Docs updates

client/options.go

@@ -88,6 +88,11 @@ func WithFilename(filename string) PublishOption {
 	return WithHeader("X-Filename", filename)
 }
 
+// WithSequenceID sets a sequence ID for the message, allowing updates to existing notifications
+func WithSequenceID(sequenceID string) PublishOption {
+	return WithHeader("X-Sequence-ID", sequenceID)
+}
+
 // WithEmail instructs the server to also send the message to the given e-mail address
 func WithEmail(email string) PublishOption {
 	return WithHeader("X-Email", email)

cmd/publish.go

@@ -34,6 +34,7 @@ var flagsPublish = append(
 	&cli.BoolFlag{Name: "markdown", Aliases: []string{"md"}, EnvVars: []string{"NTFY_MARKDOWN"}, Usage: "Message is formatted as Markdown"},
 	&cli.StringFlag{Name: "template", Aliases: []string{"tpl"}, EnvVars: []string{"NTFY_TEMPLATE"}, Usage: "use templates to transform JSON message body"},
 	&cli.StringFlag{Name: "filename", Aliases: []string{"name", "n"}, EnvVars: []string{"NTFY_FILENAME"}, Usage: "filename for the attachment"},
+	&cli.StringFlag{Name: "sequence-id", Aliases: []string{"sequence_id", "sid", "S"}, EnvVars: []string{"NTFY_SEQUENCE_ID"}, Usage: "sequence ID for updating notifications"},
 	&cli.StringFlag{Name: "file", Aliases: []string{"f"}, EnvVars: []string{"NTFY_FILE"}, Usage: "file to upload as an attachment"},
 	&cli.StringFlag{Name: "email", Aliases: []string{"mail", "e"}, EnvVars: []string{"NTFY_EMAIL"}, Usage: "also send to e-mail address"},
 	&cli.StringFlag{Name: "user", Aliases: []string{"u"}, EnvVars: []string{"NTFY_USER"}, Usage: "username[:password] used to auth against the server"},
@@ -70,6 +71,7 @@ Examples:
   ntfy pub --icon="http://some.tld/icon.png" 'Icon!'      # Send notification with custom icon
   ntfy pub --attach="http://some.tld/file.zip" files      # Send ZIP archive from URL as attachment
   ntfy pub --file=flower.jpg flowers 'Nice!'              # Send image.jpg as attachment
+  ntfy pub -S my-id mytopic 'Update me'                   # Send with sequence ID for updates
   echo 'message' | ntfy publish mytopic                   # Send message from stdin
   ntfy pub -u phil:mypass secret Psst                     # Publish with username/password
   ntfy pub --wait-pid 1234 mytopic                        # Wait for process 1234 to exit before publishing
@@ -101,6 +103,7 @@ func execPublish(c *cli.Context) error {
 	markdown := c.Bool("markdown")
 	template := c.String("template")
 	filename := c.String("filename")
+	sequenceID := c.String("sequence-id")
 	file := c.String("file")
 	email := c.String("email")
 	user := c.String("user")
@@ -154,6 +157,9 @@ func execPublish(c *cli.Context) error {
 	if filename != "" {
 		options = append(options, client.WithFilename(filename))
 	}
+	if sequenceID != "" {
+		options = append(options, client.WithSequenceID(sequenceID))
+	}
 	if email != "" {
 		options = append(options, client.WithEmail(email))
 	}

docs/publish.md

@@ -937,6 +937,445 @@ Here's an example with a custom message, tags and a priority:
     file_get_contents('https://ntfy.sh/mywebhook/publish?message=Webhook+triggered&priority=high&tags=warning,skull');
     ```
 
+## Updating + deleting notifications
+_Supported on:_ :material-android: :material-firefox:
+
+!!! info
+    **This feature is not yet released.** It will be available in ntfy v2.16.x and later and ntfy Android v1.22.x and later.
+
+You can **update, clear (mark as read and dismiss), or delete notifications** that have already been delivered. This is useful for scenarios
+like download progress updates, replacing outdated information, or dismissing notifications that are no longer relevant.
+
+* [Updating notifications](#updating-notifications) will alter the content of an existing notification.
+* [Clearing notifications](#clearing-notifications) will mark them as read and dismiss them from the notification drawer.
+* [Deleting notifications](#deleting-notifications) will remove them from the notification drawer and remove them in the clients as well (if supported).
+
+Here's an example of a download progress notification being updated over time on Android:
+
+<div id="updating-notifications-screenshots" class="screenshots">
+    <a href="../../static/img/android-screenshot-notification-update-1.png"><img src="../../static/img/android-screenshot-notification-update-1.png"/></a>
+    <a href="../../static/img/android-screenshot-notification-update-2.png"><img src="../../static/img/android-screenshot-notification-update-2.png"/></a>
+</div>
+
+To facilitate updating notifications and altering existing notifications, ntfy messages are linked together in a sequence,
+using a **sequence ID**. When a notification is meant to be updated, cleared, or deleted, you publish a new message with the
+same sequence ID and the clients will perform the appropriate action on the existing notification.
+
+Existing ntfy messages will not be updated on the server or in the message cache. Instead, a new message is created that indicates
+the update, clear, or delete action. This append-only behavior ensures that message history remains intact.
+
+### Updating notifications
+To update an existing notification, publish a new message with the same sequence ID. Clients will replace the previous
+notification with the new one. You can either:
+
+1. **Use the message ID**: First publish like normal to `POST /<topic>` without a sequence ID, then use the returned message `id` as the sequence ID for updates
+2. **Use a custom sequence ID**: Publish directly to `POST /<topic>/<sequence_id>` with your own identifier, or use `POST /<topic>` with the 
+   `X-Sequence-ID` header (or any of its aliases: `Sequence-ID` or`SID`)
+
+If you don't know the sequence ID ahead of time, you can publish a message first and then use the returned 
+message `id` to update it. Here's an example:
+
+=== "Command line (curl)"
+    ```bash
+    # First, publish a message and capture the message ID
+    curl -d "Downloading file..." ntfy.sh/mytopic
+    # Returns: {"id":"xE73Iyuabi","time":1673542291,...}
+
+    # Then use the message ID to update it (via URL path)
+    curl -d "Download 50% ..." ntfy.sh/mytopic/xE73Iyuabi
+
+    # Or update using the X-Sequence-ID header
+    curl -H "X-Sequence-ID: xE73Iyuabi" -d "Download complete" ntfy.sh/mytopic
+    ```
+
+=== "ntfy CLI"
+    ```bash
+    # First, publish a message and capture the message ID
+    ntfy pub mytopic "Downloading file..."
+    # Returns: {"id":"xE73Iyuabi","time":1673542291,...}
+
+    # Then use the message ID to update it
+    ntfy pub --sequence-id=xE73Iyuabi mytopic "Download 50% ..."
+
+    # Update again with the same sequence ID
+    ntfy pub -S xE73Iyuabi mytopic "Download complete"
+    ```
+
+=== "HTTP"
+    ``` http
+    # First, publish a message and capture the message ID
+    POST /mytopic HTTP/1.1
+    Host: ntfy.sh
+
+    Downloading file...
+
+    # Returns: {"id":"xE73Iyuabi","time":1673542291,...}
+
+    # Then use the message ID to update it
+    POST /mytopic/xE73Iyuabi HTTP/1.1
+    Host: ntfy.sh
+
+    Download 50% ...
+
+    # Update again with the same sequence ID, this time using the header
+    POST /mytopic HTTP/1.1
+    Host: ntfy.sh
+    X-Sequence-ID: xE73Iyuabi
+
+    Download complete
+    ```
+
+=== "JavaScript"
+    ``` javascript
+    // First, publish and get the message ID
+    const response = await fetch('https://ntfy.sh/mytopic', {
+      method: 'POST',
+      body: 'Downloading file...'
+    });
+    const { id } = await response.json();
+
+    // Update via URL path
+    await fetch(`https://ntfy.sh/mytopic/${id}`, {
+      method: 'POST',
+      body: 'Download 50% ...'
+    });
+
+    // Or update using the X-Sequence-ID header
+    await fetch('https://ntfy.sh/mytopic', {
+      method: 'POST',
+      headers: { 'X-Sequence-ID': id },
+      body: 'Download complete'
+    });
+    ```
+
+=== "Go"
+    ``` go
+    // Publish and parse the response to get the message ID
+    resp, _ := http.Post("https://ntfy.sh/mytopic", "text/plain",
+        strings.NewReader("Downloading file..."))
+    var msg struct { ID string `json:"id"` }
+    json.NewDecoder(resp.Body).Decode(&msg)
+    
+    // Update via URL path
+    http.Post("https://ntfy.sh/mytopic/"+msg.ID, "text/plain",
+        strings.NewReader("Download 50% ..."))
+
+    // Or update using the X-Sequence-ID header
+    req, _ := http.NewRequest("POST", "https://ntfy.sh/mytopic",
+        strings.NewReader("Download complete"))
+    req.Header.Set("X-Sequence-ID", msg.ID)
+    http.DefaultClient.Do(req)
+    ```
+
+=== "PowerShell"
+    ``` powershell
+    # Publish and get the message ID
+    $response = Invoke-RestMethod -Method POST -Uri "https://ntfy.sh/mytopic" -Body "Downloading file..."
+    $messageId = $response.id
+    
+    # Update via URL path
+    Invoke-RestMethod -Method POST -Uri "https://ntfy.sh/mytopic/$messageId" -Body "Download 50% ..."
+
+    # Or update using the X-Sequence-ID header
+    Invoke-RestMethod -Method POST -Uri "https://ntfy.sh/mytopic" `
+        -Headers @{"X-Sequence-ID"=$messageId} -Body "Download complete"
+    ```
+
+=== "Python"
+    ``` python
+    import requests
+    
+    # Publish and get the message ID
+    response = requests.post("https://ntfy.sh/mytopic", data="Downloading file...")
+    message_id = response.json()["id"]
+    
+    # Update via URL path
+    requests.post(f"https://ntfy.sh/mytopic/{message_id}", data="Download 50% ...")
+
+    # Or update using the X-Sequence-ID header
+    requests.post("https://ntfy.sh/mytopic",
+        headers={"X-Sequence-ID": message_id}, data="Download complete")
+    ```
+
+=== "PHP"
+    ``` php-inline
+    // Publish and get the message ID
+    $response = file_get_contents('https://ntfy.sh/mytopic', false, stream_context_create([
+        'http' => ['method' => 'POST', 'content' => 'Downloading file...']
+    ]));
+    $messageId = json_decode($response)->id;
+    
+    // Update via URL path
+    file_get_contents("https://ntfy.sh/mytopic/$messageId", false, stream_context_create([
+        'http' => ['method' => 'POST', 'content' => 'Download 50% ...']
+    ]));
+
+    // Or update using the X-Sequence-ID header
+    file_get_contents('https://ntfy.sh/mytopic', false, stream_context_create([
+        'http' => [
+            'method' => 'POST',
+            'header' => "X-Sequence-ID: $messageId",
+            'content' => 'Download complete'
+        ]
+    ]));
+    ```
+
+You can also use a **custom sequence ID** (e.g., a download ID, job ID, etc.) when publishing the first message. 
+**This is less cumbersome**, since you don't need to capture the message ID first. Just publish directly to
+`/<topic>/<sequence_id>`:
+
+=== "Command line (curl)"
+    ```bash
+    # Publish with a custom sequence ID
+    curl -d "Downloading file..." ntfy.sh/mytopic/my-download-123
+
+    # Update using the same sequence ID (via URL path)
+    curl -d "Download 50% ..." ntfy.sh/mytopic/my-download-123
+
+    # Or update using the X-Sequence-ID header
+    curl -H "X-Sequence-ID: my-download-123" -d "Download complete" ntfy.sh/mytopic
+    ```
+
+=== "ntfy CLI"
+    ```bash
+    # Publish with a sequence ID
+    ntfy pub --sequence-id=my-download-123 mytopic "Downloading file..."
+
+    # Update using the same sequence ID
+    ntfy pub --sequence-id=my-download-123 mytopic "Download 50% ..."
+
+    # Update again
+    ntfy pub -S my-download-123 mytopic "Download complete"
+    ```
+
+=== "HTTP"
+    ``` http
+    # Publish a message with a custom sequence ID
+    POST /mytopic/my-download-123 HTTP/1.1
+    Host: ntfy.sh
+
+    Downloading file...
+
+    # Update again using the X-Sequence-ID header
+    POST /mytopic HTTP/1.1
+    Host: ntfy.sh
+    X-Sequence-ID: my-download-123
+
+    Download complete
+    ```
+
+=== "JavaScript"
+    ``` javascript
+    // First message
+    await fetch('https://ntfy.sh/mytopic/my-download-123', {
+      method: 'POST',
+      body: 'Downloading file...'
+    });
+
+    // Update via URL path
+    await fetch('https://ntfy.sh/mytopic/my-download-123', {
+      method: 'POST',
+      body: 'Download 50% ...'
+    });
+
+    // Or update using the X-Sequence-ID header
+    await fetch('https://ntfy.sh/mytopic', {
+      method: 'POST',
+      headers: { 'X-Sequence-ID': 'my-download-123' },
+      body: 'Download complete'
+    });
+    ```
+
+=== "Go"
+    ``` go
+    // Publish with sequence ID in URL path
+    http.Post("https://ntfy.sh/mytopic/my-download-123", "text/plain",
+        strings.NewReader("Downloading file..."))
+    
+    // Update via URL path
+    http.Post("https://ntfy.sh/mytopic/my-download-123", "text/plain",
+        strings.NewReader("Download 50% ..."))
+
+    // Or update using the X-Sequence-ID header
+    req, _ := http.NewRequest("POST", "https://ntfy.sh/mytopic",
+        strings.NewReader("Download complete"))
+    req.Header.Set("X-Sequence-ID", "my-download-123")
+    http.DefaultClient.Do(req)
+    ```
+
+=== "PowerShell"
+    ``` powershell
+    # Publish with sequence ID
+    Invoke-RestMethod -Method POST -Uri "https://ntfy.sh/mytopic/my-download-123" -Body "Downloading file..."
+    
+    # Update via URL path
+    Invoke-RestMethod -Method POST -Uri "https://ntfy.sh/mytopic/my-download-123" -Body "Download 50% ..."
+
+    # Or update using the X-Sequence-ID header
+    Invoke-RestMethod -Method POST -Uri "https://ntfy.sh/mytopic" `
+        -Headers @{"X-Sequence-ID"="my-download-123"} -Body "Download complete"
+    ```
+
+=== "Python"
+    ``` python
+    import requests
+    
+    # Publish with sequence ID
+    requests.post("https://ntfy.sh/mytopic/my-download-123", data="Downloading file...")
+    
+    # Update via URL path
+    requests.post("https://ntfy.sh/mytopic/my-download-123", data="Download 50% ...")
+
+    # Or update using the X-Sequence-ID header
+    requests.post("https://ntfy.sh/mytopic",
+        headers={"X-Sequence-ID": "my-download-123"}, data="Download complete")
+    ```
+
+=== "PHP"
+    ``` php-inline
+    // Publish with sequence ID
+    file_get_contents('https://ntfy.sh/mytopic/my-download-123', false, stream_context_create([
+        'http' => ['method' => 'POST', 'content' => 'Downloading file...']
+    ]));
+    
+    // Update via URL path
+    file_get_contents('https://ntfy.sh/mytopic/my-download-123', false, stream_context_create([
+        'http' => ['method' => 'POST', 'content' => 'Download 50% ...']
+    ]));
+
+    // Or update using the X-Sequence-ID header
+    file_get_contents('https://ntfy.sh/mytopic', false, stream_context_create([
+        'http' => [
+            'method' => 'POST',
+            'header' => 'X-Sequence-ID: my-download-123',
+            'content' => 'Download complete'
+        ]
+    ]));
+    ```
+
+You can also set the sequence ID via the `sequence-id` [query parameter](#list-of-all-parameters), or when
+[publishing as JSON](#publish-as-json) using the `sequence_id` field.
+
+If the message ID (`id`) and the sequence ID (`sequence_id`) are different, the ntfy server will include the `sequence_id`
+field the response. A sequence of updates may look like this (first example from above):
+
+```json
+{"id":"xE73Iyuabi","time":1673542291,"event":"message","topic":"mytopic","message":"Downloading file..."}
+{"id":"yF84Jzvbcj","time":1673542295,"event":"message","topic":"mytopic","sequence_id":"xE73Iyuabi","message":"Download 50% ..."}
+{"id":"zG95Kawdde","time":1673542300,"event":"message","topic":"mytopic","sequence_id":"xE73Iyuabi","message":"Download complete"}
+```
+
+### Clearing notifications
+Clearing a notification means **marking it as read and dismissing it from the notification drawer**. 
+
+To do this, send a PUT request to the `/<topic>/<sequence_id>/clear` endpoint (or `/<topic>/<sequence_id>/read` as an alias). 
+This will then emit a `message_clear` event that is used by the clients (web app and Android app) to update the read status
+and dismiss the notification.
+
+=== "Command line (curl)"
+    ```bash
+    curl -X PUT ntfy.sh/mytopic/my-download-123/clear
+    ```
+
+=== "HTTP"
+    ``` http
+    PUT /mytopic/my-download-123/clear HTTP/1.1
+    Host: ntfy.sh
+    ```
+
+=== "JavaScript"
+    ``` javascript
+    await fetch('https://ntfy.sh/mytopic/my-download-123/clear', {
+      method: 'PUT'
+    });
+    ```
+
+=== "Go"
+    ``` go
+    req, _ := http.NewRequest("PUT", "https://ntfy.sh/mytopic/my-download-123/clear", nil)
+    http.DefaultClient.Do(req)
+    ```
+
+=== "PowerShell"
+    ``` powershell
+    Invoke-RestMethod -Method PUT -Uri "https://ntfy.sh/mytopic/my-download-123/clear"
+    ```
+
+=== "Python"
+    ``` python
+    requests.put("https://ntfy.sh/mytopic/my-download-123/clear")
+    ```
+
+=== "PHP"
+    ``` php-inline
+    file_get_contents('https://ntfy.sh/mytopic/my-download-123/clear', false, stream_context_create([
+        'http' => ['method' => 'PUT']
+    ]));
+    ```
+
+An example response from the server with the `message_clear` event may look like this:
+
+```json
+{"id":"jkl012","time":1673542305,"event":"message_clear","topic":"mytopic","sequence_id":"my-download-123"}
+```
+
+### Deleting notifications
+Deleting a notification means **removing it from the notification drawer and from the client's database**.
+
+To do this, send a DELETE request to the `/<topic>/<sequence_id>` endpoint. This will emit a `message_delete` event
+that is used by the clients (web app and Android app) to remove the notification entirely.
+
+=== "Command line (curl)"
+    ```bash
+    curl -X DELETE ntfy.sh/mytopic/my-download-123
+    ```
+
+=== "HTTP"
+    ``` http
+    DELETE /mytopic/my-download-123 HTTP/1.1
+    Host: ntfy.sh
+    ```
+
+=== "JavaScript"
+    ``` javascript
+    await fetch('https://ntfy.sh/mytopic/my-download-123', {
+      method: 'DELETE'
+    });
+    ```
+
+=== "Go"
+    ``` go
+    req, _ := http.NewRequest("DELETE", "https://ntfy.sh/mytopic/my-download-123", nil)
+    http.DefaultClient.Do(req)
+    ```
+
+=== "PowerShell"
+    ``` powershell
+    Invoke-RestMethod -Method DELETE -Uri "https://ntfy.sh/mytopic/my-download-123"
+    ```
+
+=== "Python"
+    ``` python
+    requests.delete("https://ntfy.sh/mytopic/my-download-123")
+    ```
+
+=== "PHP"
+    ``` php-inline
+    file_get_contents('https://ntfy.sh/mytopic/my-download-123', false, stream_context_create([
+        'http' => ['method' => 'DELETE']
+    ]));
+    ```
+
+An example response from the server with the `message_delete` event may look like this:
+
+```json
+{"id":"mno345","time":1673542400,"event":"message_delete","topic":"mytopic","sequence_id":"my-download-123"}
+```
+
+!!! info
+    Deleted sequences can be revived by publishing a new message with the same sequence ID. The notification will
+    reappear as a new message.
+
 ## Message templating
 _Supported on:_ :material-android: :material-apple: :material-firefox:
 
@@ -2695,134 +3134,6 @@ Here's an example that will open Reddit when the notification is clicked:
     ]));
     ```
 
-## Updating + deleting notifications
-_Supported on:_ :material-android: :material-firefox:
-
-You can update, clear (mark as read), or delete notifications that have already been delivered. This is useful for scenarios 
-like download progress updates, replacing outdated information, or dismissing notifications that are no longer relevant.
-
-The key concept is the **sequence ID** (`sequence_id` or `sid`): notifications with the same sequence ID are treated as 
-belonging to the same sequence, and clients will update/replace the notification accordingly.
-
-### Updating notifications
-To update an existing notification, publish a new message with the same sequence ID. Clients will replace the previous 
-notification with the new one.
-
-You can either:
-
-1. **Use the message ID**: First publish without a sequence ID, then use the returned message `id` as the sequence ID for updates
-2. **Use a custom sequence ID**: Publish directly to `/<topic>/<sequence_id>` with your own identifier
-
-=== "Using the message ID"
-    ```bash
-    # First, publish a message and capture the message ID
-    $ curl -d "Downloading file..." ntfy.sh/mytopic
-    {"id":"xE73Iyuabi","time":1673542291,...}
-    
-    # Then use the message ID to update it
-    $ curl -d "Download complete!" ntfy.sh/mytopic/xE73Iyuabi
-    ```
-
-=== "Using a custom sequence ID"
-    ```bash
-    # Publish with a custom sequence ID
-    $ curl -d "Downloading file..." ntfy.sh/mytopic/my-download-123
-    
-    # Update using the same sequence ID  
-    $ curl -d "Download complete!" ntfy.sh/mytopic/my-download-123
-    ```
-
-=== "Using the X-Sequence-ID header"
-    ```bash
-    # Publish with a sequence ID via header
-    $ curl -H "X-Sequence-ID: my-download-123" -d "Downloading..." ntfy.sh/mytopic
-    
-    # Update using the same sequence ID
-    $ curl -H "X-Sequence-ID: my-download-123" -d "Done!" ntfy.sh/mytopic
-    ```
-
-You can also set the sequence ID via the `sid` query parameter or when [publishing as JSON](#publish-as-json) using the 
-`sequence_id` field.
-
-### Clearing notifications
-To clear a notification (mark it as read and dismiss it from the notification drawer), send a PUT request to 
-`/<topic>/<sequence_id>/clear` (or `/<topic>/<sequence_id>/read` as an alias):
-
-=== "Command line (curl)"
-    ```bash
-    curl -X PUT ntfy.sh/mytopic/my-download-123/clear
-    ```
-
-=== "HTTP"
-    ```http
-    PUT /mytopic/my-download-123/clear HTTP/1.1
-    Host: ntfy.sh
-    ```
-
-This publishes a `message_clear` event, which tells clients to:
-
-- Mark the notification as read in the app
-- Dismiss the browser/Android notification
-
-### Deleting notifications
-To delete a notification entirely, send a DELETE request to `/<topic>/<sequence_id>`:
-
-=== "Command line (curl)"
-    ```bash
-    curl -X DELETE ntfy.sh/mytopic/my-download-123
-    ```
-
-=== "HTTP"
-    ```http
-    DELETE /mytopic/my-download-123 HTTP/1.1
-    Host: ntfy.sh
-    ```
-
-This publishes a `message_delete` event, which tells clients to:
-
-- Delete the notification from the database
-- Dismiss the browser/Android notification
-
-!!! info
-    Deleted sequences can be revived by publishing a new message with the same sequence ID. The notification will 
-    reappear as a new message.
-
-### Full example
-Here's a complete example showing the lifecycle of a notification with updates, clearing, and deletion:
-
-```bash
-# 1. Create a notification with a custom sequence ID
-$ curl -d "Starting backup..." ntfy.sh/mytopic/backup-2024
-
-# 2. Update the notification with progress
-$ curl -d "Backup 50% complete..." ntfy.sh/mytopic/backup-2024
-
-# 3. Update again when complete
-$ curl -d "Backup finished successfully!" ntfy.sh/mytopic/backup-2024
-
-# 4. Clear the notification (dismiss from notification drawer)
-$ curl -X PUT ntfy.sh/mytopic/backup-2024/clear
-
-# 5. Later, delete the notification entirely
-$ curl -X DELETE ntfy.sh/mytopic/backup-2024
-```
-
-When polling the topic, you'll see the complete sequence of events:
-
-```bash
-$ curl -s "ntfy.sh/mytopic/json?poll=1&since=all" | jq .
-```
-
-```json
-{"id":"abc123","time":1673542291,"event":"message","topic":"mytopic","sequence_id":"backup-2024","message":"Starting backup..."}
-{"id":"def456","time":1673542295,"event":"message","topic":"mytopic","sequence_id":"backup-2024","message":"Backup 50% complete..."}
-{"id":"ghi789","time":1673542300,"event":"message","topic":"mytopic","sequence_id":"backup-2024","message":"Backup finished successfully!"}
-{"id":"jkl012","time":1673542305,"event":"message_clear","topic":"mytopic","sequence_id":"backup-2024"}
-{"id":"mno345","time":1673542400,"event":"message_delete","topic":"mytopic","sequence_id":"backup-2024"}
-```
-
-Clients process these events in order, keeping only the latest state for each sequence ID.
-
 ## Attachments
 _Supported on:_ :material-android: :material-firefox:
 
@@ -4060,6 +4371,7 @@ table in their canonical form.
 |-----------------|--------------------------------------------|-----------------------------------------------------------------------------------------------|
 | `X-Message`     | `Message`, `m`                             | Main body of the message as shown in the notification                                         |
 | `X-Title`       | `Title`, `t`                               | [Message title](#message-title)                                                               |
+| `X-Sequence-ID` | `Sequence-ID`, `SID`                       | [Sequence ID](#updating-deleting-notifications) for updating/clearing/deleting notifications  |
 | `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)                             |

docs/static/css/extra.css

@@ -1,10 +1,10 @@
 :root > * {
-    --md-primary-fg-color:        #338574;
+    --md-primary-fg-color: #338574;
     --md-primary-fg-color--light: #338574;
-    --md-primary-fg-color--dark:  #338574;
+    --md-primary-fg-color--dark: #338574;
-    --md-footer-bg-color:         #353744;
+    --md-footer-bg-color: #353744;
-    --md-text-font:               "Roboto";
+    --md-text-font: "Roboto";
-    --md-code-font:               "Roboto Mono";
+    --md-code-font: "Roboto Mono";
 }
 
 .md-header__button.md-logo :is(img, svg) {
@@ -34,7 +34,7 @@ figure img, figure video {
 }
 
 header {
-    background: linear-gradient(150deg, rgba(51,133,116,1) 0%, rgba(86,189,168,1) 100%);
+    background: linear-gradient(150deg, rgba(51, 133, 116, 1) 0%, rgba(86, 189, 168, 1) 100%);
 }
 
 body[data-md-color-scheme="default"] header {
@@ -93,7 +93,7 @@ figure video {
 
 .screenshots img {
     max-height: 230px;
-    max-width: 300px;
+    max-width: 350px;
     margin: 3px;
     border-radius: 5px;
     filter: drop-shadow(2px 2px 2px #ddd);
@@ -107,7 +107,7 @@ figure video {
     opacity: 0;
     visibility: hidden;
     position: fixed;
-    left:0;
+    left: 0;
     right: 0;
     top: 0;
     bottom: 0;
@@ -119,7 +119,7 @@ figure video {
 }
 
 .lightbox.show {
-    background-color: rgba(0,0,0, 0.75);
+    background-color: rgba(0, 0, 0, 0.75);
     opacity: 1;
     visibility: visible;
     z-index: 1000;