JustFill MCP server

JustFill is a helper that lets your AI work with PDF forms. You point it at a form, your AI finds the blanks, you check them, and it fills them in with your data. It is handy if you deal with the same forms again and again, like intake sheets, tax forms or supplier paperwork.

What this MCP server does

You tell your AI which PDF you want to work with. The AI uses this helper to open the file and look for fillable blanks. If the PDF already has proper form fields, it reads them straight away. If it is a scan or a flat form, the helper makes a best guess and shows you a picture with boxes drawn around each guess. You look at the preview, fix anything that is wrong, and then ask the AI to fill the form and save a new copy.

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What you can do with it

• Open a PDF form and list all the blanks it found
• See a preview image with boxes around each detected field
• Add, move or remove fields that the detection got wrong
• Preview the form with your values filled in before saving
• Fill the form and export a new PDF file
• Save a reviewed layout as a template to reuse later
• Reuse a saved template so the same form fills the same way every time

Try asking your AI

• “Open the W-9 form in my Documents folder and show me the fields you found”
• “Fill this intake form with Jane Doe, 12 Oak Street, and today's date, then save it to my Desktop”
• “Show me a preview of the filled form before you export it”
• “Save this layout as Client intake form so we can reuse it next time”

What it gives back to you

You get back lists of fields, preview images with boxes drawn on them, and warnings if a value is too long and will be shrunk or cut off. When you fill a form, it gives you a new PDF file saved where you asked. If something looks off, you can ask for another preview before exporting.

Before you start

Who it's for

Anyone who fills the same PDF forms over and over, like office admins, operations teams, HR staff or small business owners.