---
title: Fill PDF Form Fields API
slug: fill-pdf-form-fields-api
url: https://apyhub.com/freedailypro/service/fill-pdf-form-fields-api
provider: FreeDailyPro
categories: [Developer Tools, File Conversion, File Manipulation]
auth: api_key
version: v1
service_type: sync
endpoints: 1
atoms: 10
mcp: true
---

# Fill PDF Form Fields API

Fill PDF forms programmatically by providing field values, updating form fields, and generating a completed PDF document through an API.

## Endpoints

| Method | URL | Description | Atoms |
| --- | --- | --- | --- |
| POST | `https://api.eu.apyhub.com/freedailypro/fill-pdf-form-fields-api/form-fill` | What it does Uploads a PDF form and fills its fields with the provided values. The response is the… | 10 |

## Endpoint reference

### Fill a PDF form

`POST https://api.eu.apyhub.com/freedailypro/fill-pdf-form-fields-api/form-fill` · 10 atoms · accepts `multipart/form-data` · returns `application/json`

| Parameter | In | Type | Required | Description |
| --- | --- | --- | --- | --- |
| `file` | body | string (binary) | yes | The PDF form. Up to 20 MB. |
| `values` | body | string | no | JSON object of text field values, for example {"Name":"Ada"} |
| `checked` | body | string | no | JSON object of checkbox states, for example {"Agree":true} |
| `flatten` | body | string | no | true to flatten the form so it can no longer be edited |

#### Quickstart

Fill a PDF form by uploading the PDF file.

```bash
curl -X POST "https://api.eu.apyhub.com/freedailypro/fill-pdf-form-fields-api/form-fill" \
  -H "apy-token: $APY_TOKEN" \
  -F "file=@/path/to/form.pdf"
```

#### What you'll get back

Returns the filled PDF as a binary file response.

## About

## What it does
PDF Form Filler fills an existing PDF form with field values and returns a completed PDF file. Send the form file, map text fields in `values`, set checkbox states in `checked`, and optionally set `flatten` to make the result non-editable.

Use it when you need to generate signed-up PDFs, onboarding packets, application forms, or internal paperwork from structured data. The input is a binary PDF form up to 20 MB. The field mappings are passed as JSON strings, so you can assemble them from your app data before upload.

The response is a binary PDF, ready to store, email, or hand off to the next step in your workflow. If you set `flatten`, the filled values are preserved in the document rather than left as editable form fields.

This is a fit for document automation pipelines where you already have the data and need a predictable way to render it into a PDF form.

## Usage

Base URL: `https://api.eu.apyhub.com` (default region — see
`GET https://apyhub.com/api/public/regions` for the rest).

Authenticate with an ApyHub API key in the `apy-token` header.
Full docs and a live playground: https://apyhub.com/freedailypro/service/fill-pdf-form-fields-api