vercel-common-errors

# Vercel Common Errors ## Overview Diagnose and resolve the most common Vercel errors across three layers: build pipeline, serverless function runtime, and edge network. Each error includes the error code, root cause, and step-by-step fix. ## Prerequisites - Vercel CLI installed - Access to deployment logs (`vercel logs <url>`) - Access to Vercel dashboard for build logs ## Instructions ### Step 1: Identify the Error Layer ```bash # Check deployment status and error details vercel inspect <deployment-url> # View function runtime logs vercel logs <deployment-url> --follow # View build logs via API curl -s -H "Authorization: Bearer $VERCEL_TOKEN" \ "https://api.vercel.com/v13/deployments/dpl_xxx" | jq '.state, .errorMessage' ``` **Three error layers:** 1. **Build errors** — appear during `vercel deploy`, exit codes in build log 2. **Runtime errors** — appear when functions are invoked, visible in function logs 3. **Edge/routing errors** — HTTP errors from Vercel's edge network ### Step 2: Build Errors **`BUILD_FAILED` — Build command exited with non-zero code** ``` Error: Command "npm run build" exited with 1 ``` - Check: `vercel.json` → `buildCommand` matches your build script - Check: all dependencies listed in `package.json` (not just devDependencies for runtime deps) - Fix: run `npm run build` locally to reproduce **`MISSING_BUILD_SCRIPT` — No build command found** ``` Error: Missing Build Command ``` - Fix: add `"build"` to `package.json` scripts or set `buildC...