Mastodon is a federated network of independently operated instances. A publishing workflow must understand the connected instance, its policies, its limits, and the chosen visibility. The default contract is a starting point, not a claim that every server behaves identically.
Current BlendDuck publishing contract
BlendDuck's default Mastodon contract supports up to 500 characters, up to four images or one video, and no mixing of image and video media. It supports reply threads, hashtags, and per-channel settings.
Publishers choose public, quiet public, followers-only, or mentioned-people-only visibility. They may add a content warning of up to 500 characters, mark media as sensitive, and provide a two-letter language code such as en.
The connected instance can report or enforce different limits and policies. Confirm the account's current capability, especially for character count, media, federation, and moderation-sensitive content.
Choose visibility before writing the call to action
Public posts are broadly discoverable and federated according to instance behavior. Quiet public posts remain public but reduce some discovery surfaces. Followers-only posts are intended for followers, while direct visibility should name the people who need access.
Visibility changes the expected audience and interaction. Do not write a broad public invitation and then silently select a narrow audience. Record the intended visibility in the brief and approval.
For a thread, make each reply useful and keep its media within the same four-image or one-video rule. Do not assume every reader will see the complete sequence immediately across federated timelines.
Use content warnings and language deliberately
A content warning should describe what is behind it clearly enough for a reader to decide whether to open the post. It is useful for sensitive subjects, spoilers, intense imagery, or community-specific norms. Do not use vague wording that hides a marketing hook.
Mark sensitive media when appropriate and write meaningful alt text. A sensitive flag does not replace consent, rights, or a content warning when the surrounding text also needs context.
Set the language accurately so clients and accessibility tools can interpret the post. Check names, links, custom emoji, mentions, and character counting near the limit. Instance-specific URL reservation can affect counting.
Approval, federation, and recovery
Approval should bind the exact account and instance, visibility, content warning, sensitive flag, language, text, thread order, media, alt text, sources, and rights. A move to another instance or visibility level changes the context.
After publishing, verify the local public result and delivery state. Federation to every remote server is not instantaneous or guaranteed. Do not equate a remote delay with a local publish failure without evidence.
For partial threads or unknown states, inspect which posts exist before retrying. Record the root URL, reply relationships, and recovery decision so a repair does not create disconnected duplicates.
Measure community fit
Use metrics and qualitative signals appropriate to the post: replies, boosts, favorites, link actions, follower changes, or useful domain feedback. Include moderation response and instance-specific context.
Record the instance, visibility, warning use, topic, format, outcome, and next action. Compare similar audience conditions rather than treating all federated delivery as one uniform network.
Mastodon publishing checklist
- Connected account, instance rules, and current limits verified
- Text and every reply fit the applicable character limit
- Media uses up to four images or one video, without mixing
- Visibility matches the intended audience and call to action
- Content warning, sensitive flag, language, and alt text reviewed
- Sources, rights, mentions, and community norms checked
- Approved instance and settings match the scheduled version
- Local URL, thread relationships, and delivery state recorded
Default product limits were verified on 2026-08-23 against BlendDuck's Mastodon contract. The connected instance remains authoritative for its own limits and policies.
