Port Not Detected
Fix an app that shows Running but whose URL times out or returns nothing by binding to 0.0.0.0, matching the port, and making the port public.
If your app shows as Running but its URL times out or returns nothing, the platform cannot reach it on the expected port.
Checklist
Bind to 0.0.0.0
An app that listens on localhost is unreachable. Listen on 0.0.0.0.
Match the Port
The port your app listens on must match the port you exposed in
Networking. Reading a PORT variable with a sensible default
keeps the two in sync.
Make the Port Public
To reach the app from the internet, the port must be marked Public. A public HTTP or H2C port gets an HTTPS URL.
Use the Right Protocol
Use HTTP or H2C for web traffic. A TCP port is not served over the
outplane.app URL and cannot take a custom domain.
Port changes apply on the next deployment.
Related
Application Won't Start
Fix an app that builds but crashes, keeps restarting, or never reaches Running, from binding to 0.0.0.0 to the start command and missing variables.
Custom Domain Not Resolving
Fix a custom domain that does not load or shows a TLS error by copying the exact DNS record, waiting for propagation, and binding it to an HTTP port.