Build an App with ChatGPT
You can build an app with ChatGPT in two ways. Add Mythex to ChatGPT as an app over MCP, so ChatGPT works in a Mythex cloud project that has a live preview, a database and publishing; or type the same request into Mythex and let its agent do the building.
Who it's for
ChatGPT users who keep getting code blocks with no idea where to paste them, founders who worked out an idea in a long ChatGPT thread and now want it running, and teams that spend their day in ChatGPT and would rather not switch tools to ship a small app.
What you can build
- A quote calculator you sketched in a ChatGPT conversation, built and published
- A feature request board where users upvote ideas
- A stock list for a small shop with a database behind it
- An event sign-up page you can share the same afternoon
- A waitlist page whose signups land in a table you can export
Path 1: add Mythex to ChatGPT
Mythex exposes a remote MCP server, the standard ChatGPT uses for apps and connectors. Copy the MCP URL from Account settings in Mythex, add it in ChatGPT's apps and connectors settings, and approve access on the Mythex consent screen. From then on ChatGPT can create a project, write and edit files, attach a database, start the preview and publish, and each result links back to the project in Mythex. Connecting works on any Mythex plan; the sandbox tools need Pro. ChatGPT itself is billed by OpenAI under your ChatGPT plan.
- Get the MCP URL from Mythex Account settings
- Add it in ChatGPT as a custom app or connector (some ChatGPT plans need developer mode switched on for this)
- Sign in to Mythex and click Allow access
- Ask ChatGPT to build something, then open the project link it returns
Path 2: build the app in Mythex
Prefer a single window? Paste the idea you shaped in ChatGPT into Mythex as your first message. The Mythex agent plans the app, writes the code, runs it in a live preview and attaches a database once there is data worth keeping. This works on the Free plan, so it is the cheapest way to learn whether your idea holds up as a working app before you spend money on anything.
What a ChatGPT app builder adds to the chat
ChatGPT is good at drafting code, explaining errors and turning a loose idea into a clear spec. The gap is everything after the code: a server to run it, a database that keeps records between visits, storage for uploads and an address other people can open. Done by hand, that means copying files into a project, picking a host and wiring a database yourself. Mythex covers those steps, whether ChatGPT drives it through the connector or you build inside Mythex.
Requests ChatGPT can act on
Through the connector ChatGPT calls tools, so concrete requests beat open questions. Name the project, the screens and the data, and ask for the preview link after each larger change so you can check the result with your own eyes. If a page errors, ask ChatGPT to pull the logs from Mythex and fix the cause rather than rewrite the page. Keep API keys in the project's environment settings, where Mythex lists only key names and never the values.
- "Create a Mythex project for a feature request board"
- "Add a database table for requests and votes"
- "Show me the preview link"
- "Publish the app and give me the public URL"
A prompt to start from
Build a feature request board: visitors submit an idea with a title and description, anyone can upvote, and each request has a status (new, planned, in progress, shipped). Add an admin view to change statuses and merge duplicates. Store everything in a database.
Questions
Can ChatGPT make an app for me?
ChatGPT can write the code for an app, but on its own it does not host it, attach a database or give it a public URL. With Mythex connected, ChatGPT does those steps through Mythex's tools, and the finished app runs in your Mythex account.
What does it cost to use Mythex from ChatGPT?
Connecting is allowed on every Mythex plan. Building through the connector uses Mythex's sandbox tools, which need Pro at $25/month plus credits for sandbox time, while ChatGPT is billed by OpenAI. Building directly in Mythex works on the Free plan.
Who owns an app ChatGPT built?
You do. The project lives in your Mythex account like any other, so you can keep editing it in Mythex, publish it, and on Pro export the code or sync it to GitHub.
Can I use the same setup in Claude or Cursor?
Yes. Claude, Cursor and Codex connect with the same MCP URL, so you can switch assistants and keep working on the same projects.
Will ChatGPT see my other projects or secrets?
ChatGPT only sees what Mythex's tools return for your own account after you allow access. Secret values are never listed back, only their names, and other users' projects are never reachable.
Do I need to know how to code?
No. You describe what you want in plain language and Mythex writes the code, shows a live preview, and lets you change things by chatting. The code editor and terminal are there if you ever want them.
Do I have to explain my business every time?
No. Mythex remembers who you are and how you work across every project, and follows the standing notes you set for a project, so you are not re-briefing it in each new chat. You can read, edit or switch all of it off.
How much does it cost?
There is a Free plan with daily credits, enough to build and publish a first version. Pro is $25/month and adds full code editing, GitHub export, custom domains, and credit top-ups.
Templates to start from
- Waitlist Landing Page Template — Countdown, live counter, lead admin
- Analytics Dashboard Template — KPI cards, charts, and activity table
- AI Moodboard Canvas Template — Drag-and-drop moodboards with notes
- Metrics Dashboard Template — Governed metrics and self-serve charts
- Budget Dashboard Template — CSV import with variance analytics
- Customer Health Dashboard Template — Churn scoring with explainable charts
- Account Health Dashboard Template — Renewal view with risk scores
- Sales Attribution Dashboard Template — Multi-model revenue attribution
More ways to build with AI
- Build an App with Claude
- Prompt to App: Create an App With an AI Prompt
- A Vibe Coding Platform Where Apps Ship, Not Just Run
- AI App Maker: Describe Your App, Get One That Works
- AI Web App Builder
- AI Website Maker: From One Prompt to a Live Site
- AI Booking App Builder
- AI Restaurant Website Builder
- AI Portfolio Website Builder
- AI Online Store Builder
- AI Landing Page Builder
- AI Dashboard Generator