diff --git a/.envrc b/.envrc
deleted file mode 100644
index ed1e8be..0000000
--- a/.envrc
+++ /dev/null
@@ -1,3 +0,0 @@
-watch_file flake.nix flake.lock
-
-use flake . --no-pure-eval
diff --git a/2025/cmd/generate/cmd.go b/2025/cmd/generate/cmd.go
new file mode 100644
index 0000000..1145924
--- /dev/null
+++ b/2025/cmd/generate/cmd.go
@@ -0,0 +1,49 @@
+package generate
+
+import (
+	"fmt"
+	"log"
+	"os"
+	"strconv"
+
+	"github.com/spf13/cobra"
+)
+
+func handleErr(err error, folder string) {
+	os.RemoveAll(folder)
+	log.Fatal(err)
+}
+
+var GenerateCmd = &cobra.Command{
+	Use:   "generate",
+	Short: "Generate a new day directory",
+	Args:  cobra.ExactArgs(1),
+	Run: func(cmd *cobra.Command, args []string) {
+		day, err := strconv.Atoi(args[0])
+		if err != nil {
+			log.Fatal(err)
+		}
+
+		folder := fmt.Sprintf("./day%02d", day)
+		if err := os.Mkdir(folder, 0755); err != nil {
+			log.Fatal(err)
+		}
+
+		if err := generateMainCode(day); err != nil {
+			handleErr(err, folder)
+		}
+
+		if err := generateTestCode(day); err != nil {
+			handleErr(err, folder)
+		}
+
+		if err := retrieveInput(day); err != nil {
+			handleErr(err, folder)
+		}
+
+		filename := fmt.Sprintf("./day%02d/test.txt", day)
+		if err := os.WriteFile(filename, []byte{}, 0755); err != nil {
+			handleErr(err, folder)
+		}
+	},
+}
diff --git a/2025/cmd/generate/fetch_input.go b/2025/cmd/generate/fetch_input.go
new file mode 100644
index 0000000..3cd1852
--- /dev/null
+++ b/2025/cmd/generate/fetch_input.go
@@ -0,0 +1,92 @@
+package generate
+
+import (
+	"fmt"
+	"io"
+	"net/http"
+	"net/http/cookiejar"
+	"net/url"
+	"os"
+)
+
+const (
+	baseURL       = "https://adventofcode.com/2025/day/%d/input"
+	host          = "adventofcode.com"
+	userAgent     = "github.com/C4theBomb/advent-of-code by c4patino@gmail.com"
+	cookieEnvName = "COOKIE"
+)
+
+func getCookie() (string, error) {
+	cookieValue := os.Getenv(cookieEnvName)
+	if cookieValue == "" {
+		return "", fmt.Errorf("%s environment variable not set", cookieEnvName)
+	}
+
+	return cookieValue, nil
+
+}
+
+func createHTTPClient(cookieValue string) (*http.Client, error) {
+	jar, err := cookiejar.New(nil)
+	if err != nil {
+		return nil, fmt.Errorf("failed to create cookie jar: %w", err)
+	}
+
+	domainURL := &url.URL{Scheme: "https", Host: host}
+
+	client := &http.Client{Jar: jar}
+	jar.SetCookies(domainURL, []*http.Cookie{{Name: "session", Value: cookieValue}})
+
+	return client, nil
+}
+
+func fetchInput(client *http.Client, day int) ([]byte, error) {
+	url := fmt.Sprintf(baseURL, day)
+	req, err := http.NewRequest("GET", url, nil)
+	if err != nil {
+		return nil, fmt.Errorf("failed to create request: %w", err)
+	}
+
+	req.Header.Set("User-Agent", userAgent)
+
+	resp, err := client.Do(req)
+	if err != nil {
+		return nil, fmt.Errorf("request failed: %w", err)
+	}
+	defer resp.Body.Close()
+
+	body, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return nil, fmt.Errorf("failed to read response body: %w", err)
+	}
+
+	if resp.StatusCode != http.StatusOK {
+		return nil, fmt.Errorf("unexpected status code %d: %s", resp.StatusCode, string(body))
+	}
+
+	return body, nil
+}
+
+func retrieveInput(day int) error {
+	cookieValue, err := getCookie()
+	if err != nil {
+		return err
+	}
+
+	client, err := createHTTPClient(cookieValue)
+	if err != nil {
+		return err
+	}
+
+	body, err := fetchInput(client, day)
+	if err != nil {
+		return err
+	}
+
+	filename := fmt.Sprintf("./day%02d/input.txt", day)
+	if err := os.WriteFile(filename, []byte(body), 0755); err != nil {
+		return err
+	}
+
+	return nil
+}
diff --git a/2025/cmd/generate/main_template.go b/2025/cmd/generate/main_template.go
new file mode 100644
index 0000000..70b87e4
--- /dev/null
+++ b/2025/cmd/generate/main_template.go
@@ -0,0 +1,66 @@
+package generate
+
+import (
+	"fmt"
+	"os"
+	"os/exec"
+)
+
+const mainCodeTemplate = `package day%02d
+
+import (
+	"bufio"
+	"fmt"
+	"os"
+)
+
+
+func Part1() int {
+	return -1
+}
+
+func Part2() int {
+	return -1
+}
+
+func Run(filename string) (any, any) {
+	file, err := os.Open(filename)
+	if err != nil {
+		panic(err)
+	}
+	defer file.Close()
+
+	scanner := bufio.NewScanner(file)
+	for scanner.Scan() {
+		line := scanner.Text()
+
+		fmt.Println(line)
+	}
+
+	if err := scanner.Err(); err != nil {
+		panic(err)
+	}
+
+	part1 := Part1()
+	part2 := Part2()
+
+	return part1, part2
+}
+`
+
+func generateMainCode(day int) error {
+	testCode := fmt.Sprintf(mainCodeTemplate, day)
+
+	filename := fmt.Sprintf("./day%02d/day%02d.go", day, day)
+
+	if err := os.WriteFile(filename, []byte(testCode), 0755); err != nil {
+		return err
+	}
+
+	cmd := exec.Command("go", "fmt", filename)
+	if err := cmd.Run(); err != nil {
+		return err
+	}
+
+	return nil
+}
diff --git a/2025/cmd/generate/test_template.go b/2025/cmd/generate/test_template.go
new file mode 100644
index 0000000..3d9020e
--- /dev/null
+++ b/2025/cmd/generate/test_template.go
@@ -0,0 +1,60 @@
+package generate
+
+import (
+	"fmt"
+	"os"
+	"os/exec"
+)
+
+const testCodeTemplate = `package day%02d
+
+import (
+	"os"
+	"testing"
+)
+
+type TestCase struct {
+	FileName string
+	Part1    any
+	Part2    any
+}
+
+func TestDay%02d(t *testing.T) {
+	tests := []TestCase{
+		{"test.txt", -1, -1},
+		// {"input.txt", -1, -1},
+	}
+
+	for _, test := range tests {
+		if _, err := os.Stat(test.FileName); os.IsNotExist(err) {
+			t.Fatalf("test file does not exist: %%v", test.FileName)
+		}
+
+		part1, part2 := Run(test.FileName)
+		if test.Part1 != nil && part1 != test.Part1 {
+			t.Fatalf("%%s: unexpected part1:\nwant:\t%%v\ngot:\t%%v", test.FileName, test.Part1, part1)
+		}
+
+		if test.Part2 != nil && part2 != test.Part2 {
+			t.Fatalf("%%s: unexpected part2:\nwant:\t%%v\ngot:\t%%v", test.FileName, test.Part2, part2)
+		}
+	}
+}
+`
+
+func generateTestCode(day int) error {
+	testCode := fmt.Sprintf(testCodeTemplate, day, day)
+
+	filename := fmt.Sprintf("./day%02d/day%02d_test.go", day, day)
+
+	if err := os.WriteFile(filename, []byte(testCode), 0755); err != nil {
+		return err
+	}
+
+	cmd := exec.Command("go", "fmt", filename)
+	if err := cmd.Run(); err != nil {
+		return err
+	}
+
+	return nil
+}
diff --git a/2025/cmd/root.go b/2025/cmd/root.go
new file mode 100644
index 0000000..77d6f87
--- /dev/null
+++ b/2025/cmd/root.go
@@ -0,0 +1,61 @@
+package cmd
+
+import (
+	"fmt"
+	"log"
+	"os"
+	"strconv"
+
+	"cpatino.com/advent-of-code/2025/cmd/generate"
+	"github.com/spf13/cobra"
+)
+
+var days = map[int]func(string) (any, any){}
+
+var rootCmd = &cobra.Command{
+	Use:   "advent-of-code",
+	Short: "Advent of Code 2024",
+	Args:  cobra.ExactArgs(1),
+	Run: func(cmd *cobra.Command, args []string) {
+		day, err := strconv.Atoi(args[0])
+		if err != nil {
+			log.Fatal(err)
+		}
+
+		file, _ := cmd.Flags().GetString("file")
+		if file == "" {
+			file = fmt.Sprintf("./day%02d/input.txt", day)
+		}
+
+		if _, err := os.Stat(file); os.IsNotExist(err) {
+			log.Fatalf("file does not exist: %s", file)
+		}
+
+		log.Printf("Day: %d, Input File: %s\n", day, file)
+
+		part1, part2 := days[day](file)
+
+		log.Printf("Part 1: %v\n", part1)
+		log.Printf("Part 2: %v\n", part2)
+	},
+}
+
+func init() {
+	rootCmd.AddCommand(generate.GenerateCmd)
+	rootCmd.Flags().String("file", "", "Path to a file")
+}
+
+func Execute() error {
+	if len(os.Args) == 1 {
+		return rootCmd.Execute()
+	}
+
+	subCmd := os.Args[1]
+	for _, cmd := range rootCmd.Commands() {
+		if cmd.Use == subCmd {
+			return cmd.Execute()
+		}
+	}
+
+	return rootCmd.Execute()
+}
diff --git a/2025/cmd/update/main.go b/2025/cmd/update/main.go
new file mode 100644
index 0000000..dda2e91
--- /dev/null
+++ b/2025/cmd/update/main.go
@@ -0,0 +1,118 @@
+package main
+
+import (
+	"fmt"
+	"log"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"strconv"
+	"strings"
+)
+
+func main() {
+	const mainTemplate = `package cmd
+
+import (
+	"fmt"
+	"log"
+	"os"
+	"strconv"
+
+	"github.com/spf13/cobra"
+	"cpatino.com/advent-of-code/2025/cmd/generate"
+
+	%s
+)
+
+var days = map[int]func(string) (any, any){
+	%s
+}
+
+var rootCmd = &cobra.Command{
+	Use:   "advent-of-code",
+	Short: "Advent of Code 2024",
+	Args:  cobra.ExactArgs(1),
+	Run: func(cmd *cobra.Command, args []string) {
+		day, err := strconv.Atoi(args[0])
+		if err != nil {
+			log.Fatal(err)
+		}
+
+		file, _ := cmd.Flags().GetString("file")
+		if file == "" {
+			file = fmt.Sprintf("./day%%02d/input.txt", day)
+		}
+
+		if _, err := os.Stat(file); os.IsNotExist(err) {
+			log.Fatalf("file does not exist: %%s", file)
+		}
+
+		log.Printf("Day: %%d, Input File: %%s\n", day, file)
+
+		part1, part2 := days[day](file)
+
+		log.Printf("Part 1: %%v\n", part1)
+		log.Printf("Part 2: %%v\n", part2)
+	},
+}
+
+func init() {
+	rootCmd.AddCommand(generate.GenerateCmd)
+	rootCmd.Flags().String("file", "", "Path to a file")
+}
+
+func Execute() error {
+	if len(os.Args) == 1 {
+		return rootCmd.Execute()
+	}
+
+	subCmd := os.Args[1]
+	for _, cmd := range rootCmd.Commands() {
+		if cmd.Use == subCmd {
+			return cmd.Execute()
+		}
+	}
+
+	return rootCmd.Execute()
+}
+`
+
+	var imports, mappings strings.Builder
+
+	err := filepath.Walk("./", func(path string, info os.FileInfo, err error) error {
+		if !info.IsDir() || !strings.HasPrefix(info.Name(), "day") {
+			return nil
+		}
+
+		dayStr := strings.TrimPrefix(info.Name(), "day")
+
+		day, err := strconv.Atoi(dayStr)
+		if err != nil {
+			log.Fatal(err)
+		}
+
+		imports.WriteString(fmt.Sprintf("\t\"cpatino.com/advent-of-code/2025/day%02d\"\n", day))
+		mappings.WriteString(fmt.Sprintf("\t%d: day%02d.Run,\n", day, day))
+
+		return nil
+	})
+
+	importsStr := strings.TrimSpace(imports.String())
+	mappingsStr := strings.TrimSpace(mappings.String())
+
+	if err != nil {
+		fmt.Println("Error walking the path:", err)
+		os.Exit(1)
+	}
+
+	mainCode := fmt.Sprintf(mainTemplate, importsStr, mappingsStr)
+
+	os.WriteFile("./cmd/root.go", []byte(mainCode), 0644)
+
+	cmd := exec.Command("go", "fmt", "./cmd/root.go")
+	if err := cmd.Run(); err != nil {
+		fmt.Println("Error running go fmt:", err)
+		os.Exit(1)
+	}
+}
diff --git a/2025/go.mod b/2025/go.mod
new file mode 100644
index 0000000..0f96860
--- /dev/null
+++ b/2025/go.mod
@@ -0,0 +1,10 @@
+module cpatino.com/advent-of-code/2025
+
+go 1.23.3
+
+require github.com/spf13/cobra v1.8.1
+
+require (
+	github.com/inconshreveable/mousetrap v1.1.0 // indirect
+	github.com/spf13/pflag v1.0.5 // indirect
+)
diff --git a/2025/go.sum b/2025/go.sum
new file mode 100644
index 0000000..912390a
--- /dev/null
+++ b/2025/go.sum
@@ -0,0 +1,10 @@
+github.com/cpuguy83/go-md2man/v2 v2.0.4/go.mod h1:tgQtvFlXSQOSOSIRvRPT7W67SCa46tRHOmNcaadrF8o=
+github.com/inconshreveable/mousetrap v1.1.0 h1:wN+x4NVGpMsO7ErUn/mUI3vEoE6Jt13X2s0bqwp9tc8=
+github.com/inconshreveable/mousetrap v1.1.0/go.mod h1:vpF70FUmC8bwa3OWnCshd2FqLfsEA9PFc4w1p2J65bw=
+github.com/russross/blackfriday/v2 v2.1.0/go.mod h1:+Rmxgy9KzJVeS9/2gXHxylqXiyQDYRxCVz55jmeOWTM=
+github.com/spf13/cobra v1.8.1 h1:e5/vxKd/rZsfSJMUX1agtjeTDf+qv1/JdBF8gg5k9ZM=
+github.com/spf13/cobra v1.8.1/go.mod h1:wHxEcudfqmLYa8iTfL+OuZPbBZkmvliBWKIezN3kD9Y=
+github.com/spf13/pflag v1.0.5 h1:iy+VFUOCP1a+8yFto/drg2CJ5u0yRoB7fZw3DKv/JXA=
+github.com/spf13/pflag v1.0.5/go.mod h1:McXfInJRrz4CZXVZOBLb0bTZqETkiAhM9Iw0y3An2Bg=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
diff --git a/2025/main.go b/2025/main.go
new file mode 100644
index 0000000..3e1fd17
--- /dev/null
+++ b/2025/main.go
@@ -0,0 +1,14 @@
+//go:generate go run ./cmd/update
+package main
+
+import (
+	"log"
+
+	"cpatino.com/advent-of-code/2025/cmd"
+)
+
+func main() {
+	log.SetFlags(0)
+
+	cmd.Execute()
+}