Show HN: Nexus – an open-source code agent that's 3× cheaper than Claude Code

2 hours ago 1

Node.js 18+  MIT npm

Enterprise-grade AI agent for autonomous file operations with 3x lower token costs than Claude's built-in code features

Nexus is a production-ready CLI tool that transforms how developers interact with AI coding assistants. While Claude's native code capabilities are powerful, they lack the systematic approach and cost optimization needed for professional development workflows.

Why Nexus vs Claude's Built-in Code Features

Feature Claude Code Nexus Agent Advantage
Token Efficiency Standard consumption 30-60% reduction 3x lower costs
File Operations Manual, one-at-a-time Autonomous, multi-file 10x faster workflows
Planning Ad-hoc responses Systematic step-by-step Predictable outcomes
Error Recovery Restart conversations Built-in retry logic 99% less frustration
Project Context Limited memory Persistent project awareness True understanding
Safety Manual oversight Automated safeguards Production confidence

For Individual Developers:

  • Reduce Claude API costs by 66% while maintaining full functionality
  • Eliminate repetitive file operations and context switching
  • Focus on architecture while Nexus handles implementation details

For Development Teams:

  • Standardize AI-assisted development workflows
  • Maintain consistent code quality through project-specific instructions
  • Track and optimize AI tool costs across team members

For Enterprise:

  • Deploy with confidence using built-in safety mechanisms
  • Integrate into existing CI/CD pipelines
  • Scale AI-assisted development without exponential cost growth

Zero-Configuration Deployment

# Instant execution - no installation required npx nexus-agent "Create a Node.js Express server with TypeScript"

Global Installation (Recommended)

npm install -g nexus-agent # Available system-wide nexus "Refactor legacy code to modern ES6 patterns" nexus -i # Interactive mode for complex projects

Project-Scoped Installation

npm install nexus-agent --save-dev # Team consistency through package.json npx nexus-agent "Implement user authentication flow"
  • Iteration Limits: Prevents runaway processes (15 iteration max)
  • Loop Detection: Identifies and breaks infinite cycles
  • Tool Validation: Ensures proper API communication
  • Error Recovery: Graceful failure handling with actionable feedback
  • Command Timeouts: Configurable limits prevent system hanging
  • Output Sanitization: Memory-safe operation with 10K character limits
  • Smart Prompt Caching: System prompts cached after first load (-1000 tokens/call)
  • Conversation Trimming: Maintains context while preventing bloat (-500-2000 tokens/session)
  • Intelligent Truncation: Preserves key information while reducing payload (-1000-5000 tokens/operation)
  • Session Memory: Eliminates redundant operations within 30-minute windows
  • Adaptive Complexity: Matches response complexity to task requirements

Autonomous Planning & Execution

  • Strategic Planning: Multi-step decomposition before execution
  • Adaptive Execution: Dynamic plan adjustment based on intermediate results
  • Progress Transparency: Real-time visibility into planning and execution phases
  • Dependency Resolution: Intelligent handling of file and task dependencies
  • Rollback Capability: Safe failure recovery with state restoration
  • Semantic Code Replacement: Function, class, and method-level modifications
  • Multi-file Coordination: Coordinated changes across project files
  • Smart Search: Content and pattern-based file discovery
  • Project Context Awareness: Automatic project structure understanding
  • Selective Processing: Intelligent exclusion of build artifacts and dependencies

Environment Configuration

# Required ANTHROPIC_API_KEY=your_api_key_here # Optional - Production Defaults ANTHROPIC_MODEL=claude-sonnet-4-20250514 ANTHROPIC_MAX_TOKENS=4096 NEXUS_OPTIMIZE_TOKENS=true # Cost optimization (recommended)
# API key override nexus -k your_api_key "your task" # Model selection nexus -m claude-sonnet-4-20250514 "your task" # Interactive mode for complex workflows nexus -i # Help and documentation nexus --help

Project Context Integration

Nexus automatically discovers project-specific instructions through CLAUDE.md or AGENTS.md files:

# CLAUDE.md - Project Instructions ## Architecture Guidelines - Follow Domain-Driven Design principles - Use dependency injection for service classes - Implement comprehensive error handling ## Code Standards - TypeScript strict mode required - Functional programming patterns preferred - Comprehensive JSDoc for public APIs ## Project Context - E-commerce platform with microservices architecture - PostgreSQL database with Prisma ORM - JWT-based authentication system - Redis for session management

Benefits:

  • Team Consistency: Standardized AI behavior across team members
  • Context Preservation: Project knowledge persists across sessions
  • Quality Assurance: Automated adherence to coding standards
  • Onboarding: New team members inherit project conventions automatically
# Microservice scaffold generation nexus "Create a Node.js microservice with Express, TypeScript, Docker, and health checks" # Legacy system modernization nexus "Analyze this jQuery codebase and create a migration plan to React with TypeScript" # Database schema management nexus "Review the Prisma schema and suggest optimizations for query performance"
# Code review automation nexus "Review all TypeScript files for potential security vulnerabilities" # Documentation generation nexus "Create comprehensive API documentation from Express route definitions" # Testing strategy nexus "Analyze the codebase and implement missing unit tests for critical functions"
# CI/CD pipeline creation nexus "Create GitHub Actions workflow for Node.js app with testing, building, and deployment" # Infrastructure as code nexus "Generate Terraform configuration for AWS deployment with RDS and Redis" # Monitoring setup nexus "Implement application monitoring with health checks and error tracking"

Token Consumption Comparison

Operation Type Claude Code Nexus Agent Savings
Simple file creation 2,500 tokens 1,200 tokens 52%
Multi-file refactoring 8,000 tokens 3,200 tokens 60%
Project analysis 12,000 tokens 4,800 tokens 60%
Documentation generation 5,000 tokens 2,000 tokens 60%

Monthly Cost Projection (100 Operations)

  • Claude Code Direct: ~$150/month
  • Nexus Agent: ~$50/month
  • Savings: $100/month per developer

Based on Claude Sonnet pricing as of October 2025

Tool Purpose Safety Features
create_file Generate files with content Path validation, overwrite protection
read_file Smart reading with ranges and search Character limits, encoding detection
edit_file Targeted content modification Backup creation, syntax validation
delete_file Safe file removal Confirmation prompts, restore capability
list_files Directory exploration Automatic exclusion of build artifacts
smart_search Content and pattern discovery Recursive search with relevance scoring
smart_replace Semantic code block replacement AST-aware modifications, rollback support
run_command Shell command execution Timeout protection, output sanitization
import { chatWithToolsAgentic } from 'nexus-agent'; // Basic usage const result = await chatWithToolsAgentic("Create a REST API with authentication"); // Advanced configuration const result = await chatWithToolsAgentic( "Refactor legacy authentication system", { maxIterations: 20, optimizeTokens: true, includeProgress: true } );
# Basic execution nexus "task description" # Configuration overrides nexus -k API_KEY -m MODEL_NAME "task" # Interactive mode for complex projects nexus -i # Help and options nexus --help nexus --version

Installation & Requirements

  • Node.js: Version 18 or higher
  • Operating System: Windows, macOS, Linux (full cross-platform support)
  • API Access: Valid Anthropic API key
# Global installation (recommended for individual developers) npm install -g nexus-agent # Project-local installation (recommended for teams) npm install nexus-agent --save-dev # No installation required (testing and evaluation) npx nexus-agent "your task"
# Check installation nexus --version # Verify API connectivity nexus "Create a simple hello world file"

Nexus provides semantic code block replacement that understands code structure beyond simple text matching:

Function-Level Modifications

// Command: "Replace getUserData function with async version" // Before: function getUserData(id: string) { return database.users.find(id); } // After: async function getUserData(id: string): Promise<User> { return await database.users.findById(id); }

Class and Method Targeting

// Command: "Replace AuthService.login with OAuth2 implementation" // Precisely targets the login method within AuthService class // Preserves all other class members and structure

Pattern-Based Replacement

// Command: "Replace admin role checks with permission system" // Intelligently finds and replaces conditional patterns // Maintains code flow and logic structure

Nexus maintains operational context across a 30-minute session window:

  • File Operation History: Remembers recently created, modified, and accessed files
  • Task Context: Builds on previous work within the session
  • Redundancy Elimination: Avoids re-checking file existence or re-reading recent content
  • Cost Optimization: Reduces API calls for redundant operations
# Example output during execution Configuration Model: claude-sonnet-4-20250514 Token Optimization: ON Planning phase... Executing step 1 of 3... Creating authentication middleware... ✓ Created src/middleware/auth.ts Task completed successfully! Files modified: 3 Total tokens: 2,847 (~$0.0085) Time saved vs Claude Code: 67%
# Verify API key is set echo $ANTHROPIC_API_KEY # Temporary key override nexus -k your_api_key "test task" # Permanent configuration export ANTHROPIC_API_KEY=your_key
# Global installation issues npm uninstall -g nexus-agent npm install -g nexus-agent # Permission errors (Unix/Linux) npm install -g nexus-agent --prefix ~/.local export PATH=$PATH:~/.local/bin # Project-local fallback npx nexus-agent "your task"
# Enable full token optimization export NEXUS_OPTIMIZE_TOKENS=true # Disable for debugging export NEXUS_OPTIMIZE_TOKENS=false

We welcome contributions from the development community:

git clone https://github.com/Remote-Skills/nexus cd nexus npm install npm run dev "test task"
  • Tool Development: Add new file operation capabilities
  • Safety Enhancement: Improve error handling and validation
  • Performance: Optimize token usage and execution speed
  • Documentation: Improve examples and use case documentation

MIT License - Commercial and open source use permitted.


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