Preview your APK build from Antigravity: the missing device

Antigravity is built around agents that do the work and show their proof — plans, artifacts, browser recordings. For web projects that proof is built in. For an Android project it stops at the APK: your agent can write the app, build the app, and then… nothing. There is no phone in Antigravity. PreviewAPK is the phone: a cloud Android your agent connects over MCP, pushes builds to, drives, and screenshots — so its Android work gets the same verify-then-show loop as its web work.

An agent platform with a device-shaped hole

Antigravity's whole pitch is that agents shouldn't just generate code, they should operate the software — that's what its browser control is for. But browser control ends at the browser. A native Android build isn't a web page: it needs a device, an install, real taps on real UI, and its own log stream when it crashes. None of that exists in Antigravity's built-in integrations, and the curated MCP Store — hand-picked by Google — has no Android device on the shelf.

So Android projects in Antigravity today end the old way: the agent produces an APK and a confident summary, and a human goes off to find a device, install it, and discover what the agent couldn't see.

Connect PreviewAPK (raw config, 2 minutes)

PreviewAPK isn't in the MCP Store — Google curates that shelf and publishes no submission path — but Antigravity accepts any custom MCP server through its raw config, shared by the IDE, the App, and the CLI:

1. Get the server file: curl -o previewapk_mcp.py https://previewapk.siteport.site/mcp/previewapk_mcp.py
2. Get an API key from your PreviewAPK portal (API keys → create). Free during the private beta — join the waitlist.
3. Open the raw config: agent panel → … → MCP Servers → Manage MCP Servers → View raw config (the file is ~/.gemini/config/mcp_config.json), and add:

   {
     "mcpServers": {
       "previewapk": {
         "command": "python3",
         "args": ["/path/to/previewapk_mcp.py"],
         "env": { "PREVIEWAPK_API_KEY": "<your key>" }
       }
     }
   }

4. Save and click Refresh in the MCP servers panel. Seventeen PreviewAPK tools join the agent's toolset — the full list is in the MCP reference.

Give the agent a task it can now finish

Build the APK and run it on PreviewAPK. Sign in with the
test account, add an item to the cart, and screenshot the
cart screen. Check the logs for errors, fix anything you
find, and finish by handing me the preview link.

The phone boots the build in seconds, in the cloud — no local SDK, no emulator image, nothing installed on your machine. The agent works the app with real senses:

• Drive: tap (by coordinates or by a button's label), swipe, hardware keys, and real text typing.
• See: screenshots returned as images inside the conversation, plus the live screen streamed to a browser.
• Understand: the screen's UI hierarchy — elements with labels and positions, so it navigates by meaning, not pixel-guessing.
• Hear: the app's debug log for the session, including the crash trace with its reason attached.

Its proof changes accordingly: instead of a summary that says "implemented," you get screenshots from a real run and a link to the session itself — the agent testing loop Antigravity's philosophy points at, completed for Android.

The handoff is the artifact

When the agent finishes, it hands the wheel to you and returns the session's share link. Open it and the same phone, running the build it just verified, is in your browser — drive it yourself, or pass the view-only link to whoever the app is for. The agent drove it with a key, you drive it in the portal; a link never drives, by design.

Same server, other editors: Cursor and Windsurf connect identically, and the agent guide covers the API and CLI doors for agents that don't speak MCP.

FAQ

Can Antigravity's agents test Android apps?

They can write Android code and even verify web work with browser control, but Antigravity ships no Android device: nothing in its built-in toolset installs an APK, taps through a native app, or reads its logs. An agent building an Android app in Antigravity is building blind unless you connect a device — which is what the PreviewAPK MCP server is for.

Is PreviewAPK in Antigravity's MCP Store?

No — and there's no way to apply. Google hand-picks the Store's direct integrations itself; it publishes no submission form or review queue. The supported route is a custom server in the raw config (Manage MCP Servers → View raw config), which is exactly how PreviewAPK connects. It takes about two minutes.

Where does the config go?

In ~/.gemini/config/mcp_config.json — one file shared by the Antigravity IDE, App, and CLI. Add the previewapk entry from this page with your API key in its env block, save, and click Refresh in the MCP servers panel.

What does the agent need before it can preview?

A built APK (from Gradle, EAS, or any Android build) and a PreviewAPK account with an API key, created in the portal under API keys. The agent then pushes, starts, and tests the build itself.

How much does it cost?

A flat $19/month per device — unlimited runs, no per-minute metering. One device runs one app at a time; swap apps freely while it's off.

Is PreviewAPK affiliated with Google?

No. PreviewAPK is an independent product. Antigravity is a Google product; this page describes a workflow that connects the two, nothing more.