vercel-logs

Vercel Logs

Safety

1. Read-only. NEVER run vercel deploy, vercel rollback, vercel alias, vercel env add/rm, vercel project rm, or any mutation. This skill only reads logs.
2. NEVER print secrets from log output. If a log line contains env var values, API keys, or tokens, redact before presenting.
3. Use --no-branch always. The CLI auto-detects the local git branch and silently filters to it — wrong for production debugging. Always pass --no-branch or --environment production explicitly.
4. Detach stdin. Append < /dev/null to every vercel command. Without it the CLI sniffs the TTY and hangs in agent shells.
5. Bound output. Always pass --limit N (default 20, max 100). For --follow runs, cap the observation window and kill the terminal when done — do not follow indefinitely.

Prerequisites

cd <repo-root>/<app>
pnpm exec vercel whoami < /dev/null 2>&1
cat .vercel/project.json 2>/dev/null | grep -o '"projectId":"[^"]*"'

If whoami fails → stop, tell user to run pnpm exec vercel login. If .vercel/project.json is missing → run:

cd <app> && pnpm exec vercel link --yes --scope <your-scope> --project <your-vercel-project>

Retention: Hobby = 1h · Pro = 24h · Pro + Observability Plus = 30 days · Enterprise = 3 days. If the user asks for logs beyond the retention window, tell them and suggest checking external log drains if configured.

Query modes

Recent errors (default diagnostic)

The go-to when the user reports “something broke in prod”:

cd <repo-root>/<app> && \
pnpm exec vercel logs \
  --no-branch \
  --environment production \
  --level error \
  --since 1h \
  --limit 20 \
  --json \
  --expand \
  --no-follow \
  < /dev/null 2>&1 | grep -E '^[{]' | jq .

Important: The CLI emits non-JSON preamble lines. Always filter with grep -E '^[{]' before piping to jq. Use [{] not ^\{ — zsh interprets bare braces.

Each line:

{
  "id": "...",
  "timestamp": 1779108733174,
  "level": "error",
  "message": "...",
  "source": "serverless|edge-middleware|edge-function",
  "requestMethod": "GET|POST",
  "requestPath": "/api/...",
  "responseStatusCode": 500,
  "environment": "production",
  "logs": [{ "level": "error", "message": "..." }]  // with --expand
}