A minimal, single-file AI coding assistant built with TypeScript and Bun. Uses Claude AI with tool-calling capabilities for intelligent code manipulation.

🚀 Self-writing code from day one! Start with just ~100 lines of basic tool framework, and nanocode writes the rest of itself. A true AI pair programmer that bootstraps its own development.

• 🛠️ 10 Built-in Tools: File operations, code search, shell execution, and more
• 🧠 Context-Aware: Knows your OS, timezone, and working directory
• ⚡ Zero Dependencies: Single TypeScript file (~345 lines)
• 🔄 Live Output: Real-time streaming for long-running commands
• 🎨 Beautiful CLI: Colored output with markdown rendering
• 📊 Token Tracking: Displays API token usage after each interaction
• 🔧 Cross-Platform: Works on Windows, macOS, and Linux

# Install Bun (if not already installed)
curl -fsSL https://bun.sh/install | bash

# Set your API key
export ANTHROPIC_API_KEY=your_key_here
# Or on Windows:
# set ANTHROPIC_API_KEY=your_key_here

# Run nanocode
bun run index.ts
# Or make it executable:
chmod +x index.ts && ./index.ts

1. read - Read files with line numbers (supports offset/limit)
2. write - Write content to files
3. edit - Find and replace in files (supports single or all occurrences)
4. glob - Find files by pattern (sorted by modification time)
5. grep - Search files with regex (limited to 50 results)
6. exec - Execute commands with live output and custom timeout (1ms - 300s)
7. list - List directory contents (supports recursive listing)
8. delete - Delete files/directories (supports recursive deletion)
9. move - Move or rename files
10. copy - Copy files/directories (supports recursive copy)

|> What files are in this directory?
⏺ glob({"pattern":"*"})
  |> README.md ... +5 files

|> Read the first 10 lines of index.ts
⏺ read({"path":"index.ts","limit":10})
  |> 1| #!/usr/bin/env bun ... +9 lines

|> Find all TODO comments
⏺ grep({"pattern":"TODO"})
  |> index.ts:42:// TODO: Add error handling ... +2 lines

|> Run tests with live output
⏺ exec({"command":"npm test","timeout":60000})
  [stdout] Running tests...
  [stdout] ✓ Test 1 passed
  [stderr] Warning: deprecated API
  [exit: 0]

📊 Tokens: 1250 in, 340 out, 1590 total

Environment variables:

API_URL=http://127.0.0.1:8045/v1/messages  # API endpoint
MODEL=claude-opus-4-5                       # Claude model
GREP_LIMIT=50                               # Max grep results
MAX_FILE_SIZE=10485760                      # Max file size (10MB)
ANTHROPIC_API_KEY=sk-ant-...                # Your API key

• Code Generation: "Create a React component with TypeScript"
• Refactoring: "Refactor this function to use async/await"
• Bug Fixing: "Fix the type errors in this file"
• Code Review: "Review this code and suggest improvements"
• Documentation: "Add JSDoc comments to all functions"
• Testing: "Generate unit tests for this module"

The AI knows your system environment:

System Prompt includes:
- OS: win32 x64 (or darwin arm64, linux x64, etc.)
- Current time: 2026-01-11T11:26:56.779Z
- Working directory: /path/to/project

Use exec for commands with real-time output:

|> Run build with live output
⏺ exec({"command":"npm run build","timeout":120000})
  [stdout] Building...
  [stdout] ✓ Compiled successfully
  [exit: 0]

Automatically ignores common directories:

• .git, node_modules, dist, build
• .next, coverage, .cache

• CLAUDE.md - Architecture and design notes for AI

This is a minimal, educational project. Key principles:

• Single file - Keep everything in index.ts
• Zero dependencies - Only use Bun APIs
• Simple & clear - Readable code over clever abstractions

MIT License - Feel free to use, modify, and distribute.

Built with:

• Bun - Fast JavaScript runtime
• Claude AI - Anthropic's AI assistant
• TypeScript - Type-safe JavaScript

Version: Enhanced - January 2026
Lines of Code: ~345
Dependencies: 0
Awesomeness: ∞