App Service not saving environment variable SENDGRID_API_KEY – value returns null

Question

App Service not saving environment variable SENDGRID_API_KEY – value returns null

Youc 20

Subject: App setting variable SENDGRID_API_KEY not recognized in Azure App Service – value returns null

Description: Hi Microsoft Support,

We have deployed a .NET-based email API (isupplier-emailapi) using Azure App Service under the resource group youUIGrp. We have set the SENDGRID_API_KEY both through the Azure Portal (under Environment Variables) and CLI:

az webapp config appsettings set --name isupplier-emailapi --resource-group youUIGrp --settings "SENDGRID_API_KEY=SG.xxxxxx"

However, our deployed application cannot read this environment variable at runtime. It returns null, resulting in an error: "Missing SENDGRID_API_KEY"

We’ve also tried:

Setting via CLI multiple formats (--settings key=value, JSON, etc.)

Restarting the app

Verifying the variable appears in the App Settings list

The value is still not picked up. Could you please investigate and fix this for us? We’re happy to provide access or any additional details you need.

Thank you,

Kate Trieu

******@youc.com.au

Prabhavathi Manchala 1,220 Reputation points Microsoft External Staff Moderator

2025-05-09T06:48:55.42+00:00
Hi Youc,

Your .NET-based email API in Azure App Service isn't recognizing the SENDGRID_API_KEY environment variable, leading to a Missing SENDGRID_API_KEY error.

This could be due to a delay or caching issue preventing the App Settings from being applied, incorrect access methods causing the variable to not be recognized, or an issue in the code where the environment variable is not being accessed correctly. Make sure you're using Environment.GetEnvironmentVariable to retrieve the value properly in your .NET code.

Try setting the SENDGRID_API_KEY directly in the Azure Portal under Application Settings instead of using the CLI. Go to your App Service → Configuration → Application Settings.

Ensure your application is correctly accessing environment variables by using Environment.GetEnvironmentVariable("SENDGRID_API_KEY") in .NET, and make sure this runs after the application initializes.

Once the environment variable is set, restart your app to apply the new settings. You can do this in the Azure Portal under the Overview section of your App Service.

Make sure the environment variable name is exactly SENDGRID_API_KEY with no typos or extra spaces, and that its value is correctly set to your SendGrid API key.

Please check your Azure App Service logs for environment variable errors, and test locally by setting SENDGRID_API_KEY to see if the issue is with the variable or the Azure configuration.

https://learn.microsoft.com/en-us/azure/app-service/configure-common?tabs=portal#configure-app-settings
Harshitha Veeramalla 1,116 Reputation points Microsoft External Staff Moderator

2025-05-12T06:16:59.26+00:00

Hi @Youc,
How you are reading the value ?
Can you please add more details about the app version and the type of deployment your are doing ?

Your answer

Prabhavathi Manchala 1,220 Reputation points Microsoft External Staff Moderator

2025-05-09T06:48:55.42+00:00

Hi Youc,

Your .NET-based email API in Azure App Service isn't recognizing the SENDGRID_API_KEY environment variable, leading to a Missing SENDGRID_API_KEY error.

This could be due to a delay or caching issue preventing the App Settings from being applied, incorrect access methods causing the variable to not be recognized, or an issue in the code where the environment variable is not being accessed correctly. Make sure you're using Environment.GetEnvironmentVariable to retrieve the value properly in your .NET code.

Try setting the SENDGRID_API_KEY directly in the Azure Portal under Application Settings instead of using the CLI. Go to your App Service → Configuration → Application Settings.

Ensure your application is correctly accessing environment variables by using Environment.GetEnvironmentVariable("SENDGRID_API_KEY") in .NET, and make sure this runs after the application initializes.

Once the environment variable is set, restart your app to apply the new settings. You can do this in the Azure Portal under the Overview section of your App Service.

Make sure the environment variable name is exactly SENDGRID_API_KEY with no typos or extra spaces, and that its value is correctly set to your SendGrid API key.

Please check your Azure App Service logs for environment variable errors, and test locally by setting SENDGRID_API_KEY to see if the issue is with the variable or the Azure configuration.

https://learn.microsoft.com/en-us/azure/app-service/configure-common?tabs=portal#configure-app-settings
Harshitha Veeramalla 1,116 Reputation points Microsoft External Staff Moderator

2025-05-12T06:16:59.26+00:00

Hi @Youc,
How you are reading the value ?
Can you please add more details about the app version and the type of deployment your are doing ?

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App Service not saving environment variable SENDGRID_API_KEY – value returns null

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