Castwyn
AI content engine7-day trial
Start your 7-day trial
The 7-day trial starts when you add a card, before you add your AI key.
How the trial works
- Seven days of the Creator plan. A card is required to start. You will not be charged until the trial ends. AI provider usage is billed separately to your own key, including during the trial.
- You will get an email about a day before any charge. You can cancel anytime before then from Account and billing. If you cancel before the trial ends, you are not charged.
- After the trial, Creator is $24 per month and renews monthly until you cancel. Professional is $59 per month if you need unlimited connected accounts, API access, and cross-network performance. If a payment fails, paid features stop and your posts and keys stay in the account.
Four steps to your first week of posts
- Start your 7-day trial.
- Add a card to start the 7-day trial from the dashboard. The 7-day trial starts when you add a card, before you add your AI key.
- Add your AI key. Castwyn is bring-your-own-key: you pay OpenAI, Anthropic, or xAI (Grok) directly for variable usage at their rates, with no AI markup from us. The key is encrypted with AES-256-GCM before it is saved.
- Write your first draft, then connect a network when you want Castwyn to publish for you.
What “publishing” honestly means
Castwyn writes posts for 13 networks. LinkedIn, Bluesky, Mastodon, Telegram and Discord publish automatically. Threads and Reddit publishing is not open to everyone yet, so they are copy and paste for now. X publishes only with your own X API keys. The rest are one-click copy and paste.
- Publishes automatically: LinkedIn, Bluesky, Mastodon, Telegram and Discord.
- Threads and Reddit publishing is not open to everyone yet.
- Publishes only with your own API keys: X. X charges per post through its API, so you connect your own X app and X bills you directly. Copy and open stays available and is free.
- One-click copy and paste: Instagram, Facebook, TikTok, YouTube and Substack. Castwyn writes the post, copies it, and opens the network so you paste it.
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. Castwyn does not meter your posts or resell AI credits, but generating more can increase your separate provider bill. Check your provider usage and limits.