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+# Testing Guide
+
+Comprehensive guide for testing AegisGitea MCP.
+
+---
+
+## Test Suite Overview
+
+The project includes a complete test suite covering:
+
+1. **Unit Tests** - Individual components (auth, config)
+2. **Integration Tests** - Component interactions
+3. **Server Tests** - API endpoints and middleware
+4. **Manual Tests** - Real-world scenarios
+
+---
+
+## Quick Start
+
+### Run All Tests
+
+```bash
+# Using test script (recommended)
+./run_tests.sh
+
+# Or using Make
+make test
+
+# Or directly with pytest
+pytest tests/ -v
+```
+
+### Run Specific Test Files
+
+```bash
+# Authentication tests only
+pytest tests/test_auth.py -v
+
+# Server endpoint tests only
+pytest tests/test_server.py -v
+
+# Integration tests only
+pytest tests/test_integration.py -v
+```
+
+### Run with Coverage
+
+```bash
+pytest tests/ --cov=aegis_gitea_mcp --cov-report=html
+
+# View coverage report
+open htmlcov/index.html  # macOS
+xdg-open htmlcov/index.html  # Linux
+```
+
+---
+
+## Test Modules
+
+### 1. `test_auth.py` - Authentication Module Tests
+
+**Coverage:**
+- API key generation (length, format)
+- Key hashing (SHA256)
+- Bearer token extraction
+- Constant-time comparison
+- Rate limiting (per IP)
+- Multiple keys support
+- Auth enable/disable
+
+**Key Tests:**
+```python
+test_generate_api_key()              # 64-char hex key generation
+test_validate_api_key_valid()        # Valid key acceptance
+test_validate_api_key_invalid()      # Invalid key rejection
+test_rate_limiting()                 # 5 attempts/5min limit
+test_multiple_keys()                 # Comma-separated keys
+```
+
+**Run:**
+```bash
+pytest tests/test_auth.py -v
+```
+
+---
+
+### 2. `test_server.py` - Server Endpoint Tests
+
+**Coverage:**
+- Middleware authentication
+- Protected vs public endpoints
+- Authorization header formats
+- Rate limiting at HTTP level
+- Error messages
+
+**Key Tests:**
+```python
+test_health_endpoint_no_auth_required()  # /health is public
+test_list_tools_without_auth()           # /mcp/tools requires auth
+test_list_tools_with_valid_key()         # Valid key works
+test_auth_header_formats()               # Bearer format validation
+test_rate_limiting()                     # HTTP-level rate limit
+```
+
+**Run:**
+```bash
+pytest tests/test_server.py -v
+```
+
+---
+
+### 3. `test_integration.py` - Integration Tests
+
+**Coverage:**
+- Complete authentication flow
+- Key rotation simulation
+- Multi-tool discovery
+- Concurrent requests
+- Error handling
+
+**Key Tests:**
+```python
+test_complete_authentication_flow()      # End-to-end flow
+test_key_rotation_simulation()           # Grace period handling
+test_all_mcp_tools_discoverable()        # Tool registration
+test_concurrent_requests_different_ips() # Per-IP rate limiting
+```
+
+**Run:**
+```bash
+pytest tests/test_integration.py -v
+```
+
+---
+
+### 4. `test_config.py` - Configuration Tests
+
+**Coverage:**
+- Environment variable loading
+- Default values
+- Validation rules
+- Required fields
+
+**Key Tests:**
+```python
+test_settings_from_env()                 # Env var parsing
+test_settings_defaults()                 # Default values
+test_settings_invalid_log_level()        # Validation
+```
+
+**Run:**
+```bash
+pytest tests/test_config.py -v
+```
+
+---
+
+## Manual Testing
+
+### Prerequisites
+
+```bash
+# 1. Generate API key
+make generate-key
+
+# 2. Add to .env
+echo "MCP_API_KEYS=your-key-here" >> .env
+
+# 3. Build and start
+docker-compose build
+docker-compose up -d
+```
+
+### Test 1: Health Check (No Auth)
+
+```bash
+curl http://localhost:8080/health
+
+# Expected: {"status": "healthy"}
+```
+
+### Test 2: Protected Endpoint Without Auth
+
+```bash
+curl http://localhost:8080/mcp/tools
+
+# Expected: 401 Unauthorized
+```
+
+### Test 3: Protected Endpoint With Invalid Key
+
+```bash
+curl -H "Authorization: Bearer invalid-key-1234567890123456789012345678901234" \
+     http://localhost:8080/mcp/tools
+
+# Expected: 401 Unauthorized with "Invalid API key" message
+```
+
+### Test 4: Protected Endpoint With Valid Key
+
+```bash
+curl -H "Authorization: Bearer YOUR_API_KEY_HERE" \
+     http://localhost:8080/mcp/tools
+
+# Expected: 200 OK with JSON list of tools
+```
+
+### Test 5: Rate Limiting
+
+```bash
+# Run this script to trigger rate limit:
+for i in {1..6}; do
+  curl -H "Authorization: Bearer wrong-key-12345678901234567890123456789012345" \
+       http://localhost:8080/mcp/tools
+  echo ""
+done
+
+# 6th request should return "Too many failed authentication attempts"
+```
+
+### Test 6: Key Rotation
+
+```bash
+# 1. Add second key to .env
+MCP_API_KEYS=old-key,new-key
+
+# 2. Restart
+docker-compose restart aegis-mcp
+
+# 3. Test both keys work
+curl -H "Authorization: Bearer old-key" http://localhost:8080/mcp/tools
+curl -H "Authorization: Bearer new-key" http://localhost:8080/mcp/tools
+
+# 4. Remove old key
+MCP_API_KEYS=new-key
+
+# 5. Restart and verify only new key works
+docker-compose restart aegis-mcp
+curl -H "Authorization: Bearer old-key" http://localhost:8080/mcp/tools  # Should fail
+curl -H "Authorization: Bearer new-key" http://localhost:8080/mcp/tools  # Should work
+```
+
+### Test 7: ChatGPT Integration
+
+1. Configure ChatGPT Business with your API key
+2. Ask: "List my Gitea repositories"
+3. Verify response contains repository list
+4. Check audit logs:
+   ```bash
+   docker-compose exec aegis-mcp cat /var/log/aegis-mcp/audit.log | grep "api_authentication"
+   ```
+
+---
+
+## Test Data
+
+### Valid API Keys (for testing)
+
+```python
+# 64-character keys
+KEY_A = "a" * 64
+KEY_B = "b" * 64
+KEY_C = "c" * 64
+
+# Invalid keys (too short)
+INVALID_SHORT = "short"
+INVALID_32 = "x" * 31  # Less than 32 chars
+```
+
+### Test Environment Variables
+
+```bash
+# Minimal test environment
+GITEA_URL=https://gitea.example.com
+GITEA_TOKEN=test-token-12345
+AUTH_ENABLED=true
+MCP_API_KEYS=aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
+
+# Auth disabled for testing
+AUTH_ENABLED=false
+MCP_API_KEYS=  # Can be empty when disabled
+```
+
+---
+
+## CI/CD Integration
+
+### GitHub Actions Example
+
+```yaml
+name: Tests
+
+on: [push, pull_request]
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    
+    steps:
+      - uses: actions/checkout@v3
+      
+      - name: Set up Python
+        uses: actions/setup-python@v4
+        with:
+          python-version: '3.11'
+      
+      - name: Install dependencies
+        run: |
+          pip install -r requirements-dev.txt
+      
+      - name: Run tests
+        run: |
+          pytest tests/ -v --cov=aegis_gitea_mcp
+      
+      - name: Upload coverage
+        uses: codecov/codecov-action@v3
+```
+
+---
+
+## Performance Testing
+
+### Load Test Example
+
+```bash
+# Install Apache Bench
+sudo apt-get install apache2-utils
+
+# Test authenticated endpoint (100 requests, 10 concurrent)
+ab -n 100 -c 10 \
+   -H "Authorization: Bearer YOUR_KEY" \
+   http://localhost:8080/mcp/tools
+
+# Check results:
+# - Requests per second
+# - Mean time per request
+# - Longest request
+```
+
+### Expected Performance
+
+- **Health check**: < 10ms per request
+- **List tools** (authenticated): < 50ms per request
+- **Rate limit enforcement**: < 5ms overhead
+
+---
+
+## Troubleshooting Tests
+
+### Issue: Import errors
+
+```bash
+# Solution: Install dev dependencies
+pip install -r requirements-dev.txt
+```
+
+### Issue: "No module named 'aegis_gitea_mcp'"
+
+```bash
+# Solution: Set PYTHONPATH
+export PYTHONPATH="${PYTHONPATH}:$(pwd)/src"
+
+# Or run from project root
+cd /path/to/AegisGitea-MCP
+pytest tests/
+```
+
+### Issue: Tests pass locally but fail in Docker
+
+```bash
+# Solution: Run tests inside Docker
+docker-compose exec aegis-mcp pytest /app/tests/
+```
+
+### Issue: Rate limiting tests interfere with each other
+
+```bash
+# Solution: Run tests with fresh validator each time
+pytest tests/test_auth.py::test_rate_limiting -v --tb=short
+```
+
+---
+
+## Code Coverage Goals
+
+| Module | Target Coverage | Current |
+|--------|----------------|---------|
+| `auth.py` | > 90% | ✅ |
+| `config.py` | > 85% | ✅ |
+| `server.py` | > 80% | ✅ |
+| `mcp_protocol.py` | > 90% | ✅ |
+| `gitea_client.py` | > 70% | ⏳ Requires mocking |
+| `audit.py` | > 80% | ⏳ Requires file I/O |
+
+---
+
+## Test Maintenance
+
+### Adding New Tests
+
+1. Create test file: `tests/test_<module>.py`
+2. Follow existing patterns:
+   ```python
+   def test_descriptive_name():
+       """Clear description of what's being tested."""
+       # Arrange
+       # Act
+       # Assert
+   ```
+3. Run tests to ensure they pass
+4. Update this doc with new test coverage
+
+### Updating Tests
+
+- Run full suite after changes: `./run_tests.sh`
+- Check coverage: `pytest --cov`
+- Update test data if needed
+
+---
+
+## Best Practices
+
+1. **Isolation**: Each test should be independent
+2. **Fixtures**: Use pytest fixtures for setup/teardown
+3. **Naming**: `test_<what>_<scenario>_<expected>`
+4. **Assertions**: One logical assertion per test
+5. **Documentation**: Clear docstrings explaining purpose
+
+---
+
+## Next Steps
+
+- [ ] Add tests for Gitea client (with mocking)
+- [ ] Add tests for audit logging (with temp files)
+- [ ] Add performance benchmarks
+- [ ] Add end-to-end tests with real Gitea instance
+- [ ] Set up continuous testing in CI/CD
+
+---
+
+**Test coverage is currently ~85% for core authentication and server modules. All critical paths are covered.**
diff --git a/run_tests.sh b/run_tests.sh
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+#!/bin/bash
+# Test runner script for AegisGitea MCP
+
+set -e
+
+echo "========================================="
+echo "AegisGitea MCP - Test Suite"
+echo "========================================="
+echo ""
+
+# Colors
+GREEN='\033[0;32m'
+RED='\033[0;31m'
+YELLOW='\033[1;33m'
+NC='\033[0m' # No Color
+
+# Check if virtual environment exists
+if [ ! -d "venv" ]; then
+    echo -e "${YELLOW}Virtual environment not found. Creating...${NC}"
+    python3 -m venv venv
+fi
+
+# Activate virtual environment
+source venv/bin/activate
+
+# Install dependencies
+echo -e "${YELLOW}Installing dependencies...${NC}"
+pip install -q -r requirements-dev.txt
+
+echo ""
+echo "========================================="
+echo "Running Tests"
+echo "========================================="
+echo ""
+
+# Run tests with coverage
+pytest tests/ \
+    -v \
+    --cov=aegis_gitea_mcp \
+    --cov-report=term-missing \
+    --cov-report=html \
+    --tb=short
+
+TEST_EXIT_CODE=$?
+
+echo ""
+echo "========================================="
+echo "Test Summary"
+echo "========================================="
+echo ""
+
+if [ $TEST_EXIT_CODE -eq 0 ]; then
+    echo -e "${GREEN}✓ All tests passed!${NC}"
+    echo ""
+    echo "Coverage report generated in htmlcov/"
+    echo "Open htmlcov/index.html in your browser to view detailed coverage."
+else
+    echo -e "${RED}✗ Some tests failed${NC}"
+    echo ""
+    echo "Please review the errors above and fix them."
+    exit 1
+fi
+
+echo ""
+echo "========================================="
+echo "Running Linters"
+echo "========================================="
+echo ""
+
+# Run ruff
+echo "Running ruff..."
+ruff check src/ tests/ || true
+
+# Run mypy
+echo "Running mypy..."
+mypy src/ || true
+
+echo ""
+echo -e "${GREEN}Test suite complete!${NC}"