SwiftChat
A production-ready iOS chat template powered by the OpenAI Responses API, built with SwiftUI
| Chat |
Reasoning |
Web Search |
Attachments |
|
|
|
|
## Overview
SwiftChat is a fully functional AI chat app template for iOS. It connects to any OpenAI-compatible API and supports streaming responses, reasoning/thinking models, web search, image attachments, voice input, and LaTeX rendering out of the box.
Use it as a starting point for your own AI-powered chat app, or as a reference for how to integrate the OpenAI Responses API into a SwiftUI project.
## Features
- **Streaming responses** via the OpenAI Responses API with real-time token display
- **Reasoning model support** with collapsible thinking boxes (o3, o4-mini, etc.)
- **Web search** with live search status indicators and source citations
- **Image attachments** with camera, photo library, and multimodal model support
- **Document attachments** (PDF, TXT, MD, CSV, HTML) injected as context
- **Voice input** with audio recording and Whisper transcription
- **LaTeX and Markdown rendering** with syntax-highlighted code blocks
- **Chat history** with sidebar navigation and swipe gestures
- **Auto-generated titles** for conversations using a lightweight model
- **Dark mode and Light mode** with adaptive theming
- **iPad support** with side-by-side sidebar layout
- **Liquid Glass icon** for iOS 26+ with legacy icon fallback
## Getting Started
### Prerequisites
- Xcode 26+
- iOS 26+ deployment target
- An OpenAI API key (or any OpenAI-compatible API)
### Setup
1. **Clone the repository**
```bash
git clone https://github.com/user/SwiftChat.git
cd SwiftChat
```
2. **Open in Xcode**
```bash
open SwiftChat.xcodeproj
```
3. **Run the app** on a simulator or device. On first launch, you'll be prompted to enter your API key.
That's it. No additional configuration needed.
### Configuration
All configuration lives in `AppConfig.swift`:
```swift
class AppConfig: ObservableObject {
/// Your API key (prompted on first launch, saved to UserDefaults)
var apiKey: String = "YOUR_API_KEY"
/// OpenAI-compatible API host
var apiHost: String = "api.openai.com"
/// Base path for the API
var apiBasePath: String = "/v1"
/// System prompt sent with every conversation
var systemPrompt: String = "You are a helpful AI assistant."
/// Additional rules appended to the system prompt
var rules: String = ""
}
```
To use a different OpenAI-compatible API (e.g. Azure, a local model, or a proxy), change `apiHost` and `apiBasePath`.
### Models
Default models are configured in `AppConfig.setupDefaultModels()`:
```swift
availableModels = [
ModelType(id: "gpt-4.1", displayName: "GPT-4.1", ...),
ModelType(id: "gpt-4.1-mini", displayName: "GPT-4.1 Mini", ...),
ModelType(id: "o4-mini", displayName: "o4-mini", ...),
]
```
Add or remove models by editing this array. Set `isMultimodal: true` for models that accept image input.
## Architecture
```
SwiftChat/
├── Config/
│ ├── AppConfig.swift # API configuration, model definitions
│ ├── Constants.swift # App-wide constants
│ ├── SettingsManager.swift # User preferences (persisted)
│ └── Theme.swift # Design system tokens
├── Models/
│ ├── ChatModels.swift # Chat, Message, WebSearchState
│ └── AttachmentModels.swift # Attachment types (image, document)
├── ViewModels/
│ └── ChatViewModel.swift # Core logic: streaming, chat management
├── Views/
│ ├── ChatView.swift # Main container with sidebar
│ ├── ChatListView.swift # Message list (UITableView-backed)
│ ├── MessageView.swift # Individual message bubbles
│ ├── MessageInputView.swift # Input bar with attachments, mic, send
│ ├── ChatSidebar.swift # Chat history sidebar
│ ├── LaTeXMarkdownView.swift # Rich text rendering
│ └── ... # Supporting views
├── Services/
│ ├── AudioRecordingService.swift # Voice recording + transcription
│ ├── StreamingMarkdownChunker.swift # Incremental markdown parsing
│ ├── ThinkingSummaryService.swift # Thinking content summarizer
│ └── ThinkingTextChunker.swift # Thinking text paragraph splitter
├── Utilities/
│ ├── ChatQueryBuilder.swift # Builds Responses API queries
│ └── NetworkMonitor.swift # Connectivity monitoring
└── Extensions/
├── Color.swift # App color palette
└── Color+Hex.swift # Hex color initializer
```
### Key Components
**`ChatQueryBuilder`** converts your chat history into a `CreateModelResponseQuery` for the Responses API, handling system prompts, multimodal content, document context, and web search tools.
**`ChatViewModel`** manages the streaming loop, processing `ResponseStreamEvent` variants:
- `.outputText(.delta)` for response content
- `.reasoning(.delta)` for thinking/reasoning content
- `.webSearchCall(...)` for search status updates
- `.outputTextAnnotation(.added)` for citations
**`StreamingMarkdownChunker`** breaks streaming content into semantic chunks (paragraphs, code blocks, tables, etc.) so only the active chunk re-renders during streaming.
## Customization
### System Prompt
Edit `AppConfig.systemPrompt` to change the AI's behavior. You can use placeholders:
- `{MODEL_NAME}` - replaced with the current model's display name
- `{LANGUAGE}` - replaced with the user's selected language
- `{CURRENT_DATETIME}` - replaced with the current date/time
- `{TIMEZONE}` - replaced with the user's timezone
### Theming
Colors are defined in `Extensions/Color.swift`. The `Theme.swift` file provides semantic design tokens. Both light and dark mode are fully supported.
### Adding New Models
Add entries to `AppConfig.setupDefaultModels()`:
```swift
ModelType(
id: "your-model-id", // API model identifier
displayName: "Display Name", // Shown in model picker
fullName: "Full Model Name", // Used in system prompt
iconName: "openai-icon", // Asset catalog image name
isMultimodal: true // Set true if model accepts images
)
```
## Dependencies
| Package | Purpose |
|---------|---------|
| [OpenAI](https://github.com/tinfoilsh/openai-swift-fork) | OpenAI API client with Responses API + streaming support |
| [Textual](https://github.com/tinfoilsh/textual) | Markdown/rich text rendering for SwiftUI |
| [SwiftMath](https://github.com/mgriebling/SwiftMath) | Native LaTeX math rendering |
All dependencies are managed via Swift Package Manager and resolve automatically when you open the project.
## Requirements
- iOS 26.0+
- Xcode 26.0+
- Swift 5.0+
## License
This project is available under the MIT License. See the [LICENSE](LICENSE) file for details.