GuidesTechnology

How to use Antigravity with Fabapp AI

Figures from September 17, 2026

Connecting Antigravity to your account

Antigravity adds MCP servers from the editor's own panel, and that is where the usual block goes:

{ "mcpServers": { "fabapp": { "command": "npx", "args": ["-y", "@fabappai/cli", "mcp"] } } }

After adding it, the panel lists the tools that came through. That list is your connection test: empty means the server did not start; short means that machine's credential is read-only.

What you need

Node 20 or newer, a Fabapp account on the Builder plan or above, and a single login:

npx @fabappai/cli login

The credential goes into the system keychain. It is never displayed, and it is revoked from one place, in the panel.

The loop

npx @fabappai/cli create "My store"
npx @fabappai/cli dev

dev assembles the app on your machine on the same template the platform publishes with, installs the dependencies and starts the local server. With it running, ask for what you would do by hand: read the definition, create the entities, write the screens. Then:

npx @fabappai/cli deploy

It uploads what you changed and publishes, in that order. Publishing before uploading would publish what is on the server, and your work would be left behind.

What is different about Antigravity

Antigravity is an agentic editor: the assistant does not wait request by request, it works through longer tasks and shows you what it did. That suits a platform where the work has chained steps, and it asks for one precaution: a long task is where a contract mistake propagates.

So when you ask for something big, ask for it in order. Documentation first, then the definition, then the schema, and only then the screens. An agent that writes five pages on top of an invented schema rewrites all five.

The other thing that helps on long tasks is leaving dev running the whole time. The error shows up in the browser while the agent is still on the subject, instead of showing up at build time when it has moved on.

What to ask for

"Read the platform documentation before writing the schema." The field types are a closed list and anything else is refused; the access rules are the only thing between an app's data and the public.

"Read the current definition before changing it." Without the schema at hand, a wrong model id answers 404 and an invented field answers 422.

"Schema first, screens after." The SDK is generated against the data model.

Frequently asked questions

Can Antigravity publish on its own?
It can, if that machine's credential has write permission. It is worth deciding whether you want that: `deploy` publishes. To review first, `--no-publish` uploads without publishing.
How do I know the connection is up?
Through the editor's MCP panel: it lists the tools the server offered. An empty list is a server that did not start; a short list is a read-only credential.
Can it break my published app?
What is published only changes when somebody publishes. Until then the work sits in the draft and you watch it through `dev`.
Start building for free
Read next
Command line and MCP in app builders: what changes when the project leaves the browserBest AI app builders in 2026