Using reflection to build a dictionary of methods -> attributes at runtime

[Request(GET, "/something/{0}")]
public static async Task<...> GetSomethingAsync(int foo, ...)
{
    var request = CreateRequest(foo);
}

private static HttpRequestMessage CreateRequest(params object[] data)
{
    // I'd like to be able to access the values of the [Request] attribute in GetSomethingAsync()
    // via a lookup table (dictionary) generated once at runtime, so that I don't have to use StackTrace/StackFrame
    // every single time, which hurts performance greatly.
    var method = GetCallingMethodInfoFromLookup();
    var requestAttribute = method.GetCustomAttribute<RequestAttribute>();
    return new HttpRequestMessage(requestAttribute.Method, string.Format(requestAttribute.Route, data));
}