Create PDF Fields

This endpoint adds interactive form fields to any existing PDF. It supports two methods for placing fields, which can be used independently or combined in the same request:

• Placeholder tags - embed special tags directly in your PDF as plain text. The API detects each tag, removes it, and replaces it with a real form field at the exact position where the tag appeared.
• Manual coordinates - pass field definitions with explicit page number, x/y position, width, and height. No changes to the source PDF are required.

Both methods can be used together in a single request. For example, you can have placeholder tags in your PDF for some fields and supply additional fields via manual coordinates at the same time.

Method 1: Placeholder tags

Tags are written as plain text in any PDF editor or document editor that exports PDFs. They look like regular text. For example, the tag {signature;n:sign_here;r:signer}, when processed, will be replaced with a digital signature field named "sign_here" assigned to the role "signer".

Our API automatically removes placeholder tags from the PDF after processing. However, in some cases, the original tag text may remain visible. To prevent this, we recommend setting the tag text color to match the background.

Note: Tags must be written on a single line. If they are split across multiple lines, they will not be detected.

Tag syntax

Each tag starts with the field type. Additional properties are optional and use a key:value format separated by semicolons.

Example tags:

Tags are case-sensitive. Keys and field types must be written exactly as shown below.

1{text;n:fullName;r:signer;h:24;w:200}2{number;n:amount;r:signer}3{textarea;n:notes;h:80;w:300}4{date;n:startDate;r:signer}5{time;n:startTime;r:signer}6{datetime;n:signedAt;r:signer}7{checkbox;n:agree;r:signer}8{radio;n:gender;c:male}9{radio;n:gender;c:female}10{select;n:status;o:Active,Inactive,Pending}11{signature;n:sig;r:signer}

Supported field types

Method 2: Manual field coordinates

Pass a fields array in the request body. Each entry defines one field with explicit coordinates. No placeholder tags are needed in the PDF.

1[2  { "name": "full_name",  "type": "text",      "page": 1, "x": 100, "y": 600, "width": 200, "height": 24, "role": "signer" },3  { "name": "status",     "type": "select",    "page": 1, "x": 100, "y": 560, "width": 160, "height": 24, "role": "signer", "options": ["Active", "Inactive"] },4  { "name": "dob",        "type": "date",      "page": 1, "x": 100, "y": 520, "width": 160, "height": 24, "role": "signer" },5  { "name": "start_time", "type": "time",      "page": 1, "x": 100, "y": 480, "width": 120, "height": 24, "role": "signer" },6  { "name": "agree",      "type": "checkbox",  "page": 1, "x": 100, "y": 440, "width": 14,  "height": 14, "role": "signer" },7  { "name": "gender",     "type": "radio",     "page": 1, "x": 100, "y": 400, "width": 14,  "height": 14, "role": "signer", "value": "male" },8  { "name": "gender",     "type": "radio",     "page": 1, "x": 100, "y": 380, "width": 14,  "height": 14, "value": "female" },9  { "name": "signed_at",  "type": "datetime",  "page": 1, "x": 100, "y": 340, "width": 180, "height": 24, "role": "signer", "autoFill": true },10  { "name": "signature",  "type": "signature", "page": 1, "x": 100, "y": 260, "width": 200, "height": 80, "role": "signer" }11]

Coordinates use the PDF coordinate system where the origin (0, 0) is at the bottom-left of the page and the y-axis increases upward. All values are in points.

For radio buttons, each entry represents one button. Buttons sharing the same name are grouped together. Use the value field to set the export value for each button.