What is a programmatic PDF generation?

Programmatic PDF generation is the process of creating PDF documents through code rather than manual export — a script, API call, or AI agent supplies a source (HTML, a URL, or a template + data), and a PDF file is produced automatically, with no person opening a "Print" or "Export" dialog.

Expanding the concept

Most documents — invoices, receipts, reports, contracts, shipping labels — used to be produced by a human filling out a template and manually saving it as a PDF. Programmatic PDF generation removes that manual step. Instead, a piece of software (a backend service, a serverless function, a workflow automation tool, or an AI agent) sends a request that specifies what the document should contain, and a rendering engine turns that request into a finished, downloadable PDF file. The same request format, run a thousand times, produces a thousand consistently formatted documents with zero human involvement per document.

This is what makes it useful at scale: a SaaS product generating an invoice PDF every time a subscription renews, a logistics system stamping out shipping labels, or an AI agent drafting and exporting a report as part of a longer task — all of these are programmatic PDF generation, because the trigger and the formatting logic live in code, not in a person's hands.

How it works

A typical programmatic PDF generation flow has three parts:

1. A source. Usually one of: raw HTML/CSS, a public URL to render as-is, or a saved template combined with JSON data to fill it in.
2. A rendering engine. Something has to lay out that source and paint it to a page — commonly a headless browser (Chromium) that runs HTML/CSS the same way a normal browser would, then prints it to PDF.
3. A trigger. The code path that decides when to generate: an API request, a webhook, a scheduled job, or a tool call from an AI agent.

Here is what that looks like as a single API call:

curl https://docweave.dev/api/v1/pdf \
  -H "Authorization: Bearer dw_live_your_key" \
  -H "Content-Type: application/json" \
  -H "Accept: application/pdf" \
  -d '{
    "source": { "type": "template", "templateId": "invoice-v2", "data": { "customer": "Acme Co", "total": "$1,204.00" } },
    "options": { "format": "A4" }
  }' \
  --output invoice.pdf

How Docweave relates to this

Docweave is a programmatic PDF generation API built specifically for this pattern. One REST call — POST /api/v1/pdf — accepts HTML, a URL, or a template + JSON as the source, renders it with Chromium, and returns a PDF. It is billed per document rather than per page, and every request can carry an idempotencyKey so retries never generate the same document twice — a common failure mode in automated, programmatic pipelines. For AI agents specifically, Docweave ships an open-source, MCP-native generate_pdf tool (npx @docweave/mcp) so an agent can generate a PDF as a direct tool call instead of hand-rolling HTTP requests.

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