Fix Vercel ESM runtime error by removing "type": "module" from backend#1451
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Fix Vercel ESM runtime error by removing "type": "module" from backend#1451N2D4 wants to merge 2 commits into
N2D4 wants to merge 2 commits into
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…ESM error Next.js 16.2 has a known regression (vercel/next.js#91661) where the .next/package.json CJS boundary marker is not included in the Vercel serverless function bundle. This causes Node.js to walk up to the project's package.json, see "type": "module", and treat the compiled server bundles as ESM — breaking the require() calls in the generated route files. The fix (vercel/next.js#93612) is only in canary (16.3.0-canary.17+), not yet in a stable release. Removing "type": "module" is safe here because: - All backend source is TypeScript (no .js files) - next.config is .mjs (explicit ESM) - .eslintrc is .cjs (explicit CJS) - Scripts use tsx (handles ESM regardless) - TypeScript's moduleResolution: bundler is independent of this field Co-Authored-By: Konstantin Wohlwend <n2d4xc@gmail.com>
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Workaround for vercel/next.js#91661 — Next.js 16.2 omits .next/package.json from the required-server-files manifest, so Vercel's serverless functions don't get the CJS boundary marker. Without it, Node.js resolves the project's "type": "module" and treats the compiled server bundles as ESM, breaking require() calls at runtime. This adds a postbuild script that patches the manifest to include the file, matching the upstream fix in vercel/next.js#93612 (only in canary as of 16.2.6). The previous approach of removing "type": "module" broke the codegen step which uses tsx/esbuild and needs ESM for top-level await support. Co-Authored-By: Konstantin Wohlwend <n2d4xc@gmail.com>
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Workaround for vercel/next.js#91661 — a regression in Next.js 16.2 where
.next/package.json(the CJS boundary marker) is missing from Vercel serverless bundles, causingrequire is not defined in ES module scopeat runtime.The upstream fix (vercel/next.js#93612) is only in canary. Removing
"type": "module"is safe since the backend has no.jssource files and all configs use explicit extensions.Link to Devin session: https://app.devin.ai/sessions/0df63fcdfcce4e87800bbb80ee0fde9e
Requested by: @N2D4