Castwyn
Help CenterFAQs
The short answers. Something missing? Ask us.
Which networks can Castwyn post to?
Castwyn writes for all eleven. Three publish automatically on a schedule: LinkedIn, Bluesky, and Mastodon. The rest are one-click copy & paste until each platform approves automatic posting, and some never will. X also auto-publishes once you connect your own X API keys, because X bills per post — see the X questions below. Threads direct publishing is in a limited beta while Castwyn completes Meta's app review. Reddit closed new API access to small products in late 2025, so Reddit is copy & paste only and Castwyn will not promise a date it does not control. Instagram, TikTok, YouTube, Facebook, Threads, Reddit, X, and Substack all support one-click copy & paste as a free alternative: Castwyn writes the post, copies it, and opens the network so you just paste.
What does "bring your own keys" mean?
You paste your own OpenAI or Anthropic API key, and generation bills straight to your provider account at cost — Castwyn never marks up AI usage or resells credits. Your keys are encrypted at rest and used only for your generations.
How does the 7-day trial work?
Sign up with email and password — no credit card. You get the full Creator plan free for 7 days (Professional features like the API and cross-network analytics stay on Professional). After that Creator is a flat $24/month; Professional is $59/month if you need unlimited connected accounts, REST API and MCP access, and cross-network performance. Add a card only if you decide to continue, and cancel anytime in one click.
How do the seven post variations work?
Compose opens in "Write my week": one topic or source becomes 7 distinct posts (3–10 if you prefer), each a different angle — educational, personal story, contrarian take, practical tips, common mistake, discussion prompt, key takeaway. Near-duplicates get flagged so you can regenerate them.
When exactly do scheduled posts publish?
Automatically, within about five minutes of the time you picked. A background publisher sweeps for due posts every five minutes around the clock, plus every time you open the app — you do not need to be online for scheduled posts to go out.
Are the recommended posting times based on my audience?
Not yet — they're clearly labeled general estimates from platform-wide patterns. Once your connected accounts build enough engagement history, recommendations become personal to your audience.
Why does X need my own API keys when other networks don't?
Because X charges per post. It removed its free tier in February 2026 and now bills roughly $0.015 for a plain post and $0.20 for a post containing a link. Castwyn charges a flat monthly price, so bundling an unbounded per-post cost would mean either raising the price for everyone or capping how much you can post. Instead X works exactly like your AI key: you connect your own X app, X bills you directly, and Castwyn marks up nothing. You can also ignore this completely and keep using one-click Copy & open, which is free.
How do I connect X with my own keys?
Create an app at developer.x.com with Read and write permissions, then open Keys and tokens and copy four values: API Key, API Key Secret, Access Token, and Access Token Secret. Paste all four into Castwyn's Connect X page. Castwyn verifies them immediately, so a wrong paste fails right there instead of on a scheduled post days later. All four are encrypted before storage and used only to publish posts you approve.
Once X is connected, can I schedule posts to it?
Yes. With your own keys connected, X behaves like every other connected network: scheduling, the queue, the calendar, and Write my week all work. Just keep the pricing in mind — a scheduled week of seven link posts costs about $1.40 at X's rates, billed by X to you.
What does X cost me per month?
It depends entirely on how much you post there. Thirty plain posts is about $0.45. Thirty posts containing links is about $6.00, because X charges 13x more for posts with URLs. There is no monthly minimum and no subscription — you pay only for what you publish. If that math does not appeal, use Copy & open instead and pay nothing.
How do I make my account more secure?
Turn on two-step sign-in from Account and billing. After that, signing in needs your password plus a 6-digit code emailed to you, so a stolen or reused password is not enough on its own to reach your saved AI keys and connected accounts. Codes expire in 10 minutes and work once. It is optional, and you can turn it off the same way.
What if I turn on two-step sign-in and lose access to my email?
When you switch it on, Castwyn gives you eight recovery codes and shows them once. Save them somewhere safe. Each one works a single time and gets you in without the emailed code. Enter one in the same box you would put the 6-digit code. If you run out or never saved them, contact support and your identity can be verified another way.
What is Mastodon, and do I need it?
Mastodon works like Twitter/X, except no single company owns it — there are thousands of independent servers that all connect to each other, so you pick a server and can still follow anyone on any other one. It is smaller than the big networks but active with tech, privacy, design, and indie-creator audiences. It is entirely optional: skip it if that is not where your people are. It is worth offering because it is the one network with no approval process, so Castwyn can publish there automatically from day one.
How do I connect Mastodon?
First create a free account at joinmastodon.org (mastodon.social is the largest and a safe default). Your address has two parts, your name and your server, like @you@mastodon.social — if you are not sure which server you are on, open your Mastodon profile and the server name is shown right under your profile name. Then in Mastodon go to Preferences, Development, New application; name it anything; tick the write:statuses scope; submit; and copy "Your access token". Paste that token plus your full address into Castwyn's Connect Mastodon page. That token is not your password and only lets Castwyn post.
Why is Substack "one-click paste" instead of direct publishing?
Substack has no public posting API, so no tool can publish there directly. Castwyn does everything up to the last step: writes the Note in your voice, copies it, and opens Substack so you just paste and publish.
Does Castwyn have an API?
Yes — on the Professional plan: a REST API for n8n, Make, and curl, plus an MCP server so Claude (or any MCP client) can generate, queue, schedule, and publish for you. Create a token and grab copy-paste examples on the API & MCP page in the app.
Is my data safe?
AI keys and social tokens are encrypted at rest and used only to generate and publish for you. We never resell your compute, your content, or your data. Revoke any connection or API token at any time.
Can I edit posts before they go out?
Always. Nothing publishes without you queueing it. Every generated post can be edited, regenerated on the same angle, copied, queued as a draft, or scheduled — and scheduled posts can be edited, paused, or rescheduled until the moment they publish.
How do I cancel?
One click from Account & billing in the app sidebar. No clawback, no retention call. You keep access until the end of what you've paid for, and your data stays until you tell us to delete it.
I forgot my password (or which email I used) — how do I get back in?
Your username is your email address. Use "Forgot your password?" on the login page and a one-time reset link is emailed to you right away, any time of day. (If email delivery ever fails, we queue it manually during office hours, Mon–Fri 8–5 ET.) Forgot which email you signed up with? Email blakesmurphy@gmail.com with your name or social handles and we'll find your account.
How do I delete my account?
Account & billing → Delete account. It asks you to type DELETE because it's permanent: your subscription is canceled immediately and your saved AI keys, social connections, posts, and API tokens are permanently deleted.