25 KiB
Z.AI Chat for Android
Full-stack AI chat client for the Z.AI GLM Coding Plan
Native Android app with Chat, Coding, Brainstorm & Agentic modes.
| Dark Mode | Light Mode |
|
|
|
Get 10% OFF your Z.AI Coding Plan
World-class GLM-5.1 models for coding agents. Monthly access from just $18/mo.
Use the link above for an exclusive 10% discount on your subscription.
Table of Contents
- Overview
- Architecture
- Technology Stack
- Features
- Design System
- Development Process
- Project Structure
- Building from Source
- Configuration
- API Reference
- Changelog
- License
Overview
Z.AI Chat for Android is a self-contained, production-ready Android application that connects to the Z.AI GLM Coding Plan API. It provides four specialized AI interaction modes — general Chat, Coding assistant, Brainstorm partner, and autonomous Agentic coding — all accessible from a single native Android app.
The app targets Android 15 (API 35) and Android 16 (API 36), built with Capacitor for the hybrid architecture, wrapping a performant single-page web application inside a native Android WebView.
Key Differentiators
| Feature | Implementation |
|---|---|
| Zero-config start | Enter your Z.AI coding plan token and start chatting immediately |
| 4 Specialized Modes | Each mode has a tailored system prompt optimized for its use case |
| Real-time Streaming | Server-Sent Events (SSE) for token-by-token response rendering |
| Dark & Light Themes | Full theme system with 30+ CSS custom properties per palette |
| Conversation Management | Multi-conversation sidebar with auto-titling and JSON export |
| Markdown + Code | Full GFM markdown with syntax highlighting and copy buttons |
| 940 KB Release APK | Minified, shrunk, ProGuard-optimized, self-signed |
Architecture
High-Level Architecture
┌─────────────────────────────────────────────────────┐
│ Android APK │
│ │
│ ┌───────────────────────────────────────────────┐ │
│ │ Capacitor Shell │ │
│ │ ┌─────────────┐ ┌────────────────────────┐ │ │
│ │ │ MainActivity│ │ WebView (Chrome-based) │ │ │
│ │ │ (Java) │──│ │ │ │
│ │ └─────────────┘ │ ┌──────────────────┐ │ │ │
│ │ │ │ SPA (HTML/CSS/JS)│ │ │ │
│ │ ┌─────────────┐ │ │ │ │ │ │
│ │ │ Capacitor │ │ │ ┌────────────┐ │ │ │ │
│ │ │ Bridge │◄─┤ │ │ Chat UI │ │ │ │ │
│ │ └─────────────┘ │ │ │ (Vue-like) │ │ │ │ │
│ │ │ │ └────────────┘ │ │ │ │
│ │ │ │ │ │ │ │
│ │ │ │ ┌────────────┐ │ │ │ │
│ │ │ │ │ API Layer │ │ │ │ │
│ │ │ │ │ (fetch) │ │ │ │ │
│ │ │ │ └──────┬─────┘ │ │ │ │
│ │ │ └─────────┼────────┘ │ │ │
│ │ └────────────┼────────────┘ │ │
│ └───────────────────────────────┼────────────────┘ │
│ │ HTTPS │
└──────────────────────────────────┼────────────────────┘
│
┌──────────────▼──────────────┐
│ Z.AI Coding Plan API │
│ api.z.ai/api/coding/paas/v4 │
│ │
│ OpenAI-compatible endpoint │
│ Models: GLM-5.1, GLM-5, │
│ GLM-4.7, GLM-4.5-air │
└─────────────────────────────┘
Component Architecture
www/
├── index.html ← Entry point, all screens defined
├── css/styles.css ← 30+ CSS custom properties, dual theme system
└── js/
├── app.js ← Core application logic (state machine, API, UI)
├── marked.min.js ← Markdown parser (GFM compatible)
└── highlight.min.js← Syntax highlighting for 180+ languages
The app uses a state-machine pattern with three screens:
- Setup Screen — API key entry, endpoint selection, mode overview
- Chat Screen — Message history, mode selector, input area, sidebar
- Settings Screen — API config, model tuning, theme, data management, changelog
Data Flow
User Input → State Manager → API Request Builder → fetch() → Z.AI API
│
User Sees ← Markdown Renderer ← SSE Parser ← Stream Response ◄┘
│
└→ Syntax Highlighter → Code Headers (Copy button)
State Management
All state is persisted in localStorage with the zai_chat_ prefix:
state = {
apiKey, // Bearer token for Z.AI API
baseUrl, // API endpoint (coding plan vs general)
model, // GLM model selection
temperature, // 0.0 - 1.0 randomness control
maxTokens, // 256 - 16384 response length
streaming, // SSE toggle
webSearch, // web_search tool toggle
currentMode, // chat | coding | brainstorm | agentic
theme, // dark | light
conversations[], // Full message history
activeConversationId
}
Technology Stack
Frontend (WebView SPA)
| Technology | Version | Purpose |
|---|---|---|
| HTML5 | Living Standard | Semantic markup, meta viewport, PWA-ready |
| CSS3 | Custom Properties, Grid, Flexbox | Dual-theme design system with 30+ variables |
| Vanilla JavaScript | ES2020 (IIFE pattern) | Zero-dependency state management, async/await |
| Marked.js | Latest | GitHub-Flavored Markdown parsing |
| Highlight.js | 11.9.0 | Syntax highlighting for 180+ programming languages |
Android Native Layer
| Technology | Version | Purpose |
|---|---|---|
| Capacitor | 8.3.4 | Hybrid app framework, WebView bridge |
| Android SDK | API 36 | Targeting Android 16 (Baklava) |
| Gradle | 8.14.3 | Build automation |
| Android Gradle Plugin | 8.13.0 | Compilation, resource processing |
| JDK | 21 | Java compilation |
| ProGuard | Android Optimize | Release APK minification and shrinking |
API Integration
| Protocol | Implementation |
|---|---|
| OpenAI Chat Completions | POST /chat/completions with Bearer auth |
| Server-Sent Events (SSE) | stream: true with ReadableStream parsing |
| Web Search | Tool calling via web_search tool type |
Build & Signing
| Component | Details |
|---|---|
| Debug Keystore | debug.keystore — android / androiddebugkey |
| Release Keystore | release.keystore — zaichat / zai-chat |
| RSA Key Size | 2048-bit |
| Validity | 10,000 days |
Features
1. Four Specialized Chat Modes
Each mode injects a purpose-built system prompt:
| Mode | System Prompt Strategy | Use Case |
|---|---|---|
| Chat | Concise, knowledgeable assistant | General Q&A, explanations |
| Coding | Expert coder; markdown code blocks, edge cases, error handling | Code generation, debugging |
| Brainstorm | Creative partner; diverse ideas, trade-off evaluation | Ideation, planning |
| Agentic | Autonomous agent; step-by-step tasks, tool-calling format | Complex multi-step coding |
2. Real-Time Streaming
- Uses
fetch()withReadableStreamfor SSE parsing - Token-by-token rendering with Markdown re-parsing on each chunk
- Abort support via
AbortController— stop generation at any time
3. Dark & Light Theme System
30+ CSS Custom Properties per Theme
├── Backgrounds (7 levels: primary → code)
├── Text (3 levels: primary → muted)
├── Accent (main, hover, dim)
├── Borders
├── Status colors (danger, success, warning)
└── UI chrome (shadows, overlays, scrollbars)
Theme is toggled via:
- Header button — sun/moon icon, instant toggle
- Settings toggle — Dark Mode switch
- Persisted —
localStoragesurvives app restarts
4. Conversation Management
- Unlimited conversations stored in
localStorage - Auto-titling from first message (first 50 chars)
- Sidebar with conversation list, active indicator, swipe-to-delete
- JSON export for backup/migration
5. Markdown & Code Rendering
- Full GitHub-Flavored Markdown (tables, task lists, strikethrough)
- Syntax highlighting for 180+ languages via Highlight.js
- Code block headers with language label and copy button
- Inline code with distinct styling
6. Network Security
network_security_config.xmlwhitelists only Z.AI domains- HTTPS-only communication
android:usesCleartextTraffic="false"
Design System
Color Palette
Dark Theme (Default)
| Token | Hex | Usage |
|---|---|---|
--bg-primary |
#0f0f23 |
Main background |
--bg-secondary |
#1a1a2e |
Headers, cards |
--bg-tertiary |
#16213e |
Tertiary surfaces |
--accent |
#6c63ff |
Primary brand color |
--text-primary |
#e0e0ff |
Main text |
--border |
#2a2a4a |
Dividers |
Light Theme
| Token | Hex | Usage |
|---|---|---|
--bg-primary |
#f5f5fa |
Main background |
--bg-secondary |
#ffffff |
Headers, cards |
--bg-tertiary |
#eef0f6 |
Tertiary surfaces |
--accent |
#6c63ff |
Primary brand color (shared) |
--text-primary |
#1a1a2e |
Main text |
--border |
#d8dae6 |
Dividers |
Typography
- Font Stack:
-apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif - Base Size: 15px
- Code Font:
'Fira Code', 'JetBrains Mono', 'Cascadia Code', monospace - Code Size: 13px
Spacing & Sizing
| Token | Value | Usage |
|---|---|---|
--radius |
16px | Message bubbles, cards |
--radius-sm |
10px | Buttons, inputs |
--transition |
0.2s ease | All interactive elements |
Development Process
This project was built end-to-end using a systematic Plan → Code → Test → Iterate workflow powered by the Z.AI GLM-5.1 model itself (meta: the tool that built this app is powered by the same API it targets).
Phase 1: Research & Planning
Objective: Understand the Z.AI API surface and design the app architecture.
-
API Research: Fetched and analyzed the z-ai-sdk-python repository to understand:
- Authentication flow (Bearer token)
- Endpoint structure (OpenAI-compatible
/chat/completions) - Streaming protocol (SSE with
data:lines) - Available models and their capabilities
- Tool calling format (web search)
-
Endpoint Discovery: Discovered from Z.AI docs that the Coding Plan uses a dedicated endpoint:
- Coding Plan:
https://api.z.ai/api/coding/paas/v4 - General API:
https://api.z.ai/api/paas/v4 - This distinction was critical — using the wrong endpoint would not consume the coding plan quota.
- Coding Plan:
-
Architecture Decision: Chose Capacitor (over Cordova/React Native) because:
- Zero-framework frontend (vanilla JS) for minimal APK size
- Direct access to native Android WebView
- Smaller learning curve for a single-developer project
- Production-ready Android project scaffolding
Phase 2: Frontend Development
Objective: Build the complete web application (HTML/CSS/JS).
Step 1: HTML Structure (index.html)
- Designed three-screen layout: Setup → Chat → Settings
- Semantic HTML with proper ARIA considerations
- Mode selector, sidebar, conversation list
- Theme toggle integration
Step 2: CSS Design System (styles.css)
- Started with CSS Custom Properties for theming
- Built component library: buttons, inputs, toggles, cards
- Implemented responsive layout (mobile-first)
- Added animations:
fadeInfor messages,bouncefor thinking dots,spinfor loaders
Step 3: JavaScript Application (app.js)
- IIFE pattern to avoid global scope pollution
- State machine with localStorage persistence
- API layer:
apiRequest()for non-streaming callsstreamResponse()withReadableStream+TextDecoderfor SSEAbortControllerfor cancellation support
- Markdown pipeline:
marked.parse()→hljs.highlight()→ DOM injection - Theme engine:
data-themeattribute switching with CSS custom properties
Step 4: Theme System (v1.2.0)
- Extended
:rootvariables into dual theme blocks [data-theme="light"]override block with 30+ light-palette values- Added
applyTheme()function that:- Sets
data-themeon<html> - Updates meta
theme-colorfor browser chrome - Toggles header button icon (sun/moon)
- Syncs settings toggle
- Persists to localStorage
- Sets
Phase 3: Android Build Pipeline
Objective: Create a signed, optimized APK.
Step 1: Environment Setup
- Downloaded JDK 21 (required by Capacitor 8.x — JDK 17 fails with
invalid source release: 21) - Downloaded Android SDK Command-Line Tools (146 MB)
- Installed SDK components:
platforms;android-36,build-tools;36.0.0,platform-tools
Step 2: Project Scaffolding
npm init→ Capacitor initializationnpx cap add android— generates full Android project- Customized
AndroidManifest.xmlwith network security config - Added
network_security_config.xmlfor domain whitelisting
Step 3: Build Configuration
- Created debug and release keystores with
keytool - Configured
signingConfigsinapp/build.gradle - Enabled ProGuard minification + resource shrinking for release
- Set Java 17 compatibility
Step 4: Build & Sign
./gradlew assembleRelease --no-daemon # → 940 KB release APK
./gradlew assembleDebug --no-daemon # → 4.0 MB debug APK
Phase 4: Testing & Validation
| Test | Method | Result |
|---|---|---|
| APK install | Manual (Android 15 emulator) | Pass |
| API connection | testConnection() with real key |
Pass |
| Streaming | SSE parsing with real API | Pass |
| Theme persistence | Kill/restart app | Pass |
| Conversation save | Kill/restart app | Pass |
| Multi-conversation | Create/switch/delete | Pass |
| Code rendering | Python, JS, Go code blocks | Pass |
| Copy button | Clipboard API | Pass |
| Export | JSON file download | Pass |
| Light mode contrast | Visual inspection | Pass |
| ProGuard release | 940 KB (77% size reduction) | Pass |
Project Structure
zai-chat/
├── www/ # Web application (SPA)
│ ├── index.html # Entry point with all 3 screens
│ ├── css/
│ │ └── styles.css # Full design system + dual themes
│ └── js/
│ ├── app.js # Core application logic
│ ├── marked.min.js # Markdown parser
│ └── highlight.min.js # Syntax highlighter
│
├── android/ # Native Android project
│ ├── app/
│ │ ├── build.gradle # App-level build config + signing
│ │ ├── proguard-rules.pro # ProGuard keep rules
│ │ ├── debug.keystore # Debug signing key
│ │ ├── release.keystore # Release signing key
│ │ └── src/main/
│ │ ├── AndroidManifest.xml # Permissions, activities, config
│ │ ├── assets/public/ # WebView assets (copied from www/)
│ │ └── res/
│ │ ├── xml/
│ │ │ └── network_security_config.xml
│ │ ├── values/
│ │ │ ├── strings.xml
│ │ │ ├── colors.xml
│ │ │ └── styles.xml
│ │ └── mipmap-*/ # App icons
│ ├── build.gradle # Root build config
│ ├── variables.gradle # SDK version constants
│ ├── settings.gradle # Module includes
│ └── gradle/wrapper/ # Gradle wrapper
│
├── capacitor.config.json # Capacitor configuration
├── package.json # NPM dependencies
└── README.md # This file
Building from Source
Prerequisites
| Requirement | Version |
|---|---|
| Node.js | 18+ |
| JDK | 21 |
| Android SDK | Platform 36, Build-Tools 36.0.0 |
| npm | 9+ |
Quick Build
# Clone the repository
git clone https://github.rommark.dev/admin/Z.AI-Chat-for-Android.git
cd Z.AI-Chat-for-Android/zai-chat
# Install dependencies
npm install
# Sync web assets to Android
npx cap sync android
# Build debug APK
cd android && ./gradlew assembleDebug
# Build release APK (signed)
./gradlew assembleRelease
# APKs will be at:
# android/app/build/outputs/apk/debug/app-debug.apk
# android/app/build/outputs/apk/release/app-release.apk
Environment Setup (from scratch)
# 1. Install JDK 21
curl -fsSL "https://download.java.net/java/GA/jdk21.0.2/f2283984656d49d69e91c558476027ac/13/GPL/openjdk-21.0.2_linux-x64_bin.tar.gz" | tar xz -C /opt/
export JAVA_HOME=/opt/jdk-21.0.2
# 2. Install Android SDK
mkdir -p ~/android-sdk/cmdline-tools
curl -fsSL "https://dl.google.com/android/repository/commandlinetools-linux-11076708_latest.zip" -o /tmp/cmdline-tools.zip
unzip /tmp/cmdline-tools.zip -d ~/android-sdk/cmdline-tools/
mv ~/android-sdk/cmdline-tools/cmdline-tools ~/android-sdk/cmdline-tools/latest
# 3. Install SDK components
export ANDROID_HOME=~/android-sdk
yes | $ANDROID_HOME/cmdline-tools/latest/bin/sdkmanager \
--sdk_root=$ANDROID_HOME \
"platforms;android-36" "build-tools;36.0.0" "platform-tools"
# 4. Set environment
export PATH=$JAVA_HOME/bin:$ANDROID_HOME/platform-tools:$ANDROID_HOME/cmdline-tools/latest/bin:$PATH
Configuration
API Endpoints
| Name | URL | Purpose |
|---|---|---|
| Coding Plan | https://api.z.ai/api/coding/paas/v4 |
GLM Coding Plan subscription |
| General API | https://api.z.ai/api/paas/v4 |
Pay-per-use API |
| China | https://open.bigmodel.cn/api/paas/v4 |
Zhipu AI (mainland China) |
Available Models
| Model | Description | Recommended For |
|---|---|---|
glm-5.1 |
Flagship foundation model | Complex coding, agentic tasks |
glm-5-turbo |
Faster variant | Quick queries |
glm-4.7 |
Previous generation | General purpose |
glm-4.5-air |
Lightweight, fast | Speed-critical tasks |
glm-5v-turbo |
Vision model | Image understanding |
System Prompts
Chat Mode
You are a helpful, knowledgeable AI assistant. Be concise and accurate.
Coding Mode
You are an expert coding assistant. Write clean, efficient, well-documented code.
Always use markdown code blocks with language tags. Explain your approach briefly
before and after code. Handle edge cases and errors properly.
Brainstorm Mode
You are a creative brainstorming partner. Generate diverse ideas, explore
unconventional angles, build on concepts, and help evaluate trade-offs. Think
freely and expansively. Present ideas in organized lists or tables when appropriate.
Agentic Mode
You are an autonomous coding agent. Break down complex tasks into clear steps.
Write production-quality code with proper error handling, tests, and documentation.
Think through the architecture before coding. Use tool-calling format when appropriate:
[SEARCH], [CREATE_FILE], [EDIT_FILE], [RUN_COMMAND]. Always verify your work.
API Reference
POST /chat/completions
Request:
{
"model": "glm-5.1",
"messages": [
{"role": "system", "content": "..."},
{"role": "user", "content": "..."},
{"role": "assistant", "content": "..."}
],
"temperature": 0.7,
"max_tokens": 4096,
"stream": true,
"tools": [{"type": "web_search", "web_search": {"search_query": "...", "search_result": true}}]
}
Streaming Response (SSE):
data: {"choices":[{"delta":{"content":"Hello"},"index":0}]}
data: {"choices":[{"delta":{"content":" world"},"index":0}]}
data: [DONE]
Non-Streaming Response:
{
"choices": [{
"message": {"role": "assistant", "content": "Hello world"},
"finish_reason": "stop"
}]
}
Changelog
v1.2.0 (2026-05-19)
- Added light mode / dark mode toggle
- Theme persists across sessions via localStorage
- Theme toggle button (sun/moon) in chat header
- Theme setting in Settings > Appearance
- Added changelog section to Settings
- Optimized light theme color palette with 30+ CSS variables
- Android
theme-colormeta updates on theme switch
v1.1.0 (2026-05-19)
- Z.AI Coding Plan endpoint support (
api.z.ai/api/coding/paas/v4) - Fixed default API base URL to use coding plan endpoint
- Updated model list: GLM-5.1, GLM-5 Turbo, GLM-4.7, GLM-4.5 Air, GLM-5V Turbo
- Added coding plan subscription links to setup screen
v1.0.0 (2026-05-19)
- Initial release
- 4 chat modes: Chat, Coding, Brainstorm, Agentic
- Real-time SSE streaming responses
- Markdown rendering with syntax highlighting (180+ languages)
- Code block headers with copy buttons
- Multi-conversation management with sidebar
- Settings: model, temperature, max tokens, web search, streaming
- Conversation export to JSON
- Android 15/16 support (targetSdk 36, compileSdk 36)
- Dark theme with Material Design 3 aesthetics
- Self-signed release APK (940 KB)
License
This project is licensed under the MIT License — see the LICENSE file for details.
Built with Z.AI GLM-5.1 · Powered by Z.AI Coding Plan