[FEATURE] Opt-in flag to strip unused @vercel/og dynamic import (saves ~2 MiB, keeps Worker under free-tier 3 MiB)

[mushan0x0]

Is your feature request related to a problem?

When an app does not use next/og (ImageResponse, opengraph-image, etc.), the built .open-next/server-functions/default/handler.mjs still contains a dynamic import:

import("next/dist/compiled/@vercel/og/index.edge.js")

This comes from Next.js's internal externalImport helper and survives the existing patchVercelOgImport / patchVercelOgFallbackFont AST rules in packages/cloudflare/src/cli/build/patches/ast/vercel-og.ts, because those rules only rewrite the module specifier (index.node.js → index.edge.js); they don't strip the call site when @vercel/og is never actually reached at runtime.

Wrangler treats that dynamic import as a real module graph entry and pulls in:

• @vercel/og edge bundle (~800 KiB uncompressed / ~260 KiB gzip)
• resvg.wasm (~1.4 MiB)

For a CSR-heavy app that doesn't use OG images at all, this single dynamic import pushes the Worker over the Cloudflare free-tier 3 MiB limit (observed ~3.8 MiB vs ~1.6 MiB after rewrite).

Describe the solution you'd like

Add an opt-in flag to @opennextjs/cloudflare, e.g.:

// open-next.config.ts
export default defineCloudflareConfig({
  cloudflare: { disableVercelOg: true },
});

When enabled, an AST rule under packages/cloudflare/src/cli/build/patches/ast/ rewrites the remaining import("next/dist/compiled/@vercel/og/index.edge.js") call sites to a rejected Promise (or a no-op stub), so Wrangler no longer bundles the @vercel/og edge module and resvg.wasm.

This keeps the default behavior safe and gives free-tier users a supported escape hatch without a post-build regex script.

Happy to send a PR (config flag + AST rule) if maintainers are open to it.

Describe alternatives you've considered

1. Auto-detect and stub. Scan user sources for next/og / ImageResponse / opengraph-image / twitter-image usage and, when none are found, automatically rewrite the call site. Safer defaults but more moving parts and edge cases.

2. Post-build regex patch (current workaround). We run a small script before wrangler deploy:

   source = source.replace(
     /import\("next\/dist\/compiled\/@vercel\/og\/index\.edge\.js"\)/g,
     'Promise.reject(new Error("@vercel/og disabled"))',
   );

   After this patch our Worker is ~1.6 MiB instead of ~3.8 MiB and everything else (ProForm, admin UI, D1, R2, KV, Vectorize) works unchanged. But it's fragile — it depends on the exact emitted string and has to live in every project that hits the 3 MiB limit.

3. Do nothing / upgrade to paid plan. Not acceptable for free-tier / hobby projects that never use OG images.

@opennextjs/cloudflare version

1.19.2

Additional context

• Next.js: 16.1.1
• Wrangler: 4.83.0
• Repro: any Next 15 / 16 app deployed via @opennextjs/cloudflare that does not import next/og. Compare .open-next/server-functions/default/handler.mjs and wrangler deploy --dry-run size with and without the regex rewrite above.
• Previous issue closed by maintainer asking to re-file with the template: Bundle size: unused @vercel/og dynamic import inflates Worker by ~2 MiB on free tier #1211.

Before submitting

• I have checked that there isn't already a similar feature request
• This is a single feature (not multiple features in one request)

[vicb]

Thanks for the additional details @mushan0x0

Could you please try with 1.19.1 and report if it has the same issue?

Thanks!

[mushan0x0]

Just tested with @opennextjs/cloudflare@1.19.1 on the same project — the issue reproduces identically.

1.19.1 build, without patch

$ grep -c 'next/dist/compiled/@vercel/og/index.edge.js' \
    .open-next/server-functions/default/handler.mjs
2
$ wrangler deploy --dry-run
Total Upload: 14098.57 KiB / gzip: 3119.42 KiB   # over the 3 MiB free-tier limit

1.19.1 build, after the regex patch (replace the two import("…@vercel/og/index.edge.js") call sites with a rejected Promise)

$ wrangler deploy --dry-run
Total Upload: 11812.98 KiB / gzip: 2384.02 KiB   # ~735 KiB gzip / ~2.2 MiB raw smaller

So the behavior is the same on 1.19.1 as on 1.19.2: the externalImport("next/dist/compiled/@vercel/og/index.edge.js") call site survives into the emitted handler, Wrangler pulls in the @vercel/og edge bundle + resvg.wasm, and that single import is what pushes the Worker past Cloudflare's 3 MiB free-tier gzip limit for apps that don't use next/og at all.

Env:

• @opennextjs/cloudflare: 1.19.1 (also reproduced on 1.19.2)
• next: 16.2.4 (also tested on 16.1.1)
• wrangler: 4.83.0
• Node: 22.x

Happy to bisect further or test a specific earlier version if that helps.

[vicb]

Thanks for the fast turn-around.

I was wondering if #1139 release 1.19.2 could have an impact. It looks like it doesn't.

We'll take a look at that.

[mushan0x0]

Opened a PR with a fix: #1221

Root cause turned out to be simple: when patchVercelOgLibrary sets useOg=false, bundle-server.ts marks next/dist/compiled/@vercel/og/index.edge.js as external in esbuild, so the import("…@vercel/og/index.edge.js") call site emitted by Next survives untouched, and Wrangler then resolves it against node_modules and drags the real library + resvg.wasm (~2 MiB) into the Worker.

PR aliases that module to the existing throw.js shim when useOg=false instead. Measured on my app:

• before: wrangler deploy --dry-run → 14098.57 KiB / gzip 3119.42 KiB (over free-tier limit)
• after: wrangler deploy --dry-run → 11875.51 KiB / gzip 2415.74 KiB

pnpm --filter cloudflare test + pnpm code:checks pass. Happy to iterate on the approach if you'd prefer a different shape.