Wow, this is literally exactly what I was looking for. Thank you. Hopefully, it works well.

From https://developer.clarifai.com/quick-start/

Seems simple to train

  // add inputs with concepts
  app.inputs.create([{
    "url": "https://samples.clarifai.com/dog1.jpeg",
    "concepts": [
      { "id": "cat", "value": false },
      { "id": "dog", "value": true }
    ]
  }, {
    "url": "https://samples.clarifai.com/dog2.jpeg",
    "concepts": [
      { "id": "cat", "value": false },
      { "id": "dog", "value": true }
    ]

Then you predict what the another image is:

  // predict the contents of an image by passing in a url
  app.models.predict(Clarifai.GENERAL_MODEL,  
      'https://samples.clarifai.com/metro-north.jpg').then(
    function(response) {
      console.log(response);
    },
    function(err) {
      console.error(err);
    }
  );