How to Run an ASP.NET Core App as Production on Your Machine

A lot of what differs in production never runs on your machine, until you make it. dotnet run --no-launch-profile starts an ASP.NET Core app as Production, so you can see those differences before your users do.

Why Not Just Set the Variable?

dotnet run uses launchSettings.json, whose profile sets ASPNETCORE_ENVIRONMENT=Development, and Microsoft's documentation says "Environment values set in launchSettings.json override values set by the system environment." So a variable in your shell doesn't change it. Fixed: dotnet run -e Staging Still Starts in Development has the details.

Step 1: Run with No Profile

With no profile and no variable, the environment defaults to Production. User-secrets aren't read in Production, so the connection string has to come from an environment variable. ASPNETCORE_URLS sets the address, because the profile that used to set it isn't there:

macOS / Linux

Terminal

ASPNETCORE_URLS=http://localhost:5190 ConnectionStrings__Inventory="Server=127.0.0.1;Port=3306;Database=inventory;User ID=inventory_app;Password=$(grep '^MYSQL_PASSWORD=' .env | cut -d= -f2-);SslMode=Required" dotnet run --no-launch-profile --project src/Dewiride.Inventory.Api

Windows (PowerShell)

PowerShell

$password = (Get-Content .env | Where-Object { $_ -like 'MYSQL_PASSWORD=*' }).Substring('MYSQL_PASSWORD='.Length)
$env:ASPNETCORE_URLS = "http://localhost:5190"
$env:ConnectionStrings__Inventory = "Server=127.0.0.1;Port=3306;Database=inventory;User ID=inventory_app;Password=$password;SslMode=Required"
dotnet run --no-launch-profile --project src/Dewiride.Inventory.Api

API log (shortened)

{"Timestamp":"2026-11-06T06:15:08.353Z","EventId":0,"LogLevel":"Information","Category":"Microsoft.Hosting.Lifetime","Message":"Hosting environment: Production","State":{"EnvName":"Production","{OriginalFormat}":"Hosting environment: {EnvName}"}}

Step 2: See What Changes

Here's what I saw on a real API:

With no connection string at all, it stops right away, because this app checks at startup. In Development, user-secrets hid that this was needed:

Output

Unhandled exception. System.InvalidOperationException: The connection string 'ConnectionStrings:Inventory' is missing. In development, set it with dotnet user-secrets. Everywhere else, set the ConnectionStrings__Inventory environment variable.

Development-only endpoints are gone:

Status codes

/openapi/v1.json 404
/scalar/v1 404

Everything in appsettings.Development.json is gone, such as verbose logging. Here, that means no SQL statements in the log.

Errors stop showing detail. Any IsDevelopment block in your own code stops running too. How to Run Code Only in Development in ASP.NET Core explains that.

What to Check While You're There

Check	What you want to see
It starts	With a clear error if a setting is missing
The API's documentation	404
A bad request	A clean error, with no stack trace
The log	No passwords, and no personal data
Requests with the database stopped	A 503, not a hang

The Other Ways

dotnet run can set it for one run, with the profile still in use for the rest:

Terminal

dotnet run -e ASPNETCORE_ENVIRONMENT=Production --project src/Dewiride.Inventory.Api

For the closest match to a server, publish it and run that, with the same two variables set:

Terminal

dotnet publish src/Dewiride.Inventory.Api -c Release -o publish
cd publish
dotnet Dewiride.Inventory.Api.dll

Start it from inside that folder. From anywhere else, appsettings.json is ignored, with no error.

Common Mistakes

Mistake	What happens	Do this instead
Setting ASPNETCORE_ENVIRONMENT in the shell only	The launch profile overrides it	Use --no-launch-profile
Expecting user-secrets to load	They're Development only	Use an environment variable
Leaving variables set in PowerShell	Later runs use them	Remove them when you're done

Troubleshooting

Symptom	Likely cause	Fix
Hosting environment: Development	A profile, or a variable left over	The fix
The connection string … is missing	User-secrets aren't read here	Set the variable
It listens on port 5000	No URL was set	Set ASPNETCORE_URLS
Log levels look wrong from a published folder	It started in another folder	The fix

Conclusion

dotnet run --no-launch-profile gives you Production, with no user-secrets and no developer pages. Run your app that way before you ship it, and check that what you see is what you want.

Additional Resources

• Use multiple environments in ASP.NET Core — how the environment is chosen.
• dotnet run — --no-launch-profile and -e.

Related

• How to Pass a Connection String with an Environment Variable in .NET C#
• How to Write JSON Logs in ASP.NET Core
• How to Run Code Only in Development in ASP.NET Core