The core of VeriWorkly ATS Engine holds no I/O, no global state and makes no network calls, so it runs in Cloudflare Workers, Vercel Edge Functions and other runtimes that provide the standard Request, Response and fetch. This guide shows a Worker that scores JSON input and lists what is safe to import there.

What works at the edge

Sizes are for 0.11.0 and are not additive: the core is shared between entry points. Check the figures against your own bundler's output before you pick a plan tier. Workers and Edge Functions have size limits of their own.

Reading PDF and DOCX is the one thing you cannot do at the edge. Send the file to a Node route instead (Next.js) or score text the user pasted.

A Worker that scores JSON

This Worker takes POST / with { "text": "..." } or { "document": { "format": "ats-resume@1", ... } }, with an optional job string, and returns a report. It scores with the community policy and pins nothing but the input.

import {
  AtsInputError,
  check,
  isResumeDocument,
  shapeReport,
  type AtsResumeDocument,
} from "@veriworkly/ats-engine";

const MAX_BODY_BYTES = 256 * 1024;

type Body = { text?: unknown; document?: unknown; job?: unknown };

export default {
  async fetch(request: Request): Promise<Response> {
    if (request.method !== "POST") {
      return Response.json({ error: "Use POST." }, { status: 405 });
    }

    // Refuse early when the client declares a large body. Content-Length can be missing or wrong.
    if (Number(request.headers.get("content-length")) > MAX_BODY_BYTES) {
      return Response.json({ error: "The body is too large." }, { status: 413 });
    }

    // text() has already buffered the body, and length counts UTF-16 units, not bytes.
    const raw = await request.text();
    if (raw.length > MAX_BODY_BYTES) {
      return Response.json({ error: "The body is too large." }, { status: 413 });
    }

    let body: Body;
    try {
      body = JSON.parse(raw) as Body;
    } catch {
      return Response.json({ error: "The body is not valid JSON." }, { status: 400 });
    }

    const resume: string | AtsResumeDocument | undefined =
      typeof body.text === "string"
        ? body.text
        : isResumeDocument(body.document)
          ? body.document
          : undefined;
    if (resume === undefined) {
      return Response.json(
        { error: "Send { text } or { document } with format ats-resume@1." },
        { status: 400 },
      );
    }

    try {
      const report = check(resume, undefined, {
        ...(typeof body.job === "string" ? { jobDescription: body.job } : {}),
      });
      return Response.json(shapeReport(report, "full"));
    } catch (error) {
      if (error instanceof AtsInputError) {
        return Response.json({ error: error.message, issues: error.issues }, { status: 422 });
      }
      throw error;
    }
  },
};

isResumeDocument only checks the format field. A document that claims ats-resume@1 but breaks the schema makes check throw AtsInputError, whose issues list each failing path. The Worker returns them as a 422. See structured input.

On Vercel

A Next.js route with export const runtime = "edge" runs the same code. The route in Next.js shows it with NextResponse.

What to watch for

• A score from text or a structured document has no layout signals, so the layout rules drop out (pasted text).
• Locale packs cost 48.7 KB (withLocales alone) to 75.5 KB (/locales) gzipped. Attach them once at module scope with withLocales and reuse the policy across requests (languages and regions).
• Bound the body yourself, as above. The check on raw.length runs after request.text() has buffered the body and counts UTF-16 units, not bytes, so the Content-Length check is what refuses early. The engine cuts resume text at 50,000 characters and a job posting at 20,000, but it reads the whole string first.
• Do not import @veriworkly/ats-engine/node in an edge bundle. Keep file handling in a separate Node route.

Next steps

• Run the same call in the page: browser.
• Choose between the surfaces: choose a surface.
• Call a model from a server: AI.