integrations/vercel

[giscus[bot]]

integrations/vercel

Vercel Function support Web Standard Framework by default, so you can run Elysia on Vercel Function without any additional configuration.

https://elysiajs.com/integrations/vercel

[Zeryther]

How do you deploy without having the entire code in one file?

• When having more files in the api directory, they're all deployed as functions; and
• When putting files into a separate src/ directory, the function crashes because it can't find the files

I can't find any example for this that uses more than one file.

[KiriyamaRei96]

For anyone have the turborepo vercel deploy issues

Idea: Emit the Build Output API layout so Vercel unambiguously treats the output as a Serverless Function (not a static file).

New folder structure

.vercel/output/
  ├─ config.json
  └─ functions/
     └─ index.func/
        ├─ index.js          # bundled entry
        ├─ .vc-config.json   # runtime config
        └─ package.json      # { "type": "module" } (only if ESM)

Build script (Bun → Node runtime, bundled ESM)

Create apps/server/scripts/vercel-build-node-bun.ts:

import { $ } from "bun";
import { promises as fs } from "node:fs";
import path from "node:path";

const outDir = ".vercel/output";
const funcDir = path.join(outDir, "functions", "index.func");
const staticDir = path.join(outDir, "static");
const entryJs = path.join(funcDir, "index.js");

async function main() {
  await fs.rm(outDir, { recursive: true, force: true });
  await fs.mkdir(funcDir, { recursive: true });
  await fs.mkdir(staticDir, { recursive: true });

  // Bundle a single ESM file for Node runtime (not --target bun)
  await $`bun build src/index.ts \
    --target=node \
    --format=esm \
    --minify-syntax --minify-whitespace \
    --outfile ${entryJs}`;

  // Make Node treat index.js as ESM inside the function mount
  await fs.writeFile(path.join(funcDir, "package.json"), JSON.stringify({ type: "module" }, null, 2));

  // Function runtime config
  await fs.writeFile(
    path.join(funcDir, ".vc-config.json"),
    JSON.stringify({ runtime: "nodejs22.x", handler: "index.js", launcherType: "Nodejs", shouldAddHelpers: true }, null, 2)
  );

  // Routes: static first, then all to the function
  await fs.writeFile(
    path.join(outDir, "config.json"),
    JSON.stringify({
      version: 3,
      routes: [ { handle: "filesystem" }, { src: "/(.*)", dest: "/index" } ]
    }, null, 2)
  );

  console.log("✅ Build Output API ready at .vercel/output");
}

main().catch((err) => {
  console.error("❌ Build failed:", err);
  process.exit(1);
});

Build command

In apps/server/package.json:

{
  "type": "module",
  "scripts": {
    "build": "bun run scripts/vercel-build-node-bun.ts"
  }
}

Run:

bun run build