> ## Documentation Index
> Fetch the complete documentation index at: https://hercules.app/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Dev Machines

> Temporary servers for building and testing. Restart if issues. Published apps run separately.

Use Hercules Dev Machines to build and test your app before your publish it.

<div className="screenshot sunset">
  <img src="https://mintcdn.com/zeus-0f6dadbf/vyfZOWPi9KdyCPiO/images/apps/dev-machine-setup.png?fit=max&auto=format&n=vyfZOWPi9KdyCPiO&q=85&s=997ea8b4d55ecadbf62f820444d3079e" alt="Dev machine setup panel with start and stop controls" style={{ maxWidth: "400px" }} width="656" height="626" data-path="images/apps/dev-machine-setup.png" />
</div>

### How do dev machines work?

We create a temporary server, download your code to it, then set up a local development environment. We then show you a preview inside the Hercules App Builder.

### My dev machine is having issues. How do I fix it?

We recommend you **restart the dev machine**.

1. Click the Dev Machine icon in the top right of the preview
2. Click "Stop"
3. Click "start"

If it's still not working, please "Support & feedback".

<div className="screenshot fire">
  <img src="https://mintcdn.com/zeus-0f6dadbf/vyfZOWPi9KdyCPiO/images/apps/dev-machine-status.png?fit=max&auto=format&n=vyfZOWPi9KdyCPiO&q=85&s=ab95011e4c9d392dbdef5d2dbee29832" alt="Dev machine setup panel with start and stop controls" width="830" height="482" data-path="images/apps/dev-machine-status.png" />
</div>

### Additional FAQ

<AccordionGroup>
  <Accordion title="If there is a dev machine outage what happens to my published app?">
    Your published app is safe. Published apps are hosted separately on more scalable, robust, and reliable machines. They rarely have issues and are completely separate from Dev machines.
  </Accordion>

  <Accordion title="Can I get a faster dev machine?">
    Users on paid plans get dev machines with more RAM and CPU and have longer timeout limits. Larger
    machines are faster for large codebases and make it faster for multiple agents to run at the same
    time.
  </Accordion>

  <Accordion title="What are common dev machine issues?">
    Dev machine issues often happen after dev machines timeout from inactivity. They most commonly happen:

    1. While starting up:
       1. Loading forever on a specific step (eg on cloning repository)
       2. Showing a gray browser error screen saying a `hercules-dev.com` URL does not exist
    2. After loading
       1. Crashing in the middle of an agent run (404/500)

    **"Container is not running"** – Sometimes happens when restarting the dev machine. Stop the dev machine, then refresh your browser.

    **White screen** – Can happen on first load. Give it 30 seconds. If not, refresh the preview or refresh your whole page.

    If any of these are happening, please try restarting your dev machine. If still happening, please "Support & feedback" so we can investigate.
  </Accordion>
</AccordionGroup>