Gamestage, made by Monterosa, takes a game you have vibe coded in a browser and puts it into production. The answers, the scoring, the play limits and the settlement move to a server. The interface stays as you built it.
A prototype keeps its answers in the page, where anyone who opens the developer tools can read them. That is fine for a demo and stops being fine the moment strangers play for something. Moving the answers off the page also brings the things a live game needs and a prototype has none of: logs, monitoring, and limits on how often one person can play.
How does Gamestage change your game?
Your web app keeps its interface and sends each play to Gamestage. The Engine holds the material a player must not see, works out the result and sends back what it decided.
BROWSER BEFORE BROWSER AFTER
────────────────────────────── ──────────────────────────────
interface and input interface and input
answers and values ↓ intent
scoring and limits ┌────────────────────────────┐
│ ENGINE │
│ answers, scoring, locks, │
│ attempts, settlement │
└────────────────────────────┘
↓ committed outcome
the page renders what it is toldThe decisions move to the server and you keep the interface.
Who Gamestage is for
Gamestage is made for creators or developers with a game prototype that runs in a browser and a coding agent like Claude Code or Codex doing the work. You install our CLI tool, then the agent reads its existing source, moves private material into the App Manifest, wires a newly generated client and runs a series of checks.
You make the decisions an agent should not: rights, audience, identity, and anything that changes what a live audience can touch.
You do not need to have used Monterosa before. Inspecting your game and scaffolding its manifest need no account; running it against the Engine does, once you reach that step.
What Gamestage is not
It is not a front-end game engine. Gamestage does not draw anything, own a scene graph or ask you to adopt a framework. The Engine holds one game format's rules and answers questions about a play. Your app is still your app.
It is not a cloud hosting company. Every deployed game, on Starter and above, is a project on Monterosa Interaction Cloud with real editions, and Starter games are served from a Playground environment so a game has somewhere to live. A paid plan changes which Space your projects sit in and adds Studio's content management and live-operations tooling; it does not change whether the platform is involved at all. Hosting comes with the Monterosa platform.
It does not log players in. Gamestage ships no identity provider and expects you to bring one. It accepts OIDC through JWT tokens: a game that wants named players points at its own issuer and keys, and Gamestage checks the tokens your existing login already hands out.
Where the product is today
Gamestage is in Preview and being tested with Monterosa customers. The two halves of the product are at different stages.
The local route is active: inspecting a game, choosing its format and scaffolding the manifest need no account. Running the real Engine rules on your machine and proving the result in a browser do, once you get that far, because from there you are running against your account rather than reading your own files.
The hosted route is in Preview. The CLI points at https://api.gamestage.ai, and Backstage needs an approved account rather than open signup.
Where this documentation is unsure, it says so rather than rounding up.