What they did
The team behind the browser card game Sajkab makes a lot of art: card skins, standees and backgrounds. Image generation through the Gemini API is billed per image, while Google's Antigravity agent can use the same image model under its plan quota. Rather than copy prompts between the two apps by hand, they wrote one shared skill. Claude Code writes a request into a text file in the repo with the prompt, reference images, variant count and aspect ratio. A bash script polls the file every 30 seconds so the agent spends no tokens waiting. Antigravity picks up the request, generates the image and writes back the file path and a status. Claude Code then reads the reply and carries on. Both sides shut down after an hour of silence.
How it went
On the first real job, a new skin for the Jaguar Warrior card, they ran nine requests in a row in one afternoon with no manual steps, each taking 40 seconds to 2 minutes. The illustration needed four rounds of fixes, done by sending the previous image back as a reference with a narrow change. The run also produced the standee, a stadium background, and the article's own banner and diagram. Claude kept the conversation's context across rounds, which it had lost when the steps were done by hand.
Worth knowing
It handles one request at a time and uses atomic file moves so neither side reads a half-written file. Vague prompts caused trouble: asking for a weapon on the back gave two weapons, and a real team name copied an NFL logo. Antigravity is not yet in our agent list. The post also promotes the game.