Add Vercel serverless deployment support for Express app

[Copilot]

Vercel deployments currently return 404 because the Express/EJS app lacks a serverless adapter and proper routing configuration.

Changes

• api/index.js: Serverless wrapper that attempts to load Express app from common entry points (../app, ../server, ../src/app, ../src/server, ./app), wraps with serverless-http, and returns actionable error JSON if app not found
• vercel.json: Routes all requests to serverless function with Node 18 runtime
• package.json: Add serverless-http@^3.0.0 dependency
• PROPOSED_CHANGE.md: Maintainer instructions for required code changes

Required Follow-up

Current app.js calls app.listen() directly without exporting the Express instance. Maintainers must add:

// At end of app.js
module.exports = app;

Alternatively, use conditional export:

mongoose
  .connect(dbURI)
  .then((result) => {
    if (require.main === module) {
      app.listen(3000);
    }
  })
  .catch((err) => console.error(err));

module.exports = app;

See PROPOSED_CHANGE.md for complete guidance on MongoDB connection strings and environment variables.

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• nodeproject.62tovra.mongodb.net
  • Triggering command: node -e // Test that api/index.js can be required const handler = require('./api/index.js'); console.log('✓ api/index.js can be required successfully'); console.log('Handler type:', typeof handler); (dns block)
  • Triggering command: node -e const app = require('./app.js'); console.log('App loaded:', typeof app); console.log('Is function:', typeof app === 'function'); console.log('Has _router:', app && app._router !== undefined); (dns block)
  • Triggering command: node -e const handler = require('./api/index.js'); const mockReq = {}; const mockRes = { status: function(code) { this.statusCode = code; return this; }, json: function(data) { console.log('Status:', this.statusCode); console.log('Response:', JSON.stringify(data, null, 2)); } }; handler(mockReq, mockRes); (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

Original prompt

Issue: Vercel deployment returns 404 (screenshot attached). Vercel likely can't find a build output or a compatible server entrypoint for an Express/EJS app.

Goal: Create a PR that makes this repository deployable on Vercel by adding a serverless adapter for an Express app, an explicit vercel.json to route requests to the function, and add serverless-http to dependencies.

Files to add:

• api/index.js: serverless wrapper that attempts to require the Express app from common entrypoints (../app, ../server, ../src/app, ../src/server, ./app) and wraps it with serverless-http. If no app is found, it returns a helpful JSON error message.
• vercel.json: declare the Node 18 runtime for the function and rewrite all routes to /api/index.js so client-side routing won't 404.
• PROPOSED_CHANGE.md: a short explanation and instructions for maintainers.

File to modify:

• package.json: add dependency "serverless-http": "^3.0.0" under dependencies, preserving the rest of package.json content.

Notes for maintainers:

• If the project's server file currently calls app.listen() directly, update it to export the Express app instance (examples included in PROPOSED_CHANGE.md). A local server.js can call listen for development.
• If the project is actually a Next.js or static SPA app, a different approach is necessary; this PR targets an Express/EJS app.

Attached screenshot:

Please add these files and the package.json change on a new branch and open a PR against main. After merge, Vercel should install dependencies and redeploy. If any file paths differ in the repo, maintainers should update api/index.js to require the correct entrypoint. The PR should not overwrite existing files other than updating package.json to include the added dependency.

This pull request was created as a result of the following prompt from Copilot chat.

Issue: Vercel deployment returns 404 (screenshot attached). Vercel likely can't find a build output or a compatible server entrypoint for an Express/EJS app.

Goal: Create a PR that makes this repository deployable on Vercel by adding a serverless adapter for an Express app, an explicit vercel.json to route requests to the function, and add serverless-http to dependencies.

Files to add:

• api/index.js: serverless wrapper that attempts to require the Express app from common entrypoints (../app, ../server, ../src/app, ../src/server, ./app) and wraps it with serverless-http. If no app is found, it returns a helpful JSON error message.
• vercel.json: declare the Node 18 runtime for the function and rewrite all routes to /api/index.js so client-side routing won't 404.
• PROPOSED_CHANGE.md: a short explanation and instructions for maintainers.

File to modify:

• package.json: add dependency "serverless-http": "^3.0.0" under dependencies, preserving the rest of package.json content.

Notes for maintainers:

• If the project's server file currently calls app.listen() directly, update it to export the Express app instance (examples included in PROPOSED_CHANGE.md). A local server.js can call listen for development.
• If the project is actually a Next.js or static SPA app, a different approach is necessary; this PR targets an Express/EJS app.

Attached screenshot:

Please add these files and the package.json change on a new branch and open a PR against main. After merge, Vercel should install dependencies and redeploy. If any file paths differ in the repo, maintainers should update api/index.js to require the correct entrypoint. The PR should not overwrite existing files other than updating package.json to include the added dependency.

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Project	Deployment	Preview	Comments	Updated (UTC)
blog-node	Ready	Preview	Comment	Nov 4, 2025 6:47pm