bluesky··5 min read

How to Auto-Post to Bluesky Safely (App Passwords, Not Your Real One)

Bluesky automation via the AT Protocol: why app passwords exist, the 300-character limit, four-image posts, and cross-posting Bluesky with X and Threads from one composer.

App passwords: Bluesky's built-in answer to third-party tools

Bluesky designed for automation from day one. Instead of registering developer apps, you create an app password (Settings → Privacy & Security → App Passwords) — a limited credential you can revoke any time without touching your real password.

SparkSocialHq uses the app password once to open a session, stores only the resulting session tokens (encrypted), and never stores the password itself.

What a Bluesky post can contain

The 1 MB image cap trips people up more than the character limit; the composer validates both before you publish.

  • 300 characters of text
  • Up to 4 images, each 1 MB or less
  • Posts appear instantly — no processing delay

Bluesky alongside X and Threads

Bluesky's 300-character limit sits between X's 280 and Threads' 500 — Auto-Adapt produces the right cut for each automatically from one master caption. Connecting takes about thirty seconds since there's no OAuth app approval involved.

Try it on your own account — free

Connect Bluesky and publish your first auto-adapted post in five minutes. Free while in beta, no credit card.

Start posting free