Function Operating System (FOS)

Built for AI agents - Provides raw function data from TypeScript codebases. Treats functions as "citizens in a universe" rather than files in folders.

Installation

# Global installation (recommended)
npm install -g function-os

# Or use locally in a project
npm install --save-dev function-os

Quick Start

# In any TypeScript project directory
fos                    # Shows LLMs.md help + lists all functions
fos find auth          # Find auth-related functions
fos info useAuth       # Detailed function information
fos deps useAuth       # Show function dependencies

Commands

List Functions

fos                    # List all functions (shows LLMs.md first)
fos list               # Same as above
fos voice              # Smart resolution: finds voice.ts
fos src/app            # List functions in specific module

Search Functions

fos find auth          # Find functions with "auth" in name
fos find "^handle"     # Regex: find all handlers
fos find "^use"        # Regex: find all React hooks

Function Details

fos info useAuth       # Show complete function details
fos deps useAuth       # Show what function calls
fos callers useAuth    # Show what calls this function
fos type UserProfile   # Show type definition

Output Format

Raw function data for AI processing:

functionName:
  type: arrow|function|method|constructor|getter|setter
  async: true|false
  exported: true|false
  location: path/to/file.ts:startLine-endLine
  params:
    - paramName: type
  returns: ReturnType
  calls:
    → calledFunction
  complexity: number

AI Agent Integration

1. Understand the universe

   fos

2. Find specific areas

   fos find profile

3. Trace dependencies

   fos deps MiniProfile
   fos callers useAuth

4. Get type information

   fos type UserProfile

Features

• Nested function detection - finds functions inside objects
• Smart path resolution - handles files with/without extensions
• Raw data output - no visualizations, just data
• Module filtering - analyze specific parts of codebases
• Zero configuration - works with any TypeScript project

Philosophy

Functions are the atomic unit of programming. FOS provides only raw data - AI agents process it. No complex features, no visualizations, just function data.

License

APACHE 2.0