Automate Instagram with ChatGPT
Instagram is one of only two places here where images and video can share a post, and the only one that will not take a PNG.
https://api.antwork.io/mcpChatGPT reaches Antwork through a custom app in Developer mode. It is the longest setup of any client here, and the only one where you build the connector yourself rather than pasting a single line.
Custom connectors are a paid ChatGPT feature, and Developer mode has to be switched on first.
Connect it
- 01Turn on Developer modeSettings, then Apps & Connectors, then Advanced settings. Custom connectors do not appear at all until this is on, which is the usual reason the option seems to be missing.
- 02Create the appBack in Apps & Connectors, click Create app. Name it antwork, paste the MCP server URL, set the connection to OAuth, confirm and create.
- 03Turn on memory, then authorizeSwitch on "Reference memories and chats" so ChatGPT keeps your brand voice across conversations, then sign in to authorize Antwork.
What you can say once Instagram is connected
“Draft an Instagram caption for this photo in my voice, with three hashtags at the end.”
“Turn this carousel of five images into an Instagram post and schedule it for Saturday.”
“Rewrite my last Instagram caption with a stronger first line.”
“Which of my Instagram posts got the most engagement this month?”
What is different about Instagram
Only hereJPEG only
Instagram accepts .jpg and .jpeg and nothing else. A PNG, which is what most design tools export by default, is refused. Antwork checks the extension when you attach rather than letting you find out at publish.
A carousel does not have to be all one thing
Up to ten items in a post, and they can be images and video together. Most platforms here force you to pick one kind; this is not one of them.
There is no landscape
Image ratios are 4:5, 1:1 and 1.91:1, and video is 9:16, 1:1 or 4:5. Nothing 16:9 fits, so a cut made for YouTube needs recutting before it comes here.
Fifteen minutes, ten times over
Each video can run fifteen minutes at 300 MB, and ten of them can sit in one post. The limit you will hit first is almost never the length.
Questions
- Do I need an API key to connect ChatGPT?
- No. Antwork connects over OAuth — you approve a consent screen in the browser and you are done. There is no key to generate or paste into a URL, which is how most social MCP servers handle it.
- Do I need a paid account?
- No. Your first two connected accounts are free forever, with unlimited posts and workspaces, and there is no plan gate on MCP access.
- Will ChatGPT post without showing me first?
- Not unless you ask it to. Drafting and publishing are two separate steps: the agent writes, renders the post card, and only publishes when you confirm.
- Does the writing sound like AI?
- Antwork hands the agent that account's recent posts, along with how each performed, and the agent writes to match them. On Instagram that includes writing to the length the format rewards, up to 2,200 characters.
Never leave ChatGPT to post again.
One command, one consent screen, and Instagram is something you can just ask for.