Make a post cover you can still edit.
Each cover is three layers: a background, one subject and the words as live text. Move the title or scale the subject without making the picture again, then export for Instagram and X.
MCP: postkit.openkrill.app/mcp1080x1350 and 1600x900Pictures stay on your device
Want 10 covers made in your account's style? Ask for a fixed quote.
2. The pictures
The plate made from the background prompt. Pick one per size to fit each shape.
The cutout made from the subject prompt, or one cutout per scene.
Make them with your own OpenAI key
Kept for this tab only and sent only to api.openai.com.
Copy the prompts
Lay out the cover first.
3. Edit and export
Drag a layer, or pick it and use the arrow keys. Shift moves 10 times further. Ctrl or Cmd with Z undoes.
Speed log
No actions yet.
Use it from an agent
The page and the MCP server run the same make_cover action. It returns the cover spec JSON: layers in order, pixel boxes for each size, the image prompts and an SVG with live text. No key and no sign-in. Ask: Make a cover for my post about why SQLite beats Redis for a small queue.
Claude Code
claude mcp add --transport http postkit https://postkit.openkrill.app/mcpHTTP
curl -X POST https://postkit.openkrill.app/actions/make_cover -H 'content-type: application/json' -d '{"idea":"Why a SQLite table beats Redis for a small job queue","title":"SQLite is your job queue"}'Frequently asked questions
Is the title part of the picture?
No. The title, subtitle and byline stay text on their own layers. You can move them, resize them or change the words without making the picture again. They become pixels only in the PNG you export.
Where do the pictures come from?
make_cover writes one prompt for each picture: a background plate and the subject alone. Make them with a GPT image model in ChatGPT, or with your own OpenAI key on this page, then add the files here.
What is stored?
Your pictures and edits are saved in this browser only, in its own storage. The server sees the words of the cover and nothing else. An API key you paste is kept for this tab only and goes straight to OpenAI.
Which sizes can I export?
Instagram portrait 1080x1350 and X landscape 1600x900 by default, plus 1:1, 9:16, 16:9, 5:2, 4:3 and 3:4. Each size keeps its own layout.