json tags validation

<p>Hey , </p> <p>im using go-endpoints In the struct usage example , they used the endpoints:&#34;req&#34;` tag </p> <p><a href="https://github.com/GoogleCloudPlatform/go-endpoints#usage" rel="nofollow">go-endpoints</a></p> <p>that suppose to be a mandatory field ?</p> <p>I tried to pass an empty value to a field with the endpoints:req tag and <strong>i didn&#39;t get any error</strong></p> <p>What will be the best way to valid mandatory fields ?</p> <p>i can do something like that but it must be a nicer solution</p> <pre><code> if len(subscriptionToken) == 0 { return endpoints.NewAPIError(&#34;subscriptionToken is empty&#34;, &#34;subscriptionToken is empty&#34;, 400) } </code></pre> <p>these anyone has an experience with endpoints and tag validation ? </p> <p>Also im looking for alternative library to use in case the endpoints one won&#39;t work , which package you recommend ?</p> <hr/>**评论：**<br/><br/>ninja_uzumaki: <pre><p>I think you would get more answers if you provide a link to go-endpoints and give more context into your problem.</p></pre>