Seven days. No credit card.

How the trial works

• Seven days of the full Creator plan, no card required to start.
• If you never add a card, nothing charges and nothing silently renews — the account simply pauses.
• After that it is $24/month for Creator, flat. Cancel yourself in one click, any time. Professional is $59/month if you need unlimited connected accounts, API access, and cross-network performance.

Four steps to your first week of posts

1. Create your account.
2. Add your AI key. Castwyn is bring-your-own-key: you pay OpenAI or Anthropic directly, at cost, with no markup from us. The AI keys page links straight to where you create one.
3. Connect your accounts and set your voice per network.
4. Write your week. One idea in, seven distinct posts out — each one written natively for its network, not the same text copy-pasted five times.

What “publishing” honestly means

Not every network allows automatic posting, so here is the real split rather than a vague promise:

• Publishes automatically: LinkedIn, Bluesky, Mastodon.
• Publishes automatically with your own API keys: X. X charges per post through its API, so rather than bundling that cost into the price, you connect your own X app and X bills you directly — the same way your AI key works. Copy & open stays available for free.
• One-click copy & open: Threads, Instagram, Facebook, TikTok, YouTube, Reddit, Substack. Castwyn writes the post and opens that network’s composer with it ready to paste. These platforms either have no public posting API or still owe us app review.

Why bring your own key

Most tools resell AI credits with a markup and then meter your posts. Castwyn charges one flat price for the software and lets you pay your AI provider directly. No post tax, no credit tax, and no surprise bill in a heavy writing week.

Start your 7-day trial