# llm-connector v0.5.0 Release Summary

## 🎉 Major Release: Multi-modal Content Support

**Release Date**: 2025-01-XX  
**Version**: 0.5.0  
**Type**: Major Release (Breaking Change)

---

## 📋 Overview

This is a **major architectural improvement** that enables native multi-modal content support (text + images) in llm-connector.

**Breaking Change**: `Message.content` changed from `String` to `Vec<MessageBlock>`

---

## 🎯 What's New

### Core Feature: Multi-modal Content

llm-connector now natively supports multi-modal content, allowing you to send text and images in a single message.

**Before (0.4.x)**:
```rust
let message = Message {
    role: Role::User,
    content: "Hello".to_string(),  // Only text
    ..Default::default()
};
```

**After (0.5.0)**:
```rust
// Text only (simple)
let message = Message::text(Role::User, "Hello");

// Multi-modal (text + image)
let message = Message::new(
    Role::User,
    vec![
        MessageBlock::text("What's in this image?"),
        MessageBlock::image_url("https://example.com/image.jpg"),
    ],
);
```

---

## 🔧 New Types

### MessageBlock

The core type for multi-modal content:

```rust
pub enum MessageBlock {
    /// Text content
    Text {
        text: String,
    },
    
    /// Image (Anthropic format)
    Image {
        source: ImageSource,
    },
    
    /// Image URL (OpenAI format)
    ImageUrl {
        image_url: ImageUrl,
    },
}
```

### ImageSource

```rust
pub enum ImageSource {
    Base64 {
        media_type: String,
        data: String,
    },
    Url {
        url: String,
    },
}
```

### ImageUrl

```rust
pub struct ImageUrl {
    pub url: String,
    pub detail: Option<String>,  // "auto", "low", "high"
}
```

---

## ✨ New API Methods

### Message Constructors

```rust
// Create text-only message
Message::text(Role::User, "Hello")

// Create multi-modal message
Message::new(Role::User, vec![
    MessageBlock::text("..."),
    MessageBlock::image_url("..."),
])

// Convenience constructors
Message::system("You are a helpful assistant")
Message::user("Hello!")
Message::assistant("Hi!")
```

### Message Methods

```rust
// Extract all text content
message.content_as_text() -> String

// Check content type
message.is_text_only() -> bool
message.has_images() -> bool
```

### MessageBlock Constructors

```rust
// Text block
MessageBlock::text("Hello")

// Base64 image
MessageBlock::image_base64("image/jpeg", "base64_data...")

// Image URL (Anthropic format)
MessageBlock::image_url_anthropic("https://...")

// Image URL (OpenAI format)
MessageBlock::image_url("https://...")

// Image URL with detail
MessageBlock::image_url_with_detail("https://...", "high")
```

### MessageBlock Methods

```rust
// Get text content
block.as_text() -> Option<&str>

// Check block type
block.is_text() -> bool
block.is_image() -> bool
```

---

## 📝 Migration Guide

### Simple Text Messages

**Old**:
```rust
let message = Message {
    role: Role::User,
    content: "Hello".to_string(),
    ..Default::default()
};
```

**New (Recommended)**:
```rust
let message = Message::text(Role::User, "Hello");
```

**New (Alternative)**:
```rust
let message = Message::new(
    Role::User,
    vec![MessageBlock::text("Hello")],
);
```

### Multi-modal Messages

**New Feature**:
```rust
// Text + Image URL
let message = Message::new(
    Role::User,
    vec![
        MessageBlock::text("What's in this image?"),
        MessageBlock::image_url("https://example.com/image.jpg"),
    ],
);

// Text + Base64 Image
let message = Message::new(
    Role::User,
    vec![
        MessageBlock::text("Analyze this image"),
        MessageBlock::image_base64("image/jpeg", base64_data),
    ],
);

// Multiple Images
let message = Message::new(
    Role::User,
    vec![
        MessageBlock::text("Compare these images"),
        MessageBlock::image_url("https://example.com/image1.jpg"),
        MessageBlock::image_url("https://example.com/image2.jpg"),
    ],
);
```

---

## 🔄 Protocol Support

### OpenAI Protocol

- ✅ Supports both string and array formats
- Automatically converts based on content
- Pure text → string format
- Multi-modal → array format

### Anthropic Protocol

- ✅ Always uses array format
- Native multi-modal support
- Supports both Image and ImageUrl blocks

### Other Providers

- ✅ Aliyun - Converts to text format
- ✅ Zhipu - Converts to text format
- ✅ Ollama - Converts to text format
- ✅ Tencent - Converts to text format
- ✅ Volcengine - Converts to text format

---

## 🧪 Testing

### Test Coverage

- ✅ 64 unit tests passing
- ✅ 8 new tests for MessageBlock
- ✅ All protocols tested
- ✅ All providers tested

### New Example

- `examples/multimodal_basic.rs` - Comprehensive multi-modal examples

---

## 📚 Documentation

### New Documents

1. **docs/MULTIMODAL_CONTENT_DESIGN.md**
   - Design comparison
   - Multiple solution approaches
   - Pros and cons analysis

2. **docs/MULTIMODAL_NATIVE_DESIGN.md**
   - Native design approach
   - Simplified architecture
   - Implementation details

3. **docs/MULTIMODAL_MIGRATION_PLAN.md**
   - Migration plan
   - Step-by-step guide
   - Testing strategy

### Updated Documents

- **CHANGELOG.md** - Complete v0.5.0 changelog
- **README.md** - (To be updated)

---

## 🎯 Benefits

1. **Native Multi-modal Support** ✅
   - Send text and images in one message
   - Type-safe content handling
   - Extensible for future content types

2. **Unified API** ✅
   - Consistent across all providers
   - Clean and simple interface
   - Easy to use

3. **Type Safety** ✅
   - Compile-time checks
   - No runtime errors
   - Clear error messages

4. **Extensibility** ✅
   - Easy to add new content types
   - Future-proof architecture
   - Minimal breaking changes

5. **Performance** ✅
   - Efficient serialization
   - No unnecessary conversions
   - Optimized for common cases

---

## ⚠️ Breaking Changes

### Message.content Type Change

**Before**: `content: String`  
**After**: `content: Vec<MessageBlock>`

**Impact**: All code that directly accesses `message.content` needs to be updated.

**Migration**:
- Use `Message::text()` for simple text messages
- Use `message.content_as_text()` to extract text
- Use `Message::new()` for multi-modal messages

---

## 🚀 Next Steps

### For Users

1. Update to v0.5.0
2. Follow migration guide
3. Update your code
4. Test thoroughly
5. Enjoy multi-modal support!

### For Contributors

1. Update examples (in progress)
2. Add more tests
3. Improve documentation
4. Add more content types (future)

---

## 📊 Statistics

- **Files Changed**: 15
- **Lines Added**: 1937
- **Lines Removed**: 71
- **New Tests**: 8
- **Total Tests**: 64
- **Test Pass Rate**: 100%

---

## 🙏 Acknowledgments

This release was made possible by:
- Clean architecture design
- Comprehensive testing
- Detailed documentation
- Community feedback

---

## 📞 Support

If you encounter any issues:
1. Check the migration guide
2. Review the examples
3. Read the documentation
4. Open an issue on GitHub

---

**Happy Coding! 🎉**

