Why do I get ERR_INVALID_FILE_URL_PATH when using @axe-core/playwright in a Next.js API route?

I'm trying to run an accessibility scan inside a Next.js API route using Playwright and @axe-core/playwright.

Here’s a simplified version of my code:

    import { chromium } from "playwright";
    import { AxeBuilder } from "@axe-core/playwright";

    export async function POST(req: NextRequest) {
      const browser = await chromium.launch();
      const context = await browser.newContext();
      const page = await context.newPage();

      await page.goto("https://example.com");

      const results = await new AxeBuilder({ page }).analyze(); // <-- this line throws

      await browser.close();

      return NextResponse.json({ results });
    }

Error ypeError: File URL path must be absolute
at ...
code: 'ERR_INVALID_FILE_URL_PATH'

My setup: axe-core/playwright 4.10.1
playwright 1.51.1
nextjs 15

Using require.resolve() to pass axeSource manually → leads to “module not exported” error

Reading axe.min.js via fs.readFile() from node_modules → file doesn’t exist

Checked @axe-core/playwright docs — axeSource is not mentioned or required anymore

Problem is that axe-core isn't auto-loaded correctly in server (ESM) context.

Workaround is to manually load axe.min.js from axe-core and pass it to AxeBuilder:

Install axe-core via npm install axe-core and load axe.min.js manually:

import { promises as fs } from "fs";
import path from "path";
import { fileURLToPath } from "url";

const __filename = fileURLToPath(import.meta.url);
const __dirname = path.dirname(__filename);

const axePath = path.resolve(__dirname, "../../../../node_modules/axe-core/axe.min.js");
const axeSource = await fs.readFile(axePath, "utf-8");

Then use it in AxeBuilder:

const results = await new AxeBuilder({ page })
  .withSource(axeSource)
  .analyze();