Google Vertex AI: get an API key and write fiction with it on your phone

The enterprise-cloud door to Gemini: Express Mode compresses GCP onboarding down to a single API key, with a 90-day free tier for brand-new accounts; the models largely mirror the Gemini API, so you pick this for GCP-side quota, billing, or compliance. This page is the BYOK quick answer for Google Vertex AI: key steps, direct console and pricing links, and the app-side notes that matter. Verified 2026-07-18.

Two links up front: get your key at the official console and check rates on the official pricing page. Prices and free quotas move; the official pages are authoritative.

What does it power inside Foreverse?

The factory preset declares 5 modality flags for Google Vertex AI. The models actually available come from the live catalog fetched in-app — catalogs move fast, and the flag only means the protocol wiring is ready.

Modality	Used for
Text	Continuation · roleplay chat · agent
Vision	Image understanding in chat
Image	Scene illustration · moment cards · comics
Video	Scene-to-video
Embedding	Lorebook vector retrieval

How do I get a Google Vertex AI API key?

Open the Vertex AI Express Mode entry (the console URL here) and sign in with a Google account.
A brand-new Google Cloud account gets the free 90-day Express track (no card); accounts that ever touched GCP or claimed the $300 trial are routed to billing setup instead — that's the official rule, not a mistake on your end.
An API key (starting with AQ.) is auto-generated at sign-up; view or recreate keys later under APIs & Services → Credentials.
Paste the key into the app's Google Vertex AI provider and leave the preset host untouched.

Key in hand: three steps to connect

Open the app's Settings → AI models & services and find Google Vertex AI in the list (one of 62 presets, with logo and search).
Paste the key and tap the connectivity test — it fires one real request to verify key and network, and pulls back the model list while it's at it.
Enable the models you want, then set per-modality defaults (text, image, speech, and video each get their own); continuation, chat, and listening route through them from then on.

The one universal host pitfall: the API host must include its full version prefix (this provider's exact form is in the notes below) — the app never appends /v1 for you.

Google Vertex AI-specific notes

The preset host is https://aiplatform.googleapis.com/v1 (the global Express shape, Gemini native protocol, already wired; keys start with AQ.). For standard Vertex (the region/project shape — some Veo/Imagen quotas live only there), change the host to https://{region}-aiplatform.googleapis.com/v1/projects/{project}/locations/{region}; the key and host shapes must match. The product line was recently renamed (Gemini Enterprise Agent Platform) — docs redirect but endpoints are unchanged. The connectivity test doesn't cover Vertex; verify with a real message.

FAQ

Does Google Vertex AI have a free tier?

Conditionally yes: the Express free tier is 90 days within quota, but only for accounts that have never used Google Cloud (existing accounts are asked to enable billing first); after that it's pay-as-you-go, priced in line with the paid Gemini API.

Where does the key live once I paste it into the app?

It's stored on your device only, under system-level encryption — never uploaded or synced to any Foreverse server. Requests go straight from your phone to the provider's official endpoint with zero markup. To revoke access, delete the key in the provider's console.