Generate a PDF in Next.js

The simplest way to generate a PDF in Next.js is to call the Docweave API from a Route Handler or Server Action with the built-in fetch — no headless browser to run, bundle, or patch yourself. POST your HTML, a URL, or a template + JSON to one endpoint and get back a rendered PDF.

Generate a PDF from a Route Handler

Using only fetch and node:fs/promises, POST your HTML to /api/v1/pdf from a Route Handler and write the response to disk:

// app/api/generate-pdf/route.ts
import { NextResponse } from "next/server";
import { writeFile } from "node:fs/promises";

export async function POST(request: Request) {
  const { html, filename } = (await request.json()) as {
    html: string;
    filename: string;
  };

  const response = await fetch("https://docweave.dev/api/v1/pdf", {
    method: "POST",
    headers: {
      Authorization: `Bearer ${process.env.DOCWEAVE_API_KEY}`,
      "Content-Type": "application/json",
      Accept: "application/pdf",
    },
    body: JSON.stringify({
      source: { type: "html", html },
      options: { format: "A4" },
      idempotencyKey: filename,
    }),
  });

  if (!response.ok) {
    return NextResponse.json(
      { error: `Docweave API error: ${response.status}` },
      { status: 502 },
    );
  }

  // Vercel functions only allow writes under /tmp — fine for a
  // short-lived file you then stream, upload, or email.
  const pdfBuffer = Buffer.from(await response.arrayBuffer());
  const outputPath = `/tmp/${filename}.pdf`;
  await writeFile(outputPath, pdfBuffer);

  return NextResponse.json({ ok: true, path: outputPath });
}

…or from a Server Action

If the PDF comes from a form submission, skip the separate endpoint and call Docweave directly from a Server Action:

// app/actions/generate-pdf.ts
"use server";

import { writeFile } from "node:fs/promises";

export async function generateReportPdf(formData: FormData) {
  const html = String(formData.get("html"));

  const response = await fetch("https://docweave.dev/api/v1/pdf", {
    method: "POST",
    headers: {
      Authorization: `Bearer ${process.env.DOCWEAVE_API_KEY}`,
      "Content-Type": "application/json",
      Accept: "application/pdf",
    },
    body: JSON.stringify({
      source: { type: "html", html },
      options: { format: "A4" },
      idempotencyKey: `report-${Date.now()}`,
    }),
  });

  if (!response.ok) {
    throw new Error(`Docweave API error: ${response.status}`);
  }

  const pdfBuffer = Buffer.from(await response.arrayBuffer());
  await writeFile("/tmp/report.pdf", pdfBuffer);
}

…or from an AI agent

The same workflow works from an AI agent with no fetch code at all. Run npx @docweave/mcp and your agent gets a generate_pdf tool that wraps the same render orchestration as the REST endpoint:

// From an AI agent over MCP — no fetch/HTTP boilerplate:
// npx @docweave/mcp
generate_pdf({
  source: {
    type: "html",
    html: "<h1>Hello from Next.js</h1><p>Generated with Docweave.</p>",
  },
  outputPath: "/tmp/output.pdf"
})

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