# User Mentions
## Overview
You can mention users in both **activities** and **comments**. When you include `mentioned_user_ids`, the API stores the mentions and returns enriched `mentioned_users` in the response. Optionally, you can create [notification activities](/activity-feeds/docs/dotnet-csharp/notification_feeds/) for mentioned users or [send push notifications](/activity-feeds/docs/dotnet-csharp/push_introduction/).
## Adding user mentions
`mentioned_user_ids` can only contain existing user ids, you can use [`queryUsers` endpoint](/activity-feeds/docs/dotnet-csharp/user-management/#filter-examples) to search for users to mention.
Please note that it's up to you to include user mentions (for example @Alice) in the activity/comment text, the Stream API won't modify these fields based on `mentioned_user_ids`.
### Adding an activity with mentions
```swift label="Swift"
let activity = try await feed.addActivity(
request: .init(
text: "Hey @bob and @alice, check this out!",
type: "post",
mentionedUserIds: ["bob", "alice"],
createNotificationActivity: true
)
)
// activity.mentionedUsers contains enriched user objects
```
```kotlin label="Kotlin"
val activity: Result = feed.addActivity(
request = FeedAddActivityRequest(
text = "Hey @bob and @alice, check this out!",
type = "post",
mentionedUserIds = listOf("bob", "alice"),
createNotificationActivity = true
)
)
// activity.getOrNull()?.mentionedUsers contains enriched user objects
```
```js label="JavaScript"
const response = await feed.addActivity({
type: "post",
text: "Hey @bob and @alice, check this out!",
mentioned_user_ids: ["bob", "alice"],
create_notification_activity: true,
});
// response.activity.mentioned_users contains enriched user objects
```
```js label="React"
const response = await feed.addActivity({
type: "post",
text: "Hey @bob and @alice, check this out!",
mentioned_user_ids: ["bob", "alice"],
create_notification_activity: true,
});
// response.activity.mentioned_users contains enriched user objects
```
```js label="React Native"
const response = await feed.addActivity({
type: "post",
text: "Hey @bob and @alice, check this out!",
mentioned_user_ids: ["bob", "alice"],
create_notification_activity: true,
});
// response.activity.mentioned_users contains enriched user objects
```
```dart label="Dart"
final activity = await feed.addActivity(
request: FeedAddActivityRequest(
text: 'Hey @bob and @alice, check this out!',
type: 'post',
mentionedUserIds: ['bob', 'alice'],
createNotificationActivity: true,
),
);
// activity.mentionedUsers contains enriched user objects
```
```js label="Node"
const response = await client.feeds.addActivity({
feeds: ["user:eric"],
type: "post",
text: "Hey @bob and @alice, check this out!",
user_id: "eric",
mentioned_user_ids: ["bob", "alice"],
create_notification_activity: true,
});
// response.activity.mentioned_users contains enriched user objects
```
```go label="Go"
_, err = client.Feeds().AddActivity(context.Background(), &getstream.AddActivityRequest{
Feeds: []string{"user:eric"},
Type: "post",
Text: getstream.PtrTo("Hey @bob and @alice, check this out!"),
UserID: getstream.PtrTo("eric"),
MentionedUserIDs: []string{"bob", "alice"},
CreateNotificationActivity: getstream.PtrTo(true),
})
if err != nil {
log.Fatal("Error adding activity:", err)
}
```
```java label="Java"
AddActivityRequest request = AddActivityRequest.builder()
.feeds(List.of("user:eric"))
.type("post")
.text("Hey @bob and @alice, check this out!")
.userID("eric")
.mentionedUserIDs(List.of("bob", "alice"))
.createNotificationActivity(true)
.build();
AddActivityResponse response = client.feeds().addActivity(request).execute().getData();
// response.getActivity().getMentionedUsers() contains enriched user objects
```
```php label="php"
$response = $feedsClient->addActivity(
new GeneratedModels\AddActivityRequest(
feeds: ['user:eric'],
type: 'post',
text: 'Hey @bob and @alice, check this out!',
userID: 'eric',
mentionedUserIDs: ['bob', 'alice'],
createNotificationActivity: true
)
);
// $response->activity->mentionedUsers contains enriched user objects
```
```csharp label="C#"
var response = await _feedsV3Client.AddActivityAsync(
new AddActivityRequest
{
Feeds = new[] { "user:eric" },
Type = "post",
Text = "Hey @bob and @alice, check this out!",
UserID = "eric",
MentionedUserIDs = new[] { "bob", "alice" },
CreateNotificationActivity = true
}
);
// response.Activity.MentionedUsers contains enriched user objects
```
```python label="Python"
response = client.feeds.add_activity(
feeds=["user:eric"],
type="post",
text="Hey @bob and @alice, check this out!",
user_id="eric",
mentioned_user_ids=["bob", "alice"],
create_notification_activity=True,
)
# response["activity"]["mentioned_users"] contains enriched user objects
```
```ruby label="Ruby"
request = GetStream::Generated::Models::AddActivityRequest.new(
feeds: ['user:eric'],
type: 'post',
text: 'Hey @bob and @alice, check this out!',
user_id: 'eric',
mentioned_user_ids: ['bob', 'alice'],
create_notification_activity: true
)
response = client.feeds.add_activity(request)
# response.activity.mentioned_users contains enriched user objects
```
### Adding a comment with mentions
```swift label="Swift"
let comment = try await feed.addComment(
request: .init(
comment: "Thanks @bob for the tip!",
objectId: "activity_123",
objectType: "activity",
mentionedUserIds: ["bob"],
createNotificationActivity: true
)
)
// comment.mentionedUsers contains enriched user objects
```
```kotlin label="Kotlin"
val comment: Result = feed.addComment(
request = ActivityAddCommentRequest(
comment = "Thanks @bob for the tip!",
activityId = "activity_123",
mentionedUserIds = listOf("bob"),
createNotificationActivity = true
)
)
// comment.getOrNull()?.mentionedUsers contains enriched user objects
```
```js label="JavaScript"
const response = await client.addComment({
comment: "Thanks @bob for the tip!",
object_id: "activity_123",
object_type: "activity",
mentioned_user_ids: ["bob"],
create_notification_activity: true,
});
// response.comment.mentioned_users contains enriched user objects
```
```js label="React"
const response = await client.addComment({
comment: "Thanks @bob for the tip!",
object_id: "activity_123",
object_type: "activity",
mentioned_user_ids: ["bob"],
create_notification_activity: true,
});
// response.comment.mentioned_users contains enriched user objects
```
```js label="React Native"
const response = await client.addComment({
comment: "Thanks @bob for the tip!",
object_id: "activity_123",
object_type: "activity",
mentioned_user_ids: ["bob"],
create_notification_activity: true,
});
// response.comment.mentioned_users contains enriched user objects
```
```dart label="Dart"
final comment = await feed.addComment(
request: ActivityAddCommentRequest(
comment: 'Thanks @bob for the tip!',
activityId: 'activity_123',
activityType: 'activity',
mentionedUserIds: ['bob'],
createNotificationActivity: true,
),
);
// comment.mentionedUsers contains enriched user objects
```
```js label="Node"
const response = await client.feeds.addComment({
comment: "Thanks @bob for the tip!",
object_id: "activity_123",
object_type: "activity",
user_id: "alice",
mentioned_user_ids: ["bob"],
create_notification_activity: true,
});
// response.comment.mentioned_users contains enriched user objects
```
```go label="Go"
_, err = client.Feeds().AddComment(context.Background(), &getstream.AddCommentRequest{
Comment: "Thanks @bob for the tip!",
ObjectID: "activity_123",
ObjectType: "activity",
UserID: getstream.PtrTo("alice"),
MentionedUserIDs: []string{"bob"},
CreateNotificationActivity: getstream.PtrTo(true),
})
if err != nil {
log.Fatal("Error adding comment:", err)
}
```
```java label="Java"
AddCommentRequest request = AddCommentRequest.builder()
.comment("Thanks @bob for the tip!")
.objectID("activity_123")
.objectType("activity")
.userID("alice")
.mentionedUserIDs(List.of("bob"))
.createNotificationActivity(true)
.build();
AddCommentResponse response = feeds.addComment(request).execute().getData();
// response.getComment().getMentionedUsers() contains enriched user objects
```
```php label="php"
$response = $feedsClient->addComment(
new GeneratedModels\AddCommentRequest(
comment: 'Thanks @bob for the tip!',
objectID: 'activity_123',
objectType: 'activity',
userID: 'alice',
mentionedUserIDs: ['bob'],
createNotificationActivity: true
)
);
// $response->comment->mentionedUsers contains enriched user objects
```
```csharp label="C#"
var response = await _feedsV3Client.AddCommentAsync(
new AddCommentRequest
{
Comment = "Thanks @bob for the tip!",
ObjectID = "activity_123",
ObjectType = "activity",
UserID = "alice",
MentionedUserIDs = new[] { "bob" },
CreateNotificationActivity = true
}
);
// response.Comment.MentionedUsers contains enriched user objects
```
```python label="Python"
response = client.feeds.add_comment(
comment="Thanks @bob for the tip!",
object_id="activity_123",
object_type="activity",
user_id="alice",
mentioned_user_ids=["bob"],
create_notification_activity=True,
)
# response["comment"]["mentioned_users"] contains enriched user objects
```
```ruby label="Ruby"
request = GetStream::Generated::Models::AddCommentRequest.new(
comment: 'Thanks @bob for the tip!',
object_id: 'activity_123',
object_type: 'activity',
user_id: 'alice',
mentioned_user_ids: ['bob'],
create_notification_activity: true
)
response = client.feeds.add_comment(request)
# response.comment.mentioned_users contains enriched user objects
```
## Reading mentioned users
Activities and comments returned by the API include a `mentioned_users` array with enriched user objects (id, name, image, etc.). Use them to render @mentions in your UI.
```swift label="Swift"
// From activities
let feedResponse = try await feed.getOrCreate()
for activity in feedResponse.activities {
if let mentioned = activity.mentionedUsers, !mentioned.isEmpty {
print("Mentioned: \(mentioned.map(\.name).joined(separator: ", "))")
}
}
// From comments (e.g. activity with latest replies)
let activity = try await feed.getActivity(activityId: "activity_123", withReactions: false, withReactionCounts: false, withRecentReplies: 10)
for comment in activity.latestReplies ?? [] {
if let mentioned = comment.mentionedUsers, !mentioned.isEmpty {
print("Comment mentioned: \(mentioned.map(\.name).joined(separator: ", "))")
}
}
```
```kotlin label="Kotlin"
// From activities
feed.getOrCreate()
feed.state.activities.collect { activities ->
activities.forEach { activity ->
println("Mentioned: ${activity.mentionedUsers.joinToString { it.name.orEmpty() }}")
}
}
// From comments
val activity = client.activity(
activityId = "activity_123",
fid = FeedId(group = "user", id = "john")
)
activity.get()
activity.state.comments.collect { comments ->
comments.forEach { comment ->
println("Comment mentioned: ${comment.mentionedUsers.joinToString { it.name.orEmpty() }}")
}
}
```
```js label="JavaScript"
// From activities
const { activities } = await feed.getOrCreate();
activities.forEach((activity) => {
if (activity.mentioned_users?.length) {
console.log(
"Mentioned:",
activity.mentioned_users.map((u) => u.name).join(", "),
);
}
});
// From comments
const { activity } = await feed.getActivity(activityId, {
withRecentReplies: 10,
});
(activity.latest_replies || []).forEach((comment) => {
if (comment.mentioned_users?.length) {
console.log(
"Comment mentioned:",
comment.mentioned_users.map((u) => u.name).join(", "),
);
}
});
```
```js label="React"
// From activities
const { activities } = await feed.getOrCreate();
activities.forEach((activity) => {
if (activity.mentioned_users?.length) {
console.log(
"Mentioned:",
activity.mentioned_users.map((u) => u.name).join(", "),
);
}
});
// From comments
const { activity } = await feed.getActivity(activityId, {
withRecentReplies: 10,
});
(activity.latest_replies || []).forEach((comment) => {
if (comment.mentioned_users?.length) {
console.log(
"Comment mentioned:",
comment.mentioned_users.map((u) => u.name).join(", "),
);
}
});
```
```js label="React Native"
// From activities
const { activities } = await feed.getOrCreate();
activities.forEach((activity) => {
if (activity.mentioned_users?.length) {
console.log(
"Mentioned:",
activity.mentioned_users.map((u) => u.name).join(", "),
);
}
});
// From comments
const { activity } = await feed.getActivity(activityId, {
withRecentReplies: 10,
});
(activity.latest_replies || []).forEach((comment) => {
if (comment.mentioned_users?.length) {
console.log(
"Comment mentioned:",
comment.mentioned_users.map((u) => u.name).join(", "),
);
}
});
```
```dart label="Dart"
// From activities
await feed.getOrCreate();
for (final activity in feed.state.activities) {
if (activity.mentionedUsers != null && activity.mentionedUsers!.isNotEmpty) {
print('Mentioned: ${activity.mentionedUsers!.map((u) => u.name).join(', ')}');
}
}
// From comments
final activity = await feed.getActivity(activityId, withRecentReplies: 10);
for (final comment in activity.latestReplies ?? []) {
if (comment.mentionedUsers != null && comment.mentionedUsers!.isNotEmpty) {
print('Comment mentioned: ${comment.mentionedUsers!.map((u) => u.name).join(', ')}');
}
}
```
```js label="Node"
// From activities
const response = await client.feeds.getOrCreateFeed("user", "eric", {
user_id: "eric",
});
response.activities.forEach((activity) => {
if (activity.mentioned_users?.length) {
console.log(
"Mentioned:",
activity.mentioned_users.map((u) => u.name).join(", "),
);
}
});
// From comments
const activityResponse = await client.feeds.getActivity(activityId, {
with_recent_replies: 10,
});
(activityResponse.activity.latest_replies || []).forEach((comment) => {
if (comment.mentioned_users?.length) {
console.log(
"Comment mentioned:",
comment.mentioned_users.map((u) => u.name).join(", "),
);
}
});
```
```go label="Go"
// From activities
resp, err := client.Feeds().GetOrCreateFeed(context.Background(), "user", "eric", &getstream.GetOrCreateFeedRequest{
UserID: getstream.PtrTo("eric"),
})
if err != nil {
log.Fatal(err)
}
for _, a := range resp.Data.Activities {
if len(a.MentionedUsers) > 0 {
names := make([]string, len(a.MentionedUsers))
for i, u := range a.MentionedUsers {
names[i] = u.Name
}
log.Println("Mentioned:", strings.Join(names, ", "))
}
}
// From comments
activityResp, err := client.Feeds().GetActivity(context.Background(), activityID, &getstream.GetActivityRequest{
WithRecentReplies: getstream.PtrTo(int32(10)),
})
if err != nil {
log.Fatal(err)
}
for _, c := range activityResp.Data.Activity.LatestReplies {
if len(c.MentionedUsers) > 0 {
names := make([]string, len(c.MentionedUsers))
for i, u := range c.MentionedUsers {
names[i] = u.Name
}
log.Println("Comment mentioned:", strings.Join(names, ", "))
}
}
```
```java label="Java"
// From activities
GetOrCreateFeedResponse response = feed.getOrCreate().execute().getData();
response.getActivities().forEach(activity -> {
if (activity.getMentionedUsers() != null && !activity.getMentionedUsers().isEmpty()) {
String names = activity.getMentionedUsers().stream()
.map(UserResponse::getName)
.collect(Collectors.joining(", "));
System.out.println("Mentioned: " + names);
}
});
// From comments
GetActivityResponse activityResponse = client.feeds().getActivity(activityId).withRecentReplies(10).execute().getData();
activityResponse.getActivity().getLatestReplies().forEach(comment -> {
if (comment.getMentionedUsers() != null && !comment.getMentionedUsers().isEmpty()) {
String names = comment.getMentionedUsers().stream()
.map(UserResponse::getName)
.collect(Collectors.joining(", "));
System.out.println("Comment mentioned: " + names);
}
});
```
```php label="php"
// From activities
$response = $feedsClient->getOrCreateFeed('user', 'eric', new GetOrCreateFeedRequest(userID: 'eric'));
foreach ($response->activities as $activity) {
if (!empty($activity->mentionedUsers)) {
$names = array_map(fn($u) => $u->name, $activity->mentionedUsers);
echo 'Mentioned: ' . implode(', ', $names) . PHP_EOL;
}
}
// From comments
$activityResponse = $feedsClient->getActivity($activityId, new GetActivityRequest(withRecentReplies: 10));
foreach ($activityResponse->activity->latestReplies ?? [] as $comment) {
if (!empty($comment->mentionedUsers)) {
$names = array_map(fn($u) => $u->name, $comment->mentionedUsers);
echo 'Comment mentioned: ' . implode(', ', $names) . PHP_EOL;
}
}
```
```csharp label="C#"
// From activities
var response = await _feedsV3Client.GetOrCreateFeedAsync("user", "eric", new GetOrCreateFeedRequest { UserID = "eric" });
foreach (var activity in response.Activities) {
if (activity.MentionedUsers?.Count > 0) {
var names = string.Join(", ", activity.MentionedUsers.Select(u => u.Name));
Console.WriteLine($"Mentioned: {names}");
}
}
// From comments
var activityResponse = await _feedsV3Client.GetActivityAsync(activityId, new GetActivityRequest { WithRecentReplies = 10 });
foreach (var comment in activityResponse.Activity.LatestReplies ?? Array.Empty()) {
if (comment.MentionedUsers?.Count > 0) {
var names = string.Join(", ", comment.MentionedUsers.Select(u => u.Name));
Console.WriteLine($"Comment mentioned: {names}");
}
}
```
```python label="Python"
# From activities
response = client.feeds.get_or_create_feed("user", "eric", user_id="eric")
for activity in response["activities"]:
mentioned = activity.get("mentioned_users") or []
if mentioned:
print("Mentioned:", ", ".join(u.get("name", "") for u in mentioned))
# From comments
activity_response = client.feeds.get_activity(activity_id, with_recent_replies=10)
for comment in activity_response.get("activity", {}).get("latest_replies") or []:
mentioned = comment.get("mentioned_users") or []
if mentioned:
print("Comment mentioned:", ", ".join(u.get("name", "") for u in mentioned))
```
```ruby label="Ruby"
# From activities
response = client.feeds.get_or_create_feed('user', 'eric', GetStream::Generated::Models::GetOrCreateFeedRequest.new(user_id: 'eric'))
response.activities.each do |activity|
next if activity.mentioned_users.nil? || activity.mentioned_users.empty?
puts "Mentioned: #{activity.mentioned_users.map(&:name).join(', ')}"
end
# From comments
activity_response = client.feeds.get_activity(activity_id, GetStream::Generated::Models::GetActivityRequest.new(with_recent_replies: 10))
(activity_response.activity.latest_replies || []).each do |comment|
next if comment.mentioned_users.nil? || comment.mentioned_users.empty?
puts "Comment mentioned: #{comment.mentioned_users.map(&:name).join(', ')}"
end
```
## Mentions in notification feed
- **Activities:** When `create_notification_activity` is `true`, each mentioned user receives a `mention` notification in their notification feed.
- **Comments:** When `create_notification_activity` is `true`, each mentioned user receives a `comment_mention` notification (the activity author does not get an extra notification for mentions; they already get a comment notification).
For updating or deleting activities/comments and managing mention notifications (e.g. `handle_mention_notifications`, `delete_notification_activity`), see [Notification feeds](/activity-feeds/docs/dotnet-csharp/notification_feeds/).
## Push notifications
Use the `skip_push` parameter to control if push notifications are sent to mentioned users or not. For more information check the [Push notification guide](/activity-feeds/docs/dotnet-csharp/push_introduction/) that contains all relevant information about setting up push notification providers, customizing notifications and user preferences.
---
This page was last updated at 2026-05-08T12:56:50.298Z.
For the most recent version of this documentation, visit [https://getstream.io/activity-feeds/docs/dotnet-csharp/user-mentions/](https://getstream.io/activity-feeds/docs/dotnet-csharp/user-mentions/).