Merge pull request #1 from Joeharrison94/Joeharrison94-patch-1

Update to publish.md to add PowerShell examples

docs/publish.md

@@ -1,6 +1,7 @@
 # Publishing
-Publishing messages can be done via HTTP PUT or POST. Topics are created on the fly by subscribing or publishing to them.
-Because there is no sign-up, **the topic is essentially a password**, so pick something that's not easily guessable.
+Publishing messages can be done via HTTP PUT/POST or via the [ntfy CLI](install.md). Topics are created on the fly by 
+subscribing or publishing to them. Because there is no sign-up, **the topic is essentially a password**, so pick 
+something that's not easily guessable.
 
 Here's an example showing how to publish a simple message using a POST request:
 
@@ -9,6 +10,11 @@ Here's an example showing how to publish a simple message using a POST request:
     curl -d "Backup successful 😀" ntfy.sh/mytopic
     ```
 
+=== "ntfy CLI"
+    ```
+    ntfy publish mytopic "Backup successful 😀"
+    ```
+
 === "HTTP"
     ``` http
     POST /mytopic HTTP/1.1
@@ -30,6 +36,17 @@ Here's an example showing how to publish a simple message using a POST request:
         strings.NewReader("Backup successful 😀"))
     ```
 
+=== "PowerShell"
+    ``` powershell
+    Invoke-RestMethod -Method 'Post' -Uri https://ntfy.sh/topic -Body "Backup Successful 😀" -UseBasicParsing
+    ```
+
+=== "Python"
+    ``` python
+    requests.post("https://ntfy.sh/mytopic", 
+        data="Backup successful 😀".encode(encoding='utf-8'))
+    ```
+
 === "PHP"
     ``` php-inline
     file_get_contents('https://ntfy.sh/mytopic', false, stream_context_create([
@@ -44,12 +61,12 @@ Here's an example showing how to publish a simple message using a POST request:
 If you have the [Android app](subscribe/phone.md) installed on your phone, this will create a notification that looks like this:
 
 <figure markdown>
-  ![basic notification](static/img/basic-notification.png){ width=500 }
+  ![basic notification](static/img/android-screenshot-basic-notification.png){ width=500 }
   <figcaption>Android notification</figcaption>
 </figure>
 
 There are more features related to publishing messages: You can set a [notification priority](#message-priority), 
-a [title](#message-title), and [tag messages](#tags-emojis) 🥳 🎉. Here's an example that uses all of them at once:
+a [title](#message-title), and [tag messages](#tags-emojis) 🥳 🎉. Here's an example that uses some of them at together:
 
 === "Command line (curl)"
     ```
@@ -61,6 +78,16 @@ a [title](#message-title), and [tag messages](#tags-emojis) 🥳 🎉. Here's an
       ntfy.sh/phil_alerts
     ```
 
+=== "ntfy CLI"
+    ```
+    ntfy publish \
+        --title "Unauthorized access detected" \
+        --tags warning,skull \
+        --priority urgent \
+        mytopic \
+        "Remote access to phils-laptop detected. Act right away."
+    ```
+
 === "HTTP"
     ``` http
     POST /phil_alerts HTTP/1.1
@@ -95,6 +122,27 @@ a [title](#message-title), and [tag messages](#tags-emojis) 🥳 🎉. Here's an
 	http.DefaultClient.Do(req)
     ```
 
+=== "PowerShell"
+    ``` powershell
+    $uri = "https://ntfy.sh/phil_alerts"
+    $headers = @{ Title="Unauthorized access detected"
+                  Priority="Urgent"
+                  Tags="warning,skull" }
+    $body = "Remote access to phils-laptop detected. Act right away."              
+    Invoke-RestMethod -Method 'Post' -Uri $uri -Headers $headers -Body $body -UseBasicParsing
+    ```
+    
+=== "Python"
+    ``` python
+    requests.post("https://ntfy.sh/phil_alerts",
+        data="Remote access to phils-laptop detected. Act right away.",
+        headers={
+            "Title": "Unauthorized access detected",
+            "Priority": "urgent",
+            "Tags": "warning,skull"
+        })
+    ```
+
 === "PHP"
     ``` php-inline
     file_get_contents('https://ntfy.sh/phil_alerts', false, stream_context_create([
@@ -126,6 +174,13 @@ you can set the `X-Title` header (or any of its aliases: `Title`, `ti`, or `t`).
     curl -H "t: Dogs are better than cats" -d "Oh my ..." ntfy.sh/controversial
     ```
 
+=== "ntfy CLI"
+    ```
+    ntfy publish \
+        -t "Dogs are better than cats" \
+        controversial "Oh my ..."
+    ```
+
 === "HTTP"
     ``` http
     POST /controversial HTTP/1.1
@@ -151,6 +206,21 @@ you can set the `X-Title` header (or any of its aliases: `Title`, `ti`, or `t`).
     http.DefaultClient.Do(req)
     ```
 
+=== "PowerShell"
+    ``` powershell
+    $uri = "https://ntfy.sh/controversial"
+    $headers = @{ Title="Dogs are better than cats" }
+    $body = "Oh my ..."
+    Invoke-RestMethod -Method 'Post' -Uri $uri -Headers $headers -Body $body -UseBasicParsing
+    ```
+
+=== "Python"
+    ``` python
+    requests.post("https://ntfy.sh/controversial",
+        data="Oh my ...",
+        headers={ "Title": "Dogs are better than cats" })
+    ```
+
 === "PHP"
     ``` php-inline
     file_get_contents('https://ntfy.sh/controversial', false, stream_context_create([
@@ -192,6 +262,13 @@ You can set the priority with the header `X-Priority` (or any of its aliases: `P
     curl -H p:4 -d "A high priority message" ntfy.sh/phil_alerts
     ```
 
+=== "ntfy CLI"
+    ```
+    ntfy publish \ 
+        -p 5 \
+        phil_alerts An urgent message
+    ```
+
 === "HTTP"
     ``` http
     POST /phil_alerts HTTP/1.1
@@ -217,6 +294,21 @@ You can set the priority with the header `X-Priority` (or any of its aliases: `P
     http.DefaultClient.Do(req)
     ```
 
+=== "PowerShell"
+    ``` powershell
+    $uri = "https://ntfy.sh/phil_alerts"
+    $headers = @{ Priority="Urgent" }
+    $body = "An urgent message"
+    Invoke-RestMethod -Method 'Post' -Uri $uri -Headers $headers -Body $body -UseBasicParsing
+    ```
+    
+=== "Python"
+    ``` python
+    requests.post("https://ntfy.sh/phil_alerts",
+        data="An urgent message",
+        headers={ "Priority": "5" })
+    ```
+
 === "PHP"
     ``` php-inline
     file_get_contents('https://ntfy.sh/phil_alerts', false, stream_context_create([
@@ -279,7 +371,7 @@ Here's an **excerpt of emojis** I've found very useful in alert messages:
 </td>
 </tr></table>
 
-You can set tags with the `X-Tags` header (or any of its aliases: `Tags`, or `ta`). Specify multiple tags by separating
+You can set tags with the `X-Tags` header (or any of its aliases: `Tags`, `tag`, or `ta`). Specify multiple tags by separating
 them with a comma, e.g. `tag1,tag2,tag3`.
 
 === "Command line (curl)"
@@ -289,6 +381,13 @@ them with a comma, e.g. `tag1,tag2,tag3`.
     curl -H ta:dog -d "Dogs are awesome" ntfy.sh/backups
     ```
 
+=== "ntfy CLI"
+    ```
+    ntfy publish \
+        --tags=warning,mailsrv13,daily-backup \
+        backups "Backup of mailsrv13 failed"
+    ```
+
 === "HTTP"
     ``` http
     POST /backups HTTP/1.1
@@ -314,6 +413,21 @@ them with a comma, e.g. `tag1,tag2,tag3`.
     http.DefaultClient.Do(req)
     ```
 
+=== "PowerShell"
+    ``` powershell
+    $uri = "https://ntfy.sh/backups"
+    $headers = @{ Tags="warning,mailsrv13,daily-backup" }
+    $body = "Backup of mailsrv13 failed"
+    Invoke-RestMethod -Method 'Post' -Uri $uri -Headers $headers -Body $body -UseBasicParsing
+    ```
+
+=== "Python"
+    ``` python
+    requests.post("https://ntfy.sh/backups",
+        data="Backup of mailsrv13 failed",
+        headers={ "Tags": "warning,mailsrv13,daily-backup" })
+    ```
+
 === "PHP"
     ``` php-inline
     file_get_contents('https://ntfy.sh/backups', false, stream_context_create([
@@ -332,3 +446,1043 @@ them with a comma, e.g. `tag1,tag2,tag3`.
   <figcaption>Detail view of notifications with tags</figcaption>
 </figure>
 
+## Scheduled delivery
+You can delay the delivery of messages and let ntfy send them at a later date. This can be used to send yourself 
+reminders or even to execute commands at a later date (if your subscriber acts on messages).
+
+Usage is pretty straight forward. You can set the delivery time using the `X-Delay` header (or any of its aliases: `Delay`, 
+`X-At`, `At`, `X-In` or `In`), either by specifying a Unix timestamp (e.g. `1639194738`), a duration (e.g. `30m`, 
+`3h`, `2 days`), or a natural language time string (e.g. `10am`, `8:30pm`, `tomorrow, 3pm`, `Tuesday, 7am`, 
+[and more](https://github.com/olebedev/when)). 
+
+As of today, the minimum delay you can set is **10 seconds** and the maximum delay is **3 days**. This can currently
+not be configured otherwise ([let me know](https://github.com/binwiederhier/ntfy/issues) if you'd like to change 
+these limits).
+
+For the purposes of [message caching](config.md#message-cache), scheduled messages are kept in the cache until 12 hours 
+after they were delivered (or whatever the server-side cache duration is set to). For instance, if a message is scheduled
+to be delivered in 3 days, it'll remain in the cache for 3 days and 12 hours. Also note that naturally, 
+[turning off server-side caching](#message-caching) is not possible in combination with this feature.  
+
+=== "Command line (curl)"
+    ```
+    curl -H "At: tomorrow, 10am" -d "Good morning" ntfy.sh/hello
+    curl -H "In: 30min" -d "It's 30 minutes later now" ntfy.sh/reminder
+    curl -H "Delay: 1639194738" -d "Unix timestamps are awesome" ntfy.sh/itsaunixsystem
+    ```
+
+=== "ntfy CLI"
+    ```
+    ntfy publish \
+        --at="tomorrow, 10am" \
+        hello "Good morning"
+    ```
+
+=== "HTTP"
+    ``` http
+    POST /hello HTTP/1.1
+    Host: ntfy.sh
+    At: tomorrow, 10am
+
+    Good morning
+    ```
+
+=== "JavaScript"
+    ``` javascript
+    fetch('https://ntfy.sh/hello', {
+        method: 'POST',
+        body: 'Good morning',
+        headers: { 'At': 'tomorrow, 10am' }
+    })
+    ```
+
+=== "Go"
+    ``` go
+    req, _ := http.NewRequest("POST", "https://ntfy.sh/hello", strings.NewReader("Good morning"))
+    req.Header.Set("At", "tomorrow, 10am")
+    http.DefaultClient.Do(req)
+    ```
+
+=== "PowerShell"
+    ``` powershell
+    $uri = "https://ntfy.sh/hello"
+    $headers = @{ At="tomorrow, 10am" }
+    $body = "Good morning"
+    Invoke-RestMethod -Method 'Post' -Uri $uri -Headers $headers -Body $body -UseBasicParsing
+    ```
+    
+=== "Python"
+    ``` python
+    requests.post("https://ntfy.sh/hello",
+        data="Good morning",
+        headers={ "At": "tomorrow, 10am" })
+    ```
+
+=== "PHP"
+    ``` php-inline
+    file_get_contents('https://ntfy.sh/backups', false, stream_context_create([
+        'http' => [
+            'method' => 'POST',
+            'header' =>
+                "Content-Type: text/plain\r\n" .
+                "At: tomorrow, 10am",
+            'content' => 'Good morning'
+        ]
+    ]));
+    ```
+
+Here are a few examples (assuming today's date is **12/10/2021, 9am, Eastern Time Zone**):
+
+<table class="remove-md-box"><tr>
+<td>
+    <table><thead><tr><th><code>Delay/At/In</code> header</th><th>Message will be delivered at</th><th>Explanation</th></tr></thead><tbody>
+    <tr><td><code>30m</code></td><td>12/10/2021, 9:<b>30</b>am</td><td>30 minutes from now</td></tr>
+    <tr><td><code>2 hours</code></td><td>12/10/2021, <b>11:30</b>am</td><td>2 hours from now</td></tr>
+    <tr><td><code>1 day</code></td><td>12/<b>11</b>/2021, 9am</td><td>24 hours from now</td></tr>
+    <tr><td><code>10am</code></td><td>12/10/2021, <b>10am</b></td><td>Today at 10am (same day, because it's only 9am)</td></tr>
+    <tr><td><code>8am</code></td><td>12/<b>11</b>/2021, <b>8am</b></td><td>Tomorrow at 8am (because it's 9am already)</td></tr>
+    <tr><td><code>1639152000</code></td><td>12/10/2021, 11am (EST)</td><td> Today at 11am (EST)</td></tr>
+    </tbody></table>
+</td>
+</tr></table>
+
+## Webhooks (publish via GET) 
+In addition to using PUT/POST, you can also send to topics via simple HTTP GET requests. This makes it easy to use 
+a ntfy topic as a [webhook](https://en.wikipedia.org/wiki/Webhook), or if your client has limited HTTP support (e.g.
+like the [MacroDroid](https://play.google.com/store/apps/details?id=com.arlosoft.macrodroid) Android app).
+
+To send messages via HTTP GET, simply call the `/publish` endpoint (or its aliases `/send` and `/trigger`). Without 
+any arguments, this will send the message `triggered` to the topic. However, you can provide all arguments that are 
+also supported as HTTP headers as URL-encoded arguments. Be sure to check the list of all 
+[supported parameters and headers](#list-of-all-parameters) for details.
+
+For instance, assuming your topic is `mywebhook`, you can simply call `/mywebhook/trigger` to send a message 
+(aka trigger the webhook):
+
+=== "Command line (curl)"
+    ```
+    curl ntfy.sh/mywebhook/trigger
+    ```
+
+=== "ntfy CLI"
+    ```
+    ntfy trigger mywebhook
+    ```
+
+=== "HTTP"
+    ``` http
+    GET /mywebhook/trigger HTTP/1.1
+    Host: ntfy.sh
+    ```
+
+=== "JavaScript"
+    ``` javascript
+    fetch('https://ntfy.sh/mywebhook/trigger')
+    ```
+
+=== "Go"
+    ``` go
+    http.Get("https://ntfy.sh/mywebhook/trigger")
+    ```
+
+=== "PowerShell"
+    ``` powershell
+    Invoke-RestMethod -Method 'Get' -Uri "ntfy.sh/mywebhook/trigger"
+    ```    
+
+=== "Python"
+    ``` python
+    requests.get("https://ntfy.sh/mywebhook/trigger")
+    ```
+
+=== "PHP"
+    ``` php-inline
+    file_get_contents('https://ntfy.sh/mywebhook/trigger');
+    ```
+
+To add a custom message, simply append the `message=` URL parameter. And of course you can set the 
+[message priority](#message-priority), the [message title](#message-title), and [tags](#tags-emojis) as well. 
+For a full list of possible parameters, check the list of [supported parameters and headers](#list-of-all-parameters).
+
+Here's an example with a custom message, tags and a priority:
+
+=== "Command line (curl)"
+    ```
+    curl "ntfy.sh/mywebhook/publish?message=Webhook+triggered&priority=high&tags=warning,skull"
+    ```
+
+=== "ntfy CLI"
+    ```
+    ntfy publish \
+        -p 5 --tags=warning,skull \
+        mywebhook "Webhook triggered"
+    ```
+
+=== "HTTP"
+    ``` http
+    GET /mywebhook/publish?message=Webhook+triggered&priority=high&tags=warning,skull HTTP/1.1
+    Host: ntfy.sh
+    ```
+
+=== "JavaScript"
+    ``` javascript
+    fetch('https://ntfy.sh/mywebhook/publish?message=Webhook+triggered&priority=high&tags=warning,skull')
+    ```
+
+=== "Go"
+    ``` go
+    http.Get("https://ntfy.sh/mywebhook/publish?message=Webhook+triggered&priority=high&tags=warning,skull")
+    ```
+
+=== "PowerShell"
+    ``` powershell
+    Invoke-RestMethod -Method 'Get' -Uri "ntfy.sh/mywebhook/publish?message=Webhook+triggered&priority=high&tags=warning,skull"
+    ```
+
+=== "Python"
+    ``` python
+    requests.get("https://ntfy.sh/mywebhook/publish?message=Webhook+triggered&priority=high&tags=warning,skull")
+    ```
+
+=== "PHP"
+    ``` php-inline
+    file_get_contents('https://ntfy.sh/mywebhook/publish?message=Webhook+triggered&priority=high&tags=warning,skull');
+    ```
+
+## Publish as JSON
+For some integrations with other tools (e.g. [Jellyfin](https://jellyfin.org/), [overseerr](https://overseerr.dev/)), 
+adding custom headers to HTTP requests may be tricky or impossible, so ntfy also allows publishing the entire message 
+as JSON in the request body.
+
+To publish as JSON, simple PUT/POST the JSON object directly to the ntfy root URL. The message format is described below
+the example.
+
+!!! info
+    To publish as JSON, you must **PUT/POST to the ntfy root URL**, not to the topic URL. Be sure to check that you're
+    POST-ing to `https://ntfy.sh/` (correct), and not to `https://ntfy.sh/mytopic` (incorrect). 
+
+Here's an example using all supported parameters. The `topic` parameter is the only required one:
+
+=== "Command line (curl)"
+    ```
+    curl ntfy.sh \
+      -d '{
+        "topic": "mytopic",
+        "message": "Disk space is low at 5.1 GB",
+        "title": "Low disk space alert",
+        "tags": ["warning","cd"],
+        "priority": 4,
+        "attach": "https://filesrv.lan/space.jpg",
+        "filename": "diskspace.jpg",
+        "click": "https://homecamera.lan/xasds1h2xsSsa/"
+      }'
+    ```
+
+=== "HTTP"
+    ``` http
+    POST / HTTP/1.1
+    Host: ntfy.sh
+
+    {
+        "topic": "mytopic",
+        "message": "Disk space is low at 5.1 GB",
+        "title": "Low disk space alert",
+        "tags": ["warning","cd"],
+        "priority": 4,
+        "attach": "https://filesrv.lan/space.jpg",
+        "filename": "diskspace.jpg",
+        "click": "https://homecamera.lan/xasds1h2xsSsa/"
+    }
+    ```
+
+=== "JavaScript"
+    ``` javascript
+    fetch('https://ntfy.sh', {
+        method: 'POST',
+        body: JSON.stringify({
+            "topic": "mytopic",
+            "message": "Disk space is low at 5.1 GB",
+            "title": "Low disk space alert",
+            "tags": ["warning","cd"],
+            "priority": 4,
+            "attach": "https://filesrv.lan/space.jpg",
+            "filename": "diskspace.jpg",
+            "click": "https://homecamera.lan/xasds1h2xsSsa/"
+        })
+    })
+    ```
+
+=== "Go"
+    ``` go
+    // You should probably use json.Marshal() instead and make a proper struct,
+    // or even just use req.Header.Set() like in the other examples, but for the 
+    // sake of the example, this is easier.
+    
+    body := `{
+        "topic": "mytopic",
+        "message": "Disk space is low at 5.1 GB",
+        "title": "Low disk space alert",
+        "tags": ["warning","cd"],
+        "priority": 4,
+        "attach": "https://filesrv.lan/space.jpg",
+        "filename": "diskspace.jpg",
+        "click": "https://homecamera.lan/xasds1h2xsSsa/"
+    }`
+    req, _ := http.NewRequest("POST", "https://ntfy.sh/", strings.NewReader(body))
+    http.DefaultClient.Do(req)
+    ```
+
+=== "PowerShell"
+    ``` powershell
+    $uri = "https://ntfy.sh"
+    $body = @{
+            "topic"="powershell"
+            "title"="Low disk space alert"
+            "message"="Disk space is low at 5.1 GB"
+            "priority"=4
+            "attach"="https://filesrv.lan/space.jpg"
+            "filename"="diskspace.jpg"
+            "tags"=@("warning","cd")
+            "click"= "https://homecamera.lan/xasds1h2xsSsa/"
+          } | ConvertTo-Json
+    Invoke-RestMethod -Method 'Post' -Uri $uri -Body $body -ContentType "application/json" -UseBasicParsing
+    ```
+
+=== "Python"
+    ``` python
+    requests.post("https://ntfy.sh/",
+        data=json.dumps({
+            "topic": "mytopic",
+            "message": "Disk space is low at 5.1 GB",
+            "title": "Low disk space alert",
+            "tags": ["warning","cd"],
+            "priority": 4,
+            "attach": "https://filesrv.lan/space.jpg",
+            "filename": "diskspace.jpg",
+            "click": "https://homecamera.lan/xasds1h2xsSsa/"
+        })
+    )
+    ```
+
+=== "PHP"
+    ``` php-inline
+    file_get_contents('https://ntfy.sh/', false, stream_context_create([
+        'http' => [
+            'method' => 'POST',
+            'header' => "Content-Type: application/json",
+            'content' => json_encode([
+                "topic": "mytopic",
+                "message": "Disk space is low at 5.1 GB",
+                "title": "Low disk space alert",
+                "tags": ["warning","cd"],
+                "priority": 4,
+                "attach": "https://filesrv.lan/space.jpg",
+                "filename": "diskspace.jpg",
+                "click": "https://homecamera.lan/xasds1h2xsSsa/"
+            ])
+        ]
+    ]));
+    ```
+
+The JSON message format closely mirrors the format of the message you can consume when you [subscribe via the API](subscribe/api.md) 
+(see [JSON message format](subscribe/api.md#json-message-format) for details), but is not exactly identical. Here's an overview of
+all the supported fields:
+
+| Field      | Required | Type                             | Example                        | Description                                                           |
+|------------|----------|----------------------------------|--------------------------------|-----------------------------------------------------------------------|
+| `topic`    | ✔️       | *string*                         | `topic1`                       | Target topic name                                                     |
+| `message`  | -        | *string*                         | `Some message`                 | Message body; set to `triggered` if empty or not passed               |
+| `title`    | -        | *string*                         | `Some title`                   | Message [title](#message-title)                                       |
+| `tags`     | -        | *string array*                   | `["tag1","tag2"]`              | List of [tags](#tags-emojis) that may or not map to emojis            |
+| `priority` | -        | *int (one of: 1, 2, 3, 4, or 5)* | `4`                            | Message [priority](#message-priority) with 1=min, 3=default and 5=max |
+| `click`    | -        | *URL*                            | `https://example.com`          | Website opened when notification is [clicked](#click-action)          |
+| `attach`   | -        | *URL*                            | `https://example.com/file.jpg` | URL of an attachment, see [attach via URL](#attach-file-from-url)     |
+| `filename` | -        | *string*                         | `file.jpg`                     | File name of the attachment                                           |
+
+
+## Click action
+You can define which URL to open when a notification is clicked. This may be useful if your notification is related 
+to a Zabbix alert or a transaction that you'd like to provide the deep-link for. Tapping the notification will open
+the web browser (or the app) and open the website.
+
+Here's an example that will open Reddit when the notification is clicked:
+
+=== "Command line (curl)"
+    ```
+    curl \
+        -d "New messages on Reddit" \
+        -H "Click: https://www.reddit.com/message/messages" \
+        ntfy.sh/reddit_alerts
+    ```
+
+=== "ntfy CLI"
+    ```
+    ntfy publish \
+        --click="https://www.reddit.com/message/messages" \
+        reddit_alerts "New messages on Reddit"
+    ```
+
+=== "HTTP"
+    ``` http
+    POST /reddit_alerts HTTP/1.1
+    Host: ntfy.sh
+    Click: https://www.reddit.com/message/messages 
+
+    New messages on Reddit
+    ```
+
+=== "JavaScript"
+    ``` javascript
+    fetch('https://ntfy.sh/reddit_alerts', {
+        method: 'POST',
+        body: 'New messages on Reddit',
+        headers: { 'Click': 'https://www.reddit.com/message/messages' }
+    })
+    ```
+
+=== "Go"
+    ``` go
+    req, _ := http.NewRequest("POST", "https://ntfy.sh/reddit_alerts", strings.NewReader("New messages on Reddit"))
+    req.Header.Set("Click", "https://www.reddit.com/message/messages")
+    http.DefaultClient.Do(req)
+    ```
+
+=== "PowerShell"
+    ``` powershell
+    $uri = "https://ntfy.sh/reddit_alerts"
+    $headers = @{ Click="https://www.reddit.com/message/messages" }
+    $body = "New messages on Reddit"
+    Invoke-RestMethod -Method 'Post' -Uri $uri -Headers $headers -Body $body -UseBasicParsing
+    ```
+
+=== "Python"
+    ``` python
+    requests.post("https://ntfy.sh/reddit_alerts",
+        data="New messages on Reddit",
+        headers={ "Click": "https://www.reddit.com/message/messages" })
+    ```
+
+=== "PHP"
+    ``` php-inline
+    file_get_contents('https://ntfy.sh/reddit_alerts', false, stream_context_create([
+        'http' => [
+            'method' => 'POST',
+            'header' =>
+                "Content-Type: text/plain\r\n" .
+                "Click: https://www.reddit.com/message/messages",
+            'content' => 'New messages on Reddit'
+        ]
+    ]));
+    ```
+
+## Attachments
+You can **send images and other files to your phone** as attachments to a notification. The attachments are then downloaded
+onto your phone (depending on size and setting automatically), and can be used from the Downloads folder.
+
+There are two different ways to send attachments: 
+
+* sending [a local file](#attach-local-file) via PUT, e.g. from `~/Flowers/flower.jpg` or `ringtone.mp3`
+* or by [passing an external URL](#attach-file-from-a-url) as an attachment, e.g. `https://f-droid.org/F-Droid.apk` 
+
+### Attach local file
+To **send a file from your computer** as an attachment, you can send it as the PUT request body. If a message is greater 
+than the maximum message size (4,096 bytes) or consists of non UTF-8 characters, the ntfy server will automatically 
+detect the mime type and size, and send the message as an attachment file. To send smaller text-only messages or files 
+as attachments, you must pass a filename by passing the `X-Filename` header or query parameter (or any of its aliases 
+`Filename`, `File` or `f`). 
+
+By default, and how ntfy.sh is configured, the **max attachment size is 15 MB** (with 100 MB total per visitor). 
+Attachments **expire after 3 hours**, which typically is plenty of time for the user to download it, or for the Android app
+to auto-download it. Please also check out the [other limits below](#limitations).
+
+Here's an example showing how to upload an image:
+
+=== "Command line (curl)"
+    ```
+    curl \
+        -T flower.jpg \
+        -H "Filename: flower.jpg" \
+        ntfy.sh/flowers
+    ```
+
+=== "ntfy CLI"
+    ```
+    ntfy publish \
+        --file=flower.jpg \
+        flowers
+    ```
+
+=== "HTTP"
+    ``` http
+    PUT /flowers HTTP/1.1
+    Host: ntfy.sh
+    Filename: flower.jpg
+    Content-Type: 52312
+
+    <binary JPEG data>
+    ```
+
+=== "JavaScript"
+    ``` javascript
+    fetch('https://ntfy.sh/flowers', {
+        method: 'PUT',
+        body: document.getElementById("file").files[0],
+        headers: { 'Filename': 'flower.jpg' }
+    })
+    ```
+
+=== "Go"
+    ``` go
+    file, _ := os.Open("flower.jpg")
+    req, _ := http.NewRequest("PUT", "https://ntfy.sh/flowers", file)
+    req.Header.Set("Filename", "flower.jpg")
+    http.DefaultClient.Do(req)
+    ```
+
+=== "Python"
+    ``` python
+    requests.put("https://ntfy.sh/flowers",
+        data=open("flower.jpg", 'rb'),
+        headers={ "Filename": "flower.jpg" })
+    ```
+
+=== "PHP"
+    ``` php-inline
+    file_get_contents('https://ntfy.sh/flowers', false, stream_context_create([
+        'http' => [
+            'method' => 'PUT',
+            'header' =>
+                "Content-Type: application/octet-stream\r\n" . // Does not matter
+                "Filename: flower.jpg",
+            'content' => file_get_contents('flower.jpg') // Dangerous for large files 
+        ]
+    ]));
+    ```
+
+Here's what that looks like on Android:
+
+<figure markdown>
+  ![image attachment](static/img/android-screenshot-attachment-image.png){ width=500 }
+  <figcaption>Image attachment sent from a local file</figcaption>
+</figure>
+
+### Attach file from a URL
+Instead of sending a local file to your phone, you can use **an external URL** to specify where the attachment is hosted.
+This could be a Dropbox link, a file from social media, or any other publicly available URL. Since the files are 
+externally hosted, the expiration or size limits from above do not apply here.
+
+To attach an external file, simple pass the `X-Attach` header or query parameter (or any of its aliases `Attach` or `a`)
+to specify the attachment URL. It can be any type of file. 
+
+ntfy will automatically try to derive the file name from the URL (e.g `https://example.com/flower.jpg` will yield a 
+filename `flower.jpg`). To override this filename, you may send the `X-Filename` header or query parameter (or any of its
+aliases `Filename`, `File` or `f`).
+
+Here's an example showing how to attach an APK file:
+
+=== "Command line (curl)"
+    ```
+    curl \
+        -X POST \
+        -H "Attach: https://f-droid.org/F-Droid.apk" \
+        ntfy.sh/mydownloads
+    ```
+
+=== "ntfy CLI"
+    ```
+    ntfy publish \
+        --attach="https://f-droid.org/F-Droid.apk" \
+        mydownloads
+    ```
+
+=== "HTTP"
+    ``` http
+    POST /mydownloads HTTP/1.1
+    Host: ntfy.sh
+    Attach: https://f-droid.org/F-Droid.apk
+    ```
+
+=== "JavaScript"
+    ``` javascript
+    fetch('https://ntfy.sh/mydownloads', {
+        method: 'POST',
+        headers: { 'Attach': 'https://f-droid.org/F-Droid.apk' }
+    })
+    ```
+
+=== "Go"
+    ``` go
+    req, _ := http.NewRequest("POST", "https://ntfy.sh/mydownloads", file)
+    req.Header.Set("Attach", "https://f-droid.org/F-Droid.apk")
+    http.DefaultClient.Do(req)
+    ```
+
+=== "PowerShell"
+    ``` powershell
+    $uri = "https://ntfy.sh/mydownloads"
+    $headers = @{ Attach="https://f-droid.org/F-Droid.apk" }
+    Invoke-RestMethod -Method 'Post' -Uri $uri -Headers $headers -UseBasicParsing
+    ```
+
+=== "Python"
+    ``` python
+    requests.put("https://ntfy.sh/mydownloads",
+        headers={ "Attach": "https://f-droid.org/F-Droid.apk" })
+    ```
+
+=== "PHP"
+    ``` php-inline
+    file_get_contents('https://ntfy.sh/mydownloads', false, stream_context_create([
+        'http' => [
+        'method' => 'PUT',
+        'header' =>
+            "Content-Type: text/plain\r\n" . // Does not matter
+            "Attach: https://f-droid.org/F-Droid.apk",
+        ]
+    ]));
+    ```
+
+<figure markdown>
+  ![file attachment](static/img/android-screenshot-attachment-file.png){ width=500 }
+  <figcaption>File attachment sent from an external URL</figcaption>
+</figure>
+
+## E-mail notifications
+You can forward messages to e-mail by specifying an address in the header. This can be useful for messages that 
+you'd like to persist longer, or to blast-notify yourself on all possible channels. 
+
+Usage is easy: Simply pass the `X-Email` header (or any of its aliases: `X-E-mail`, `Email`, `E-mail`, `Mail`, or `e`).
+Only one e-mail address is supported.
+
+Since ntfy does not provide auth (yet), the rate limiting is pretty strict (see [limitations](#limitations)). In the 
+default configuration, you get **16 e-mails per visitor** (IP address) and then after that one per hour. On top of 
+that, your IP address appears in the e-mail body. This is to prevent abuse.
+
+=== "Command line (curl)"
+    ```
+    curl \
+        -H "Email: phil@example.com" \
+        -H "Tags: warning,skull,backup-host,ssh-login" \
+        -H "Priority: high" \
+        -d "Unknown login from 5.31.23.83 to backups.example.com" \
+        ntfy.sh/alerts
+    curl -H "Email: phil@example.com" -d "You've Got Mail" 
+    curl -d "You've Got Mail" "ntfy.sh/alerts?email=phil@example.com"
+    ```
+
+=== "ntfy CLI"
+    ```
+    ntfy publish \
+        --email=phil@example.com \
+        --tags=warning,skull,backup-host,ssh-login \
+        --priority=high \
+        alerts "Unknown login from 5.31.23.83 to backups.example.com"
+    ```
+
+=== "HTTP"
+    ``` http
+    POST /alerts HTTP/1.1
+    Host: ntfy.sh
+    Email: phil@example.com
+    Tags: warning,skull,backup-host,ssh-login
+    Priority: high
+
+    Unknown login from 5.31.23.83 to backups.example.com
+    ```
+
+=== "JavaScript"
+    ``` javascript
+    fetch('https://ntfy.sh/alerts', {
+        method: 'POST',
+        body: "Unknown login from 5.31.23.83 to backups.example.com",
+        headers: { 
+            'Email': 'phil@example.com',
+            'Tags': 'warning,skull,backup-host,ssh-login',
+            'Priority': 'high'
+        }
+    })
+    ```
+
+=== "Go"
+    ``` go
+    req, _ := http.NewRequest("POST", "https://ntfy.sh/alerts", 
+        strings.NewReader("Unknown login from 5.31.23.83 to backups.example.com"))
+    req.Header.Set("Email", "phil@example.com")
+    req.Header.Set("Tags", "warning,skull,backup-host,ssh-login")
+    req.Header.Set("Priority", "high")
+    http.DefaultClient.Do(req)
+    ```
+
+=== "PowerShell"
+    ``` powershell
+    $uri = "https://ntfy.sh/alerts"
+    $headers = @{ Title"="Low disk space alert"
+                  Priority=4
+                  Tags="warning,skull,backup-host,ssh-login")
+                  Email="phil@example.com" }
+    $body = "Unknown login from 5.31.23.83 to backups.example.com"
+    Invoke-RestMethod -Method 'Post' -Uri $uri -Body $body -UseBasicParsing
+    ```
+    
+=== "Python"
+    ``` python
+    requests.post("https://ntfy.sh/alerts",
+        data="Unknown login from 5.31.23.83 to backups.example.com",
+        headers={ 
+            "Email": "phil@example.com",
+            "Tags": "warning,skull,backup-host,ssh-login",
+            "Priority": "high"
+        })
+    ```
+
+=== "PHP"
+    ``` php-inline
+    file_get_contents('https://ntfy.sh/alerts', false, stream_context_create([
+        'http' => [
+            'method' => 'POST',
+            'header' =>
+                "Content-Type: text/plain\r\n" .
+                "Email: phil@example.com\r\n" .
+                "Tags: warning,skull,backup-host,ssh-login\r\n" .
+                "Priority: high",
+            'content' => 'Unknown login from 5.31.23.83 to backups.example.com'
+        ]
+    ]));
+    ```
+
+Here's what that looks like in Google Mail:
+
+<figure markdown>
+  ![e-mail notification](static/img/screenshot-email.png){ width=600 }
+  <figcaption>E-mail notification</figcaption>
+</figure>
+
+## E-mail publishing
+You can publish messages to a topic via e-mail, i.e. by sending an email to a specific address. For instance, you can
+publish a message to the topic `sometopic` by sending an e-mail to `ntfy-sometopic@ntfy.sh`. This is useful for e-mail 
+based integrations such as for statuspage.io (though these days most services also support webhooks and HTTP calls).
+
+Depending on the [server configuration](config.md#e-mail-publishing), the e-mail address format can have a prefix to 
+prevent spam on topics. For ntfy.sh, the prefix is configured to `ntfy-`, meaning that the general e-mail address 
+format is:
+
+```
+ntfy-$topic@ntfy.sh
+```
+
+As of today, e-mail publishing only supports adding a [message title](#message-title) (the e-mail subject). Tags, priority,
+delay and other features are not supported (yet). Here's an example that will publish a message with the 
+title `You've Got Mail` to topic `sometopic` (see [ntfy.sh/sometopic](https://ntfy.sh/sometopic)):
+
+<figure markdown>
+  ![e-mail publishing](static/img/screenshot-email-publishing-gmail.png){ width=500 }
+  <figcaption>Publishing a message via e-mail</figcaption>
+</figure>
+
+## Advanced features
+
+### Authentication
+Depending on whether the server is configured to support [access control](config.md#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](https://en.wikipedia.org/wiki/Basic_access_authentication)
+with a valid username/password. For your self-hosted server, **be sure to use HTTPS to avoid eavesdropping** and exposing
+your password. 
+
+Here's a simple example:
+
+=== "Command line (curl)"
+    ```
+    curl \
+      -u phil:mypass \
+      -d "Look ma, with auth" \
+      https://ntfy.example.com/mysecrets
+    ```
+
+=== "ntfy CLI"
+    ```
+    ntfy publish \
+      -u phil:mypass \
+      ntfy.example.com/mysecrets \
+      "Look ma, with auth"
+    ```
+
+=== "HTTP"
+    ``` http
+    POST /mysecrets HTTP/1.1
+    Host: ntfy.example.com
+    Authorization: Basic cGhpbDpteXBhc3M=
+
+    Look ma, with auth
+    ```
+
+=== "JavaScript"
+    ``` javascript
+    fetch('https://ntfy.example.com/mysecrets', {
+        method: 'POST', // PUT works too
+        body: 'Look ma, with auth',
+        headers: {
+            'Authorization': 'Basic cGhpbDpteXBhc3M='
+        }
+    })
+    ```
+
+=== "Go"
+    ``` go
+    req, _ := http.NewRequest("POST", "https://ntfy.example.com/mysecrets",
+    strings.NewReader("Look ma, with auth"))
+    req.Header.Set("Authorization", "Basic cGhpbDpteXBhc3M=")
+    http.DefaultClient.Do(req)
+    ```
+
+=== "PowerShell"
+    ``` powershell
+    $uri = "https://ntfy.example.com/mysecrets"
+    $basicAuthValue = "Basic [user:pass-bese64encoded]"
+    $headers = @{ Authorization=$basicAuthValue }
+    $body = "Look ma, with auth"
+    Invoke-RestMethod -Method 'Post' -Uri $uri -Body $body -Headers $headers -UseBasicParsing
+    ```
+
+=== "Python"
+    ``` python
+    requests.post("https://ntfy.example.com/mysecrets",
+    data="Look ma, with auth",
+    headers={
+        "Authorization": "Basic cGhpbDpteXBhc3M="
+    })
+    ```
+
+=== "PHP"
+    ``` php-inline
+    file_get_contents('https://ntfy.example.com/mysecrets', false, stream_context_create([
+        'http' => [
+            'method' => 'POST', // PUT also works
+            'header' =>
+                'Content-Type: text/plain\r\n' .
+                'Authorization: Basic cGhpbDpteXBhc3M=',
+            'content' => 'Look ma, with auth'
+        ]
+    ]));
+    ```
+
+### Message caching
+!!! info
+    If `Cache: no` is used, messages will only be delivered to connected subscribers, and won't be re-delivered if a 
+    client re-connects. If a subscriber has (temporary) network issues or is reconnecting momentarily, 
+    **messages might be missed**.
+
+By default, the ntfy server caches messages on disk for 12 hours (see [message caching](config.md#message-cache)), so
+all messages you publish are stored server-side for a little while. The reason for this is to overcome temporary 
+client-side network disruptions, but arguably this feature also may raise privacy concerns.
+
+To avoid messages being cached server-side entirely, you can set `X-Cache` header (or its alias: `Cache`) to `no`. 
+This will make sure that your message is not cached on the server, even if server-side caching is enabled. Messages
+are still delivered to connected subscribers, but [`since=`](subscribe/api.md#fetch-cached-messages) and 
+[`poll=1`](subscribe/api.md#poll-for-messages) won't return the message anymore.
+
+=== "Command line (curl)"
+    ```
+    curl -H "X-Cache: no" -d "This message won't be stored server-side" ntfy.sh/mytopic
+    curl -H "Cache: no" -d "This message won't be stored server-side" ntfy.sh/mytopic
+    ```
+
+=== "ntfy CLI"
+    ```
+    ntfy publish \
+        --no-cache \
+        mytopic "This message won't be stored server-side"
+    ```
+
+=== "HTTP"
+    ``` http
+    POST /mytopic HTTP/1.1
+    Host: ntfy.sh
+    Cache: no
+
+    This message won't be stored server-side
+    ```
+
+=== "JavaScript"
+    ``` javascript
+    fetch('https://ntfy.sh/mytopic', {
+        method: 'POST',
+        body: 'This message won't be stored server-side',
+        headers: { 'Cache': 'no' }
+    })
+    ```
+
+=== "Go"
+    ``` go
+    req, _ := http.NewRequest("POST", "https://ntfy.sh/mytopic", strings.NewReader("This message won't be stored server-side"))
+    req.Header.Set("Cache", "no")
+    http.DefaultClient.Do(req)
+    ```
+
+=== "PowerShell"
+    ``` powershell
+    $uri = "https://ntfy.sh/mytopic"
+    $headers = @{ Cache="no" }
+    $body = "This message won't be stored server-side"
+    Invoke-RestMethod -Method 'Post' -Uri $uri -Body $body -Headers $headers -UseBasicParsing
+    ```
+
+=== "Python"
+    ``` python
+    requests.post("https://ntfy.sh/mytopic",
+        data="This message won't be stored server-side",
+        headers={ "Cache": "no" })
+    ```
+
+=== "PHP"
+    ``` php-inline
+    file_get_contents('https://ntfy.sh/mytopic', false, stream_context_create([
+        'http' => [
+            'method' => 'POST',
+            'header' =>
+                "Content-Type: text/plain\r\n" .
+                "Cache: no",
+            'content' => 'This message won't be stored server-side'
+        ]
+    ]));
+    ```
+
+### Disable Firebase
+!!! info
+    If `Firebase: no` is used and [instant delivery](subscribe/phone.md#instant-delivery) isn't enabled in the Android 
+    app (Google Play variant only), **message delivery will be significantly delayed (up to 15 minutes)**. To overcome 
+    this delay, simply enable instant delivery.
+
+The ntfy server can be configured to use [Firebase Cloud Messaging (FCM)](https://firebase.google.com/docs/cloud-messaging)
+(see [Firebase config](config.md#firebase-fcm)) for message delivery on Android (to minimize the app's battery footprint). 
+The ntfy.sh server is configured this way, meaning that all messages published to ntfy.sh are also published to corresponding
+FCM topics.
+
+If you'd like to avoid forwarding messages to Firebase, you can set the `X-Firebase` header (or its alias: `Firebase`)
+to `no`. This will instruct the server not to forward messages to Firebase.
+
+=== "Command line (curl)"
+    ```
+    curl -H "X-Firebase: no" -d "This message won't be forwarded to FCM" ntfy.sh/mytopic
+    curl -H "Firebase: no" -d "This message won't be forwarded to FCM" ntfy.sh/mytopic
+    ```
+
+=== "ntfy CLI"
+    ```
+    ntfy publish \
+        --no-firebase \
+        mytopic "This message won't be forwarded to FCM"
+    ```
+
+=== "HTTP"
+    ``` http
+    POST /mytopic HTTP/1.1
+    Host: ntfy.sh
+    Firebase: no
+
+    This message won't be forwarded to FCM
+    ```
+
+=== "JavaScript"
+    ``` javascript
+    fetch('https://ntfy.sh/mytopic', {
+        method: 'POST',
+        body: 'This message won't be forwarded to FCM',
+        headers: { 'Firebase': 'no' }
+    })
+    ```
+
+=== "Go"
+    ``` go
+    req, _ := http.NewRequest("POST", "https://ntfy.sh/mytopic", strings.NewReader("This message won't be forwarded to FCM"))
+    req.Header.Set("Firebase", "no")
+    http.DefaultClient.Do(req)
+    ```
+
+=== "PowerShell"
+    ``` powershell
+    $uri = "https://ntfy.sh/mytopic"
+    $headers = @{ Firebase="no" }
+    $body = "This message won't be forwarded to FCM"
+    Invoke-RestMethod -Method 'Post' -Uri $uri -Body $body -Headers $headers -UseBasicParsing
+    ```
+    
+=== "Python"
+    ``` python
+    requests.post("https://ntfy.sh/mytopic",
+        data="This message won't be forwarded to FCM",
+        headers={ "Firebase": "no" })
+    ```
+
+=== "PHP"
+    ``` php-inline
+    file_get_contents('https://ntfy.sh/mytopic', false, stream_context_create([
+        'http' => [
+            'method' => 'POST',
+            'header' =>
+                "Content-Type: text/plain\r\n" .
+                "Firebase: no",
+            'content' => 'This message won't be stored server-side'
+        ]
+    ]));
+    ```
+
+### UnifiedPush
+!!! info
+    This setting is not relevant to users, only to app developers and people interested in [UnifiedPush](https://unifiedpush.org). 
+
+[UnifiedPush](https://unifiedpush.org) is a standard for receiving push notifications without using the Google-owned
+[Firebase Cloud Messaging (FCM)](https://firebase.google.com/docs/cloud-messaging) service. It puts push notifications
+in the control of the user. ntfy can act as a **UnifiedPush distributor**, forwarding messages to apps that support it.
+
+When publishing messages to a topic, apps using ntfy as a UnifiedPush distributor can set the `X-UnifiedPush` header or query
+parameter (or any of its aliases `unifiedpush` or `up`) to `1` to [disable Firebase](#disable-firebase). As of today, this
+option is mostly equivalent to `Firebase: no`, but was introduced to allow future flexibility. The flag additionally 
+enables auto-detection of the message encoding. If the message is binary, it'll be encoded as base64.
+
+## Public topics
+Obviously all topics on ntfy.sh are public, but there are a few designated topics that are used in examples, and topics
+that you can use to try out what [authentication and access control](#authentication) looks like.
+
+| Topic                                          | User                              | Permissions                                          | Description                          |
+|------------------------------------------------|-----------------------------------|------------------------------------------------------|--------------------------------------|
+| [announcements](https://ntfy.sh/announcements) | `*` (unauthenticated)             | Read-only for everyone                               | Release announcements and such       |
+| [stats](https://ntfy.sh/stats)                 | `*` (unauthenticated)             | Read-only for everyone                               | Daily statistics about ntfy.sh usage |
+| [mytopic-rw](https://ntfy.sh/mytopic-rw)       | `testuser` (password: `testuser`) | Read-write for `testuser`, no access for anyone else | Test topic                           |
+| [mytopic-ro](https://ntfy.sh/mytopic-ro)       | `testuser` (password: `testuser`) | Read-only for `testuser`, no access for anyone else  | Test topic                           |
+| [mytopic-wo](https://ntfy.sh/mytopic-wo)       | `testuser` (password: `testuser`) | Write-only for `testuser`, no access for anyone else | Test topic                           |
+
+## Limitations
+There are a few limitations to the API to prevent abuse and to keep the server healthy. Almost all of these settings 
+are configurable via the server side [rate limiting settings](config.md#rate-limiting). Most of these limits you won't run into,
+but just in case, let's list them all:
+
+| Limit                      | Description                                                                                                                                                              |
+|----------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| **Message length**         | Each message can be up to 4,096 bytes long. Longer messages are treated as [attachments](#attachments).                                                                  |
+| **Requests**               | By default, the server is configured to allow 60 requests per visitor at once, and then refills the your allowed requests bucket at a rate of one request per 5 seconds. |
+| **E-mails**                | By default, the server is configured to allow sending 16 e-mails per visitor at once, and then refills the your allowed e-mail bucket at a rate of one per hour.         |
+| **Subscription limit**     | By default, the server allows each visitor to keep 30 connections to the server open.                                                                                    |
+| **Attachment size limit**  | By default, the server allows attachments up to 15 MB in size, up to 100 MB in total per visitor and up to 5 GB across all visitors.                                     |
+| **Attachment expiry**      | By default, the server deletes attachments after 3 hours and thereby frees up space from the total visitor attachment limit.                                             |
+| **Attachment bandwidth**   | By default, the server allows 500 MB of GET/PUT/POST traffic for attachments per visitor in a 24 hour period. Traffic exceeding that is rejected.                        |
+| **Total number of topics** | By default, the server is configured to allow 15,000 topics. The ntfy.sh server has higher limits though.                                                                |
+
+## List of all parameters
+The following is a list of all parameters that can be passed when publishing a message. Parameter names are **case-insensitive**,
+and can be passed as **HTTP headers** or **query parameters in the URL**. They are listed in the table in their canonical form.
+
+| Parameter       | Aliases (case-insensitive)                 | Description                                                                                   |
+|-----------------|--------------------------------------------|-----------------------------------------------------------------------------------------------|
+| `X-Message`     | `Message`, `m`                             | Main body of the message as shown in the notification                                         |
+| `X-Title`       | `Title`, `t`                               | [Message title](#message-title)                                                               |
+| `X-Priority`    | `Priority`, `prio`, `p`                    | [Message priority](#message-priority)                                                         |
+| `X-Tags`        | `Tags`, `Tag`, `ta`                        | [Tags and emojis](#tags-emojis)                                                               |
+| `X-Delay`       | `Delay`, `X-At`, `At`, `X-In`, `In`        | Timestamp or duration for [delayed delivery](#scheduled-delivery)                             |
+| `X-Click`       | `Click`                                    | URL to open when [notification is clicked](#click-action)                                     |
+| `X-Attach`      | `Attach`, `a`                              | URL to send as an [attachment](#attachments), as an alternative to PUT/POST-ing an attachment |
+| `X-Filename`    | `Filename`, `file`, `f`                    | Optional [attachment](#attachments) filename, as it appears in the client                     |
+| `X-Email`       | `X-E-Mail`, `Email`, `E-Mail`, `mail`, `e` | E-mail address for [e-mail notifications](#e-mail-notifications)                              |
+| `X-Cache`       | `Cache`                                    | Allows disabling [message caching](#message-caching)                                          |
+| `X-Firebase`    | `Firebase`                                 | Allows disabling [sending to Firebase](#disable-firebase)                                     |
+| `X-UnifiedPush` | `UnifiedPush`, `up`                        | [UnifiedPush](#unifiedpush) publish option, only to be used by UnifiedPush apps               |
+| `Authorization` | -                                          | If supported by the server, you can [login to access](#authentication) protected topics       |