Custom Headers in API Gateway HTTP API

Question

Hi,

In our API Gateway, we have created an API type 'HTTP API' and routes to our Services(running in ECS Fargate) via VPC Loadbalancer.

Currently, we are facing an issue where the custom request headers that are passed from the client are not passed through to the services. Below are the custom headers that we are trying to pass through the API GW, which is failing:

apigw-clientapp
apigw-api-key
apigw-tracking-header

Can you please help us resolve this.?

Please note that, if we are sending an uppercase letter in the above headers, it is passing through(but converts all the uppercase letters to lowercase when services receive the headers). We are not sure about this behaviour and require your support to analyze this as well. Thanks in advance

Accepted Answer

The list of API Gateway Reserved Headers contains `apigw-`: https://docs.aws.amazon.com/apigateway/latest/developerguide/http-api-parameter-mapping.html#http-api-mapping-reserved-headers

I recommend selecting a different header name.

Answer

Hi,

This seems to have been a problem already in the past: see https://github.com/aws/aws-lambda-dotnet/issues/915
But ticket is closed probably because according to documentation

```
Header names and query parameters are processed in a case-sensitive way.
```

See https://docs.aws.amazon.com/apigateway/latest/developerguide/api-gateway-known-issues.html
and check the full table on this page for all standard parameters

Custom Headers in API Gateway HTTP API

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