ChatGPT GPT connecting via API and creating Blank data fields in HubSpot

[SparkGrowthWork]

Hi, I have spent hours and hours and hours trying to get my ChatGPT GPT I am setting up to go out and find leads and put them in the HubSpot as companies with information. I have litterally combed through hundreds of commands to put in actions and checked the API which I have confirmed works and tried so many types of ways to connect the API but bottom line no matter what I do it creates a blank contact in HubSot. I have the starter edition and I am doing it throught the legacy creation way. I have set all schemas read write and gone through so many python, JSON, and ChatGPT commands and I am at my wits end trying to get this. Cleaned browser cache, disconnected the HubSpot ChatGPT conrecter and reconnected. I get in the log and still I have tested the simplest thing like a contact name or just a company to strip it down to the bare bones and it still creates a blank company record or contact or email everytime. I am completely lost and feel like its something no AI command and or google search AI search can find the solution.

[MuhammadAmjad]

Hi @SparkGrowthWork,

I've built several ChatGPT-to-CRM integrations and this exact issue is common when using custom GPT actions with HubSpot's API. The problem isn't your API key or authentication—it's how the JSON payload is being constructed inside your GPT action.

The Root Cause

When ChatGPT creates blank records in HubSpot, the API call is succeeding but the properties object is either:
1. Empty or malformed
2. Using incorrect property internal names
3. Missing the required properties wrapper

HubSpot's API doesn't reject these requests—it just creates the record shell with no data populated.

Step 1: Test Your API Call Outside ChatGPT

Before debugging the GPT action, verify the API works:
- Open Postman or use curl
- POST to: https://api.hubapi.com/crm/v3/objects/companies
- Headers: Authorization: Bearer YOUR_TOKEN, Content-Type: application/json
- Body: {"properties": {"name": "Test Company", "domain": "test.com"}}

If this works in Postman but fails in ChatGPT, the issue is in your GPT action schema.

Step 2: Fix Your GPT Action Schema

The critical mistake is usually the nested properties structure. Your OpenAPI schema needs:
- A properties wrapper in the schema definition
- Correct property internal names
- Proper required fields

Step 3: Verify Property Internal Names

HubSpot is strict about property names:
- Company name: "name" (NOT "company_name")
- Contact first name: "firstname" (NOT "first_name")
- Contact last name: "lastname"
- Email: "email"

Step 4: Check Execution Logs

In your GPT dashboard, check the execution logs. Look for what JSON is actually being sent. If you see an empty properties object or missing the properties wrapper entirely, that's your issue.

Common Mistakes:
- Sending empty strings ("") instead of omitting the property
- Using legacy v1 endpoints instead of v3
- Authentication format (must be "Bearer YOUR_TOKEN")
- Not wrapping data in the properties object

If you share your OpenAPI schema from the GPT action, I can identify the specific issue.

[RubenBurdin]

Hi @SparkGrowthWork , I can hear the frustration, and you’re not crazy. When HubSpot creates a “blank” contact or company via the API, it almost always means the request technically succeeded but none of the properties you sent were actually recognized or written.

A few important things to ground this. First, the legacy endpoints are very forgiving in terms of HTTP response, but very strict about payload shape. If even one layer is off, HubSpot will still create the object shell with no properties populated. In 2025, this happens most often when the payload is missing the properties wrapper or when property names don’t match the internal names exactly. For example, firstname and name are valid, but First Name or companyName are silently ignored (https://developers.hubspot.com/docs/api-reference/crm-contacts-v3/guide )

Second, the ChatGPT “HubSpot connector” doesn’t validate your JSON the way Postman or curl does. If ChatGPT sends an empty object, a null value, or a string where HubSpot expects a key/value map, HubSpot happily creates a blank record. That’s why stripping it down to “just a name” still results in empties. The API call is firing, but the body is effectively unusable. This is especially common when schemas are set to read/write but the action still outputs an empty properties object at runtime.

What usually helps is testing the exact same request outside ChatGPT first. Use Postman or curl to create a contact with one property only, confirm it works, then copy that exact JSON structure back into your GPT action. Also make sure you’re not sending empty strings, HubSpot treats "" differently than not sending the property at all (https://developers.hubspot.com/docs/api-reference/crm-companies-v3/guide )

One quick check: when you inspect the execution logs, do you actually see a populated properties object being sent, or just the object type and auth? That detail usually reveals the root cause very fast.

[BérangèreL]

Hi @SparkGrowthWork and welcome, we are thrilled to have you here! 🤗

Thanks for reaching out to the HubSpot Community!

I understand that you are using the HubSpot connector for ChatGPT. Please let me know if that's not the case.

Did you check these resources yet, they might help you:

- Create a contact
- Create a company
- Using Object APIs

Now, let's consult our Top Experts: Hi @Anton, @Mike_Eastwood and @SteveHTM do you have suggestions to help @SparkGrowthWork, please?

Thanks so much and have a brilliant day!
Bérangère

[SparkGrowthWork]

I am using HubSpot connector for ChatGPT yes.

However that is not for the GPT agent. 

I hope that helps,

Thank you,

[BérangèreL]

Hi @SparkGrowthWork and thanks for getting back to us!

The hs get-started command you referenced is a HubSpot CLI command for local development, which is separate from the ChatGPT connector functionality.
 

For this behavior related to the ChatGPT connector creating blank fields in HubSpot, I'd recommend to:
 

- Check the ChatGPT connector settings in your HubSpot account under Settings > Integrations > Connected Apps

- Review field mappings to ensure data is being passed correctly

If the above doesn't help, the best next step is to contact our Support Team directly (sharing this Community thread) for connector-specific questions.

If you're building a custom GPT agent that connects to HubSpot, you may want to explore this documentation "Integrate with the HubSpot MCP server (BETA)".

Thanks and have a lovely day!
Bérangère

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