Generate a PDF in n8n

Setup: one credential

Create a free API key at /signup. In n8n open Credentials → Add credential → Header Auth and set Name to Authorization and Value to Bearer dp_your_key. Call the credential PaperType API; the workflows below reference it by that name. The key never appears in the workflow JSON, so you can share or export the workflow safely.

Markdown to PDF with the HTTP Request node

Import markdown-to-pdf.json (Workflow menu → Import from URL, or paste the JSON onto the canvas), pick the credential in the Render PDF node and run it. It is three nodes: a manual trigger, a Set node holding title and markdown (replace it with whatever produces your text: a database row, a form, an AI node), and the HTTP Request node configured like this:

• Method POST, URL https://papertype.dev/v1/pdf.
• Authentication Generic Credential Type → Header Auth → PaperType API.
• Send Body on, Body Content Type JSON, Specify Body Using JSON, with this expression as the body (building the body with JSON.stringify keeps newlines and quotes in your Markdown correctly escaped):

{{ JSON.stringify({
  markdown: $json.markdown,
  title: $json.title,
  theme: 'clean',
  toc: true,
  page_numbers: true
}) }}

• Options → Response → Response Format File, Put Output in Field data.

The node's output item carries the PDF in the binary field data with the right MIME type and a filename. For HTML instead of Markdown, send html: $json.html; the other options (theme, page_size, cover, footer, css) are the same and listed in the API docs.

Invoice PDF from a webhook

invoice-webhook.json turns n8n into a small invoice service: a Webhook node receives the invoice as JSON, the HTTP Request node renders it with the hosted invoice template, and a Respond to Webhook node (Respond With Binary File) returns the PDF to the caller. The request body in the HTTP Request node is:

{{ JSON.stringify({
  template: 'invoice',
  data: $json.body,
  page_size: 'Letter',
  filename: $json.body.number + '.pdf'
}) }}

Test it from a terminal once the workflow is active (use the test URL shown on the Webhook node while you are still in the editor):

curl -X POST https://your-n8n.example.com/webhook/invoice \
  -H 'Content-Type: application/json' \
  -d '{"number":"INV-1042","date":"2026-10-21","due_date":"2026-11-20","currency":"USD",
       "from":{"name":"Northwind Studio","address_lines":["12 Example Road","Springfield"]},
       "to":{"name":"Acme Client Ltd","address_lines":["1 Sample Street","Shelbyville"]},
       "items":[{"description":"Design, October","quantity":10,"unit_price":120}],
       "tax_rate":8.25,"tax_label":"Sales tax"}' \
  -o INV-1042.pdf

A missing required field (for example date) comes back as a 422 whose message names the field; the certificate and report templates work the same way with their own fields.

Send the PDF somewhere

Every n8n node that accepts a file reads it from a binary field, so connect the HTTP Request node directly to the destination and point it at data:

• Gmail / Send Email: Attachments → field data.
• Google Drive, Dropbox, S3, Nextcloud: Upload with Input Data Field Name data.
• Slack, Telegram, Discord: send a file from binary field data.
• Write Binary File (self-hosted) to keep a copy on disk.

To rename the file, use the Edit Fields or Rename Keys node, or set filename in the request as the invoice workflow does.

Limits that matter in n8n

• Images. The renderer has no network access. Images, fonts and stylesheets at external URLs are never fetched; inline them as data: URIs. A request that references an external URL fails with a 422 that names the URL, rather than silently dropping the asset. In n8n, run the image through Extract from File → Move File to Base64 String and build the data:image/png;base64,… URI in an expression.
• 2 MB of source per request, 300 pages per document, 2 concurrent renders per account. Larger inputs return 413; split long reports into several documents.
• Quota. Free-plan output carries a small papertype.dev footer mark. Paid plans (from $9/month) do not. A workflow that fires on every webhook call can use the free plan's 50 documents quickly; the response headers X-Quota-Used and X-Quota-Limit are available under Response → Include Response Headers and Status.
• Errors. Set the HTTP Request node's On Error to Continue (using error output) to route a 401, 413, 422 or 429 to an error branch instead of stopping the workflow; the JSON error body says what went wrong. Failed renders are not counted against the quota.
• No JavaScript is executed. Send the final HTML; anything a script would have drawn or filled in will not appear.

Related

• Generate invoice PDFs from JSON
• Markdown to PDF API
• HTML to PDF API
• Generate a PDF in GitHub Actions