Add self-update command (same update)

- Check GitHub releases for latest version
- Download correct binary for platform (darwin-arm64, linux-amd64, windows-amd64)
- Atomically replace the current binary
- --force flag to reinstall even if on latest
- Gracefully handle dev builds
- Update version check to suggest `same update` instead of curl

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: sgx-labs

CHANGELOG.md

@@ -1,5 +1,24 @@
 # Changelog
 
+## v0.5.2 — Self-Update
+
+One-command updates, no more curl.
+
+### Added
+
+- **`same update`** — Check for and install the latest version from GitHub releases
+  - Detects platform (darwin-arm64, linux-amd64, windows-amd64)
+  - Downloads correct binary
+  - Replaces itself atomically
+  - `--force` flag to reinstall even if on latest
+- Handles dev builds gracefully (warns instead of failing)
+
+### Changed
+
+- Version check now suggests `same update` instead of curl command
+
+---
+
 ## v0.5.1 — Onboarding & UX Polish
 
 Better first-run experience and vibe-coder friendly commands.

Makefile

@@ -1,6 +1,6 @@
 BINARY_NAME := same
 BUILD_DIR := build
-VERSION := 0.5.0
+VERSION := 0.5.2
 LDFLAGS := -ldflags "-s -w -X main.Version=$(VERSION)"
 
 # CGO is required for sqlite3 + sqlite-vec

cmd/same/main.go

@@ -9,6 +9,7 @@ import (
 	"os"
 	"os/exec"
 	"path/filepath"
+	"runtime"
 	"sort"
 	"strings"
 	"time"
@@ -65,6 +66,7 @@ Need help? https://discord.gg/GZGHtrrKF2`,
 
 	root.AddCommand(initCmd())
 	root.AddCommand(versionCmd())
+	root.AddCommand(updateCmd())
 	root.AddCommand(reindexCmd())
 	root.AddCommand(statsCmd())
 	root.AddCommand(migrateCmd())
@@ -155,13 +157,213 @@ func runVersionCheck() error {
 
 	if latestVer != currentVer && latestVer > currentVer {
 		// Output as hook-compatible JSON for SessionStart hook
-		fmt.Printf(`{"hookSpecificOutput":{"hookEventName":"SessionStart","additionalContext":"\n\n**SAME update available:** %s → %s\nRun: same version --check\nInstall: curl -fsSL https://raw.githubusercontent.com/sgx-labs/statelessagent/main/install.sh | bash\n\n"}}`, currentVer, latestVer)
+		fmt.Printf(`{"hookSpecificOutput":{"hookEventName":"SessionStart","additionalContext":"\n\n**SAME update available:** %s → %s\nRun: same update\n\n"}}`, currentVer, latestVer)
 		fmt.Println()
 	}
 
 	return nil
 }
 
+func updateCmd() *cobra.Command {
+	var force bool
+	cmd := &cobra.Command{
+		Use:   "update",
+		Short: "Update SAME to the latest version",
+		Long: `Check for and install the latest version of SAME from GitHub releases.
+
+This command will:
+  1. Check the current version against GitHub releases
+  2. Download the appropriate binary for your platform
+  3. Replace the current binary with the new version
+
+Example:
+  same update          Check and install if newer version available
+  same update --force  Force reinstall even if already on latest`,
+		RunE: func(cmd *cobra.Command, args []string) error {
+			return runUpdate(force)
+		},
+	}
+	cmd.Flags().BoolVar(&force, "force", false, "Force update even if already on latest version")
+	return cmd
+}
+
+func runUpdate(force bool) error {
+	cli.Header("SAME Update")
+	fmt.Println()
+
+	// Get current version
+	currentVer := strings.TrimPrefix(Version, "v")
+	fmt.Printf("  Current version: %s%s%s\n", cli.Bold, Version, cli.Reset)
+
+	if Version == "dev" && !force {
+		fmt.Printf("\n  %s⚠%s  Running dev build (built from source)\n", cli.Yellow, cli.Reset)
+		fmt.Println("     Use --force to update anyway, or rebuild from source.")
+		return nil
+	}
+
+	// Fetch latest release from GitHub
+	fmt.Printf("  Checking GitHub releases...")
+
+	client := &http.Client{Timeout: 10 * time.Second}
+	resp, err := client.Get("https://api.github.com/repos/sgx-labs/statelessagent/releases/latest")
+	if err != nil {
+		fmt.Printf(" %sfailed%s\n", cli.Red, cli.Reset)
+		return fmt.Errorf("cannot reach GitHub: %w", err)
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != 200 {
+		fmt.Printf(" %sfailed%s\n", cli.Red, cli.Reset)
+		return fmt.Errorf("GitHub API returned %d", resp.StatusCode)
+	}
+
+	body, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return fmt.Errorf("read response: %w", err)
+	}
+
+	var release struct {
+		TagName string `json:"tag_name"`
+		HTMLURL string `json:"html_url"`
+		Assets  []struct {
+			Name               string `json:"name"`
+			BrowserDownloadURL string `json:"browser_download_url"`
+		} `json:"assets"`
+	}
+	if err := json.Unmarshal(body, &release); err != nil {
+		return fmt.Errorf("parse release: %w", err)
+	}
+
+	latestVer := strings.TrimPrefix(release.TagName, "v")
+	fmt.Printf(" %s✓%s\n", cli.Green, cli.Reset)
+	fmt.Printf("  Latest version:  %s%s%s\n", cli.Bold, release.TagName, cli.Reset)
+
+	// Compare versions
+	if latestVer == currentVer && !force {
+		fmt.Printf("\n  %s✓%s Already on the latest version.\n\n", cli.Green, cli.Reset)
+		return nil
+	}
+
+	if latestVer <= currentVer && !force {
+		fmt.Printf("\n  %s✓%s Already up to date.\n\n", cli.Green, cli.Reset)
+		return nil
+	}
+
+	// Determine the asset to download
+	goos := runtime.GOOS
+	goarch := runtime.GOARCH
+
+	var assetName string
+	switch {
+	case goos == "darwin" && goarch == "arm64":
+		assetName = "same-darwin-arm64"
+	case goos == "darwin" && goarch == "amd64":
+		assetName = "same-darwin-amd64"
+	case goos == "linux" && goarch == "amd64":
+		assetName = "same-linux-amd64"
+	case goos == "windows" && goarch == "amd64":
+		assetName = "same-windows-amd64.exe"
+	default:
+		return fmt.Errorf("unsupported platform: %s/%s", goos, goarch)
+	}
+
+	// Find the download URL
+	var downloadURL string
+	for _, asset := range release.Assets {
+		if asset.Name == assetName {
+			downloadURL = asset.BrowserDownloadURL
+			break
+		}
+	}
+
+	if downloadURL == "" {
+		return fmt.Errorf("no binary found for %s/%s in release %s", goos, goarch, release.TagName)
+	}
+
+	fmt.Printf("\n  Downloading %s...", assetName)
+
+	// Download to temp file
+	dlResp, err := client.Get(downloadURL)
+	if err != nil {
+		fmt.Printf(" %sfailed%s\n", cli.Red, cli.Reset)
+		return fmt.Errorf("download: %w", err)
+	}
+	defer dlResp.Body.Close()
+
+	if dlResp.StatusCode != 200 {
+		fmt.Printf(" %sfailed%s\n", cli.Red, cli.Reset)
+		return fmt.Errorf("download returned %d", dlResp.StatusCode)
+	}
+
+	// Get current executable path
+	execPath, err := os.Executable()
+	if err != nil {
+		return fmt.Errorf("cannot determine executable path: %w", err)
+	}
+	execPath, err = filepath.EvalSymlinks(execPath)
+	if err != nil {
+		return fmt.Errorf("resolve symlinks: %w", err)
+	}
+
+	// Create temp file in same directory (for atomic rename)
+	tmpFile, err := os.CreateTemp(filepath.Dir(execPath), "same-update-*")
+	if err != nil {
+		fmt.Printf(" %sfailed%s\n", cli.Red, cli.Reset)
+		return fmt.Errorf("create temp file: %w", err)
+	}
+	tmpPath := tmpFile.Name()
+
+	// Download the file
+	_, err = io.Copy(tmpFile, dlResp.Body)
+	tmpFile.Close()
+	if err != nil {
+		os.Remove(tmpPath)
+		fmt.Printf(" %sfailed%s\n", cli.Red, cli.Reset)
+		return fmt.Errorf("write file: %w", err)
+	}
+
+	// Make executable
+	if err := os.Chmod(tmpPath, 0755); err != nil {
+		os.Remove(tmpPath)
+		fmt.Printf(" %sfailed%s\n", cli.Red, cli.Reset)
+		return fmt.Errorf("chmod: %w", err)
+	}
+
+	fmt.Printf(" %s✓%s\n", cli.Green, cli.Reset)
+
+	// Replace the binary
+	fmt.Printf("  Installing...")
+
+	// On Windows, we need to rename the old binary first
+	if goos == "windows" {
+		oldPath := execPath + ".old"
+		os.Remove(oldPath) // ignore error
+		if err := os.Rename(execPath, oldPath); err != nil {
+			os.Remove(tmpPath)
+			fmt.Printf(" %sfailed%s\n", cli.Red, cli.Reset)
+			return fmt.Errorf("backup old binary: %w", err)
+		}
+	}
+
+	// Atomic rename
+	if err := os.Rename(tmpPath, execPath); err != nil {
+		os.Remove(tmpPath)
+		fmt.Printf(" %sfailed%s\n", cli.Red, cli.Reset)
+		return fmt.Errorf("install: %w", err)
+	}
+
+	fmt.Printf(" %s✓%s\n", cli.Green, cli.Reset)
+
+	// Success message
+	fmt.Println()
+	fmt.Printf("  %s✓%s Updated to %s%s%s\n", cli.Green, cli.Reset, cli.Bold, release.TagName, cli.Reset)
+	fmt.Println()
+	fmt.Printf("  Run %ssame doctor%s to verify.\n", cli.Bold, cli.Reset)
+
+	cli.Footer()
+	return nil
+}
+
 func reindexCmd() *cobra.Command {
 	var force bool
 	cmd := &cobra.Command{