Preview Dev Servers
Use this guide to start a project dev server, register it with Sero, and open the preview URL.
This page is task-focused. To choose Host, Apple Container, or Docker / Podman first, see Choose a Workspace Runtime. For the exact support matrix, see Support Scope.
Before you start
- Open the project as a Sero workspace.
- Confirm which runtime the workspace uses.
- Use the path style for that runtime:
- Host: commands run in the real workspace folder on your computer.
- Container runtimes: commands run inside the selected container, where the primary project is mounted at
/workspace.
Host path caveat: /workspace is for container runtimes except Sero compatibility aliases. Do not use /workspace as a Host shell path.
Start and register a Host dev server
Host is the default on supported platforms. Start the server normally from your project folder:
Register the port and command Sero should show:
Open the registered 127.0.0.1 URL from Dev Servers in Explorer, or ask the agent to preview it.
Start and register a container dev server
For Apple Container or Docker / Podman, start the server inside the workspace runtime. Many frameworks need the server to bind to all interfaces inside the container:
Register the same port and command:
Open the forwarded loopback URL from Dev Servers in Explorer, or ask the agent to preview the registered URL. Do not use a container IP.
List and stop registered servers
| Command | Use it for |
|---|---|
sero devserver list | List registered servers for the current workspace. |
sero devserver register --name <name> --port <port> --command <cmd> [--framework <name>] | Add a server entry with the command Sero can show or restart. |
sero devserver stop <id> | Stop the entry through the active workspace runtime. For a Host server that you started outside Sero, this marks the entry stopped but does not kill your process. |
The registry is in memory. Re-register servers after restarting the app if the entry is gone or the URL changed.
Preview the app
Use one of these paths:
- Open the server from Dev Servers in Explorer.
- Run
sero devserver listand open the current URL. - Ask the agent to preview the registered URL.
- Use the CLI preview command when you already have a URL:
Troubleshooting quick checks
- Server works in the terminal but preview fails in a container: restart it with a
0.0.0.0bind option if your framework requires one. - Host preview fails: confirm the reported
127.0.0.1URL opens in your normal browser. - URL stopped working after a restart: run
sero devserver list, then open the fresh URL or register the server again. - A Host process continues after stop: stop it in the terminal where you started it. Sero does not kill a Host process that it only registered.
- Selected container runtime is unavailable: fix Apple Container, Docker, or Podman, or explicitly choose another supported runtime. Sero does not silently switch a selected container workspace to Host.