Post everywhere. In your voice. On autopilot.
One idea in. A week of posts out.
Castwyn turns a single idea into platform-native posts for every network, written in your voice and scheduled for when your audience shows up. LinkedIn, Bluesky, and Mastodon publish automatically; the rest are one-click copy & paste while each platform’s review is pending. Flat price. Bring your own keys. No post tax, no credit tax.
Write my week
One idea becomes seven distinct posts — each a different angle, written natively for its network rather than copy-pasted.
Your voice, per network
Set tone, style, cadence, and what to avoid for each platform. Castwyn adapts the idea instead of blasting the same text everywhere.
Queue and calendar
Schedule a week across every connected network and see it laid out. Edit, reschedule, or pause anything until the moment it publishes.
InsightsPro analytics
Verified engagement from the networks themselves on every plan — plus which network actually pays off per post and your best day, on Professional.
Media library
Upload once and attach images to any post. Publishes with alt text on LinkedIn, Bluesky, and Mastodon.
Bring your own AI keys
Connect your own OpenAI or Anthropic key. AI runs at cost, encrypted at rest, never logged or resold — so writing more never costs more here.
API and MCPProfessional
Connect Castwyn to n8n, Make, curl, or Claude and generate, queue, schedule, and publish from anywhere.
Affiliate program
Earn 30% of what everyone you refer pays, every month for their first year. Free to join.