diff --git a/.github/workflows/go.yml b/.github/workflows/go.yml
new file mode 100644
index 0000000..07a59c6
--- /dev/null
+++ b/.github/workflows/go.yml
@@ -0,0 +1,24 @@
+name: Go
+
+on: [ push, pull_request ]
+jobs:
+
+  build:
+    name: Build
+    runs-on: ubuntu-latest
+    steps:
+
+    - name: Set up Go 1.x
+      uses: actions/setup-go@v2
+      with:
+        go-version: ^1.21
+      id: go
+
+    - name: Check out code into the Go module directory
+      uses: actions/checkout@v2
+
+    - name: Get dependencies
+      run: go mod download
+
+    - name: Test
+      run: go test -v ./...
diff --git a/README.md b/README.md
index 1acafb5..67d8806 100644
--- a/README.md
+++ b/README.md
@@ -1,2 +1,13 @@
-# pdfcopy
-Quickie script to take screenshots of URLs for copyright submissions
+# pdfcopy [![GoDoc](https://godoc.org/github.com/spotlightpa/pdfcopy?status.svg)](https://godoc.org/github.com/spotlightpa/pdfcopy) [![Go Report Card](https://goreportcard.com/badge/github.com/spotlightpa/pdfcopy)](https://goreportcard.com/report/github.com/spotlightpa/pdfcopy)
+
+Quickie script to take screenshots of URLs for copyright submissions.
+
+## Installation
+
+First install [Go](http://golang.org).
+
+If you just want to install the binary to your current directory and don't care about the source code, run
+
+```bash
+GOBIN="$(pwd)" go install github.com/spotlightpa/pdfcopy@latest
+```
diff --git a/app/app.go b/app/app.go
new file mode 100644
index 0000000..06783ca
--- /dev/null
+++ b/app/app.go
@@ -0,0 +1,180 @@
+package app
+
+import (
+	"context"
+	"crypto/md5"
+	"errors"
+	"flag"
+	"fmt"
+	"io"
+	"io/fs"
+	"log"
+	"os"
+	"os/exec"
+	"os/signal"
+	"path/filepath"
+
+	"github.com/carlmjohnson/csv"
+	"github.com/carlmjohnson/flagx"
+	"github.com/carlmjohnson/flagx/lazyio"
+	"github.com/carlmjohnson/flowmatic"
+	"github.com/carlmjohnson/versioninfo"
+)
+
+const AppName = "pdfcopy"
+
+func CLI(args []string) error {
+	var app appEnv
+	err := app.ParseArgs(args)
+	if err != nil {
+		return err
+	}
+	if err = app.Exec(); err != nil {
+		fmt.Fprintf(os.Stderr, "Error: %v\n", err)
+	}
+	return err
+}
+
+func (app *appEnv) ParseArgs(args []string) error {
+	fl := flag.NewFlagSet(AppName, flag.ContinueOnError)
+	src := lazyio.FileOrURL(lazyio.StdIO, nil)
+	app.src = src
+	fl.Var(src, "src", "source file or URL")
+	fl.StringVar(&app.dst, "dst", "output.pdf", "destination `filepath`")
+	fl.StringVar(&app.temp, "temp", "", "temporary `filepath` for downloads and intermediate PDFs")
+	fl.IntVar(&app.maxProcs, "workers", 10, "number of workers")
+	app.Logger = log.New(os.Stderr, AppName+" ", log.LstdFlags)
+	flagx.BoolFunc(fl, "silent", "log debug output", func() error {
+		app.Logger.SetOutput(io.Discard)
+		return nil
+	})
+	fl.Usage = func() {
+		fmt.Fprintf(fl.Output(), `copyrightpdfs - %s
+
+Download stuff and screenshot it
+
+Usage:
+
+	copyrightpdfs [options]
+
+Options:
+`, versioninfo.Version)
+		fl.PrintDefaults()
+	}
+	versioninfo.AddFlag(fl)
+	if err := fl.Parse(args); err != nil {
+		return err
+	}
+	if err := flagx.ParseEnv(fl, AppName); err != nil {
+		return err
+	}
+	return nil
+}
+
+type appEnv struct {
+	src       io.ReadCloser
+	temp, dst string
+	maxProcs  int
+	*log.Logger
+}
+
+func (app *appEnv) Exec() (err error) {
+	// Open list of URLs
+	urls, err := app.readURLs()
+	if err != nil {
+		return err
+	}
+	if app.temp == "" {
+		// Make temp directory
+		tempdir, err := os.MkdirTemp("", "")
+		if err != nil {
+			return err
+		}
+		app.temp = tempdir
+	}
+	app.Logger.Printf("tempdir %q", app.temp)
+
+	// Start some Flowmatic groups
+	ctx, stop := signal.NotifyContext(context.Background(), os.Interrupt)
+	defer stop()
+
+	err = flowmatic.Each(app.maxProcs, urls, func(url string) error {
+		return app.buildPDF(ctx, url)
+	})
+	if err != nil {
+		return err
+	}
+
+	// Once they're all done'
+	// pdftk ./*.pdf cat output merged.pdf
+	// TODO: The order of PDFs is random. Fix that somehow
+	args, err := filepath.Glob(filepath.Join(app.temp, "*.pdf"))
+	if err != nil {
+		return err
+	}
+	args = append(args, "cat", "output", app.dst)
+	cmd := exec.CommandContext(ctx, "pdftk", args...)
+	cmd.Stdout = os.Stdout
+	cmd.Stderr = os.Stderr
+	app.Logger.Printf("pdftk cat %s", app.dst)
+	if err := cmd.Run(); err != nil {
+		return err
+	}
+
+	return err
+}
+
+func (app *appEnv) readURLs() ([]string, error) {
+	var urls []string
+	fr := csv.NewFieldReader(app.src)
+	for fr.Scan() {
+		urls = append(urls, fr.Field("url"))
+	}
+	return urls, fr.Err()
+}
+
+func (app *appEnv) buildPDF(ctx context.Context, url string) error {
+	hash := md5.Sum([]byte(url))
+	png := fmt.Sprintf("%0x.png", hash)
+	pdf := fmt.Sprintf("%0x.pdf", hash)
+
+	// Skip if stat file
+	_, err := os.Stat(filepath.Join(app.temp, png))
+	switch {
+	case err == nil:
+		app.Logger.Printf("have %s", png)
+	case !errors.Is(err, fs.ErrNotExist):
+		return err
+	default:
+		app.Logger.Printf("start %0x from %q", hash, url)
+		// TODO retry in loop
+		cmd := exec.CommandContext(ctx, "shot-scraper", "--reduced-motion",
+			// TODO figure out whether to use #content or not
+			"-s", "#content",
+			"-p", "16", "--output", png, url)
+		cmd.Dir = app.temp
+		cmd.Stderr = os.Stderr
+		cmd.Stdout = os.Stdout
+		if err := cmd.Run(); err != nil {
+			// mark this up
+			return fmt.Errorf("problem with %q from %q: %w", png, url, err)
+		}
+	}
+	// Skip if stat file
+	_, err = os.Stat(filepath.Join(app.temp, pdf))
+	switch {
+	case err == nil:
+		app.Logger.Printf("have %s", pdf)
+		return nil
+	case !errors.Is(err, fs.ErrNotExist):
+		return err
+	default:
+		cmd := exec.CommandContext(ctx, "convert", png, pdf)
+		cmd.Dir = app.temp
+		if err := cmd.Run(); err != nil {
+			return err
+		}
+	}
+	app.Logger.Printf("done %0x from %q", hash, url)
+	return nil
+}
diff --git a/go.mod b/go.mod
new file mode 100644
index 0000000..4ad05f7
--- /dev/null
+++ b/go.mod
@@ -0,0 +1,13 @@
+module github.com/spotlightpa/pdfcopy
+
+go 1.21
+
+require (
+	github.com/carlmjohnson/csv v1.20.0
+	github.com/carlmjohnson/exitcode v0.20.2
+	github.com/carlmjohnson/flagx v0.22.2
+	github.com/carlmjohnson/flowmatic v0.23.4
+	github.com/carlmjohnson/versioninfo v0.22.5
+)
+
+require github.com/carlmjohnson/deque v0.23.1 // indirect
diff --git a/go.sum b/go.sum
new file mode 100644
index 0000000..c5e88de
--- /dev/null
+++ b/go.sum
@@ -0,0 +1,14 @@
+github.com/carlmjohnson/be v0.22.3 h1:XwpxXz+wHvZ6O+i/IxcVQaGinsDkF99bpq0VXno6Voc=
+github.com/carlmjohnson/be v0.22.3/go.mod h1:KAgPUh0HpzWYZZI+IABdo80wTgY43YhbdsiLYAaSI/Q=
+github.com/carlmjohnson/csv v1.20.0 h1:/QBKcZdJY0FMerK6m+uMgZRwmQ33Uj5NBqkqcitstcY=
+github.com/carlmjohnson/csv v1.20.0/go.mod h1:I2Bsj5YPd8aGaLfXelcf4ANJpFlrPYkgpJnwCsTdNbI=
+github.com/carlmjohnson/deque v0.23.1 h1:X2HOJM9xcglY03deMZ0oZ1V2xtbqYV7dJDnZiSZN4Ak=
+github.com/carlmjohnson/deque v0.23.1/go.mod h1:LF5NJjICBrEOPx84pxPL4nCimy5n9NQjxKi5cXkh+8U=
+github.com/carlmjohnson/exitcode v0.20.2 h1:vE6rmkCGNA4kO4m1qwWIa77PKlUBVg46cNjs22eAOXE=
+github.com/carlmjohnson/exitcode v0.20.2/go.mod h1:MZ6ThCDx517DQcrpYnnns1pLh8onjFl+B/AsrOrdmpc=
+github.com/carlmjohnson/flagx v0.22.2 h1:UXf7gL4Ffv5RIH/HKp8CGNzDyopgezFLrDO1m4F8jWc=
+github.com/carlmjohnson/flagx v0.22.2/go.mod h1:obobISvBnxgEXPLBITVXhRUOlSlzza1SGt34M64CPJc=
+github.com/carlmjohnson/flowmatic v0.23.4 h1:SfK6f+zKUlw4aga1ph+7/csqVeUAWnBxfqKN5gvQzzs=
+github.com/carlmjohnson/flowmatic v0.23.4/go.mod h1:Jpvyl591Dvkt9chYpnVupjxlKvqkZ9CtCmqL4wfQD7U=
+github.com/carlmjohnson/versioninfo v0.22.5 h1:O00sjOLUAFxYQjlN/bzYTuZiS0y6fWDQjMRvwtKgwwc=
+github.com/carlmjohnson/versioninfo v0.22.5/go.mod h1:QT9mph3wcVfISUKd0i9sZfVrPviHuSF+cUtLjm2WSf8=
diff --git a/main.go b/main.go
new file mode 100644
index 0000000..6d28033
--- /dev/null
+++ b/main.go
@@ -0,0 +1,12 @@
+package main
+
+import (
+	"os"
+
+	"github.com/carlmjohnson/exitcode"
+	"github.com/spotlightpa/pdfcopy/app"
+)
+
+func main() {
+	exitcode.Exit(app.CLI(os.Args[1:]))
+}