cometchat-angular-customization— agent skill

Purpose

Teaches Claude how to change the behaviour or appearance of the CometChat Angular UI Kit v5 (@cometchat/chat-uikit-angular@5) without modifying the kit itself. Four tiers, from cheapest to deepest:

Tier 1 — Slot views (@Input ng-template)   (95% of asks solved here)
Tier 2 — RequestBuilder                     (filter what data loads)
Tier 3 — Formatters + message-action options + per-type bubble views
Tier 4 — Event bus                          (react to kit activity)

Always try Tier 1 first. Escalate only when the tier can't do what the user wants.

Read `cometchat-angular-core` first, then `cometchat-angular-components`. The component catalog is the source of truth for the exact @Input slot-view names, @Output events, and request-builder inputs that this skill builds on. Never invent a binding — if it isn't in the catalog or the bundled .d.ts, it doesn't exist.

Ground truth: @cometchat/[email protected] bundled types (node_modules/@cometchat/chat-uikit-angular/types/cometchat-chat-uikit-angular.d.ts) + docs/ui-kit/angular. Verify any non-obvious symbol against the installed .d.ts before relying on it. Official docs: https://www.cometchat.com/docs/ui-kit/angular/overview · Docs MCP: claude mcp add --transport http cometchat-docs https://www.cometchat.com/docs/mcp (or fetch the URL directly without MCP).

v5 reset — what is NOT here (if you've seen the v4 Angular kit)

v5 is a clean break from the v4 (NgModule, Angular 12–15) customization model. These v4 symbols are gone — do not import or reference them:

Everything in this skill imports from `@cometchat/chat-uikit-angular` (formatters, event classes, services) or `@cometchat/chat-sdk-javascript` (the CometChat namespace + request builders). There is no uikit-shared in v5.

Verified absent in the Angular kit (v5.0.2 source): CometChatMessageTemplate, getDataSource, ChatConfigurator, DataSourceDecorator, and getAllMessageTemplates do not exist anywhere in projects/cometchat-uikit/src/lib (grep over the entire library returns no matches outside specs). The web/React kit's new CometChat.MessageTemplate(...) / getDataSource().getAllMessageTemplates() pattern has no Angular equivalent — custom bubbles go exclusively through MessageBubbleConfigService.setBubbleView (Tier 3c) and message-action overrides through the additionalOptions / optionsOverride @Inputs (Tier 3b). Do not port the React DataSource recipe here.

Four-tier triage — pick the right tier before writing any code

Start with Tier 1 every time. The Angular UI Kit follows an "inputs over components" philosophy — most additions are @Input bindings on already-mounted standalone components, not new components or custom code.

Quick task → input lookup

Before escalating, check whether an existing component @Input already does what you need (all verified in cometchat-angular-components):

v5 hide flags ARE real on the message list (unlike the old v4 kit, where most didn't exist). <cometchat-message-list> exposes hideReplyInThreadOption, hideTranslateMessageOption, hideEditMessageOption, hideDeleteMessageOption, hideReactionOption, hideCopyMessageOption, hideMessageInfoOption, hideReplyOption, hideMessagePrivatelyOption, hideFlagMessageOption, hideReceipts, hideDateSeparator, hideAvatar, and more. Prefer a [hide*] flag over optionsOverride when you just want to remove a built-in action. Confirm the exact flag in cometchat-angular-components.

If a matching input exists, add the binding and stop. No new components, no custom CSS, no new files.

Start low. If an ask fits Tier 1 but you jumped to Tier 3, you've written 50 lines that one [*View] binding could have replaced.

Tier 1 — Slot views (@Input ng-template)

Every v5 list / message component exposes named slot-view @Inputs that take a `TemplateRef`. In Angular you bind a #ref <ng-template> to the slot: [itemView]="myTemplate". The kit passes the relevant item to the template via its let- context.

Get the slot names right. They are component-specific. The list components (<cometchat-conversations>, <cometchat-users>, <cometchat-groups>, <cometchat-group-members>) expose: headerView, menuView, loadingView, emptyView, errorView, itemView, leadingView, titleView, subtitleView, trailingView (conversations also has searchView). The message list exposes a different set: headerView, footerView, emptyView, errorView, loadingView, bubbleFooterView, appendView. Always confirm per component in cometchat-angular-components.

1a. Replace a list row

// app-conversations.component.ts
import { Component } from "@angular/core";
import { CometChatConversationsComponent } from "@cometchat/chat-uikit-angular";
import { CometChat } from "@cometchat/chat-sdk-javascript";
import { DatePipe } from "@angular/common";

@Component({
  selector: "app-conversations",
  standalone: true,
  imports: [CometChatConversationsComponent, DatePipe],
  template: `
    <cometchat-conversations [itemView]="customItem">
    </cometchat-conversations>

    <ng-template #customItem let-conversation>
      <div class="custom-item">
        <span class="name">{{ conversation?.getConversationWith()?.getName() }}</span>
        <span class="time">{{ conversation?.getLastMessage()?.getSentAt() * 1000 | date: 'shortTime' }}</span>
      </div>
    </ng-template>`,
})
export class AppConversationsComponent {}

The <ng-template> lives inside the same component's template, right after the kit component — Angular resolves the #customItem reference and hands the TemplateRef to the [itemView] @Input. No @ViewChild is required when the template is declared inline like this.

1b. Replace the message-header subtitle

<cometchat-message-header [user]="selectedUser" [subtitleView]="customSubtitle">
</cometchat-message-header>

<ng-template #customSubtitle let-user>
  <span style="color: var(--cometchat-success-color); font-size: 12px;">
    {{ user?.getStatus() === 'online' ? 'Online now' : 'Offline' }}
  </span>
</ng-template>

1c. Custom empty / error / loading state

<cometchat-users [emptyView]="noUsers" [loadingView]="spinner">
</cometchat-users>

<ng-template #noUsers><div class="empty">No teammates yet.</div></ng-template>
<ng-template #spinner><div class="loading">Loading…</div></ng-template>

Keep any custom CSS to layout glue and consume --cometchat-* variables for colour / spacing / radius — see cometchat-angular-theming.

Tier 2 — RequestBuilder filtering

For "show a subset of X", use the matching [*RequestBuilder] @Input. The builders live on the chat SDK CometChat namespace. Never post-filter in-render with *ngIf.

import { CometChat } from "@cometchat/chat-sdk-javascript";

// Only conversations tagged "premium", users only
conversationsRequestBuilder = new CometChat.ConversationsRequestBuilder()
  .setLimit(20)
  .setTags(["premium"])
  .setConversationType("user");

// Only online users, exclude blocked
usersRequestBuilder = new CometChat.UsersRequestBuilder()
  .setLimit(30)
  .setStatus(CometChat.USER_STATUS.ONLINE)
  .hideBlockedUsers(true);

// Only groups you've joined
groupsRequestBuilder = new CometChat.GroupsRequestBuilder()
  .setLimit(30)
  .joinedOnly(true);

// Message list — exclude action/system messages
messagesRequestBuilder = new CometChat.MessagesRequestBuilder()
  .setLimit(30)
  .setCategories(["message"]);

<cometchat-conversations [conversationsRequestBuilder]="conversationsRequestBuilder">
</cometchat-conversations>

Construct request builders once (as class properties), not inside a getter or ngOnInit that re-runs — a new builder instance on every change-detection pass forces the list to refetch. Confirm exact builder method names against the chat SDK; they are SDK-side, not kit-side.

Tier 3 — Formatters + message-action options + per-type bubble views

3a. Text formatters — inline text patterns

[textFormatters] is an @Input on <cometchat-message-list>, <cometchat-message-composer>, and <cometchat-message-information>, taking an array of CometChatTextFormatter instances.

Built-in formatters (all exported from @cometchat/chat-uikit-angular, all zero-arg constructors): CometChatMentionsFormatter, CometChatUrlFormatter, CometChatEmojiFormatter, CometChatMarkdownFormatter. (CometChatTextFormatter is the abstract base — you can't instantiate it directly.)

import {
  CometChatMentionsFormatter,
  CometChatUrlFormatter,
  CometChatEmojiFormatter,
} from "@cometchat/chat-uikit-angular";

textFormatters = [
  new CometChatMentionsFormatter(),
  new CometChatUrlFormatter(),
  new CometChatEmojiFormatter(),
];

<cometchat-message-list [user]="selectedUser" [textFormatters]="textFormatters">
</cometchat-message-list>
<cometchat-message-composer [user]="selectedUser" [textFormatters]="textFormatters">
</cometchat-message-composer>

⚠️ Pass the same `textFormatters` array to both list and composer. If they differ, text renders differently while typing vs. after send.

Custom formatter — the v5 API. Extend CometChatTextFormatter and implement the abstract members. This is different from v4 — there is no setTrackingCharacter / setRegexPatterns / getFormattedText(input) here. v5 requires: a readonly id, getRegex(), and format(text); optionally override shouldFormat() and set priority (lower runs earlier; default 100).

// hashtag-formatter.ts
import { CometChatTextFormatter } from "@cometchat/chat-uikit-angular";
import { CometChat } from "@cometchat/chat-sdk-javascript";

export class HashtagFormatter extends CometChatTextFormatter {
  readonly id = "hashtag-formatter";
  override priority = 90;

  getRegex(): RegExp {
    return /\B#(\w+)\b/g;
  }

  format(text: string): string {
    this.originalText = text ?? "";
    this.formattedText = this.originalText.replace(
      this.getRegex(),
      '<span style="color: var(--cometchat-primary-color); font-weight: 600;">#$1</span>'
    );
    return this.formattedText;
  }

  // Optional — skip very short messages
  override shouldFormat(text: string, _message?: CometChat.BaseMessage): boolean {
    return !!text && text.length > 1;
  }
}

import { HashtagFormatter } from "./hashtag-formatter";
import { CometChatMentionsFormatter, CometChatUrlFormatter } from "@cometchat/chat-uikit-angular";

textFormatters = [
  new CometChatMentionsFormatter(),
  new CometChatUrlFormatter(),
  new HashtagFormatter(),
];

Construct formatter instances once at class level (as a property), not in ngOnInit or a getter. Recreating them every change-detection cycle drops their internal originalText / formattedText / metadata state.

3b. Message-action menu — additionalOptions / optionsOverride

To add items to the per-message action menu, pass CometChatActionsIcon[] to [additionalOptions]. To add / remove / reorder items with full control, pass an [optionsOverride] callback (message, defaultOptions) => CometChatActionsIcon[].

There is no `getMessageOptions` override point in the Angular kit (unlike the web/React DataSource path). getMessageOptions exists only as an internal component method (components/cometchat-message-list/cometchat-message-list.component.ts:398 → cometchat-message-list.option-builders.ts); the public override surface is the two @Inputs below. Verified @Input() additionalOptions: CometChatActionsIcon[] (cometchat-message-list.component.ts:174) and @Input() optionsOverride?: (message: CometChat.BaseMessage, defaultOptions: CometChatActionsIcon[]) => CometChatActionsIcon[] (cometchat-message-list.component.ts:175-178). CometChatActionsIcon is exported from @cometchat/chat-uikit-angular (modals/index.ts:9) with constructor { id: string; title: string; iconURL: string; onClick: (id: number) => void } (modals/CometChatActionsIcon.ts). A "Forward"-style action is built exactly this way — push a CometChatActionsIcon into additionalOptions (or reorder inside optionsOverride).

import { CometChatActionsIcon } from "@cometchat/chat-uikit-angular";
import { CometChat } from "@cometchat/chat-sdk-javascript";

// Add a "Pin" action to every message's menu
additionalOptions: CometChatActionsIcon[] = [
  new CometChatActionsIcon({
    id: "pin",
    title: "Pin",
    iconURL: "assets/pin.svg",
    onClick: (id: number) => {
      // your pin handler — `id` is the message id
    },
  }),
];

// Or rewrite the whole option set per message
optionsOverride = (
  message: CometChat.BaseMessage,
  defaultOptions: CometChatActionsIcon[]
): CometChatActionsIcon[] => {
  // e.g. drop the default options for system messages
  if (message.getCategory() === "action") return [];
  return [...defaultOptions, ...this.additionalOptions];
};

<cometchat-message-list
  [user]="selectedUser"
  [additionalOptions]="additionalOptions"
  [optionsOverride]="optionsOverride">
</cometchat-message-list>

To merely hide a built-in action, prefer the Tier 1 [hide*Option] flag — it's a single boolean and survives kit upgrades better than reconstructing the option array.

3c. Custom bubble views per message type

v5 has no `CometChatMessageTemplate` and no `templates` @Input. Two supported paths:

(i) Slot inputs on the message list — for an extra row under existing bubbles, use [bubbleFooterView] (per-bubble footer) or [appendView] (after the bubble). Cheapest; no service.

<cometchat-message-list [user]="selectedUser" [bubbleFooterView]="myFooter">
</cometchat-message-list>

<ng-template #myFooter let-message>
  <small class="bubble-meta">{{ message?.getId() }}</small>
</ng-template>

(ii) `MessageBubbleConfigService` — to replace a part of a specific message type's bubble globally (content, header, footer, etc.), inject the service and call setBubbleView(messageTypeKey, partMap). partMap is a BubblePartMap whose keys are bubbleView / contentView / bottomView / footerView / leadingView / headerView / statusInfoView / replyView / threadView, each a TemplateRef (verified BubblePartMap in @cometchat/chat-uikit-angular — services/message-bubble-config.types.ts:30-40).

⚠️ The `messageTypeKey` is `"{type}_{category}"`, NOT just the type. The kit builds its lookup key as ` ${message.getType()}_${message.getCategory()} (components/cometchat-message-bubble/cometchat-message-bubble.component.ts:322 → consumed in getEffectiveView at line 332). A custom message sent with type: "poll" has category "custom" (CometChat.CATEGORY_CUSTOM), so its key is **"poll_custom"** — passing just "poll" silently never matches and your view never renders. The kit's own internal map confirms this format (meeting_custom, extension_poll_custom, … at lines 55-75). Built-in standard types follow the same rule: text is "text_message", image is "image_message" (service docstring message-bubble-config.service.ts:46-58`).

import { Component, AfterViewInit, ViewChild, TemplateRef, inject } from "@angular/core";
import {
  CometChatMessageListComponent,
  MessageBubbleConfigService,
} from "@cometchat/chat-uikit-angular";

@Component({
  selector: "app-chat",
  standalone: true,
  imports: [CometChatMessageListComponent],
  template: `
    <cometchat-message-list [user]="selectedUser"></cometchat-message-list>

    <ng-template #pollContent let-message>
      <div class="poll-card">{{ message?.getCustomData()?.question }}</div>
    </ng-template>`,
})
export class AppChatComponent implements AfterViewInit {
  private bubbleConfig = inject(MessageBubbleConfigService);
  @ViewChild("pollContent") pollContent!: TemplateRef<any>;

  ngAfterViewInit(): void {
    // Replace only the content area of the "poll" custom message type.
    // KEY = `${type}_${category}` → a custom message of type "poll" is category
    // "custom", so the key is "poll_custom" (NOT "poll" — that would never match).
    this.bubbleConfig.setBubbleView("poll_custom", { contentView: this.pollContent });
  }
}

MessageBubbleConfigService is providedIn: 'root', so the config applies to every message list in the app. Call setBubbleView once (in ngAfterViewInit, after the @ViewChild template refs resolve). To render a genuinely new custom message type, register its contentView (above) and send it through the kit (next subsection) — not the raw SDK.

3d. Sending a custom message type — use the UIKit path, not the raw SDK

When you create a brand-new message type (type: "poll", "location", …), send it with `CometChatUIKit.sendCustomMessage(...)`, never the raw CometChat.sendCustomMessage(...). The UIKit wrapper sets muid, stamps the logged-in user as sender, and emits ccMessageSent — which is what makes the message append to the open list immediately. The raw SDK call skips all three, producing the two classic failures: "Cannot determine message recipient" (no proper sender/receiver wiring) and the realtime bubble replacing an existing message instead of appending (no muid for dedup).

import { CometChatUIKit } from "@cometchat/chat-uikit-angular";
import { CometChat } from "@cometchat/chat-sdk-javascript";

const receiverId = this.selectedUser.getUid();          // or group.getGuid()
const receiverType = CometChat.RECEIVER_TYPE.USER;       // or .GROUP
const custom = new CometChat.CustomMessage(
  receiverId,
  receiverType,
  "poll",                                                // matches the contentView type
  { question: "Lunch?", options: ["Yes", "No"] }
);

// ✅ kit path — sets muid + sender, emits ccMessageSent → list appends
await CometChatUIKit.sendCustomMessage(custom);

// ❌ raw SDK — no muid/sender/event → "Cannot determine recipient" + realtime replace
// await CometChat.sendCustomMessage(custom);

Verified: static sendCustomMessage(message: CometChat.CustomMessage): Promise<CometChat.BaseMessage> on CometChatUIKit (cometchat-uikit.ts:251, exported from @cometchat/chat-uikit-angular). CometChat.CustomMessage has a variadic constructor (...args: any[], chat-sdk-javascript dist/type/lib/models/CustomMessage.d.ts:13); the canonical 4-arg form is (receiverId, receiverType, type, customData).

3e. Custom attachment (composer) options — the [attachmentOptions] input is APPENDED to the defaults

<cometchat-message-composer> exposes @Input() attachmentOptions?: CometChatMessageComposerAction[] (verified components/cometchat-message-composer/cometchat-message-composer.component.ts:137). In Angular v5 this is additive, NOT a replace — the composer first builds the default menu (image / video / audio / file / polls / collaborative doc / whiteboard, each gated by its hide* flag), then appends your options: if ((self.attachmentOptions?.length ?? 0) > 0) o.push(...self.attachmentOptions) (verified cometchat-message-composer.lifecycle-utils.ts:108). So you pass only your custom option(s) and the defaults are preserved automatically — do NOT reconstruct the defaults yourself.

⚠️ This differs from the React kit, where the composer's attachmentOptions prop genuinely replaces the list (there you must seed from getDataSource().getAttachmentOptions(...)). Don't cross-port React's seed-the-defaults pattern to Angular — here it would duplicate every default option.

CometChatMessageComposerAction is exported from @cometchat/chat-uikit-angular (modals/index.ts:11); its constructor takes Partial<CometChatMessageComposerAction> with fields id, iconURL, title?, onClick: (() => void) | null (modals/CometChatMessageComposerAction.ts).

<!-- ✅ "Send Location" is ADDED after the default photo/video/file/poll options -->
<cometchat-message-composer [attachmentOptions]="[locationOption]">
</cometchat-message-composer>

import { CometChatMessageComposerAction } from "@cometchat/chat-uikit-angular";

// Pass ONLY your custom option — the kit keeps its defaults and appends this.
locationOption = new CometChatMessageComposerAction({
  id: "location",
  title: "Send Location",
  iconURL: "assets/location.svg",
  onClick: () => this.shareLocation(),
});

To only remove built-in options (the common ask), do not touch attachmentOptions — use the dedicated boolean inputs, which preserve everything else: [hideImageAttachmentOption], [hideVideoAttachmentOption], [hideAudioAttachmentOption], [hideFileAttachmentOption], [hidePollsOption], [hideCollaborativeDocumentOption], [hideCollaborativeWhiteboardOption]. All verified as @Inputs on CometChatMessageComposerComponent (components/cometchat-message-composer/cometchat-message-composer.component.ts:139-140).

Tier 4 — Event bus (RxJS subscriptions)

Subscribe to the kit's static event classes so your own code reacts to activity inside the UI Kit. All event classes are exported from @cometchat/chat-uikit-angular and expose Subjects you .subscribe() to.

import { Component, OnInit, OnDestroy } from "@angular/core";
import { Subscription } from "rxjs";
import {
  CometChatMessageEvents,
  CometChatConversationEvents,
  CometChatGroupEvents,
} from "@cometchat/chat-uikit-angular";
import { CometChat } from "@cometchat/chat-sdk-javascript";

@Component({ selector: "app-root", standalone: true, template: `...` })
export class AppComponent implements OnInit, OnDestroy {
  private subs: Subscription[] = [];

  ngOnInit(): void {
    this.subs.push(
      // payload is IMessages: { message, status, parentMessageId? }
      CometChatMessageEvents.ccMessageSent.subscribe(({ message, status }) => {
        // analytics.track("message_sent", { id: message.getId(), status });
      }),
      CometChatConversationEvents.ccConversationDeleted.subscribe(
        (conversation: CometChat.Conversation) => {
          // remove from local cache
        }
      ),
      CometChatGroupEvents.ccGroupLeft.subscribe((payload) => {
        // payload is IGroupLeft
      })
    );
  }

  ngOnDestroy(): void {
    this.subs.forEach((s) => s.unsubscribe());
  }
}

Always unsubscribe in `ngOnDestroy`. Angular components are destroyed on navigation; leaked subscriptions fire handlers twice. (Each event class also exposes typed on*(cb, destroyRef?) helpers — e.g. CometChatMessageEvents.onMessageSent(cb, destroyRef) — that auto-clean up when you pass a DestroyRef; use those if you prefer not to track Subscriptions manually.)

Available event streams (verified subjects)

Confirm the exact subject name and payload type in the bundled .d.ts before subscribing — some carry typed interfaces (IMessages, IGroupLeft, IGroupMemberJoined, IActiveChatChanged, …), not raw SDK objects.

Services / state-management layer

The kit ships a set of injectable services (verified in projects/cometchat-uikit/src/lib/services/, all exported from @cometchat/chat-uikit-angular). Most are providedIn: 'root' singletons; you inject() them and read signals (snapshot, template-friendly) or `$` Observables (RxJS). This is the seam below the @Input tiers above — use it for app-wide state and cross-component coordination, not per-instance tweaks.

ChatStateService — the active-chat single source of truth

providedIn: 'root'. Holds the currently active CometChat.User / CometChat.Group / CometChat.Conversation and enforces mutual exclusivity: setting a user clears the active group and vice versa. The kit's list components (<cometchat-conversations>, <cometchat-users>, <cometchat-groups>) call its setters on selection, and the message components subscribe to it — so in the service-based wiring you place components in the template and they sync automatically with no (itemClick) plumbing.

Each piece of state is exposed both as a readonly signal and as an $ Observable:

import { Component, inject } from "@angular/core";
import { ChatStateService } from "@cometchat/chat-uikit-angular";
import { CometChat } from "@cometchat/chat-sdk-javascript";

@Component({
  selector: "app-chat",
  standalone: true,
  template: `
    <cometchat-conversations></cometchat-conversations>
    @if (chatState.activeUser() || chatState.activeGroup()) {
      <cometchat-message-header></cometchat-message-header>
      <cometchat-message-list></cometchat-message-list>
      <cometchat-message-composer></cometchat-message-composer>
    }
  `,
})
export class ChatComponent {
  chatState = inject(ChatStateService);

  // signals (snapshot / template): activeUser(), activeGroup(), activeConversation()
  // observables: activeUser$, activeGroup$, activeConversation$  (subscribe in TS)
  // setters:     setActiveUser(u) | setActiveGroup(g) | setActiveConversation(c)
  // snapshots:   getActiveUser() | getActiveGroup() | getActiveChatEntity()
  // teardown:    clearActiveChat()  ← call on logout / ngOnDestroy
}

setActiveConversation(c) extracts the User or Group from the conversation and delegates to the right setter. Use the props-based alternative ([user] / [group] @Inputs, Tier 1 wiring) instead of the service for multi-panel layouts where each panel needs independent state.

Don't scope `ChatStateService` in a component's providers: [] — it is intentionally an app-wide singleton; a local copy breaks cross-component sync. Use props for isolated panels instead.

The customization services — concise reference

All exported from @cometchat/chat-uikit-angular; inject() them. The two search services are @Injectable() (component-provided, not root) — they back the search components and you rarely inject them directly. The rest are providedIn: 'root'.

FormatterConfigService, MessageBubbleConfigService, CometChatTemplatesService, and RichTextEditorService are the four services you can deliberately re-provide in a component's providers: [] to scope a customization to one subtree (e.g. a thread panel with minimal styling) without touching the global singleton — they cross-link directly to the formatter (Tier 3a), bubble (Tier 3c), and slot-template (Tier 1) work above.

Read signals in templates, subscribe to `$` Observables in TS. Don't call .subscribe() on a signal or invoke an Observable like a function — they are distinct APIs on the same state.

Recipes (common asks → right tier)

"Filter the conversation list to just premium users"

Tier 2 — [conversationsRequestBuilder] with .setTags(["premium"]).

"Custom empty state for the users list"

Tier 1 — [emptyView] slot on <cometchat-users>.

"Custom row for conversations"

Tier 1 — [itemView] slot on <cometchat-conversations>.

"Highlight hashtags in messages"

Tier 3a — subclass CometChatTextFormatter (id + getRegex() + format()), pass it in textFormatters to list AND composer.

"Add a 'Pin message' action to the menu"

Tier 3b — push a CometChatActionsIcon into [additionalOptions].

"Remove the Translate action"

Tier 1 — [hideTranslateMessageOption]="true" on <cometchat-message-list>.

"Render a custom card for our 'poll' message type"

Tier 3c — MessageBubbleConfigService.setBubbleView("poll_custom", { contentView: tmplRef }). The key is "{type}_{category}" — a type: "poll" custom message is category custom, so the key is poll_custom, not poll.

"When a message is sent, log it to analytics"

Tier 4 — CometChatMessageEvents.ccMessageSent.subscribe(({ message }) => …).

"When a group is deleted, navigate away"

Tier 4 — CometChatGroupEvents.ccGroupDeleted.subscribe(group => router.navigate([...])).

"Sync the active conversation across my own components"

Services — inject(ChatStateService); read activeUser() / activeGroup() signals (or activeUser$ / activeGroup$), set with setActiveConversation(c), clear with clearActiveChat().

"Apply one branded empty/loading state to every list at once"

Services — CometChatTemplatesService.setSharedTemplates({ loadingView, emptyView }); override a single list with setUserTemplates(...) etc.

Anti-patterns

1. Don't reach for v4 symbols. CometChatMessageTemplate, DataSource, DataSourceDecorator, ChatConfigurator, CometChatThemeService, CometChatUrlsFormatter (plural), and the v4 CometChatTextFormatter API are all phantom in v5. They will fail to import.

1. Don't expect a `templates` @Input on `<cometchat-message-list>`. It doesn't exist in v5. Custom bubbles go through MessageBubbleConfigService.setBubbleView or the bubbleFooterView / appendView slots.

1. Don't write the v4 formatter shape. v5 formatters need id + getRegex() + format(text) — not setTrackingCharacter / setRegexPatterns / getFormattedText(input).

1. Don't pass different `textFormatters` arrays to the list and the composer — text will render inconsistently.

1. Don't post-filter a list after render. For "only online users", use Tier 2 usersRequestBuilder.setStatus(...); don't fetch everyone and hide rows with *ngIf.

1. Don't construct formatters or request builders inside a getter / `ngOnInit` that re-runs. Build them once as class properties — recreating them per change-detection cycle drops formatter state or forces list refetches.

1. Don't forget `ngOnDestroy` unsubscribe (or pass a DestroyRef to the on* helpers). Leaked subscriptions double-fire after navigation.

1. Don't add `CUSTOM_ELEMENTS_SCHEMA` — v5 components are real Angular standalone components; import the class into imports: [].

1. Don't fork or patch `@cometchat/chat-uikit-angular`. Every customization here is achievable via Tiers 1–4. Forking breaks on kit upgrades.

1. Don't escalate past Tier 1 without checking the catalog. A [hide*] flag or a [*View] slot solves most asks in one line.

Skill routing reference

Sound (in-app message + call sounds)

Sound is a customization sub-dimension. The UI Kit plays incoming/outgoing message + call sounds via CometChatSoundManager — mute it, swap custom audio, or play a specific sound. The full API + recipe lives in `cometchat-angular-theming` (Sound section). Verify the access path against the installed kit before relying on it.