Getting "Cannot use dynamic template data with a legacy template" with non-legacy template

Question

I'm attempting to integrate with Sendgrid and am having a heck of a time. I have created a dynamic template - a new one, not a legacy one - with a single handle bar (first_name) in it. It has a subject. But I'm getting a load of errors that I could use some help with.

First the code:

public void sendEmail(String toEmail, String toName) throws IOException {
    String fromEmail = "[email protected]";
    String fromName = "Blah blah";

    SendGrid sendGrid = new SendGrid("the_api_key");
    Request request = new Request();
    try {
        request.setMethod(Method.POST);
        request.setEndpoint("mail/send");
        String body = "see below...";

        request.setBody(body);
        Response response = sendGrid.api(request);
        System.out.println(response.getStatusCode());
        System.out.println(response.getBody());
        System.out.println(response.getHeaders());
    } catch (IOException ex) {
        throw ex;
    }
}

Taken almost entirely from the Java example code.

The JSON body, pretty printed...

{
  "from": {
    "email": "[email protected]",
    "name": "Blah blah"
  },
  "personalizations": [
    {
      "to": [
        {
          "email": "[email protected]",
          "name": "Blah Blah"
        }
      ],
      "dynamic_template_data": {
        "first_name": "Babaloo"
      }
    }
  ],
  "template_id": "[d-lotsandlotsofcharacters]"
}

And then a bunch of errors that make no sense (all of which link to a 404):

1. Cannot use dynamic template data with a legacy template ID - I'm not using a legacy template id according to the UI
2. The template_id must be a valid GUID, you provided '[d-xxxxxxxxxxxxxx]' - I sent what I was given on the UI.
3. The subject is required. You can get around this requirement if you use a template with a subject defined or if every personalization has a subject defined. - My template has a subject
4. Unless a valid template_id is provided, the content parameter is required. There must be at least one defined content block. We typically suggest both text/plain and text/html blocks are included, but only one block is required. - A valid template_id was provided

I'm guessing the first issue is the template_id field. It's strange JSON in that the value includes the array open/close. Putting the value inside as text gives a parse error so Sendgrid must be taking that directly.

Any directional help would be most appreciated. The docs are rather challenging

Answer 1

Twilio SendGrid developer evangelist here.

In your example, you show the template_id as "template_id": "[d-lotsandlotsofcharacters]". The square brackets are not required in the template_id, it should just be "template_id": "d-lotsandlotsofcharacters".

The documentation for sending an email with a dynamic template does show the the template_id example as "template_id":"[template_id]" but the entire [template_id] string should be substituted for the real ID.