OpenGyver

March 31, 2026 · View on GitHub

openGyver

A Swiss-army-knife CLI tool with 47 commands and 180+ subcommands for everyday conversions, encoding, hashing, generation, formatting, validation, and more. Built in Go for zero-dependency, single-binary distribution across Linux, macOS, and Windows.

Designed to be used standalone, or hooked into CI/CD pipelines, shell scripts, and AI agents.

Installation

Claude Code Plugin (use openGyver as AI tools)

/plugin marketplace add https://raw.githubusercontent.com/create-flow-ai/openGyver/main/plugin/marketplace.json
/plugin install opengyver
/reload-plugins

This gives Claude 16 native MCP tools for encoding, hashing, conversion, generation, weather, stocks, and more.

CLI

# Homebrew
brew tap create-flow-ai/tap
brew install opengyver

# Go
go install github.com/mj/opengyver@latest

# From source
git clone https://github.com/create-flow-ai/openGyver.git
cd openGyver && go build -o openGyver .

Quick Start

openGyver convert 100 cm in                    # unit conversion
openGyver convert 100 usd eur                  # live currency rates
openGyver encode base64 "hello world"           # encoding
openGyver hash sha256 "hello"                   # hashing
openGyver generate password --length 32         # password generator
openGyver stock AAPL -f price                   # stock price
openGyver epoch                                 # current Unix epoch
openGyver timex now --tz Asia/Tokyo             # time in Tokyo
openGyver qr "https://example.com"              # QR code in terminal
openGyver uuid                                  # random UUID v4
openGyver json format '{"a":1}'                 # JSON beautify
openGyver validate html --file index.html       # HTML validation
openGyver format sql "select * from users"      # SQL formatting
openGyver color convert "#ff5733" --to rgb      # color conversion
openGyver finance loan --principal 300000 --rate 6.5 --years 30
openGyver testdata person --count 5 -j          # fake test data
openGyver weather "New York"                    # current weather
openGyver weather Tokyo --date 2024-12-25       # historical weather

Output Modes

Every command supports multiple output modes:

Mode	Flag	Description
JSON	`--json` / `-j`	Structured JSON output for scripting and piping
Abbreviated	`-a`, `-f`, `-b`	Single value output (command-specific)
Quiet	`--quiet` / `-q`	Suppress confirmation messages (file converters)

openGyver convert -j 100 cm in                 # {"input_value":100,"output_value":39.37,...}
openGyver stock AAPL -f price                  # 248.80
openGyver timex now -b                         # 2026-03-28T08:44:46-04:00
openGyver convertFile data.csv -o data.xlsx -q # silent

Commands

Conversion Tools

Command	Description	Docs
convert	Unit & currency conversions (9 categories, 38 currencies)	details
convertAudio	Audio format conversion (33 formats via ffmpeg)	details
convertCAD	CAD file conversion (DWG, DXF, DWF)	details
convertEbook	Ebook format conversion (25 formats via Calibre)	details
convertFile	Document & spreadsheet conversion (CSV, XLSX, MD, HTML, DOCX, PDF, PS)	details
convertFont	Font format conversion (TTF, OTF, WOFF, WOFF2, EOT + 7 more)	details
convertImage	Image format conversion (PNG, JPEG, GIF, BMP, TIFF, WebP, RAW, SVG)	details
convertPresentation	Presentation conversion (PPTX, KEY, ODP via LibreOffice)	details
convertVector	Vector graphics conversion (SVG, EPS, AI, CDR + 20 more)	details
convertVideo	Video format conversion (37 formats via ffmpeg)	details
toGif	Create animated GIF from images	details
toIco	Create Windows ICO from images	details
trimVideo	Trim video to time range (stream copy or re-encode)	details
extractFrame	Extract frames from animated GIF/APNG	details

Encoding & Hashing

Command	Description	Docs
encode	Encode/decode: Base64, Base32, Base58, URL, HTML, hex, binary, ROT13, Morse, Punycode, JWT	details
hash	Hashing: MD5, SHA-1/256/384/512, HMAC, bcrypt, CRC32, Adler-32	details
checksum	File checksum calculator and verifier (MD5, SHA-1/256/512, CRC32)	details

Data & Format Tools

Command	Description	Docs
dataformat	Convert between YAML, TOML, XML, CSV, and JSON	details
json	JSON format, minify, validate, path query, escape/unescape	details
format	Format/beautify/minify HTML, XML, CSS, SQL	details
validate	Validate HTML, CSV, XML, YAML, TOML	details
diff	Compare files: text (unified diff), JSON (structural), CSV	details
regex	Regex test, replace, extract	details

Generators

Command	Description	Docs
generate	Password, passphrase, API key, secret, OTP, nanoid, snowflake, short ID	details
uuid	UUID v4 (random) and v6 (time-sorted)	details
qr	QR code generator (ASCII terminal, PNG, SVG)	details
barcode	Barcode generator (Code128, EAN-13, QR, DataMatrix)	details
testdata	Fake data: people, CSV, JSON, random numbers	details

Time & Date

Command	Description	Docs
epoch	Unix epoch: current time, add/subtract durations	details
timex	Time tools: now, to-utc, to-tz, to-unix, from-unix, format, diff, add, info	details
cron	Cron expression parser, validator, and next-run calculator	details

Lookup & Reference

Command	Description	Docs
stock	Stock ticker lookup from 35+ global markets (Yahoo Finance, no API key)	details
weather	Weather: current, forecast (16 days), historical (back to 1940) for any city	details
network	DNS lookup, public IP, WHOIS, CIDR calculator, URL parser, HTTP status codes	details
color	Color convert (hex/RGB/HSL/CMYK), WCAG contrast, palette, name lookup	details
number	Number base conversion (2-36), Roman numerals, IEEE 754	details
mime	MIME type lookup, reverse lookup, and file detection	details
ascii	ASCII art banners, table reference, character lookup	details
phone	Phone number formatter, validator, and country code lookup	details

Text Tools

Command	Description	Docs
text	Count, case convert, reverse, sort, dedupe, slug, lorem, diff, wrap, trim, replace	details

Math & Calculators

Command	Description	Docs
math	Math expression evaluator, percentage, GCD, LCM, factorial, Fibonacci	details
chmod	Unix file permission calculator (octal/symbolic/umask)	details

File Tools

Command	Description	Docs
pdf	PDF merge, split, page count, metadata (pure Go, no external tools)	details

Crypto & Security

Command	Description	Docs
crypto	AES encrypt/decrypt, RSA keygen, SSH keygen, self-signed cert, CSR	details

Science & Engineering

Command	Description	Docs
electrical	Ohm's law, resistor color codes, LED resistor, voltage divider	details
geo	Haversine distance, DMS/decimal converter, lat/lon to UTM	details
accessibility	WCAG contrast checker, Flesch/Gunning Fog readability scores	details

Finance

Command	Description	Docs
finance	Loan/mortgage, compound interest, ROI, tip, tax, salary, discount, margin	details

Command	Description	Docs
archive	Create/extract ZIP, TAR, TAR.GZ, 7Z, RAR	details

Claude Code Integration

openGyver is available as a Claude Code plugin with native MCP tools. Once installed, Claude can call openGyver commands directly.

Install as Claude Code Plugin

Option A: MCP server (recommended)

Add to your Claude Code MCP config (~/.claude/mcp.json):

{
  "mcpServers": {
    "opengyver": {
      "command": "npx",
      "args": ["-y", "mcp-server-opengyver"]
    }
  }
}

Or clone and build locally:

git clone https://github.com/create-flow-ai/openGyver.git
cd openGyver/plugin/mcp-server
npm install && npm run build

# Add to ~/.claude/mcp.json:
# "opengyver": { "command": "node", "args": ["/path/to/plugin/mcp-server/dist/index.js"] }

Option B: Skill file (simplest)

Copy the skill into your project:

mkdir -p .claude/skills
cp -r openGyver/plugin/skills/opengyver .claude/skills/

This gives Claude 16 native tools: opengyver_encode, opengyver_hash, opengyver_convert, opengyver_json, opengyver_generate, opengyver_color, opengyver_time, opengyver_network, opengyver_dataformat, opengyver_validate, opengyver_format, opengyver_crypto, opengyver_weather, opengyver_stock, opengyver_math, and opengyver_run (catch-all).

See plugin/README.md for details.

Plugin Architecture

openGyver uses a plugin-based architecture where each command is a self-contained Go package. Adding a new command requires no changes to existing code.

Adding a New Command

Create a new package under cmd/:

// cmd/yourcommand/yourcommand.go
package yourcommand

import (
    "github.com/mj/opengyver/cmd"
    "github.com/spf13/cobra"
)

var yourCmd = &cobra.Command{
    Use:   "yourcommand <args>",
    Short: "One-line description",
    Long:  `Detailed help text with examples.`,
    RunE: func(c *cobra.Command, args []string) error {
        // implementation
        return nil
    },
}

func init() {
    yourCmd.Flags().StringVarP(&output, "output", "o", "default", "description")
    cmd.Register(yourCmd)
}

Add a blank import in main.go:

_ "github.com/mj/opengyver/cmd/yourcommand"

Build and run. Your command appears in openGyver --help.

Building from Source

git clone https://github.com/create-flow-ai/openGyver.git
cd openGyver
go build -o openGyver .

Run tests:

go test ./...

Cross-Compilation

GOOS=linux   GOARCH=amd64 go build -o openGyver-linux-amd64 .
GOOS=linux   GOARCH=arm64 go build -o openGyver-linux-arm64 .
GOOS=windows GOARCH=amd64 go build -o openGyver-windows-amd64.exe .
GOOS=darwin  GOARCH=arm64 go build -o openGyver-darwin-arm64 .
GOOS=darwin  GOARCH=amd64 go build -o openGyver-darwin-amd64 .
GOOS=freebsd GOARCH=amd64 go build -o openGyver-freebsd-amd64 .

Each produces a single static binary with zero runtime dependencies.