PDF Tools

PDF AcroForm Filler

Fill standard PDF forms programmatically (text, checkbox, radio, dropdown/list) using JSON data injection

file· File resultOpen tool

Quick start

Call this tool from your code in three languages.

cURL

# 1) Request a presigned URL → returns { uploadUrl, storageKey }
curl -X POST 'https://api.elysiatools.com/api/upload/presign/pdf-acroform-filler' \
  -H 'Content-Type: application/json' \
  -d '{"filename":"pdfFile.ext","contentType":"application/octet-stream","size":12345}'

# 2) PUT the file bytes directly to the presigned uploadUrl
curl -X PUT '<presigned uploadUrl>' \
  --data-binary @/path/to/file.ext

# 3) Call the tool, passing the returned storageKey for each file field
curl -X POST 'https://api.elysiatools.com/en/api/tools/pdf-acroform-filler' \
  -F 'pdfFile=/public/samples/pdf/form-sample-acroform.pdf' \
  -F 'fieldDataJson={"full_name":"Alex Doe","agree_terms":true,"tier":"pro","country":"US","hobbies":["Reading","Music"]}' \
  -F 'removeXfaBeforeFill=true' \
  -F 'flatten=true' \
  -F 'strictMode=false'

API reference

Send a POST request with your inputs as JSON. File parameters require a separate upload first.

Endpoint

HTTP

POST https://api.elysiatools.com/en/api/tools/pdf-acroform-filler

Parameters

Name	Type	Required	Description
pdfFile	fileupload required	Yes	—
fieldDataJson	textarea	Yes	JSON object where key = field name, value = field value
removeXfaBeforeFill	checkbox	No	For hybrid PDFs, remove XFA packet and fill AcroForm fallback
flatten	checkbox	No	Flatten fields to make result non-editable
strictMode	checkbox	No	Fail immediately when any field cannot be mapped/written

File-type parameters must be uploaded first via POST /upload/pdf-acroform-filler, then the returned filePath is passed to the corresponding file field.

Response format

File result

JSON

{
  "filePath": "/public/processing/randomid.ext",
  "fileName": "output.ext",
  "contentType": "application/octet-stream",
  "size": 1024,
  "metadata": {
    "key": "value"
  },
  "error": "Error message (optional)",
  "message": "Notification message (optional)"
}

MCP integration

Add this tool to your Model Context Protocol server so AI agents can list and call it.

Server configuration

Add this block to your MCP client configuration:

mcp.json

{
  "mcpServers": {
    "elysiatools-pdf-acroform-filler": {
      "name": "pdf-acroform-filler",
      "description": "Fill standard PDF forms programmatically (text, checkbox, radio, dropdown/list) using JSON data injection",
      "baseUrl": "https://api.elysiatools.com/mcp/sse?toolId=pdf-acroform-filler",
      "command": "",
      "args": [],
      "env": {},
      "isActive": true,
      "type": "sse"
    }
  }
}

List available tools

After connecting to the SSE endpoint, list the exposed tools:

tools/list

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/list"
}

Call this tool

Invoke the tool by its id, passing arguments built from its parameters:

tools/call

{
  "jsonrpc": "2.0",
  "id": 2,
  "method": "tools/call",
  "params": {
    "name": "pdf-acroform-filler",
    "arguments": {
  "pdfFile": "/public/samples/pdf/form-sample-acroform.pdf",
  "fieldDataJson": "{\"full_name\":\"Alex Doe\",\"agree_terms\":true,\"tier\":\"pro\",\"country\":\"US\",\"hobbies\":[\"Reading\",\"Music\"]}",
  "removeXfaBeforeFill": true,
  "flatten": true,
  "strictMode": false
}
  }
}

Chain multiple tools in one session with a comma-separated toolId list, e.g. /mcp/sse?toolId=png-to-webp,jpg-to-webp,gif-to-webp (max 20).

File parameters accept a public file URL only (https://…). Local paths, data: URIs, and Base64 strings are not supported.

Questions or issues? Contact [email protected]