diff --git a/LICENSE b/LICENSE
new file mode 100644
index 0000000000000000000000000000000000000000..6d37eb5860ab15ca6fc19868b4d9da38742ce9e4
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,21 @@
+The MIT License (MIT)
+
+Copyright © 2024 Kevin Lyda
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
diff --git a/cmd/root.go b/cmd/root.go
new file mode 100644
index 0000000000000000000000000000000000000000..f44849997588309f4f7ec2df3f4814160b2e688a
--- /dev/null
+++ b/cmd/root.go
@@ -0,0 +1,85 @@
+// Package cmd implements the command line interface.
+package cmd
+
+import (
+	"context"
+	"fmt"
+	"os"
+	"os/signal"
+	"syscall"
+
+	"git.lyda.ie/kevin/units/web"
+	"github.com/spf13/cobra"
+	"github.com/spf13/viper"
+)
+
+var cfgFile string
+
+// rootCmd represents the base command when called without any subcommands
+var rootCmd = &cobra.Command{
+	Use:   "units",
+	Short: "Converts unit(s) to unit(s)",
+	Long: `Converts any unit(s) to any other unit(s)
+For example:
+
+TODO: example 1
+TODO: example 2
+TODO: example 3`,
+	Run: run,
+}
+
+func run(_ *cobra.Command, _ []string) {
+	server := &web.Config{}
+
+	ctx, stop := signal.NotifyContext(context.Background(), os.Interrupt, syscall.SIGTERM)
+	defer stop()
+
+	server.Serve(ctx)
+}
+
+// Execute adds all child commands to the root command and sets flags appropriately.
+// This is called by main.main(). It only needs to happen once to the rootCmd.
+func Execute() {
+	err := rootCmd.Execute()
+	if err != nil {
+		os.Exit(1)
+	}
+}
+
+func init() {
+	cobra.OnInitialize(initConfig)
+
+	// Here you will define your flags and configuration settings.
+	// Cobra supports persistent flags, which, if defined here,
+	// will be global for your application.
+
+	rootCmd.PersistentFlags().StringVar(&cfgFile, "config", "", "config file (default is $HOME/.units.yaml)")
+
+	// Cobra also supports local flags, which will only run
+	// when this action is called directly.
+	rootCmd.Flags().BoolP("toggle", "t", false, "Help message for toggle")
+}
+
+// initConfig reads in config file and ENV variables if set.
+func initConfig() {
+	if cfgFile != "" {
+		// Use config file from the flag.
+		viper.SetConfigFile(cfgFile)
+	} else {
+		// Find home directory.
+		home, err := os.UserHomeDir()
+		cobra.CheckErr(err)
+
+		// Search config in home directory with name ".units" (without extension).
+		viper.AddConfigPath(home)
+		viper.SetConfigType("yaml")
+		viper.SetConfigName(".units")
+	}
+
+	viper.AutomaticEnv() // read in environment variables that match
+
+	// If a config file is found, read it in.
+	if err := viper.ReadInConfig(); err == nil {
+		fmt.Fprintln(os.Stderr, "Using config file:", viper.ConfigFileUsed())
+	}
+}
diff --git a/go.mod b/go.mod
new file mode 100644
index 0000000000000000000000000000000000000000..bce4e14fcba8044dfd33ab33190185cbe4044f7b
--- /dev/null
+++ b/go.mod
@@ -0,0 +1,31 @@
+module git.lyda.ie/kevin/units
+
+go 1.22.2
+
+require (
+	github.com/spf13/cobra v1.8.0
+	github.com/spf13/viper v1.19.0
+)
+
+require (
+	github.com/fsnotify/fsnotify v1.7.0 // indirect
+	github.com/hashicorp/hcl v1.0.0 // indirect
+	github.com/inconshreveable/mousetrap v1.1.0 // indirect
+	github.com/magiconair/properties v1.8.7 // indirect
+	github.com/mitchellh/mapstructure v1.5.0 // indirect
+	github.com/pelletier/go-toml/v2 v2.2.2 // indirect
+	github.com/sagikazarmark/locafero v0.4.0 // indirect
+	github.com/sagikazarmark/slog-shim v0.1.0 // indirect
+	github.com/sourcegraph/conc v0.3.0 // indirect
+	github.com/spf13/afero v1.11.0 // indirect
+	github.com/spf13/cast v1.6.0 // indirect
+	github.com/spf13/pflag v1.0.5 // indirect
+	github.com/subosito/gotenv v1.6.0 // indirect
+	go.uber.org/atomic v1.9.0 // indirect
+	go.uber.org/multierr v1.9.0 // indirect
+	golang.org/x/exp v0.0.0-20230905200255-921286631fa9 // indirect
+	golang.org/x/sys v0.18.0 // indirect
+	golang.org/x/text v0.14.0 // indirect
+	gopkg.in/ini.v1 v1.67.0 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
+)
diff --git a/go.sum b/go.sum
new file mode 100644
index 0000000000000000000000000000000000000000..a2c791286a5cbc64fbaa445091e8beced3eab017
--- /dev/null
+++ b/go.sum
@@ -0,0 +1,77 @@
+github.com/cpuguy83/go-md2man/v2 v2.0.3/go.mod h1:tgQtvFlXSQOSOSIRvRPT7W67SCa46tRHOmNcaadrF8o=
+github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/davecgh/go-spew v1.1.2-0.20180830191138-d8f796af33cc h1:U9qPSI2PIWSS1VwoXQT9A3Wy9MM3WgvqSxFWenqJduM=
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diff --git a/main.go b/main.go
new file mode 100644
index 0000000000000000000000000000000000000000..6b681e1c1001ac8b3c63b37a48cb9ebae111388e
--- /dev/null
+++ b/main.go
@@ -0,0 +1,8 @@
+// Package main is the main program.
+package main
+
+import "git.lyda.ie/kevin/units/cmd"
+
+func main() {
+	cmd.Execute()
+}
diff --git a/web/web.go b/web/web.go
new file mode 100644
index 0000000000000000000000000000000000000000..924dd6d73208e56ed25fe8a41014840db3d3032c
--- /dev/null
+++ b/web/web.go
@@ -0,0 +1,16 @@
+// Package web implements the web interface.
+package web
+
+import "context"
+
+// Config contains the web config.
+type Config struct {
+}
+
+// Serve serves the web interface
+func (c *Config) Serve(ctx context.Context) {
+	select {
+	case <-ctx.Done():
+		// exit now.
+	}
+}