Docs > Framework >

Static Files

Cofoundry automatically sets up the static file middleware, serving files from the website content root (using IHostingEnvironment.WebRootFileProvider) as well as files embedded in Cofoundry and any plugin assemblies.


The Cofoundry view helper includes a helper for for applying versioning to static files. This works in a similar way to the asp-append-version tag helper, the difference being that our version works across all registered static file providers, not just IHostingEnvironment.WebRootFileProvider.

@using Cofoundry.Domain
@inject ICofoundryHelper Cofoundry

    <img src="@Cofoundry.StaticFiles.AppendVersion("/content/my-cat.png")">

This service is also available by requesting IStaticFileViewHelper using the DI system.

Configuring the static file middleware

Cofoundry sets up the static file middleware using a default configuration that simply sets caching headers using rules that should work for most configurations.

If you need to alter the configuration this can either be done using simple configuration settings, or by overriding the default IStaticFileOptionsConfiguration for more advanced scenarios.


  • Cofoundry:StaticFiles:MaxAge The default max-age to use for the cache control header. The default value is 1 year. General advice here for a maximum is 1 year.
  • Cofoundry:StaticFiles:CacheMode The type of caching rule to use when adding caching headers. This defaults to StaticFileCacheMode.OnlyVersionedFiles which only sets caching headers for files using the "v" querystring parameter convention.

Custom configuration

If you need more control over the static file configuration you can replace the Cofoundry IStaticFileOptionsConfiguration implementation using the DI override system.

Example implementation:

using Cofoundry.Web;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.StaticFiles;

public class SimpleStaticFileOptionsConfiguration : IStaticFileOptionsConfiguration
    public void Configure(StaticFileOptions options)
        options.OnPrepareResponse = OnPrepareResponse;

    private void OnPrepareResponse(StaticFileResponseContext context)
        context.Context.Response.Headers.Add("Cache-Control", new[] { "public,max-age=31536000" });

Serving static files embedded in assemblies

If you want to expose static files embedded in an assembly, this can be done by implementing IEmbeddedResourceRouteRegistration and registering the routes you want exposed:

using Cofoundry.Core.ResourceFiles;

public class ExampleEmbeddedResourcetRouteRegistration : IEmbeddedResourceRouteRegistration
    public IEnumerable<EmbeddedResourcePath> GetEmbeddedResourcePaths()
        var path = new EmbeddedResourcePath(

        yield return path;

Note that url for the files will mirror their location in the embedded assembly.

Adding MIME type mappings to FileExtensionContentTypeProvider

In Cofoundry you can add additional MIME mappings to the ASP.NET Core FileExtensionContentTypeProvider by creating a class that implements IMimeTypeRegistration:

public class MyAdditionalMimeTypeRegistration : IMimeTypeRegistration
    public void Register(IMimeTypeRegistrationContext context)
        context.AddOrUpdate(".epub", "application/epub+zip");
        context.AddOrUpdate(".csv", "text/csv");