Create a thread (multiple posts) on X/Twitter, Bluesky, LinkedIn, Threads, Mastodon, Instagram, Facebook, or Telegram. Publish to several accounts at once by naming account_ids instead of account_id, and give one of them a thread of its own with account_configurations. X, Bluesky, Threads, Mastodon, and Telegram support native reply threading. Others degrade gracefully to standalone posts. A THREAD IS ATOMIC: if any part fails, every part already published is deleted from the platform and the whole thread's quota is refunded, and the error's `thread_rollback` says what was rolled back. Two codes tell you whether a retry is safe: `upstream_error` means nothing of the thread is on the platform, so repeating the request is safe, while `thread_rollback_incomplete` means the posts named in `thread_rollback.still_live` are still up with their ids and URLs, and repeating the request would publish them twice. On an Instagram account connected by signing in with Instagram, where Chirpie cannot delete a published post, a failed thread always reports its published parts as still live. On X, each post in the thread whose text contains a link is billed at $0.25 on paid plans; on the Free plan such threads are rejected (x_link_posts_require_paid_plan). X accounts connected with your own X API keys are exempt. A thread that would cross the monthly post or scheduled-post quota answers 429 usage_limit_exceeded and publishes nothing; the per-minute burst limit on the API key answers 429 rate_limited. Set draft: true to save the thread without sending it: nothing reaches the platform, nothing counts against the quota, a draft thread may still be a single part long, and the answer carries a `warnings` array. chirpie_update_post on any of its parts promotes it, and the whole thread goes together.