Start Codex CLI quota periods automatically with cron

I use Codex CLI on an Ubuntu server. The quota window is 5 hours, so I trigger a tiny Codex request at 07:30, 12:30, and 17:30 to get three full windows per day. You can use a similar cron job for Claude Code too.

The solution is a small shell script plus a user cron job.

Create the wakeup script

Create the job folder and copy and paste this whole block into the terminal:

mkdir -p ~/project/misc/codex_timely_job
cat > ~/project/misc/codex_timely_job/codex-wakeup.sh <<'EOF'
#!/usr/bin/env bash

JOB_DIR="$HOME/project/misc/codex_timely_job"
LOG="$JOB_DIR/log.txt"

{
  echo "===== START $(date '+%Y-%m-%d %H:%M:%S %Z') ====="

  cd "$JOB_DIR"

  "$HOME/.npm-packages/bin/codex" exec \
    --model gpt-5.4-mini \
    -c model_reasoning_effort=\"low\" \
    --skip-git-repo-check \
    --ephemeral \
    "hi"

  echo "===== END $(date '+%Y-%m-%d %H:%M:%S %Z') ====="
  echo
} >> "$LOG" 2>&1
EOF

chmod +x ~/project/misc/codex_timely_job/codex-wakeup.sh

Test it manually

~/project/misc/codex_timely_job/codex-wakeup.sh
tail -n 50 ~/project/misc/codex_timely_job/log.txt

The timestamp is important. Without it, it is hard to tell whether cron actually ran the job.

Example log:

===== START 2026-05-08 17:30:01 EDT =====
...
===== END 2026-05-08 17:30:10 EDT =====

Add the cron job

Open crontab:

crontab -e

Add this line:

30 7,12,17 * * * /home/YOUR_USER/project/misc/codex_timely_job/codex-wakeup.sh

This runs the script at 07:30, 12:30, and 17:30 every day.

Verify

List the installed cron jobs:

crontab -l

Check the server time:

date

Cron uses the server’s timezone, not the laptop timezone.

After the next scheduled run, check the log:

tail -n 50 ~/project/misc/codex_timely_job/log.txt

Notes

I first tried model_reasoning_effort="minimal", but it failed because my Codex session had tools attached that were incompatible with minimal effort. Using low worked.

The --ephemeral flag keeps the run lightweight. The prompt is only hi, so the request is intentionally tiny.

No cron restart is needed after editing the script. Cron will use the updated script the next time it runs.