Schedule posts on any instance
Connect any Mastodon server with an access token, then schedule posts and threads alongside X, Bluesky and LinkedIn.
Cancel anytime · or self-host for free
One draft, cut to fit Mastodon
Available channels
Customize per channel
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What Postbase does on Mastodon
- Characters
- 500 per post (the default most instances use)
- Threads
- Chain posts into a thread, published in order
- Instances
- Any server: mastodon.social, fosstodon.org or your own
- Sign-in
- An access token from your instance's settings
Bring your own server
Postbase stores your instance URL with the token, so it works with the big servers and your self-hosted one alike.
Plan, write and post in one place
Schedule Mastodon posts from the calendar, from the built-in agent, or from Claude and other AI tools.
Your week, on one calendar
See Mastodon next to the rest of your networks, so the fediverse doesn't get forgotten.
Ask for a post, get it scheduled
Ask the built-in agent for a post and it writes a Mastodon version that fits your instance's limit.
Here's a version for each channel, sized to fit. It's set for the time you asked.
list_channelsSee connected accounts and their platforms.create_postDraft or schedule a post/thread to any channels.list_scheduledReview what's queued to publish.cancel_postPull a scheduled post before it goes out.Or let Claude post to Mastodon
Connect Claude, Cursor or another MCP client and it can schedule Mastodon posts for you, straight from the chat.
How to schedule Mastodon posts
Three steps, and the first one you only do once.
- 1
Connect Mastodon
On your instance, open Preferences → Development, create an application with read and write access and copy its access token. Paste it with your instance URL on the Channels page.
- 2
Write the post
Open the composer and write once for all your channels, then switch to the Mastodon tab to change the wording just for Mastodon. Click Add post to turn it into a thread.
- 3
Pick a time and schedule
Choose a date and time, or start from an open slot on the calendar. Postbase publishes it on time and retries if the network has a hiccup.
Post to Mastodon from your AI tools
Add the Postbase MCP server to the AI tool you already use and ask it to schedule posts for you.
Frequently asked questions
Does Postbase work with my Mastodon instance?
Yes. Postbase works with any Mastodon server. You connect with your instance URL and an access token from that instance.
Can I schedule Mastodon threads?
Yes. Add posts to a thread in the composer and Postbase publishes each one as a reply to the one before.
My instance allows more than 500 characters. Does Postbase support that?
The composer checks against 500, the Mastodon default. If your instance allows longer posts, split longer text into a thread for now.
Is there a free trial?
Yes. Every plan starts with 7 days free and includes every network, the MCP server and the API. Or self-host the open-source version for free with your own API keys.
Every network you post to
- X
Tweets and threads up to 25 posts, with images and video.
- LinkedIn
Posts up to 3,000 characters with images and a first comment.
- Bluesky
Posts and threads up to 300 characters, with up to 4 images.
- TikTok
Videos and photo posts with captions and privacy settings.
- YouTube
Videos and Shorts with a title and description.
- InstagramComing soon
Posts, carousels and Reels.
- FacebookComing soon
Page posts with photos.
- ThreadsComing soon
Posts and threads.
From the blog
The best open-source social media schedulers in 2026
Six open-source, self-hostable social media schedulers compared on licence, networks, activity and hosted options.
28 September 2026 · 4 min read
GuidesHow to cross-post to X, Bluesky, Mastodon and LinkedIn without it looking copy-pasted
One draft, a version per network: how to cross-post to X, Bluesky, Mastodon and LinkedIn with each network's limits and habits in mind.
26 September 2026 · 2 min read
DevelopersHow to post to Bluesky with the API: app passwords, links, images and threads
Post to Bluesky through the AT Protocol: app passwords and OAuth, clickable links with facets, image uploads and threads, with working code.
24 September 2026 · 4 min read
Ready to get started?
Plan next week's Mastodon posts in one sitting. Postbase fits each post to every network and publishes it on time.
Cancel anytime · or self-host for free
Postbase