Claude Code vs Gemini: My Stateful Image Workflow

The problem with most image gen is that it's basically goldfish memory. You ask for a cyberpunk kitchen, it gives you one. You ask to add a ramen sign, and suddenly the kitchen is gone, the lighting changed, and the "cyberpunk" vibe shifted to "generic 90s sci-fi." It's stateless misery.

I've been using a setup that wraps gemini-3.1-flash-lite-image

(aka NB2Lite) into an MCP server to feed it into Google Antigravity. Unlike the usual "prompt and pray" method, this uses the Interactions API, which actually maintains state. You generate an image, get an interaction_id

, and then you can just say "add a neon sign" without re-describing the entire room.

The Technical Plumbing #

The magic happens because the server handles the interaction_id

handoffs. If you're trying to build something similar, here is how the stateful loop actually functions:

1. Initial call: client.interactions.create(prompt="...", store=True)

2. Response: You get an interaction_id

.

3. Follow-up: You send the new prompt + previous_interaction_id

.

The server implementation I'm using (via FastMCP) basically abstracts this so the agent doesn't have to manage the IDs manually. Here is a snippet of how the tool definition looks in the server.py

logic:

@mcp.tool()
async def edit_image(prompt: str, interaction_id: str):
    """Edits an existing image using its interaction ID to maintain visual state."""
    response = await client.interactions.create(
        prompt=prompt,
        previous_interaction_id=interaction_id,
        store=True
    )
    return {
        "image_url": response.url,
        "new_interaction_id": response.interaction_id
    }

Real-World Constraints (The "Gotchas") #

Since I'm the one actually dogfooding this while my team asks "why isn't it perfect yet," here are the specific technical walls you'll hit:

The Aspect Ratio Trap: You set the ratio (1:1

,16:9

, etc.) at the start. If you try to change it during a stateful edit, the pixel continuity falls apart. The server I'm using explicitly blocks aspect ratio changes during edits to prevent the model from hallucinating a new composition.Thinking Levels: The API documentation mentionsminimal

andmedium

thinking levels. In reality, if you send those to the flash-lite-image model, you get a crisp HTTP 400 error. Stick tolow

for fast drafts andhigh

for when you actually need the text in the image to be readable.ID Forking: Every edit generates anewID. If your agent accidentally references an ID from three turns ago, it doesn't error out—it just "forks" the image state back to that version, which is a nightmare to debug if you don't have logging enabled.

Deployment Workflow #

For those who want to stop wasting time with stateless prompts, the deployment is straightforward. You need the nb2lite-skill-agy

package, which acts as both the MCP server and the Antigravity skill definition.

1. Install the server dependencies.

2. Configure your Gemini API key in the environment.

3. Link the MCP server to your Antigravity config.

Once that's done, the workflow changes from "Write a 50-word prompt describing every detail" to "Change the color of that chair to red." It's significantly faster, and I've managed to cut my "prompt tweaking" time by about 60% because I'm not fighting the model to keep the background consistent.

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