSocial instance may be blocking your Mastodon domain. Ask the GoToSocial admin to check their domain block list. In GoToSocial, domain blocks are configured in the config.yaml file under the domain-blocks section. The admin can remove your domain from that list and restart the server.
Posts From GoToSocial Appear as Empty or Show “Content Unavailable”
This happens when the GoToSocial instance returns HTML that Mastodon cannot parse. GoToSocial uses a different status format for some content types. The Mastodon instance may need a software update to support the latest ActivityPub extensions. Ask your Mastodon admin to update to the latest stable release.
Federation Works Intermittently or Times Out
Network latency or rate limiting can cause timeouts. Mastodon uses a sidekiq queue to process incoming activities. If the queue is full, federation delays occur. The GoToSocial instance may also rate-limit requests from your Mastodon server. Both admins should check their server logs for 429 or 503 HTTP status codes.
Mastodon vs GoToSocial: Federation Compatibility
| Item | Mastodon | GoToSocial |
|---|---|---|
| ActivityPub version | 1.0 | 1.0 |
| WebFinger support | Required for account discovery | Required for account discovery |
| Domain blocking | Admin panel with GUI | Config file or admin API |
| HTTPS requirement | Strict — valid TLS certificate mandatory | Strict — valid TLS certificate mandatory |
| Rate limiting | Configurable per IP and per user | Configurable per IP |
| Content type support | HTML, text, and custom emoji | HTML and text (limited emoji) |
| Follower migration | Supported via Move activity | Not supported |
Federation between Mastodon and GoToSocial is fully functional for public accounts and public posts. Private accounts and direct messages may have limited visibility due to differences in how each software handles audience targeting.
You can now federate your Mastodon account with any public GoToSocial instance by verifying domain blocks, performing a WebFinger search, and sending a follow request. If federation fails, check the WebFinger endpoint and domain block lists on both sides. For advanced troubleshooting, ask both admins to review their server logs for HTTP 4xx or 5xx responses. GoToSocial does not support follower migration, so you must manually re-follow any GoToSocial accounts after moving your Mastodon account to a new instance.