Claude Code 部署避坑指南：15个常见错误与 Synteq 一键部署

Claude Code tip: works on localhost, breaks in production. These are the 15 places a vibe-coded app's first deploy usually falls over. Before you deploy, have Opus 5.5 send out 4 subagents to check them, fix everything in one pass, then ship with one command:

From your laptop to a server → Replace every hard-coded http://localhost:3000 with an environment variable or a relative path → If the server only listens on localhost, switch it to 0.0.0.0 and read the port from the PORT environment variable → If you only ever run npm run dev, run build and then start locally once. Dev lets TypeScript type errors slide; build fails on them → Check that import paths match the real file names, including case. On a Mac, ./Components/button still finds ./components/Button. On a Linux server it's "module not found" → Anything that only exists on your machine (globally installed tools, your local Node version) goes into package.json

Secrets and environment variables → List every environment variable the code reads and check it against .env. Flag what's missing and what's unused → Check every key that shows up in frontend code. Apart from the ones meant to be public (like Supabase's anon key, as long as every table has RLS on), move them all to the server → Variables starting with NEXT_PUBLIC_ or VITE_ get baked in at build time. Make them available to the build on your host, and rebuild after changing them → Check whether .env was ever committed to git. Rotate every key that's in the history

Data and new releases → User uploads and SQLite databases on local disk disappear on a restart or a new release. Move them to object storage and a managed database → Make database migrations their own command that runs before the new version takes traffic. Only add, never drop, so the old version still runs on the new schema → Login sessions and rate-limit counters kept in memory reset on every release, and each running copy keeps its own. Scheduled jobs run once per copy too

Switching to your live domain → Add your live domain to Supabase auth's Site URL and redirect URLs, and to your Google and GitHub login callbacks. Otherwise confirmation emails still open localhost → In Stripe, create a new webhook for your live URL and use its own signing secret. The one stripe listen gave you won't verify in production → Update CORS allowed origins, the cookie domain and the Secure flag for your live https domain

The moment you go live → Add a /healthz that needs no login and returns 200 within a few seconds. New versions only take traffic once they pass it → Once it's up, keep the live logs open and click through sign-up, login and payment on the live URL → Write down the rollback command so one command takes you back to the previous version. Database migrations don't roll back with it → Have it turn these 15 checks into a script in the repo, and run it before every deploy

Once the code's fixed, deploy with Cloud Apps, which @synteq launched today for indie developers and small teams. Run these three lines in your project folder and you get an https .synteq.app link: npm install -g synteq synteq login synteq deploy

Connect GitHub and every push to the branch you pick goes live on its own, or skip the terminal and drag and drop your project in. A new version only takes traffic after it passes the health check; if it fails, the old one keeps serving.

The default medium effort is enough. Get the data group wrong and you lose user data, so raise that one to high.

Send this whole post to Claude Code. If you need to, add this line at the end 👇 "Send one subagent to each of the first four groups. Check only, don't fix, and for each problem say which file it's in and how it breaks once live. Run the data subagent at high effort. Then fix everything yourself from their lists, and run build then start locally. Deploy with the Synteq CLI: I'll run login and create the app myself in a terminal (synteq login, synteq link), and you confirm with synteq status before going on. I'll put the production values in .env.production. Don't read or print it; import it at deploy time with --env-file. Before the first deploy, set the health check path and the pre-deploy command with synteq app settings set. Once it's up, curl the homepage and /healthz and check synteq app logs --search error. For sign-up, login and payment, list the steps and I'll click through myself. List any leaked keys and I'll rotate them in each dashboard. Ask me before rewriting git history, changing the database, switching storage, adding a custom domain, or running anything that needs --yes."

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