# Claude Code CLI - Performance Specifications

## Response Time Targets

### Interactive Operations

| Operation Type | Target Response Time | Degraded Performance | Critical Threshold |
|----------------|----------------------|----------------------|-------------------|
| Command parsing | < 100ms | 100-500ms | > 500ms |
| Simple response generation | < 1s | 1-3s | > 3s |
| File operations (small files) | < 200ms | 200-1000ms | > 1s |
| Local search operations | < 500ms | 500ms-2s | > 2s |

### AI-Dependent Operations

| Operation Type | Target Response Time | Degraded Performance | Critical Threshold |
|----------------|----------------------|----------------------|-------------------|
| Simple AI queries | 1-3s | 3-8s | > 8s |
| Complex code explanations | 3-8s | 8-15s | > 15s |
| Multi-file code generation | 5-15s | 15-30s | > 30s |
| Codebase analysis | 10-30s | 30-60s | > 60s |

### Background Operations

| Operation Type | Expected Duration | Progress Indication | Cancellation Point |
|----------------|-------------------|---------------------|-------------------|
| Large codebase indexing | 1-5min | Every 10s | At file boundaries |
| Command execution | Command-dependent | Real-time | Command-dependent |
| Large file operations | 1-30s | Progress percentage | 10% increments |
| Network-dependent operations | 1-30s | Activity indication | At request boundaries |

## Resource Utilization

### Memory Usage

| State | Target Usage | Maximum Allowed | Optimization Trigger |
|-------|-------------|-----------------|----------------------|
| Idle | < 100MB | 200MB | > 150MB |
| Active conversation | < 250MB | 500MB | > 350MB |
| Codebase analysis | 250-500MB | 1GB | > 700MB |
| Large file operations | Usage + 2x file size | Usage + 3x file size | > Usage + 2.5x file size |

### CPU Utilization

| Operation | Target Utilization | Duration | Cooling Period |
|-----------|-------------------|----------|---------------|
| Startup | Up to 100% | < 5s | N/A |
| Command processing | < 30% | < 2s | N/A |
| Codebase indexing | Up to 70% | < 5min | 30s if continuous |
| AI response processing | Up to 50% | < 10s | 5s between intensive operations |

### Disk I/O

| Operation | Read Rate | Write Rate | Batch Size |
|-----------|-----------|------------|------------|
| Configuration access | < 5MB/s | < 1MB/s | Small (< 100KB) |
| Code browsing | 10-50MB/s | Minimal | Medium (< 1MB) |
| Codebase indexing | 50-200MB/s | 5-20MB/s | Large (5-10MB) |
| Log writing | N/A | 1-5MB/s | Small (< 100KB) |

### Network Usage

| Operation | Bandwidth | Latency Tolerance | Retry Strategy |
|-----------|-----------|-------------------|---------------|
| Authentication | < 10KB | Low (< 500ms) | Exponential backoff, max 3 retries |
| AI requests | 10-100KB | Medium (< 2s) | Exponential backoff, max 5 retries |
| AI responses | 5-500KB | High (< 10s) | Resume from last chunk |
| Telemetry | < 50KB/session | Very high (minutes) | Queue and retry on next session |

## Scaling Characteristics

### Codebase Size Scaling

| Codebase Size | Startup Time | Memory Footprint | Search Performance |
|---------------|--------------|------------------|-------------------|
| Small (<100 files) | < 3s | Base + 50MB | < 500ms |
| Medium (100-1000 files) | 3-10s | Base + 100-250MB | 500ms-2s |
| Large (1000-10000 files) | 10-30s | Base + 250-500MB | 2-5s |
| Very Large (>10000 files) | 30-120s | Base + 500MB-1GB | 5-15s |

### Concurrent Operations

| Operation Concurrency | Response Impact | Memory Impact | CPU Impact |
|------------------------|-----------------|--------------|------------|
| Single operation | Baseline | Baseline | Baseline |
| 2-3 operations | 1.2x slower | 1.5x usage | 1.5-2x usage |
| 4+ operations | 2x slower | 2x usage | 2-3x usage |

## Optimization Techniques

### Caching Strategies

| Cache Type | Size Limit | Invalidation Trigger | Hit Rate Target |
|------------|------------|----------------------|-----------------|
| Command history | 1000 entries | Manual clear or overflow | > 20% |
| File content | 100MB | File modification or 10min | > 50% |
| AI responses | 50MB | Related file changes | > 30% |
| Search results | 25MB | 5min or file changes | > 40% |

### Lazy Loading

- On-demand file content loading
- Progressive codebase indexing
- Background initialization of non-critical components
- Deferred plugin loading

### Parallelization

- Multi-threaded file operations
- Background indexing and analysis
- Concurrent API requests where appropriate
- Pipeline processing for command outputs

### Throttling and Backpressure

- Rate limiting for API requests
- Disk I/O throttling during high load
- CPU usage monitoring and task deferral
- Memory pressure adaptive behavior

## Performance Monitoring

### Metrics Collection

- Response time by operation type
- Resource utilization trends
- Cache effectiveness statistics
- Error rates and patterns

### User Experience Indicators

- Time to first response
- Command completion rate
- Perceived latency measurements
- User wait-time tracking

### Automatic Adaptations

- Dynamic cache size adjustment
- Background task priority modulation
- Resource allocation based on operation importance
- Feature disabling under extreme resource constraints

## Performance Testing

### Benchmark Scenarios

- Small/medium/large codebase initialization
- Common command patterns execution
- Intensive operations (search, multi-file edits)
- Long-running session stability

### Test Environments

- Minimum specification machines
- Average developer workstations
- High-performance workstations
- Various operating systems (macOS, Linux)