Docs

POST /v1/pdf

Use POST /v1/pdf to print HTML, a public URL, GitHub-flavoured Markdown, or a published Handlebars template to a production PDF with Chromium. Choose it for invoices, reports, and any page you can already render in a browser. Office files go to POST /v1/convert; merging existing PDFs is POST /v1/pdf/merge.

Provide exactly one of html, url, markdown, or templateId. HTML is UTF-8 JSON — not Base64. The same endpoint powers the Node fromHtml / fromUrl / fromMarkdown / fromTemplate helpers.

Body fields

One source plus optional filename, response mode, callback, and Chromium options.

Field	Required	Description
html	one of	Raw HTML document
url	one of	Public http(s) URL. Private, loopback, and metadata hosts are rejected
markdown	one of	GFM Markdown, rendered via Chromium
templateId	one of	Published template UUID or slug
templateData	with templateId	JSON object injected into Handlebars
templateVersion	no	Pin a published version; default is latest published
strict	no	Fail if a Handlebars path is missing
filename	no	Must end with .pdf
response	no	binary (default), url, or async
callbackUrl	no	HTTPS URL POSTed when this job finishes
options	no	Chromium print options — see Rendering options

HTML to PDF

Send the document as a JSON string. printBackground defaults to true.

POST /v1/pdf

{
  "html": "<h1>Invoice #1042</h1><p>Total: $1,200.00</p>",
  "filename": "invoice.pdf",
  "options": {
    "format": "letter",
    "printBackground": true
  }
}

URL to PDF

RelayPDF fetches the page and prints it. The host must be public.

POST /v1/pdf

{
  "url": "https://example.com",
  "response": "url",
  "filename": "example.pdf"
}

Markdown to PDF

Same endpoint. Markdown is rendered to HTML then printed.

POST /v1/pdf

{
  "markdown": "# Hello from Markdown\n\nA table-ready document API."
}

Template to PDF

Create and publish a Handlebars draft first (dashboard or Template API). Then pass templateId plus templateData.

POST /v1/pdf

{
  "templateId": "invoice",
  "templateData": { "number": "INV-1042", "total": 1458 },
  "filename": "invoice.pdf"
}

Binary response

Default. 200 application/pdf with x-relaypdf-id, x-relaypdf-size, and content-disposition.

URL response

JSON with a public download that expires in 24 hours.

response: url

{
  "id": "pdf_...",
  "status": "completed",
  "url": "https://api.relaypdf.com/v1/files/pdf_...",
  "filename": "document.pdf",
  "sizeBytes": 12345,
  "expiresAt": "2026-08-19T13:51:00.000Z"
}

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