How to send a push notification with curl

What you'll need

curl (installed on virtually every Mac, Linux box, and modern Windows) and the Lert app on your iPhone. Copy your endpoint from the app — it looks like https://lert.dev/p/your-id. That URL is the authentication; there's no key or token to add. Keep it private and regenerate it in the app if it ever leaks.

Everything here is one HTTP request, which is why curl is the lowest-common-denominator way to reach your phone: it works in a Makefile target, a Git hook, a systemd ExecStopPost, a Dockerfile healthcheck, or pasted straight into a terminal. Learn the flags once and every script you own inherits them.

The minimal command

Send a JSON body. The title, body, and tag fields are all optional — send whatever subset you like.

curl -X POST "https://lert.dev/p/your-id" \
  -H "Content-Type: application/json" \
  -d '{"title":"Backup done","body":"42 GB → S3","tag":"nightly"}'

The tag is a free-form label that appears in your in-app history, so you can tell a backup ping apart from a deploy ping later.

Plain text instead of JSON

If you only need a line of text, skip JSON. Lert accepts a raw body — the whole thing becomes the notification.

curl -X POST "https://lert.dev/p/your-id" \
  -H "Content-Type: text/plain" \
  --data-binary "Server rebooted at $(date +%H:%M)"

The -d gotcha with = and &

Here's the one that bites everyone. curl -d defaults to application/x-www-form-urlencoded. That means an & in your text is read as a field separator and an = becomes a key/value split — so a message like result=ok & done arrives truncated or scrambled.

Two fixes. If you're sending JSON, you're already safe as long as you set the JSON content type. If you're sending plain text that might contain = or &, set Content-Type: text/plain and use --data-binary so curl transmits the bytes exactly as written:

# WRONG — & and = get eaten by form encoding
curl -X POST "https://lert.dev/p/your-id" \
  -d "exit=0 & user=root"

# RIGHT — text/plain + --data-binary sends it verbatim
curl -X POST "https://lert.dev/p/your-id" \
  -H "Content-Type: text/plain" \
  --data-binary "exit=0 & user=root"

--data-binary also preserves newlines, which plain -d strips — useful if you want a multi-line body.

Quiet, but safe, for scripts

In a cron job or CI step you don't want curl's progress meter, but you do want to hear about real errors. The combination is -s -S: silent, but still show errors. Add -f so an HTTP 4xx/5xx makes curl exit non-zero.

curl -fsS -X POST "https://lert.dev/p/your-id" \
  -H "Content-Type: application/json" \
  -d '{"title":"Job finished"}'

• -s — silent, no progress bar.
• -S — but still print an error message if something breaks.
• -f — fail with a non-zero exit code on HTTP errors (404, 429, 5xx).

Two more flags earn their keep in unattended scripts. Add --max-time 10 so a stalled connection can't hang your job indefinitely, and --retry 2 so a transient network blip is retried automatically before curl gives up. Together with -fsS they turn a bare request into something you can trust in a pipeline that runs at 3am with nobody watching.

Branch on success in bash

Because -f sets the exit code, you can wrap the call in a plain if. That lets you notify a fallback channel — or just log — when the notification itself fails.

LERT_URL="https://lert.dev/p/your-id"

if curl -fsS -X POST "$LERT_URL" \
     -H "Content-Type: application/json" \
     -d '{"title":"Deploy live ✅"}' > /dev/null; then
  echo "notified"
else
  echo "lert failed (exit $?)" >&2
fi

Reading the response

A success is 200 with {"delivered":1}. Pipe to jq if you want to act on the field. Watch for these:

• 200 {"delivered":0,"warning":"no device registered…"} — valid endpoint but no device yet; open the Lert app once on your phone.
• 404 {"error":"unknown endpoint"} — wrong or regenerated URL.
• 429 — rate limited (60/min per IP, 50/day on Free). Honor the Retry-After header.

delivered=$(curl -sS -X POST "$LERT_URL" \
  -H "Content-Type: application/json" \
  -d '{"title":"ping"}' | jq '.delivered')

echo "delivered = $delivered"

Why it's this simple

There's no auth flow because the endpoint URL is the credential. curl already speaks HTTP, so "notify my phone from the shell" is a single command you can paste into any script, any pipeline, any box with network access.

Once you've got the flags down — -fsS for scripts, text/plain with --data-binary for messy text, and a plain if to branch on the exit code — the same three or four lines cover everything from a one-off build to a fleet of servers. That's the payoff of a primitive small enough to memorize.