Min API: How to modify headers in responses

[tdykstra]

Description

UUF verbatim:

Missing how to modify headers in responses.

Page URL

https://learn.microsoft.com/en-us/aspnet/core/fundamentals/minimal-apis?view=aspnetcore-9.0

Content source URL

https://github.com/dotnet/AspNetCore.Docs/blob/main/aspnetcore/fundamentals/minimal-apis.md

Document ID

b09824ab-b051-75a1-13b7-b0e281cc46e0

Article author

@Rick-Anderson

Metadata

• ID: b09824ab-b051-75a1-13b7-b0e281cc46e0
• Service: aspnet-core
• Sub-service: fundamentals

Related Issues

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Associated WorkItem - 371158

[wadepickett]

Notes: I should consider what we already have at:
https://learn.microsoft.com/en-us/aspnet/core/migration/http-modules#httpcontextresponse

See HttpContext.Response.Headers in that section and example we use for both single and multiple values:

    // Set header with single value
    httpContext.Response.Headers["ResponseHeaderName"] = "headerValue";

    // Set header with multiple values
    string[] responseHeaderValues = new string[] { "headerValue1", "headerValue1" };
    httpContext.Response.Headers["ResponseHeaderName"] = responseHeaderValues;

In this Min API doc under the Example Return values section, after the string return values example I might consider adding something like this:

Modifying Headers
You can modify headers in the response using the HttpResponse object. For example:

app.MapGet("/", (HttpContext context) => {
    context.Response.Headers["X-Custom-Header"] = "CustomValue";
    return "Hello World";
});

[wadepickett]

Notes: This topic is also on the high traffic list for topics that need to be updated as part of the freshness effort. Maske sure I update the date after addressing this issue and reviewing the topic as a whole. Also see open issue on this topic: #33588

[timdeschryver]

Hello @wadepickett if you want I can add your example to the "Minimal Apis quick reference" page (this issue). I would suggest to also include it on the Create responses page as it is very similar.

However, instead of adding it behind the string examples, I was thinking to create a new sub-header.

About the review and refresh, I think there's no new features released in 9.0 that can be added to these pages.

[wadepickett]

@timdeschryver, sounds great! A new sub section seems right for this. I was not putting this on my plate to think through any further until next sprint when I had time to take it on given other high priority work we are trying to wrap up, so I just made these initial notes after looking it over a few minutes in triage.

I think your suggestions are great. If you want to take on this one, it is really appreciated.