idgen

A lightweight command-line utility for generating various types of unique identifiers:

• UUID (versions 1, 3, 4, and 5)
• NanoID
• MongoDB ObjectID

This tool is designed for developers who need to generate various types of IDs during development, testing, or data migration.

Table of Contents

• Features
• Installation
• Quick Start
• ID Types and Use Cases
  • UUID (Universal Unique Identifier)
  • MongoDB ObjectID
  • NanoID
• Usage Guide
  • Command Options
  • Format Options
  • Examples
  • Common UUID Namespaces
• Contributing
• License

Features

• Generate UUIDs with support for all major versions (v1, v3, v4, v5)
• Create MongoDB-style ObjectIDs
• Generate URL-safe NanoIDs with configurable length
• Multiple output formats (simple, hyphenated, URN)
• Support for batch generation
• Custom prefix support
• Banner-free mode for script integration

Installation

1. Install Rust if not already installed
2. Build from source:

   git clone https://github.com/maniartech/idgen.git
   cd idgen
   cargo build --release

3. Copy binary to your PATH:

   # Linux/macOS
   cp target/release/idgen /usr/local/bin/
   
   # Windows (PowerShell, adjust path as needed)
   Copy-Item target/release/idgen.exe -Destination "$env:USERPROFILE/AppData/Local/Microsoft/WindowsApps/"

Quick Start

Generate a random UUID (v4):

idgen

Generate without banner:

idgen -nb

Generate multiple IDs:

idgen -c 3

ID Types and Use Cases

UUID (Universal Unique Identifier)

Standard 128-bit identifiers with multiple versions for different needs:

UUID v1 (Time-based)

• Format: Timestamp + node ID based
• Example: 550e8400-e29b-11d4-a716-446655440000
• Best for: Logging, temporal ordering, distributed systems

UUID v4 (Random)

• Format: Random numbers
• Example: 550e8400-e29b-44d4-a716-446655440000
• Best for: Default choice, database keys, session IDs

UUID v3/v5 (Name-based)

• v3 uses MD5, v5 uses SHA-1 (preferred)
• Example: cfbff0d1-9375-5685-968c-48ce8b15ae17
• Best for: Consistent IDs from same input, content addressing

MongoDB ObjectID

12-byte identifier combining timestamp, machine ID, and counter:

• Example: 507f1f77bcf86cd799439011
• Best for: Document IDs, chronological sorting

NanoID

Compact, URL-safe identifiers:

• Example: V1StGXR8_Z5jdHi6B-myT
• Best for: Short URLs, user-facing IDs, frontend generation

Usage Guide

Command Options

idgen [OPTIONS]

FLAGS:
    -h --help       Show help information
    -v --version    Show version information
    -nb --no-banner Suppress banner output

UUID VERSION OPTIONS:
    -u1 --uuid1     UUID v1 (Time-based)
    -u3 --uuid3     UUID v3 (MD5 hash-based)
    -u4 --uuid4     UUID v4 (Random - Default)
    -u5 --uuid5     UUID v5 (SHA1 hash-based)

FORMAT OPTIONS:
    -s --simple     Output without hyphens
    -u --urn       Output as URN
    -o --objectid   Generate MongoDB ObjectID
    -d --hyphen     Standard UUID format (Default)
    -n --nanoid    Generate NanoID

OTHER OPTIONS:
    -c --count      Number of IDs to generate (Default: 1)
    -p --prefix     Add prefix to generated IDs
    --namespace     UUID namespace for v3/v5
    --name         Name string for v3/v5

Format Options

Each ID can be formatted in different ways:

• Simple: No separators (550e8400e29b44d4a716446655440000)
• Hyphenated: Standard format (550e8400-e29b-44d4-a716-446655440000)
• URN: URN format (urn:uuid:550e8400-e29b-44d4-a716-446655440000)

Examples

# Various UUID versions
idgen -u4                    # Random UUID v4
idgen -u1                    # Time-based UUID v1
idgen -u5 --namespace 6ba7b810-9dad-11d1-80b4-00c04fd430c8 --name example.com

# Different formats
idgen -s                     # Simple format (no hyphens)
idgen -u                     # URN format
idgen -o                     # MongoDB ObjectID
idgen -n 10                 # NanoID length 10

# Output options
idgen -c 5                  # Generate 5 IDs
idgen -p 'test-' -c 3       # Add prefix
idgen -nb                   # No banner output

Common UUID Namespaces

For UUID v3/v5, use these standard namespaces:

• DNS: 6ba7b810-9dad-11d1-80b4-00c04fd430c8
• URL: 6ba7b811-9dad-11d1-80b4-00c04fd430c8
• OID: 6ba7b812-9dad-11d1-80b4-00c04fd430c8
• X500: 6ba7b814-9dad-11d1-80b4-00c04fd430c8

Contributing

We welcome contributions! Please feel free to submit a Pull Request. For major changes, open an issue first.

License

MIT License - Copyright © 2021-2025 ManiarTech®