Zoho Books API adding Estimates

Question

I am very new to the Zoho API as well as curl. I am trying to develop a class that is able to create estimates for customers using the Zoho Books API, but when I run my code I keep getting a boolean false response >>. Please tell me what i'm doing wrong, and also direct me to a site with proper tutorials for this.

    $data = array(
        'authtoken'         => 'xxxxxxxxxx',
        'JSONString'        => '{
  "customer_id": "157691000000041090",
  "contact_persons": [
    "157691000000041090"
  ],
  "template_id": "157691000000041077",
  "estimate_number": "EST-000001",
  "reference_number": "QRT-123456",
  "date": "2015-08-25",
  "expiry_date": "2015-08-27"
  "exchange_rate": 1.0,
  "discount": 0.0,
  "is_discount_before_tax": true,
  "discount_type": "item_level",
  "salesperson_name": "John Michael",
  "is_inclusive_tax": "false",
  "custom_fields": [
    {
      "index": 1,
      "value": "25 Aug 2015"
    }
  ],
  "line_items": [
    {
      "item_id": "157691000000041080",
      "name": "Book1",
      "description": "book",
      "rate": 50.00,
      "item_order": 0,
      "quantity": 1.0,
      "discount": 0.0,
      "tax_id": "",
    }
  ],
  "notes": "Looking forward for your business.",
  "terms": "Terms and conditions apply.",
  "shipping_charge": 0.0,
  "adjustment": 0.0,
  "adjustment_description": "Adjustment"
}',
        "organization_id"   => '57408606'
    );

    $curl = curl_init($url);

    curl_setopt_array($curl, array(
      CURLOPT_POST => 1,
      CURLOPT_POSTFIELDS => $data,
      CURLOPT_RETURNTRANSFER => true
    ));

    $estimate = curl_exec($curl);
var_dump($estimate)

Answer 1

It looks like the JSON is not well formatted. Please do the following changes and let me know if it works

1) add "," after

"expiry_date": "2015-08-27"

2) remove "," after

"tax_id": "",