# Documentation Update Summary - Issue #41: DeepSeek API Support

## Files Updated

### 1. CHANGELOG.md
**Location:** `/Users/andrewkaszubski/Dev/Spektiv/CHANGELOG.md`

**Changes:**
- Added comprehensive entry under `## [Unreleased] ### Added` section
- Entry covers:
  - DeepSeek provider integration using ChatOpenAI with base_url
  - DEEPSEEK_API_KEY environment variable handling with validation
  - Supported models: deepseek-chat and deepseek-reasoner
  - Embedding fallback chain (OpenAI -> HuggingFace -> disable)
  - Optional HuggingFace sentence-transformers integration
  - Graceful degradation with informative warnings
  - Links to implementation files with line numbers

**Cross-references included:**
- `spektiv/graph/trading_graph.py` (lines 105-145)
- `spektiv/agents/utils/memory.py` (lines 16-57)
- `tests/integration/test_deepseek.py`

### 2. PROJECT.md
**Location:** `/Users/andrewkaszubski/Dev/Spektiv/PROJECT.md`

**Changes:**
- Added new `### DeepSeek Configuration Example` section (lines 446-468)
- Positioned after OpenRouter configuration for consistency
- Content includes:

**Description:**
- Describes DeepSeek's cost-effectiveness and quantitative analysis strengths

**Configuration Example:**
```python
config = {
    "llm_provider": "deepseek",
    "deep_think_llm": "deepseek-reasoner",
    "quick_think_llm": "deepseek-chat",
    "backend_url": "https://api.deepseek.com/v1",
}
```

**Requirements Section:**
- DEEPSEEK_API_KEY environment variable requirement
- Link to DeepSeek Platform for API key generation
- Embedding backend options (OpenAI preferred or sentence-transformers)
- Supported model options: deepseek-chat and deepseek-reasoner
- OpenAI API format compatibility note

**Embedding Fallback Chain Documentation:**
1. Primary: OPENAI_API_KEY for OpenAI embeddings (recommended)
2. Secondary: HuggingFace sentence-transformers (all-MiniLM-L6-v2)
3. Fallback: Disable memory features with warnings

## Documentation Quality Validation

- ✓ CHANGELOG.md markdown structure valid
- ✓ PROJECT.md DeepSeek section properly added
- ✓ DEEPSEEK_API_KEY documented in requirements
- ✓ All file references include proper paths
- ✓ Configuration examples complete and accurate
- ✓ Fallback chain behavior fully documented
- ✓ Links to source code with line numbers included
- ✓ Consistency with OpenRouter configuration format

## Related Code Changes Covered

- ✓ DeepSeek provider integration in trading_graph.py (ChatOpenAI setup)
- ✓ Embedding backend abstraction in memory.py (fallback chain)
- ✓ API key handling and validation
- ✓ HuggingFace optional dependency support
- ✓ Test suite for DeepSeek integration

## Summary

Documentation successfully updated for Issue #41 - DeepSeek API Support.

All configuration options, API key requirements, and embedding fallback behavior are now documented:
- CHANGELOG.md has a detailed feature entry under the Unreleased section
- PROJECT.md has a complete configuration guide with requirements and examples
- Both files follow established documentation patterns and include cross-references to implementation code