Cometchat Angular Core

Purpose

Foundational skill for every CometChat Angular UI Kit v5 (@cometchat/chat-uikit-angular@5) integration. It teaches HOW CometChat works in Angular v5 — initialization order, the UIKitSettingsBuilder pattern, login, environment config, standalone-component wiring, and the anti-patterns that break real apps.

Angular UI Kit v5 is standalone-component-based and requires Angular 17–21. This is a hard requirement — the package's peer range is @angular/core / @angular/common >=17.0.0 <22.0.0. Projects on older Angular must upgrade before using UI Kit v5.

Read this skill first, before any placement, components, or patterns skill.

Ground truth: @cometchat/chat-uikit-angular@5.0.3 kit source (projects/cometchat-uikit/src/lib) + docs/ui-kit/angular. 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). Verify any non-obvious symbol against the installed package types before relying on it.

2. Install

npm install @cometchat/chat-uikit-angular@^5
# Calls features only — also install the calls SDK peer:
npm install @cometchat/calls-sdk-javascript@^5

⚠️ Angular 22 is NOT supported — pin the CLI to 21 when scaffolding (verified — real npm install ERESOLVE). The kit's peer range is @angular/core/@angular/common >=17.0.0 <22.0.0. npx @angular/cli@latest new … now installs Angular 22, so npm install @cometchat/chat-uikit-angular@^5 then hard-fails with ERESOLVE … peer @angular/common@">=17.0.0 <22.0.0". For a fresh project scaffold with a supported major: npx -y @angular/cli@21 new <app> … (Angular 17–21 all work). Existing projects on 22 must stay on the prior major until the kit widens its range.

⚠️ ng build (production) fails the default bundle budget — raise it. The kit's initial bundle is ~3.78 MB; Angular's default production budgets cap initial at 1 MB maximumError, so the literal ng build exits non-zero with bundle initial exceeded maximum budget. In angular.json raise (or remove) the initial budget — e.g. set maximumError to 5mb — or build with --configuration development while iterating. This is a guaranteed failure otherwise; it is not a problem with your code.

The chat SDK (@cometchat/chat-sdk-javascript@^4.1.8), dompurify@^3, and (for calls only) the calls SDK are peer deps. @cometchat/calls-sdk-javascript is an optional peer — npm won't auto-install it; add it yourself when you need calling. There is no @cometchat/uikit-shared / -elements / -resources in v5 — do not install or import them.

Stylesheet (mandatory — layout + tokens break without it)

Add the kit's CSS-variable stylesheet via angular.json → ...build.options.styles (use this form — it's the one that builds):

"styles": [
  "src/styles.css",
  "node_modules/@cometchat/chat-uikit-angular/styles/css-variables.css"
]

⚠️ Do NOT use the @import package-specifier form on Angular 17+ (the default @angular/build esbuild builder). @import '@cometchat/chat-uikit-angular/styles/css-variables.css'; fails the build — Could not resolve … the path "./styles/css-variables.css" is not exported by package — because the package exports map only exposes . and ./package.json. The angular.json styles array above works because the full node_modules/... path bypasses the exports map. (Verified — real ng build.)

Assets (mandatory — icons break without it)

angular.json → projects.<app>.architect.build.options.assets:

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

The kit ships its SVG icons under src/lib/assets in the published package — map that to output: assets. Missing this = broken icons throughout the kit. It's the most commonly missed step.

3. The init → login → render order

CometChat Angular has exactly one valid lifecycle:

CometChatUIKit.init(UIKitSettings)  →  CometChatUIKit.login(uid)  →  render <cometchat-*> components

Both init() and login() return Promises. Breaking this order produces a blank component, a "CometChat is not initialized" console error, or a hung login.

File-based init with cometchat-settings.json (recommended where available)

Version requirement (ENG-35866 — Skills Telemetry). CometChatUIKit.initFromSettings(settings) reads a cometchat-settings.json object and lets the SDK self-report integrationSource = "ai-agent". It ships GA in @cometchat/chat-uikit-angular >= 5.0.3 + @cometchat/chat-sdk-javascript >= 4.1.11 (npm latest). On an older kit (<= 5.0.2) the method does not exist — only the UIKitSettingsBuilder + init() path below works (reporting integrationSource = "manual"); use that fallback. (The kit routes initFromSettings to the SDK's CometChat.initFromSettings, which stamps ai-agent — plain init(settings) does not; ENG-36203.)

Step 1 — create cometchat-settings.json at the project root (e.g. alongside angular.json). Fill appId / region / credentials.authKey from the CLI provision setup output; leave the rest at the defaults:

{
  "appId": "APP_ID_HERE",
  "region": "us",
  "credentials": {
    "authKey": "AUTH_KEY_HERE"
  },
  "chatSDK": {
    "presenceSubscription": {
      "type": "ALL_USERS",
      "roles": []
    },
    "autoEstablishSocketConnection": true,
    "adminHost": null,
    "clientHost": null
  },
  "callsSDK": {
    "host": null,
    "adminHost": null,
    "clientHost": null,
    "callsHost": null
  },
  "uiKit": {
    "subscribePresenceForAllUsers": true
  }
}

Step 2 — init in main.ts by importing the JSON. Angular CLI projects have resolveJsonModule: true by default, so the import is type-safe:

// main.ts — initFromSettings ships GA in @cometchat/chat-uikit-angular >= 5.0.3 (ENG-35866)
import { bootstrapApplication } from "@angular/platform-browser";
import { CometChatUIKit } from "@cometchat/chat-uikit-angular";
import { AppComponent } from "./app/app.component";
import { appConfig } from "./app/app.config";
import cometchatSettings from "../cometchat-settings.json";

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

• Commit cometchat-settings.json — do not gitignore it (the file is part of the integration). Its authKey is an optional demo/POC credential: a quick-start affordance so a PM or developer can see working chat before the backend auth-token flow is wired (that flow often waits on internal approvals). Because the file is committed to source control, treat the key as public — use a dedicated demo CometChat app (a committed key trips secret scanners and stays in git history; never reuse a production app's key). Switch to a server-minted authToken via loginWithAuthToken before production, where authKey must not ship.

UIKitSettingsBuilder — the init pattern (fallback — published kit; reports manual)

UIKitSettingsBuilder and UIKitSettings are exported from @cometchat/chat-uikit-angular (not uikit-shared, which no longer exists):

import { UIKitSettingsBuilder, CometChatUIKit } from "@cometchat/chat-uikit-angular";
import { environment } from "../environments/environment";

const settings = new UIKitSettingsBuilder()
  .setAppId(environment.cometchat.appId)
  .setRegion(environment.cometchat.region)          // "us" | "eu" | "in"
  .setAuthKey(environment.cometchat.authKey)        // dev only — omit in production
  .subscribePresenceForAllUsers()
  .build();

const initPromise = CometChatUIKit.init(settings);   // Promise<InitResult> | undefined

init() returns Promise<InitResult> | undefined (it returns undefined if settings are missing/invalid). Guard for the undefined case rather than blindly .then()-ing the result.

Builder methods (verified against v5 UIKitSettings.ts): setAppId, setRegion, setAuthKey, subscribePresenceForAllUsers, subscribePresenceForFriends, subscribePresenceForRoles(roles), setRoles(roles), setAutoEstablishSocketConnection(bool), setAdminHost, setClientHost, setStorageMode, setCallingEnabled(bool), setCallAppSettings, build().

Init must run once, before any chat component renders

The canonical pattern (used by both the docs and the kit's own sample app) is to init in main.ts and only bootstrap the Angular app once init resolves. Do NOT init inside a lazily-loaded route that mounts after a <cometchat-*> component could already be on screen.

// main.ts (Angular 17+ standalone bootstrap)
import { bootstrapApplication } from "@angular/platform-browser";
import { UIKitSettingsBuilder, CometChatUIKit } from "@cometchat/chat-uikit-angular";
import { AppComponent } from "./app/app.component";
import { appConfig } from "./app/app.config";
import { environment } from "./environments/environment";

// Fail loud if environment.cometchat values are EMPTY (env block missing, or
// the wrong environment file picked at build). Note: this catches empty/unset
// only — a non-empty placeholder like "YOUR_APP_ID" is truthy and passes, so
// still paste real values. Otherwise empty creds surface later as a cryptic
// init failure. (audit P0-5)
const cc = environment.cometchat;
if (!cc?.appId || !cc?.region || !cc?.authKey) {
  throw new Error(
    "CometChat credentials are empty in environment.cometchat — fill appId/region/authKey " +
      "in src/environments/environment.ts (and environment.prod.ts).",
  );
}

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

// `init(...)` is typed `Promise<InitResult> | undefined` in v5.0.2, so coalesce to a
// Promise before chaining — `init(settings)?.then(...).catch(...)` still leaves the
// `.catch` on a possibly-undefined value and fails `tsc` strict (TS2532) on Angular 21.
(CometChatUIKit.init(settings) ?? Promise.resolve())
  .then(() => {
    bootstrapApplication(AppComponent, appConfig).catch((err) => console.error(err));
  })
  .catch((err) => console.error("CometChat init failed:", err));

Bootstrapping only after init resolves means every component that mounts afterward can safely assume CometChat is initialized. Login (dev user or token) then happens in the root component / a route guard / an auth service — see §4.

Filename convention — modern CLI scaffolds differ from these examples. Examples here use the classic AppComponent in src/app/app.component.ts. Angular CLI 17+ (and 21) scaffolds the root component as App in src/app/app.ts (no .component suffix), with app.config.ts + app.routes.ts. On a freshly-scaffolded project, import App (not AppComponent) from ./app/app and adapt the filenames — the wiring is identical, only the names changed.

Alternative — APP_INITIALIZER: if you prefer to bootstrap unconditionally and block on a DI provider, register an APP_INITIALIZER factory that returns the CometChatUIKit.init(settings) Promise. Angular blocks bootstrap until it resolves. Either way the rule holds: init must finish before any <cometchat-*> renders.

4. Login

Development mode — login(uid) takes a BARE STRING

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

const user = await CometChatUIKit.getLoggedinUser();   // async getter → Promise<User | null>
if (!user) {
  await CometChatUIKit.login("cometchat-uid-1");        // ← bare string, NOT { uid: "..." }
}

login() takes a string uid, not an object — its signature is login(uid: string): Promise<CometChat.User>. Passing { uid: "..." } fails type-checking. (Token login is a separate method — see Production.)

Every new CometChat app ships 5 pre-seeded test users — cometchat-uid-1 … cometchat-uid-5.

Reading the current user — three options

// 1. Sync getter — use in components, route guards, anywhere after login completes:
const user = CometChatUIKit.getLoggedInUser();      // User | null  (note capital "In")

// 2. Async getter — use inside the init/login flow:
const user = await CometChatUIKit.getLoggedinUser(); // Promise<User | null>  (note lowercase "in")

// 3. Reactive (idiomatic Angular) — react to login/logout in templates with the async pipe:
CometChatUIKit.loggedInUser$.subscribe(u => this.currentUser = u);

CometChatUIKitLoginListener exists only as an internal kit class — it is not exported from @cometchat/chat-uikit-angular's public API and has no public getLoggedInUser(). Use the static getters or the loggedInUser$ observable instead. Never hardcode a UID to identify the current user — in production it comes from your auth system.

Production mode

await CometChatUIKit.loginWithAuthToken(tokenFromYourBackend);

The backend mints the token via the CometChat REST API using the server-only REST API Key. See cometchat-angular-production.

Logout

await CometChatUIKit.logout();   // Promise<LogoutResult> — then navigate to your login route

5. Using components — standalone imports (no NgModule, no schema)

v5 components are standalone Angular components. Import the component class into the imports: [] of whatever standalone component renders it. They are real Angular components (not generic web components), so CUSTOM_ELEMENTS_SCHEMA is NOT needed — and there is no NgModule to register.

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

@Component({
  selector: "app-chat",
  standalone: true,
  imports: [CometChatConversationsComponent],   // import the class you use; no schema
  template: `<cometchat-conversations></cometchat-conversations>`,
})
export class ChatComponent {}

• Class names carry the Component suffix (CometChatConversationsComponent); the HTML selectors do not (<cometchat-conversations>).
• Import only the components you actually use.
• There is no composite <cometchat-conversations-with-messages> in v5 — build a two-pane layout by composing cometchat-conversations with cometchat-message-header / -list / -composer (see cometchat-angular-placement).

Using an NgModule-based app (not yet migrated to standalone)? You can still add these standalone classes to an @NgModule({ imports: [...] }) — standalone components are importable into NgModules. You still do not need CUSTOM_ELEMENTS_SCHEMA.

See cometchat-angular-components for the full catalog of selectors, @Input/@Output bindings, and slot templates.

6. Environment variables

Angular has no .env / process.env. Config lives in src/environments/environment.ts.

// src/environments/environment.ts (development)
export const environment = {
  production: false,
  cometchat: {
    appId: "YOUR_APP_ID",
    region: "us",                 // "us" | "eu" | "in"
    authKey: "YOUR_AUTH_KEY",     // dev only — never in production builds
  },
};

// src/environments/environment.prod.ts (production)
export const environment = {
  production: true,
  cometchat: {
    appId: "YOUR_APP_ID",
    region: "us",
    // No authKey in production — mint auth tokens server-side
    tokenEndpoint: "https://api.yourapp.com/cometchat-token",
  },
};

Never put the REST API Key in any environment file. Angular bundles environment.ts into client JS — the REST API Key is server-only.

7. Theming — CSS variables (no theme service)

v5 has no CometChatThemeService and no programmatic palette API. Theming is done with CSS custom properties (--cometchat-*), the same model as the React kit. Light/dark mode is a single setter:

CometChatUIKit.themeMode = "dark";   // 'light' | 'dark'

/* styles.css — override brand + tokens globally */
:root {
  --cometchat-primary-color: #6852D6;
}

See cometchat-angular-theming for the full CSS-variable token reference and dark-mode strategy. Do not reach for CometChatThemeService / theme.palette.setPrimary() — no such programmatic palette API exists; theming is CSS-variable only.

8. Anti-patterns

1. Don't target Angular ≤16. UI Kit v5's peer range is Angular 17–21 (>=17.0.0 <22.0.0). On older Angular, upgrade before integrating.
2. Don't install or import @cometchat/uikit-shared / -elements / -resources. They don't exist in the v5 dependency set — everything is in @cometchat/chat-uikit-angular.
3. Don't add CUSTOM_ELEMENTS_SCHEMA for CometChat components — they are real Angular components (not generic web components), so the schema is unnecessary.
4. Don't call login({ uid }). v5 takes a bare string: login("cometchat-uid-1").
5. Don't use CometChatUIKitLoginListener — it's an internal class, not public API. Use CometChatUIKit.getLoggedInUser() / getLoggedinUser() / loggedInUser$.
6. Don't use CometChatThemeService — it doesn't exist in v5. Theme via CSS variables + themeMode.
7. Don't reach for <cometchat-conversations-with-messages> — removed in v5. Compose the layout from the individual components.
8. Don't init inside a lazy-loaded route. Init must complete before any <cometchat-*> renders — use APP_INITIALIZER or gate on an isReady flag.
9. Don't render <cometchat-*> before init+login resolve. Gate with *ngIf.
10. Don't bundle the REST API Key in any src/ file — Angular ships src/ to the client.

9. SDK access

For raw SDK calls (e.g. CometChat.getUser(uid)), import the CometChat namespace directly from the chat SDK peer dependency:

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

Use the kit's CometChatUIKit.* helpers (sendTextMessage, createUser, updateUser, etc.) when available — they emit the UI events the components listen for.

10. Docs MCP (recommended)

claude mcp add --transport http cometchat-docs https://www.cometchat.com/docs/mcp

Use it to confirm prop names, event signatures, theme tokens, or error meanings before writing non-obvious code.

11. Visual Builder — not available for Angular

The dashboard's Visual Builder export ships ZIPs for React / React Native / iOS / Android / Flutter — there is no Angular emitter. On an Angular project the dispatcher auto-routes to the code-driven path (sets customize=code), skips the Visually-vs-In-code prompt, and continues with this skill + cometchat-angular-{components,placement,patterns,theming}. If a stale customize=visual carried over from another project, the dispatcher overwrites it to code (a builder ... --platform angular call would be rejected at the CLI). Theming is via CSS variables (§7), not a builder.

Skill routing reference