Execute diagnose and fix Vercel common errors and exceptions. Use when encountering Vercel errors, debugging failed requests, or troubleshooting integration issues. Trigger with phrases like "vercel error", "fix vercel", "vercel not working", "debug vercel".
npxskills add jeremylongshore/claude-code-plugins-plus-skills--skill vercel-common-errorsLoading…
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.
vercel logs <url>)# 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:
vercel deploy, exit codes in build logBUILD_FAILED — Build command exited with non-zero codeError: Command "npm run build" exited with 1
vercel.json → buildCommand matches your build scriptpackage.json (not just devDependencies for runtime deps)npm run build locally to reproduceMISSING_BUILD_SCRIPT — No build command found
Error: Missing Build Command
"build" to package.json scripts or set buildCommand in vercel.jsonbuildCommand to empty string or "true"FUNCTION_PAYLOAD_TOO_LARGE — Serverless function bundle > 250 MB
Error: The Serverless Function "api/heavy" is 267 MB which exceeds the maximum size of 250 MB
.vercelignore, use dynamic imports, split into smaller functions@vercel/nft trace output to see what is being bundledFUNCTION_INVOCATION_FAILED — Unhandled exception in function
# View the actual error
vercel logs <deployment-url> --output=short
FUNCTION_INVOCATION_TIMEOUT — Function exceeded max duration
Error: Task timed out after 10.00 seconds
{
"functions": {
"api/slow-endpoint.ts": {
"maxDuration": 60
}
}
}
NO_RESPONSE_FROM_FUNCTION — Function didn't return a response
res.send(), res.json(), or return a ResponseFUNCTION_THROTTLED — Too many concurrent function invocations
404 NOT_FOUND
api/ or pages/api/ directoryoutputDirectory in vercel.json, verify build output contains the filevercel inspect <url> to see the deployment file listing504 GATEWAY_TIMEOUT
maxDuration or optimize function413 REQUEST_ENTITY_TOO_LARGE
DEPLOYMENT_NOT_FOUND
vercel lsReferenceError: process is not defined (Edge Runtime)
process.env in an edge functionEnv var undefined in production but works in preview
# Check which environments have the variable
vercel env ls | grep DATABASE_URL
Error occurred
├── During build? → Check build logs, run `npm run build` locally
├── During function invocation? → Check function logs with `vercel logs`
├── HTTP 404? → Verify file exists in deployment: `vercel inspect`
├── HTTP 500? → Unhandled exception in function code
├── HTTP 504? → Function timeout — increase maxDuration
└── HTTP 429? → Rate limited — implement retry with backoff
| Error Code | HTTP | Layer | Quick Fix |
|---|---|---|---|
BUILD_FAILED | — | Build | Run build locally, check deps |
FUNCTION_INVOCATION_FAILED | 500 | Runtime | Check env vars, add try/catch |
FUNCTION_INVOCATION_TIMEOUT | 504 | Runtime | Increase maxDuration in vercel.json |
FUNCTION_THROTTLED | 429 | Runtime | Reduce concurrency or upgrade plan |
FUNCTION_PAYLOAD_TOO_LARGE | 413 | Build | Reduce bundle size |
NOT_FOUND | 404 | Edge | Verify file paths and routes |
EDGE_FUNCTION_INVOCATION_FAILED | 500 | Edge | Remove Node.js APIs from edge code |
NO_RESPONSE_FROM_FUNCTION | 502 | Runtime | Return response from all code paths |
For detailed debug bundles, see vercel-debug-bundle.
Create or update AgentSkills. Use when designing, structuring, or packaging skills with scripts, references, and assets.
Create or update AgentSkills. Use when designing, structuring, or packaging skills with scripts, references, and assets.
Set up and use 1Password CLI (op). Use when installing the CLI, enabling desktop app integration, signing in (single or multi-account), or reading/injecting/running secrets via op.
CLI to manage emails via IMAP/SMTP. Use `himalaya` to list, read, write, reply, forward, search, and organize emails from the terminal. Supports multiple accounts and message composition with MML (MIME Meta Language).
Create or update AgentSkills. Use when designing, structuring, or packaging skills with scripts, references, and assets.
Create or update AgentSkills. Use when designing, structuring, or packaging skills with scripts, references, and assets.
Set up and use 1Password CLI (op). Use when installing the CLI, enabling desktop app integration, signing in (single or multi-account), or reading/injecting/running secrets via op.
CLI to manage emails via IMAP/SMTP. Use `himalaya` to list, read, write, reply, forward, search, and organize emails from the terminal. Supports multiple accounts and message composition with MML (MIME Meta Language).