Smart Fill PDF Form API by any data types (Mapping and Dynamic)

In this tutorial, we’ll guide you through how to fill a PDF form using both Mapping Data and Dynamic Data together.

This method is the most flexible and works well in real-world scenarios—especially when your data comes from multiple sources such as: Intake forms, Passport or ID images, Financial documents, Your internal database, etc.

Let’s walk through how to combine these inputs and generate a fully filled form with TakeForm.

Step 1: Get an API Key API Key

Before using any of the steps below, make sure to:

1. Register a new account on the TakeForm platform.

2. Receive $5 in free credits instantly—enough to start testing right away.

3. Generate your API key to begin integrating with our API.

Once you have your API key, you're ready to move on to the next section.

Step 2: Upload the form

Now, you need a form to work with. You have two options:

• Choose an existing form from your Form Library

• Upload your own form by following the instructions in the section below (Video guide included)

Upload new form

Step 3: Use Form Filling API to fill form in step 2

Full Code example: https://github.com/cptrodgers/takeform-examples/blob/master/fill-form-example/smart-filling-method.py

TakeForm enables you to fill a form using both Mapping Data and Dynamic Data. First, it fills the known fields using structured Mapping Data (via a schema), then it uses Dynamic Data (such as text, images, or documents) to fill the remaining fields. You can send both types of data in a single request, and TakeForm will handle the process seamlessly.

Read more about TakeForm Filling Method here TakeForm Community

# JSON Input Sample form W-9 Form Above.
mapping_data = {
	"address_line_1": "123 Main St",
	"business_name_disregarded_entity_name": "Acme Corp",
	"foreign_partners_owners_beneficiaries_indicator": False,
	"name_of_entity_individual": "John Doe",
	"requester_name_address": "Jane Smith\n456 Elm St\nAnytown, CA 91234"
}

# Dynamic Data, Free Text
dynamic_text_data = """
City, State, ZIP: Anytown, CA, 91234

Federal Tax Classification:
C Corporation: true

Exemptions:
Exempt Payee Code: 4
Exemption from FATCA Reporting Code: A

List of Account Numbers:
12345, 67890

Taxpayer Identification Number (EIN):
12-3456789
"""

def fill_form():
    url = f"https://api.takeform.app/developer/v1/forms/{FORM_ID}/fill"
    headers = {
        'X-API-Key': TAKE_FORM_API_KEY,
        'Content-Type': 'application/json; charset=utf-8',
    }

    response = requests.post(
        url,
        headers=headers,
        json={
            "mapping": mapping_data,
            "dynamic": {
                "sources": [
                    {
                        "type": "Text",
                        "text": dynamic_text_data
                    },
                ]
            }
        },
    )
    print("Fill succesfully: Filled Form Object", response.json())
    # Expected Output: Fill succesfully: Filled Form Object {'created_at': 1744736364, 'file_id': '4a1609c5-7113-4f11-b22d-af70d40f9bed', 'filled_via': 'Api', 'form_id': '854d35dc-c401-4079-aadc-63c309a052e8', 'id': 'e31c24cc-6883-4e52-ab9b-474601d89543', 'name': 'w-9.pdf', 'status': 'Filling', 'updated_at': 1744736363, 'user_id': 'df0bebb1-c460-4263-a654-6d9f5dda7428'}

    return response.json()["id"]

Step 4: Retrieve the filled form.

def download_form(filled_form_id: str):
    url = f"https://api.takeform.app/developer/v1/filled-forms/{filled_form_id}/download-url"
    headers = {
        'X-API-Key': TAKE_FORM_API_KEY,
        'Content-Type': 'application/json; charset=utf-8',
    }

    response = requests.get(
        url,
        headers=headers,
    )
    print("Filled Form", response.json())
    # Output: Filled Form https://storage.googleapis.com/takeform/8da53c8c-5334-4ebb-8074-a1c6cd79d1ca?...

That's all, now you can download the filled pdf.