Prompt
Help me write a Mastodon post asking other self-hosters how they back up their home servers. I use restic to a friend's NAS. Make it sound like a genuine question, not a poll, and add #SelfHosting #HomeLab. Save it as a draft for Mastodon.How to do it
- Mint a Mastodon agent key In https://app.socialhandoff.com, open Connections, connect your Mastodon account, then create an agent key scoped to Mastodon with draft permission only. Copy the key when it is shown; only its hash is stored.
- Turn on developer mode In ChatGPT settings, enable developer mode so you can add a custom connector.
- Add the connector Create a connector with the URL https://app.socialhandoff.com/mcp and your Mastodon key as the bearer token. ChatGPT needs an HTTPS URL it can reach, so use the hosted app or a public self-hosted instance.
- Brainstorm, then draft Talk through angles in the chat. When you pick one, ask ChatGPT to call draft_post for Mastodon. The post lands in the approval inbox, not on your profile.
Example draft
Honest question for the self-hosting crowd: how do you back up your home server, and have you ever tested a restore? I run restic every night to a friend's NAS across town. It works, but my last full restore test was a year ago and I am a little scared to try again. What is your setup, and how often do you actually test it? #SelfHosting #HomeLab
Gotchas
- Alt text is expected on the fediverse, and many people filter posts without it. The missing alt text guardrail flags drafts before they reach you.
- Read your instance rules on automated posting. Many ask that bot-driven accounts tick the automated account box in profile settings.
- Use CamelCase hashtags such as #OpenSource so screen readers say them correctly, and a content warning for long logs or spoilers.
- ChatGPT connectors need a public HTTPS endpoint. A self-hosted instance on localhost will not work; use the hosted app or expose your instance behind TLS.
- Character limit: 500 characters on a default Mastodon server. Each instance can raise it, so check yours.
- Links: Every URL counts as 23 characters, however long it is.
- Media per post: Up to 4 attachments on a default server.
- File sizes: Images up to 16 MB and video up to about 99 MB on a default install. Instances can set their own limits.
Frequently asked questions
Which ChatGPT plans can add the connector?
Custom connectors depend on ChatGPT developer mode, which OpenAI controls by plan. If you can add a custom MCP connector, you can connect to https://app.socialhandoff.com/mcp with a bearer key.
Can ChatGPT add a content warning to a Mastodon post?
Ask for one and the agent writes the warning as the opening line of the draft. Check it in the inbox preview before you approve.
Can I post to several fediverse accounts at once?
Yes. Connect each Mastodon account, and a single draft can target several. Each target is published and retried on its own.