Cometchat angular troubleshooting

Purpose

Teaches Claude how to diagnose and fix CometChat Angular UI Kit v5 (@cometchat/chat-uikit-angular@5) integration failures. This is a symptom → cause → fix reference. v5 is standalone-component-based, Angular 17–21 — there is no NgModule and no CUSTOM_ELEMENTS_SCHEMA. If you find yourself reaching for either, you are applying a v4 mental model.

Read cometchat-angular-core first — most "why doesn't this work" issues trace to the init / login / standalone-import order explained there.

Ground truth: @cometchat/[email protected] bundled types (node_modules/@cometchat/chat-uikit-angular/types/cometchat-chat-uikit-angular.d.ts), docs/ui-kit/angular, and first-hand failure modes from real v5 integrations. 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).

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1. Triage — read project state before guessing

When the user reports a problem, gather facts before proposing a fix.

1a. Does the installed Angular version satisfy the kit's peer range?

node -e "console.log(require('@angular/core/package.json').version)"
npm ls @cometchat/chat-uikit-angular

UI Kit v5 declares @angular/core / @angular/common peers of >=17.0.0 <22.0.0. On Angular ≤16 the install warns (or errors under strict peers) and standalone-component imports fail at build time. Fix: upgrade Angular to 17–21.

1b. Are the assets configured in angular.json?

grep -A5 '"assets"' angular.json | grep cometchat

If missing, icons render as broken images. The required entry under projects.<app>.architect.build.options.assets:

{ "glob": "**/*", "input": "./node_modules/@cometchat/chat-uikit-angular/src/lib/assets", "output": "assets/" }

1c. Is init complete before any <cometchat-*> component renders?

grep -rn "CometChatUIKit.init\|APP_INITIALIZER\|isReady" src/

Look for the init Promise resolved in main.ts before bootstrapApplication(...) (the v5 canonical — see cometchat-angular-core §3 / cometchat-angular-patterns), or wired into an APP_INITIALIZER factory (the alternative), or an isReady flag set after the init+login chain resolves. Components rendered before init completes produce blank output or a "CometChat is not initialized" console error.

1d. Is UIKitSettingsBuilder used (not a flat object), imported from the right package?

grep -rn "UIKitSettingsBuilder\|CometChatUIKit.init\|uikit-shared" src/

In v5 UIKitSettingsBuilder is exported from @cometchat/chat-uikit-angular. If you see an import from @cometchat/uikit-shared / -elements / -resources, that's a v4 package set that does not exist in v5 — it will fail to resolve. A flat object passed to init() (instead of a built UIKitSettings) also fails.

1e. Are the CometChat component classes imported into the standalone component that renders them?

# v5 exports class names with the `Component` suffix; selectors do not carry it.
grep -rnE "CometChat(Conversations|MessageList|MessageHeader|MessageComposer|Users|Groups|GroupMembers|CallButtons|IncomingCall|OutgoingCall|OngoingCall|CallLogs)Component" src/

Every <cometchat-*> tag requires its *Component class in the host standalone component's imports: []. There is no module to register them in, and no schema.

1f. Are the peer SDKs installed at the right major?

npm ls @cometchat/chat-sdk-javascript @cometchat/calls-sdk-javascript dompurify

Chat SDK must be ^4.1, dompurify ^3 (both auto-pulled by npm 7+). Calls features additionally require @cometchat/calls-sdk-javascript@^5 — installed explicitly.

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2. Symptom → cause → fix lookup tables

2a. Install / peer-dependency / version

Symptom	Likely cause	Fix
npm install warns ERESOLVE/peer conflict on @angular/core	Angular ≤16 against v5's >=17 <22 peer range	Upgrade Angular to 17–21 (the kit requires it)
Cannot find module '@cometchat/uikit-shared' (or -elements/-resources)	v4 package set referenced in v5	Delete those imports — everything is in @cometchat/chat-uikit-angular. Import UIKitSettingsBuilder from there
Type error: kit components not recognized after install	Angular version too old for the kit's standalone API surface	Confirm Angular 17–21 (§1a)
Calls components present but calling never starts	@cometchat/calls-sdk-javascript not installed	npm install @cometchat/calls-sdk-javascript@^5 + rebuild. See cometchat-angular-calls

2b. "is not a known element" / template binding errors

Symptom	Likely cause	Fix
'cometchat-conversations' is not a known element	The *Component class isn't in the host standalone component's imports: []	Import e.g. CometChatConversationsComponent from @cometchat/chat-uikit-angular into imports: []. (v5 does not use CUSTOM_ELEMENTS_SCHEMA — that was the v4 fix and is wrong here.)
Can't bind to 'user' since it isn't a known property of 'cometchat-message-list'	Same root cause — class not imported, so Angular treats the tag as an unknown element	Same fix: add the matching *Component to imports: []
Selector still unknown after adding CUSTOM_ELEMENTS_SCHEMA	Schema silences the error but the real component never loads → blank render	Remove the schema; import the class instead
<cometchat-conversations-with-messages> unknown	Composite removed in v5	Compose cometchat-conversations + cometchat-message-header/-list/-composer yourself — see cometchat-angular-placement

2c. Initialization + login

Symptom	Likely cause	Fix
Components render nothing, no error	Rendered before init() resolved	Resolve init() in main.ts before bootstrapApplication (canonical), or block with an APP_INITIALIZER factory, or gate the container with *ngIf="isReady" set after init+login resolve
"CometChat is not initialized" in console	<cometchat-*> mounted before init()	Same as above — init must complete first
getLoggedInUser() returns null	Login never called, or session expired	Call CometChatUIKit.login("cometchat-uid-1") after init resolves
Login fails: "UID not found"	User doesn't exist in this app	Create via dashboard / SDK / REST API. Dev users cometchat-uid-1 … cometchat-uid-5 are pre-seeded in every new app
login({ uid }) rejected / type error	v4 object-form argument	v5 takes a bare string: CometChatUIKit.login("cometchat-uid-1")
CometChatUIKit.init() fails silently	Invalid appId / region / authKey	Re-verify from dashboard → your app → Credentials
TS2532: Object is possibly 'undefined' on CometChatUIKit.init(settings).then(...)	v5 init() returns Promise<InitResult> | undefined, so .then() on it fails strict-null type-check	Coalesce before chaining: (CometChatUIKit.init(settings) ?? Promise.resolve()).then(...).catch(...). See cometchat-angular-core.
ERR_ALREADY_LOGGED_IN after a hot-reload (HMR) in dev	HMR re-runs the init/login effect while a session already exists	Non-fatal — guard it: check CometChatUIKit.getLoggedInUser() first and skip login() if a user is already present. Safe to ignore in dev; doesn't occur on a fresh load.
CometChatUIKitLoginListener is undefined / import fails	Phantom in v5	Use CometChatUIKit.getLoggedInUser() (sync), getLoggedinUser() (async), or loggedInUser$ (observable)
Production build ships the Auth Key	authKey in environment.prod.ts	Drop it; use server-minted auth tokens via loginWithAuthToken(...). See cometchat-angular-production

2d. Assets / icons

Symptom	Likely cause	Fix
Icons show as broken images (404)	Missing assets glob in angular.json	Add the @cometchat/chat-uikit-angular/src/lib/assets entry to build.options.assets (§1b)
Icons broken only in production build	output path doesn't match prod output dir	Verify the output value resolves under your production outputPath
Icons still 404 after editing angular.json	Dev server cached the old config	Restart ng serve — angular.json is read at startup, not hot-reloaded

2e. Layout / height

Symptom	Likely cause	Fix
Conversation/message list renders empty	Container has no bounded height and/or the <cometchat-*> element wasn't made a flex column	The kit's <cometchat-*> elements are display: inline by default — they won't flex or fill on their own. Give the host a resolvable height (set html, body { height: 100% } globally so a height: 100% chain has a root), make the host display: flex; flex-direction: column, and make the element itself display: flex; flex-direction: column. See cometchat-angular-placement
Components collapse to 0 height	Parent is display: block with no height, or the inline custom element wasn't given flex/display	Use display: flex; flex-direction: column; height: 100vh (or height: 100%) on the parent; make the <cometchat-*> element display: flex; flex-direction: column
Message list doesn't scroll (overflows the viewport instead)	min-height: 0 missing — a flex child defaults to min-height: auto, so it grows past the parent instead of scrolling inside it	Set flex: 1; min-height: 0; overflow: hidden on cometchat-message-list. The min-height: 0 is the load-bearing part that lets the element shrink and scroll internally. See cometchat-angular-placement
Chat dialog too small	MatDialog opened with no size	Pass { width: '480px', height: '600px' } to MatDialog.open()
Sidenav chat panel has no height	Sidenav content unconstrained	Add height: 100% / height: 100vh to the sidenav content

2f. Change detection / NgZone

Symptom	Likely cause	Fix
View doesn't update after an SDK callback (message arrives, presence flips)	SDK callbacks fire outside Angular's zone, so change detection never runs	Re-enter the zone: inject NgZone and wrap the state update in this.zone.run(() => …), or ChangeDetectorRef.detectChanges(). See cometchat-angular-patterns
loggedInUser$ subscription updates the field but template is stale	Same — emission may be outside the zone, and OnPush won't re-check	Use the async pipe (`loggedInUser$
OnPush component shows stale CometChat state	OnPush only re-checks on input change / event / observable	Drive the view from an observable via async pipe, or call markForCheck() after mutating state

2g. Theming — CSS variables

Symptom	Likely cause	Fix
No CometChat styling at all — components render unstyled / raw	css-variables.css never imported	Add it to the angular.json → build.options.styles array with the full path node_modules/@cometchat/chat-uikit-angular/styles/css-variables.css — NOT via a package-specifier @import in styles.css (that form fails the real ng build on Angular 17+/esbuild with "the path … is not exported by package", since the exports map only exposes .). The full node_modules/... path bypasses the exports map. See cometchat-angular-core §Assets and cometchat-angular-theming.
Cannot find name 'CometChatThemeService' / no provider	Phantom in v5 — there is no theme service	Theme with CSS variables; switch mode via CometChatUIKit.themeMode = 'dark'. See cometchat-angular-theming
--cometchat-* overrides have no effect	Declared inside a component with default ViewEncapsulation (Emulated) — scoped away from the kit's elements	Put global tokens in styles.css under :root (or scope under .cometchat for kit-only overrides), or use ::ng-deep / ViewEncapsulation.None for component-scoped overrides
Component-level override (e.g. .cometchat-conversations) ignored	Selector missing the .cometchat parent scope	Scope under .cometchat — use .cometchat .cometchat-conversations, not the bare class. Kit class names aren't version-stable — verify the actual class in DevTools per version rather than memorizing it.
Dark mode doesn't switch	themeMode set once and never re-applied, or data-theme="dark" not on the wrapper	Re-assign CometChatUIKit.themeMode on the user's toggle (and ensure data-theme="dark" is set on the .cometchat wrapper / document element)
Custom color ignored	Not a valid CSS color string	Use #hex / rgb() / named colors

2h. Components / bindings

Symptom	Likely cause	Fix
Slot template ([itemView], [subtitleView], …) renders nothing	@ViewChild/TemplateRef accessed too early	Read it in ngAfterViewInit, not ngOnInit
Click/selection callback never fires	Bound as an @Output event when the kit expects an @Input callback (or vice-versa)	Match the binding to the kit's declaration — @Input callback uses [onItemClick]="myFn"; an @Output uses (itemClick)="handler($event)". Confirm per-component in cometchat-angular-components
Clicking a conversation/user/group does nothing — list won't open a chat	<cometchat-conversations> auto-wiring expected, but the active chat surface isn't gated on ChatStateService (state-service mode), or props were never reassigned (props mode)	With no (itemClick) bound, the kit auto-calls ChatStateService.setActiveConversation (kit source: itemClick.observed ? emit : setActiveConversation) — gate your message pane on chatState.activeUser()/activeGroup(). If you bind (itemClick), the auto-wiring is suppressed and you must drive selection yourself (props / chatState.setActive* / routing). See cometchat-angular-placement
[user] input has no effect	Passed a UID string instead of a CometChat.User	const u = await CometChat.getUser(uid) then pass u
Conversations list empty but data exists	Over-restrictive request builder	Check [conversationsRequestBuilder] filters (tags, types, limits)

2i. Calling

Symptom	Likely cause	Fix
Call buttons / call UI inert	@cometchat/calls-sdk-javascript@^5 not installed, or calling not enabled	Install the peer; new UIKitSettingsBuilder().setCallingEnabled(true). See cometchat-angular-calls
Incoming-call UI never shows	<cometchat-incoming-call> not mounted at app root, or its listener lives in a component that gets destroyed	Mount <cometchat-incoming-call> once in AppComponent (never destroyed)
Call listener fires twice	Listener registered in a re-created component	Register once at the app root
Camera/mic never prompts	getUserMedia blocked — insecure origin or denied permission	Serve over https:// or localhost; check the browser site-permission for camera/mic

2j. Production / auth tokens

Symptom	Likely cause	Fix
loginWithAuthToken(token) fails: "user does not exist"	User not created in CometChat before minting the token	Create the user server-side via REST API in your signup flow. See cometchat-angular-production
Token endpoint returns 401	Backend auth failing	Verify Authorization: Bearer <jwt> is attached to the HttpClient request
429 on token endpoint	Minting too often (e.g. per component init)	Cache the token client-side, reuse until expiry
loginWithAuthToken "not a function"	Wrong API name	The v5 method is CometChatUIKit.loginWithAuthToken(token) (bare token string)

2k. SSR / Angular Universal

Symptom	Likely cause	Fix
window is not defined during SSR / prerender	The kit + SDK use browser-only APIs	Guard init/login with isPlatformBrowser(this.platformId); only run CometChat in the browser. See cometchat-angular-patterns
document is not defined during SSR	Same cause	Same guard
<cometchat-*> errors on the server	Components touch browser APIs at render	Gate the tags with *ngIf="isBrowser", where isBrowser = isPlatformBrowser(platformId)

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3. Deep dives on common failures

3a. "is not a known element" — the v5 standalone-import fix

v5 components are standalone Angular components (not generic web components). The fix is to import the component class into the host standalone component's imports: [] — never CUSTOM_ELEMENTS_SCHEMA:

import { Component } from "@angular/core";
import { CometChatConversationsComponent } from "@cometchat/chat-uikit-angular";

@Component({
  selector: "app-chat",
  standalone: true,
  imports: [CometChatConversationsComponent],   // ← register the class you render
  template: `<cometchat-conversations></cometchat-conversations>`,
})
export class ChatComponent {}

• The class carries the Component suffix (CometChatConversationsComponent); the selector does not (<cometchat-conversations>).
• Import only the components you actually use.
• If you add CUSTOM_ELEMENTS_SCHEMA, Angular stops complaining but the real component never instantiates — you get a blank render instead of an error. Remove it and import the class.
• On a not-yet-migrated NgModule app, standalone classes can go into @NgModule({ imports: [...] }) — still no schema.

3b. The most common "why is my chat blank" bug — inline elements + bounded height

The kit's <cometchat-*> elements are display: inline by default — they do not flex, fill, or scroll on their own. Two things are load-bearing: (1) the host is a flex column with a resolvable height, and (2) each custom element is itself made a flex column. A parent with no bounded height — or an element left inline — renders the list at 0px or makes it overflow instead of scroll.

grep -rB5 "cometchat-message-list\|cometchat-conversations" src/app

Broken:

<!-- ✗ div has no height; element left inline -->
<div>
  <cometchat-message-list [user]="selectedUser"></cometchat-message-list>
</div>

Fixed:

<!-- ✓ host is a flex column with height; element made a flex column with min-height: 0 -->
<div style="height: 100vh; display: flex; flex-direction: column;">
  <cometchat-message-list
    [user]="selectedUser"
    style="flex: 1; min-height: 0; overflow: hidden; display: flex; flex-direction: column;"
  ></cometchat-message-list>
</div>

• min-height: 0 is the part everyone forgets: a flex child defaults to min-height: auto, so without it the list grows past the parent and overflows the viewport instead of scrolling internally.
• The height: 100% chain needs a root — set html, body { height: 100% } in global styles, otherwise height: 100% resolves against an auto-height ancestor and collapses.
• See cometchat-angular-placement for the full sidebar / two-pane / Material-tab host contracts.

3c. Components render before init completes

Most reliable fix — resolve CometChatUIKit.init(...) in main.ts before bootstrapApplication(...) so nothing mounts until the SDK is ready (the v5 canonical — see cometchat-angular-core §3 and cometchat-angular-patterns):

// main.ts
import { bootstrapApplication } from "@angular/platform-browser";
import { UIKitSettingsBuilder, CometChatUIKit } from "@cometchat/chat-uikit-angular";
import { environment } from "./environments/environment";
import { App } from "./app/app";
import { appConfig } from "./app/app.config";

const settings = new UIKitSettingsBuilder()
  .setAppId(environment.cometchat.appId)
  .setRegion(environment.cometchat.region)
  .setAuthKey(environment.cometchat.authKey)
  .subscribePresenceForAllUsers()
  .build();

CometChatUIKit.init(settings)
  .then(() => bootstrapApplication(App, appConfig))
  .catch((err) => console.error("CometChat init failed:", err));

Alternative — block bootstrap with an APP_INITIALIZER factory that returns the init Promise (Angular waits for it before mounting):

// providers: [{ provide: APP_INITIALIZER, useFactory: () => () => CometChatUIKit.init(settings), multi: true }]

If you don't want to block bootstrap, init in AppComponent.ngOnInit() and gate the outlet:

isReady = false;

ngOnInit(): void {
  const settings = /* UIKitSettingsBuilder … .build() */;
  CometChatUIKit.init(settings)
    .then(() => CometChatUIKit.getLoggedinUser())
    .then((user) => user || CometChatUIKit.login("cometchat-uid-1"))  // bare string
    .then(() => (this.isReady = true))
    .catch(console.error);
}

<ng-container *ngIf="isReady">
  <router-outlet></router-outlet>
</ng-container>

3d. View not updating after an SDK callback (NgZone)

CometChat SDK listeners fire outside Angular's zone, so a field you mutate in a callback won't trigger change detection. Re-enter the zone (or prefer the async pipe over loggedInUser$):

import { NgZone } from "@angular/core";

constructor(private zone: NgZone) {}

// inside an SDK listener callback:
this.zone.run(() => {
  this.latestMessage = message;   // now change detection runs
});

Idiomatic alternative — bind the observable directly so Angular owns the subscription:

<span *ngIf="uiKit.loggedInUser$ | async as user">{{ user.getName() }}</span>

3e. ng build warns "Module '@cometchat/chat-sdk-javascript' … is not ESM" — benign

A successful ng build emits a CommonJS-interop optimization-bailout WARNING for @cometchat/chat-sdk-javascript (the chat SDK is published as CommonJS, not ESM). This is harmless — the build still exits 0 and the kit works. Do NOT try to "fix" it by switching SDK imports around. If you want to silence it, add the package to angular.json → architect.build.options.allowedCommonJsDependencies:

"allowedCommonJsDependencies": ["@cometchat/chat-sdk-javascript"]

(Verified 2026-06-14: fresh Angular 21 + @cometchat/[email protected] build succeeds with only this warning.)

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4. Escalation — when the above doesn't solve it

1. Read the raw error. "is not a known element" (missing standalone import) is a different problem from "NullInjectorError" (DI) or "window is not defined" (SSR).
2. Check the browser console + Angular DevTools. DevTools shows the component tree and change-detection state — useful for the NgZone class of bugs.
3. Confirm versions: Angular 17–21, @cometchat/chat-uikit-angular@^5, @cometchat/chat-sdk-javascript@^4.1, and @cometchat/calls-sdk-javascript@^5 for calls.
4. Search the upstream docs MCP (cometchat-docs if installed) for prop/event/error meanings.
5. If it's a kit bug, file at https://github.com/cometchat/cometchat-uikit-angular/issues with a minimal standalone-component repro.

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5. Hard rules (diagnostic best-practice)

1. Triage first (§1): Angular version, assets config, init/render order, standalone imports, peer SDKs — before proposing a fix.
2. Never suggest CUSTOM_ELEMENTS_SCHEMA for an unknown <cometchat-*> element — the v5 fix is importing the *Component class into imports: [].
3. Never suggest CometChatThemeService, CometChatUIKitLoginListener, login({ uid }), or @cometchat/uikit-shared — all are v4 and absent in v5.
4. Don't lead with "reinstall node_modules." Check version/peers, assets, init order, and imports first.
5. When recommending a rebuild/restart, say what and why — e.g. "restart ng serve after editing angular.json (read at startup)."
6. Don't propose code changes before gathering facts.

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Skill routing reference

Skill	When to route
cometchat-angular-core	Most "doesn't work" bugs trace here — init/login/standalone setup
cometchat-angular-components	Wrong input / @Input-callback vs @Output / slot template / request builder
cometchat-angular-placement	Blank chat / bounded-height / two-pane composition
cometchat-angular-patterns	Standalone wiring, route guard, lazy loading, SSR guard, NgZone
cometchat-angular-theming	CSS variables not applying, dark mode, ViewEncapsulation
cometchat-angular-features	Extension UI missing after enable
cometchat-angular-calls	Calls don't start, incoming-call UI, calls-sdk peer
cometchat-angular-customization	Formatter not rendering, listener not firing, template not showing
cometchat-angular-production	401 on token fetch, user-does-not-exist on token login
cometchat-angular-troubleshooting	This skill — cross-category v5 diagnosis