Docs › Channels › Mastodon
Connect a Mastodon account on any server
Connect an account on any Mastodon server, then post text and images with the limits your server sets.
Mastodon has no central service: every account lives on a server of its own. OmniPosts registers itself with your server when you connect, so no review by OmniPosts or by Mastodon is needed.
What you need
- An account on a Mastodon server (or a server that speaks the same API).
- The address of that server, for example
mastodon.social.
Connect it
On Channels, choose Mastodon. The server box already says mastodon.social; if your account
is on another server, type its address instead. OmniPosts sends you to that server to sign in and
approve it, and you then return to OmniPosts. You sign in on Mastodon's own page, with the email and
password you use there; OmniPosts never sees them.
OmniPosts accepts a plain address or a pasted handle such as @alice@mastodon.social. The server must
be reachable over https on a public address. Addresses that point at private networks are
refused.
OmniPosts asks for permission to read your account, read your posts, write posts and upload media. The read permissions are used to check that a post went out and to read numbers.
What you can post
- Text. Up to 500 characters on a standard server. Mastodon counts every link as a fixed length (23 by default) and a mention of a user on another server as just the username. Servers can change these numbers, and OmniPosts reads your server's limits when you connect and applies them before sending.
- Images. Up to 4 per post on a standard server, JPEG, PNG, GIF or WebP, up to 16 MB each. Alt text is supported, up to 1500 characters on a standard server. OmniPosts uses your server's own limits when they are tighter.
- Video. Not supported in OmniPosts yet.
The composer shows one Mastodon setting:
| Setting | Options |
|---|---|
| Visibility | Public (default), unlisted, or private (followers only) |
Numbers you get
Per post, Mastodon shares favourites, boosts, replies and quotes. Quotes need a server on Mastodon 4.5 or newer; on an older server that cell shows "Not available" and says the server is too old. Views, reach and impressions are not shared. Counts are your server's view of the post, not a network-wide total. Per account, OmniPosts records followers, following and post count each day.
Numbers appear only when OmniPosts has switched them on for Mastodon. See Honest numbers.
Good to know
- Tokens do not expire. Mastodon sign-ins stay valid until you revoke OmniPosts on your server. If you do, the channel needs a reconnect.
- Duplicates. OmniPosts sends an idempotency key with each post, which Mastodon honours for about an hour. After that, OmniPosts checks your recent posts before it would ever try again, and a post whose fate is unknown is never sent a second time on its own.
- Server changes. OmniPosts checks your server's address again before every call. If it stops resolving, the post is retried later. If it resolves to a private address, nothing is sent.
- Rate limits are set by your server's admin. A standard server allows 300 requests per 5 minutes per account and 30 media uploads per 30 minutes.