Zero Gravity Prototyping with Google Antigravity

The hardest part of prototyping a new feature isn’t the idea. It’s the wait.

You have a product owner with a vision. You have a designer with mockups. And you have a backend that isn’t ready yet. In a traditional workflow, the frontend sits idle until the API exists. That wait kills momentum, and momentum is everything in early-stage product work.

I recently started using Google Antigravity to break that dependency entirely. The result is a prototyping workflow that lets frontend development run at full speed, independent of the backend, with an AI agent doing the iteration work while I review and redirect.

Here is how it works.

The Setup: An Angular Frontend Running on Mock Data

The foundation of this workflow is simple: build your Angular frontend against mock data instead of real API calls.

This is not a new idea. Developers have been using mock services for testing for years. What is new is what happens when you hand that frontend to an AI agent and tell it to iterate.

In our setup, we create Angular services that return hardcoded mock data — the same shape as the eventual API response but sourced locally. The frontend has no knowledge of a backend. It just knows what data looks like.

From there, Antigravity takes over.

What Antigravity Actually Does

Google Antigravity is an agent-first IDE built on top of Gemini 3 Pro. What sets it apart from tools like Cursor or GitHub Copilot is its browser control capability.

When you give Antigravity a task, say, “update the dashboard to show a summary card at the top of the page”. The agent does not just write code and hand it back to you. It writes the code, launches your Angular app in a Chrome browser it controls, navigates to the relevant page, visually verifies the change, and produces a screenshot or walkthrough recording as an artifact. You review the artifact, leave feedback, and the agent iterates.

This loop (prompt, build, verify in browser, artifact, feedback) is what makes the workflow fast. You are not running the app yourself and checking the result. The agent does it.

The Workflow in Practice

Here is how a typical session looks:

1. A product owner describes what they want. A new filter on the orders list. A revised layout on the profile page. A new state for an empty data set.
2. I give Antigravity the task. The agent reads the existing Angular components, writes the changes, and launches the app.
3. Antigravity’s browser agent navigates to the affected view, interacts with it, and captures a screenshot or recording. That becomes the artifact.
4. I review the artifact. If something is off, I leave a comment directly on it, similar to commenting on a document, and the agent incorporates the feedback without stopping.
5. Once the result looks right, we commit the changes to a branch.
6. When the backend is ready, a second engineer picks up that branch and wires the mock service calls to real API endpoints. The component logic does not change. Only the data source does.

That last step is the key. Because the frontend was built against a defined data shape from the start, connecting it to a real backend is a wiring exercise, not a rewrite.

What Antigravity’s Browser Control Changes

Most AI coding tools operate blind. They write code and trust that it works. Antigravity’s browser agent changes that dynamic.

When the agent controls Chrome, it can click through your UI, trigger state changes, catch rendering errors, and validate that what it built matches what you asked for. It records the session so you have a playback you can review. It captures console errors it encounters along the way.

For frontend prototyping specifically, this matters. UI work is visual. A tool that can see the result is fundamentally different from one that cannot.

You Do Not Have to Use Antigravity

This workflow is not exclusive to Antigravity. The mock-data pattern and the commit-then-wire handoff work with any AI coding tool.

Cursor handles this kind of iterative frontend work well, particularly if your team is already working inside VS Code. GitHub Copilot with agent mode can take on similar tasks within your existing editor. Claude is capable of reasoning through component changes and producing solid Angular code with enough context.

What Antigravity adds is the browser verification loop. If your team is already productive with one of these tools, the mock-data approach still applies. You just handle the visual verification yourself rather than delegating it to an agent.

Why This Works

The backend is often the constraint in early product development, not because backend engineers are slow, but because good API design takes time. You want to get the data model right before you build against it.

This workflow accepts that constraint and routes around it. The frontend team moves forward. The backend team designs without pressure from a blocked frontend. And when both sides are ready, the integration is straightforward because the data shape was agreed on from the start.

Prototyping does not have to wait for everything to be ready. With the right setup, it can be weightless.

Chad Michel Chief Technology Officer

Chad is a lifelong Nebraskan. He grew up in rural Nebraska and now lives in Lincoln. Chad and his wife have a son and daughter.

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