LastSeenDocs

Quick start

Your first heartbeat monitor and your first alert, in about five minutes.

You'll add a heartbeat monitor, ping it by hand, add somewhere for alerts to go, and then watch it go down and come back up.

1. Sign in #

Go to app.lastseen.io and choose Sign in or sign up. You start in an organization of your own, on the Free plan.

2. Add a heartbeat monitor #

On Monitors, choose Add heartbeat monitor:

  • Name: something you'll recognise in an alert, like garage-sensor.
  • Heartbeat every: how often it will ping. Leave it at 60s for now.

Choose Add monitor. The next page shows the monitor's ping key and its ping URL:

https://ping.lastseen.io/abcdefghijklmnopqrstuvwxyz

3. Send a heartbeat #

From any terminal:

curl https://ping.lastseen.io/YOUR-KEY

LastSeen answers ok. Open the monitor: it's up, and "last seen" counts up from a few seconds ago.

4. Add somewhere for alerts to go #

On Channels, choose Add channel. The quickest to try is ntfy, a free push notification app:

  1. Install ntfy on your phone and subscribe to a topic with a name nobody would guess, like lastseen-7f3k2q9x.
  2. In LastSeen, choose ntfy and paste https://ntfy.sh/lastseen-7f3k2q9x.
  3. Choose Save channel, then Send test. The test arrives on your phone, and the channel shows ok.

Email works too: LastSeen sends the address a confirmation link first. See Alert channels for every kind.

5. Watch it go down, and come back #

Now stop pinging. With a heartbeat every 60s:

  • after a minute it's late (shown on the page, no alert);
  • after two missed heartbeats it's down, and the alert arrives on your phone.

Ping it again, and a back up alert follows. That's the whole loop. Late and down explains the timing and how to tune it.

6. Make it real #

Replace the curl with the thing you want to watch: