Batch contact creation through HubSpot API throwing deserialization error

[ClimbingLion]

I’m trying to send multiple contacts at once using HubSpot’s batch endpoint /contacts/v1/contact/batch/ but keep getting this error:

{"status":"error", "message":"Invalid input JSON on line 1, column 1: Can not deserialize instance of java.util.ArrayList out of VALUE_STRING token","correlationId":"7f2599b9-35g6-2h2d-c617-29fedde981176","requestId":"b96d4fa99c71b8e1f4dgf6847d920c22"}

I’ve validated my JSON multiple times and it looks correct. What could be causing this issue?

Here’s my request payload:

[
  {
    "email": "[email protected]",
    "properties": [
      {
        "property": "company",
        "value": "Acme Corp"
      },
      {
        "property": "website",
        "value": "www.acme.com"
      },
      {
        "property": "firstname",
        "value": "John"
      },
      {
        "property": "lastname",
        "value": "Doe"
      },
      {
        "property": "jobtitle",
        "value": "Manager"
      },
      {
        "property": "phone",
        "value": "555-0123"
      }
    ]
  },
  {
    "email": "[email protected]",
    "properties": [
      {
        "property": "company",
        "value": "Beta Solutions"
      },
      {
        "property": "website",
        "value": "www.betasolutions.org"
      },
      {
        "property": "firstname",
        "value": "Jane"
      },
      {
        "property": "lastname",
        "value": "Smith"
      },
      {
        "property": "jobtitle",
        "value": "Developer"
      },
      {
        "property": "phone",
        "value": "555-0456"
      }
    ]
  }
]

[SoaringEagle]

set your header to application/json for the json. that api path looks old tho - try the v3 endpoint /crm/v3/objects/contacts/batch/create instead. works much better.