> ## Documentation Index > Fetch the complete documentation index at: https://docs.bluegenai.com/llms.txt > Use this file to discover all available pages before exploring further. # Deployment Guide > Where your built application lives, why the URL format differs between projects, and how to start and stop it. A finished build runs on the platform and is reachable at a URL the agent gives you. ## Finding Your Application The agent includes the URLs in its reply when a build finishes. You can reopen them any time from **URLs** in the panel rail. The Application URLs drawer titled Access your deployed application endpoints, listing an Application row and a Backend API row, each showing a URL with an external link arrow and a copy icon. ## Why the URL Format Differs **Projects come in two architectures, and each produces a different kind of URL.** Which one you have depends on when the project was created. | | Version 1 (original) | Version 2 (gateway) | | ------------ | ----------------------------------------------------- | -------------------------------------- | | What you get | One URL per service | A single URL for the whole application | | Typical form | `http://:` and `http://:/api` | A subdomain address | | Panel shows | **Application** and **Backend API** | **Application** only | New projects are created at version 2 and get the single subdomain address. Older projects keep the direct host-and-port form and are not migrated. The panel above is a version 1 project, which is why it lists two entries. Version 1 applications are served over plain HTTP. That is why the **Preview** panel cannot embed them and offers **Open in new tab** instead. The Preview panel showing a padlock icon above the message Preview not available, explaining the app is served over HTTP and cannot be embedded in a secure context, with an Open in new tab button. ## Custom Domains A project can be given a custom domain in place of the generated address. Your chosen name becomes a subdomain of `apps.bluegenai.ai`. The name has to be lowercase letters, numbers, and hyphens only, at most 63 characters, and it cannot look like a system identifier. Custom domains are available on Web projects that are recent enough to use the gateway architecture. ## Starting and Stopping Applications can be stopped to free resources and started again from the panel rail. **Stop App** sits among the panel controls in both Prototype and Build. Two messages tell you the application is not ready rather than broken: | Message | What it means | | -------------------------------------------------------- | --------------------------------------------------------------- | | `Project has no working directory. Generate code first.` | Nothing has been built yet | | `No docker-compose file found in the project directory.` | A build exists but is missing the file describing how to run it | After starting, give the health checks a moment before retrying the URL. ## What You Should See Opening the application URL loads your built application. On a version 1 project the second entry, labelled **Backend API**, addresses the same application directly, which is useful when you want to check one part of it in isolation. ## Your Next Step With the application running, the next question is usually what is inside it. Browsing the codebase and querying the database. How the agent tests your application in a browser. ## Related topics - [Troubleshooting & FAQ](/tips-and-tricks/troubleshooting-faq.md) - [Workflow](/web-apps/build-mode/workflow.md) - [Codebase and Database view](/web-apps/codebase-and-database.md) - [Platform Overview & Architecture](/getting-started/platform-overview-architecture.md) - [BlueGenAI Documentation](/index.md)