# Issue #1: Switch Base Model Between gemini-embedding-001 and text-embedding-004
## Implementation Summary
Successfully implemented the ability to switch between embedding models via environment variable configuration.
## Changes Made
### 1. Code Changes (`src/embedder.ts`)
- Added `SUPPORTED_MODELS` constant with type-safe model names
- Modified `CodeEmbedder` constructor to accept optional model parameter
- Implemented model selection priority: constructor param → env var → default
- Added validation to reject unsupported model names with clear error messages
- Added console log to display selected model on initialization
### 2. Documentation Updates
#### README.md
- Added "Optional Configuration" section explaining EMBEDDING_MODEL variable
- Listed both supported models with descriptions
- Updated optional variables table to include EMBEDDING_MODEL
#### SETUP.md
- Added EMBEDDING_MODEL to environment variables table
- Included default value and supported models
#### QUICK_REF.md
- Added EMBEDDING_MODEL to quick reference table
#### vscode_settings.example.json
- Added EMBEDDING_MODEL with default value to example configuration
## Usage
Users can now switch models in 3 ways:
### Method 1: Environment Variable (Recommended)
```json
{
"env": {
"EMBEDDING_MODEL": "gemini-embedding-001"
}
}
```
### Method 2: Default Behavior
If not specified, uses `text-embedding-004` by default.
### Method 3: Programmatic (for library users)
```typescript
const embedder = new CodeEmbedder(apiKey, 'gemini-embedding-001');
```
## Supported Models
- ✅ `text-embedding-004` - Latest model (default)
- ✅ `gemini-embedding-001` - Earlier model for compatibility
## Error Handling
If an unsupported model is specified, the system will throw a clear error:
```
Unsupported embedding model: invalid-model. Supported models: gemini-embedding-001, text-embedding-004
```
## Testing
Tested all scenarios:
- ✅ Default model (no config) → uses `text-embedding-004`
- ✅ Environment variable → uses specified model
- ✅ Explicit constructor param → uses specified model
- ✅ Invalid model → throws descriptive error
- ✅ Build succeeds without errors
## Acceptance Criteria
- ✅ Code supports both `gemini-embedding-001` and `text-embedding-004`
- ✅ Switching between models does not require code changes (environment toggle)
- ✅ Documentation updated to explain how to set the desired model
- ✅ Proper error handling if an unsupported model name is specified
## Files Modified
1. `src/embedder.ts` - Core implementation
2. `README.md` - User documentation
3. `SETUP.md` - Setup guide
4. `QUICK_REF.md` - Quick reference
5. `vscode_settings.example.json` - Configuration example
## Ready for Release
The implementation is complete, tested, and ready to be committed and released.
