Social media cross-posting

Astropress supports two self-hosted social media schedulers. Both run as Docker Compose stacks and connect to the same platforms your audience uses.

Postiz

Postiz is an open-source social media scheduling platform (AGPL-3.0) made by GitRoom. It supports the broadest platform list of the two options and includes an AI caption assistant.

Attribute	Detail
Licence	AGPL-3.0
Image	ghcr.io/gitroomhq/postiz-app:latest
Platforms	LinkedIn, Bluesky, Mastodon, Twitter/X, Instagram, TikTok, Pinterest, Reddit, Threads, Facebook, YouTube
Hosting	Self-hosted Docker Compose (Postgres + Redis)

astropress new my-site --social postiz
astropress add --social postiz   # existing project

Scaffolding writes postiz/docker-compose.yml, postiz/.env.postiz.example, and env stubs for POSTIZ_URL and POSTIZ_API_TOKEN.

Setup

1. Copy and edit the env file:

   cd postiz
   cp .env.postiz.example .env.postiz
   # Set POSTIZ_DB_PASSWORD, JWT_SECRET, and MAIN_URL
   # Update DATABASE_URL to match POSTIZ_DB_PASSWORD

2. Start the stack:

   docker compose --env-file .env.postiz up -d

3. Open http://localhost:5000, create your admin account, then connect platforms at Settings → Socials.

When it’s the right choice:

• You need LinkedIn and Bluesky alongside Mastodon and Twitter/X
• You want an AI assistant to help write captions
• You’re publishing across more than 4–5 platforms

Limitations:

• AGPL-3.0 — if you distribute a modified version, you must publish the source
• Heavier stack than Mixpost (Node.js app + Postgres + Redis)

Further reading: docs.postiz.com

Mixpost

Mixpost is a social media scheduling tool (MIT community edition) by Inovector. It is lighter and simpler than Postiz, with a clean UI and MIT licensing.

Attribute	Detail
Licence	MIT (community edition)
Image	inovector/mixpost:latest
Platforms	Twitter/X, Facebook, Instagram, LinkedIn, Pinterest, TikTok, Mastodon
Hosting	Self-hosted Docker Compose (Postgres + Redis)

astropress new my-site --social mixpost
astropress add --social mixpost   # existing project

Scaffolding writes mixpost/docker-compose.yml, mixpost/.env.mixpost.example, and env stubs for MIXPOST_URL and MIXPOST_API_TOKEN.

Setup

1. Copy and edit the env file:

   cd mixpost
   cp .env.mixpost.example .env.mixpost
   # Set MIXPOST_DB_PASSWORD, DB_PASSWORD, and APP_KEY

2. Start the stack:

   docker compose --env-file .env.mixpost up -d

3. Open http://localhost:8080 to create your account.

When it’s the right choice:

• You want MIT licensing with no copyleft requirements
• You don’t need Bluesky or YouTube
• You prefer a simpler, lighter deployment

Limitations:

• Bluesky is not supported in the community edition (only in the Pro/Enterprise plan)
• Smaller platform list than Postiz

Further reading: mixpost.app/docs

Platform comparison

Platform	Postiz	Mixpost
LinkedIn	Yes	Yes
Bluesky	Yes	No (community)
Mastodon	Yes	Yes
Twitter/X	Yes	Yes
Instagram	Yes	Yes
TikTok	Yes	Yes
Pinterest	Yes	Yes
Reddit	Yes	No
Threads	Yes	No
Facebook	Yes	Yes
YouTube	Yes	No
Licence	AGPL-3.0	MIT

Relationship to ActivityPub federation

PeerTube and Castopod (selected under Video and Podcast) already federate natively over ActivityPub — followers on Mastodon, Pixelfed, and other Fediverse instances see new uploads automatically without any cross-posting tool. Postiz/Mixpost complement this by pushing to centralised platforms (LinkedIn, Instagram, TikTok, etc.) that do not speak ActivityPub.