binwiederhier-ntfy/docs/subscribe/cli.md

Subscribe via ntfy CLI

In addition to subscribing via the web UI, the phone app, or the API, you can subscribe to topics via the ntfy CLI. The CLI is included in the same ntfy binary that can be used to self-host a server.

!!! info The ntfy CLI is not required to send or receive messages. You can instead send messages with curl, and even use it to subscribe to topics. It may be a little more convenient to use the ntfy CLI than writing your own script. It all depends on the use case. 😀

Install + configure

To install the ntfy CLI, simply follow the steps outlined on the install page. The ntfy server and client are the same binary, so it's all very convenient. After installing, you can (optionally) configure the client by creating ~/.config/ntfy/client.yml (for the non-root user), or /etc/ntfy/client.yml (for the root user). You can find a skeleton config on GitHub.

If you just want to use ntfy.sh, you don't have to change anything. If you self-host your own server, you may want to edit the default-host option:

# Base URL used to expand short topic names in the "ntfy publish" and "ntfy subscribe" commands.
# If you self-host a ntfy server, you'll likely want to change this.
#
default-host: https://ntfy.myhost.com

Publish messages

You can send messages with the ntfy CLI using the ntfy publish command (or any of its aliases pub, send or trigger). There are a lot of examples on the page about publishing messages, but here are a few quick ones:

=== "Simple send" ntfy publish mytopic This is a message ntfy publish mytopic "This is a message" ntfy pub mytopic "This is a message"

=== "Send with title, priority, and tags" ntfy publish \ --title="Thing sold on eBay" \ --priority=high \ --tags=partying_face \ mytopic \ "Somebody just bought the thing that you sell"

=== "Send at 8:30am" ntfy pub --at=8:30am delayed_topic Laterzz

=== "Triggering a webhook" ntfy trigger mywebhook ntfy pub mywebhook

Attaching a local file

You can easily upload and attach a local file to a notification:

$ ntfy pub --file README.md mytopic | jq .
{
  "id": "meIlClVLABJQ",
  "time": 1655825460,
  "event": "message",
  "topic": "mytopic",
  "message": "You received a file: README.md",
  "attachment": {
    "name": "README.md",
    "type": "text/plain; charset=utf-8",
    "size": 2892,
    "expires": 1655836260,
    "url": "https://ntfy.sh/file/meIlClVLABJQ.txt"
  }
}

Wait for PID/command

If you have a long-running command and want to publish a notification when the command completes, you may wrap it with ntfy publish --wait-cmd (aliases: --cmd, --done). Or, if you forgot to wrap it, and the command is already running, you can wait for the process to complete with ntfy publish --wait-pid (alias: --pid).

Run a command and wait for it to complete (here: rsync ...):

$ ntfy pub --wait-cmd mytopic rsync -av ./ root@example.com:/backups/ | jq .
{
  "id": "Re0rWXZQM8WB",
  "time": 1655825624,
  "event": "message",
  "topic": "mytopic",
  "message": "Command succeeded after 56.553s: rsync -av ./ root@example.com:/backups/"
}

Or, if you already started the long-running process and want to wait for it using its process ID (PID), you can do this:

=== "Using a PID directly" $ ntfy pub --wait-pid 8458 mytopic | jq . { "id": "orM6hJKNYkWb", "time": 1655825827, "event": "message", "topic": "mytopic", "message": "Process with PID 8458 exited after 2.003s" }

=== "Using a pidof" $ ntfy pub --wait-pid $(pidof rsync) mytopic | jq . { "id": "orM6hJKNYkWb", "time": 1655825827, "event": "message", "topic": "mytopic", "message": "Process with PID 8458 exited after 2.003s" }

Subscribe to topics

You can subscribe to topics using ntfy subscribe. Depending on how it is called, this command will either print or execute a command for every arriving message. There are a few different ways in which the command can be run:

Stream messages as JSON

ntfy subscribe TOPIC

If you run the command like this, it prints the JSON representation of every incoming message. This is useful when you have a command that wants to stream-read incoming JSON messages. Unless --poll is passed, this command stays open forever.

$ ntfy sub mytopic
{"id":"nZ8PjH5oox","time":1639971913,"event":"message","topic":"mytopic","message":"hi there"}
{"id":"sekSLWTujn","time":1639972063,"event":"message","topic":"mytopic",priority:5,"message":"Oh no!"}
...

Subscribe in JSON mode

Run command for every message

ntfy subscribe TOPIC COMMAND

If you run it like this, a COMMAND is executed for every incoming messages. Scroll down to see a list of available environment variables. Here are a few examples:

ntfy sub mytopic 'notify-send "$m"'
ntfy sub topic1 /my/script.sh
ntfy sub topic1 'echo "Message $m was received. Its title was $t and it had priority $p'

Execute command on incoming messages

The message fields are passed to the command as environment variables and can be used in scripts. Note that since these are environment variables, you typically don't have to worry about quoting too much, as long as you enclose them in double-quotes, you should be fine:

Variable	Aliases	Description
$NTFY_ID	$id	Unique message ID
$NTFY_TIME	$time	Unix timestamp of the message delivery
$NTFY_TOPIC	$topic	Topic name
$NTFY_MESSAGE	$message, $m	Message body
$NTFY_TITLE	$title, $t	Message title
$NTFY_PRIORITY	$priority, $prio, $p	Message priority (1=min, 5=max)
$NTFY_TAGS	$tags, $tag, $ta	Message tags (comma separated list)
$NTFY_RAW	$raw	Raw JSON message

Subscribe to multiple topics

ntfy subscribe --from-config

To subscribe to multiple topics at once, and run different commands for each one, you can use ntfy subscribe --from-config, which will read the subscribe config from the config file. Please also check out the ntfy-client systemd service.

Here's an example config file that subscribes to three different topics, executing a different command for each of them:

=== "~/.config/ntfy/client.yml (Linux)" yaml subscribe: - topic: echo-this command: 'echo "Message received: $message"' - topic: alerts command: notify-send -i /usr/share/ntfy/logo.png "Important" "$m" if: priority: high,urgent - topic: calc command: 'gnome-calculator 2>/dev/null &' - topic: print-temp command: | echo "You can easily run inline scripts, too." temp="$(sensors | awk '/Pack/ { print substr($4,2,2) }')" if [ $temp -gt 80 ]; then echo "Warning: CPU temperature is $temp. Too high." else echo "CPU temperature is $temp. That's alright." fi

=== "~/Library/Application Support/ntfy/client.yml (macOS)" yaml subscribe: - topic: echo-this command: 'echo "Message received: $message"' - topic: alerts command: osascript -e "display notification \"$message\"" if: priority: high,urgent - topic: calc command: open -a Calculator

=== "%AppData%\ntfy\client.yml (Windows)" yaml subscribe: - topic: echo-this command: 'echo Message received: %message%' - topic: alerts command: | notifu /m "%NTFY_MESSAGE%" exit 0 if: priority: high,urgent - topic: calc command: calc

In this example, when ntfy subscribe --from-config is executed:

• Messages to echo-this simply echos to standard out
• Messages to alerts display as desktop notification for high priority messages using notify-send (Linux), notifu (Windows) or osascript (macOS)
• Messages to calc open the calculator 😀 (because, why not)
• Messages to print-temp execute an inline script and print the CPU temperature (Linux version only)

I hope this shows how powerful this command is. Here's a short video that demonstrates the above example:

Execute all the things

If most (or all) of your subscriptions use the same credentials, you can set defaults in client.yml. Use default-user and default-password or default-token (but not both). You can also specify a default-command that will run when a message is received. If a subscription does not include credentials to use or does not have a command, the defaults will be used, otherwise, the subscription settings will override the defaults.

!!! warning Because the default-user, default-password, and default-token will be sent for each topic that does not have its own username/password (even if the topic does not require authentication), be sure that the servers/topics you subscribe to use HTTPS to prevent leaking the username and password.

Using the systemd service

You can use the ntfy-client systemd service (see ntfy-client.service) to subscribe to multiple topics just like in the example above. The service is automatically installed (but not started) if you install the deb/rpm package. To configure it, simply edit /etc/ntfy/client.yml and run sudo systemctl restart ntfy-client.

!!! info The ntfy-client.service runs as user ntfy, meaning that typical Linux permission restrictions apply. See below for how to fix this.

If the service runs on your personal desktop machine, you may want to override the service user/group (User= and Group=), and adjust the DISPLAY and DBUS_SESSION_BUS_ADDRESS environment variables. This will allow you to run commands in your X session as the primary machine user.

You can either manually override these systemd service entries with sudo systemctl edit ntfy-client, and add this (assuming your user is phil). Don't forget to run sudo systemctl daemon-reload and sudo systemctl restart ntfy-client after editing the service file:

=== "/etc/systemd/system/ntfy-client.service.d/override.conf" [Service] User=phil Group=phil Environment="DISPLAY=:0" "DBUS_SESSION_BUS_ADDRESS=unix:path=/run/user/1000/bus" Or you can run the following script that creates this override config for you:

sudo sh -c 'cat > /etc/systemd/system/ntfy-client.service.d/override.conf' <<EOF
[Service]
User=$USER
Group=$USER
Environment="DISPLAY=:0" "DBUS_SESSION_BUS_ADDRESS=unix:path=/run/user/$(id -u)/bus"
EOF

sudo systemctl daemon-reload
sudo systemctl restart ntfy-client

Authentication

Depending on whether the server is configured to support access control, some topics may be read/write protected so that only users with the correct credentials can subscribe or publish to them. To publish/subscribe to protected topics, you can use Basic Auth with a valid username/password. For your self-hosted server, be sure to use HTTPS to avoid eavesdropping and exposing your password.

You can either add your username and password to the configuration file: === "~/.config/ntfy/client.yml" yaml - topic: secret command: 'notify-send "$m"' user: phill password: mypass

Or with the ntfy subscibe command:

ntfy subscribe \
  -u phil:mypass \
  ntfy.example.com/mysecrets