PdfFiller API Authentication

How to authenticate PdfFiller API requests: one Bearer API key plus a connectionId. MindCloud stores your API key securely — set it once, never resend it.

Every PdfFiller API request through MindCloud needs two things: a MindCloud API Key and a connectionId for your PdfFiller account. This page covers both, plus exactly how to send them, so you do not need to visit any other page to get authenticated.

Steps to authenticate

Create a MindCloud account at app.mindcloud.co if you do not already have one.
Generate a MindCloud API Key in API Keys. This is the Bearer token you send on every request. Keep it on your server.
Create a PdfFiller connection in Connections. PdfFiller uses an API key. You generate the key in your PdfFiller account, then paste it in when you create the connection — MindCloud stores it securely and never returns it in a response.
Copy the connection’s connectionId — you will send it on every request alongside your MindCloud API Key.

How requests are authenticated

Authentication has two layers. Your MindCloud API Key authenticates the request to MindCloud, sent as a Bearer token in the Authorization header. The connectionId selects the connected PdfFiller account that should run the action. MindCloud stores and refreshes the PdfFiller credentials behind that connection, so you never send provider tokens with your requests.

Pass connectionId in the query string for GET and DELETE actions, and in the JSON body for POST, PUT, and PATCH actions.

For example, calling List Templates with an PdfFiller connection looks like this:

curl --request POST \
  --url "https://connect.mindcloud.co/v2/universal/apps/pdfFiller/actions/list-templates/run" \
  --header "Authorization: Bearer $MINDCLOUD_API_KEY" \
  --header "Content-Type: application/json" \
  --data '{
  "connectionId": "$CONNECTION_ID",
  "arguments": {}
}'

The Authorization: Bearer <your MindCloud API Key> header authenticates you to MindCloud; the connectionId tells MindCloud which PdfFiller account to run the action against. Missing or invalid Authorization returns 401, and a missing or mismatched connectionId returns 400.

Connect PDFfiller with an access token

You need a PDFfiller account with API access and a current bearer access token.

Open the PDFfiller authentication guide
Use PDFfiller's official authentication reference to generate or refresh an access token.
PDFfiller API Reference → Authentication
Generate an access token
Follow PDFfiller's documented token flow and copy the access token value returned by the API.
Paste the token into the API Key field
In MindCloud, paste only the raw access token into the API Key field. Do not add the word Bearer; MindCloud sends that prefix for you.

Keep your key safe

Keep your MindCloud API Key on your server; do not ship it in browser code, mobile apps, public repositories, or logs. Anyone with the key can call the Universal API as your MindCloud account, across every connection you have created.