diff --git a/cmd/picoclaw-launcher-tui/ui/gateway.go b/cmd/picoclaw-launcher-tui/ui/gateway.go
index 1138c12db..397b712f7 100644
--- a/cmd/picoclaw-launcher-tui/ui/gateway.go
+++ b/cmd/picoclaw-launcher-tui/ui/gateway.go
@@ -35,24 +35,26 @@ func getPidPath() string {
 }
 
 func isProcessRunning(pid int) bool {
-	if runtime.GOOS == "windows" {
+	switch runtime.GOOS {
+	case "windows":
 		cmd := exec.Command("tasklist", "/FI", fmt.Sprintf("PID eq %d", pid))
 		output, err := cmd.Output()
 		if err != nil {
 			return false
 		}
 		return strings.Contains(string(output), strconv.Itoa(pid))
-	} else if runtime.GOOS == "darwin" {
+	case "darwin":
 		cmd := exec.Command("ps", "aux")
 		output, err := cmd.Output()
 		if err != nil {
 			return false
 		}
 		return strings.Contains(string(output), fmt.Sprintf(" %d ", pid))
+	default:
+		// Linux and other unix-like systems.
+		_, err := os.Stat(fmt.Sprintf("/proc/%d", pid))
+		return err == nil
 	}
-	// Linux
-	_, err := os.Stat(fmt.Sprintf("/proc/%d", pid))
-	return err == nil
 }
 
 func getGatewayStatus() gatewayStatus {
diff --git a/web/backend/api/router.go b/web/backend/api/router.go
index ce652d4c4..af490d8b5 100644
--- a/web/backend/api/router.go
+++ b/web/backend/api/router.go
@@ -76,6 +76,9 @@ func (h *Handler) RegisterRoutes(mux *http.ServeMux) {
 	// Launcher service parameters (port/public)
 	h.registerLauncherConfigRoutes(mux)
 
+	// Runtime build/version metadata
+	h.registerVersionRoutes(mux)
+
 	// WeChat QR login flow
 	h.registerWeixinRoutes(mux)
 
diff --git a/web/backend/api/version.go b/web/backend/api/version.go
new file mode 100644
index 000000000..6232b989b
--- /dev/null
+++ b/web/backend/api/version.go
@@ -0,0 +1,345 @@
+package api
+
+import (
+	"bufio"
+	"context"
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"os/exec"
+	"regexp"
+	"runtime"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/sipeed/picoclaw/pkg/config"
+	"github.com/sipeed/picoclaw/web/backend/utils"
+)
+
+type systemVersionResponse struct {
+	Version   string `json:"version"`
+	GitCommit string `json:"git_commit,omitempty"`
+	BuildTime string `json:"build_time,omitempty"`
+	GoVersion string `json:"go_version"`
+}
+
+type cachedSystemVersion struct {
+	value      systemVersionResponse
+	gatewayPID int
+}
+
+type systemVersionCache struct {
+	mu         sync.Mutex
+	current    cachedSystemVersion
+	hasCurrent bool
+	inflightCh chan struct{}
+}
+
+func newSystemVersionCache() *systemVersionCache {
+	return &systemVersionCache{}
+}
+
+var (
+	// 15 seconds matches the gateway startup window used elsewhere in launcher flow,
+	// giving slow/embedded hosts enough time for first command invocation while
+	// staying independent from cross-file init ordering.
+	versionCmdTimeout           = 15 * time.Second
+	maxVersionResolveAttempts   = 3
+	findPicoclawBinaryForInfo   = resolveGatewayBinaryForVersionInfo
+	runPicoclawVersionOutput    = executePicoclawVersion
+	currentGatewayVersionState  = gatewayVersionState
+	launcherBuildInfoForVersion = fallbackSystemVersionInfoFromConfig
+	versionInfoCache            = newSystemVersionCache()
+	ansiEscapePattern           = regexp.MustCompile(`\x1b\[[0-9;]*m`)
+	versionLinePattern          = regexp.MustCompile(
+		`^(?:[^A-Za-z0-9]*\s*)?picoclaw(?:\.exe)?\s+([^\s(]+)` +
+			`(?:\s+\(git:\s*([^)]+)\))?\s*$`,
+	)
+)
+
+func (h *Handler) registerVersionRoutes(mux *http.ServeMux) {
+	mux.HandleFunc("GET /api/system/version", h.handleGetVersion)
+}
+
+// handleGetVersion returns runtime version information for web clients.
+func (h *Handler) handleGetVersion(w http.ResponseWriter, r *http.Request) {
+	versionInfo := h.resolveSystemVersionInfo(r.Context())
+
+	w.Header().Set("Content-Type", "application/json")
+	if err := json.NewEncoder(w).Encode(versionInfo); err != nil {
+		http.Error(w, "Failed to encode response", http.StatusInternalServerError)
+		return
+	}
+}
+
+// resolveSystemVersionInfo prefers the actual picoclaw binary version output,
+// and falls back to launcher build metadata when command execution fails.
+func (h *Handler) resolveSystemVersionInfo(ctx context.Context) systemVersionResponse {
+	for range maxVersionResolveAttempts {
+		gatewayPID, gatewayAlive := currentGatewayVersionState()
+		if cached, ok := versionInfoCache.get(gatewayPID, gatewayAlive); ok {
+			return cached
+		}
+
+		leader, ok := versionInfoCache.waitOrStart(ctx)
+		if !ok {
+			return fallbackSystemVersionInfo()
+		}
+		if !leader {
+			continue
+		}
+
+		resolved := h.resolveSystemVersionInfoUncached(ctx)
+		gatewayPID, gatewayAlive = currentGatewayVersionState()
+		versionInfoCache.finishResolve(resolved, gatewayPID, gatewayAlive)
+		return resolved
+	}
+
+	return fallbackSystemVersionInfo()
+}
+
+func (h *Handler) resolveSystemVersionInfoUncached(ctx context.Context) systemVersionResponse {
+	if ctx == nil {
+		ctx = context.Background()
+	}
+
+	fallback := fallbackSystemVersionInfo()
+
+	execPath := strings.TrimSpace(findPicoclawBinaryForInfo())
+	if execPath == "" {
+		return fallback
+	}
+
+	cmdCtx, cancel := context.WithTimeout(ctx, versionCmdTimeout)
+	defer cancel()
+
+	output, err := runPicoclawVersionOutput(cmdCtx, execPath)
+	if err != nil {
+		return fallback
+	}
+
+	parsed, ok := parsePicoclawVersionOutput(output)
+	if !ok {
+		return fallback
+	}
+
+	if parsed.GoVersion == "" {
+		parsed.GoVersion = fallback.GoVersion
+		if parsed.GoVersion == "" {
+			parsed.GoVersion = runtime.Version()
+		}
+	}
+
+	return parsed
+}
+
+func fallbackSystemVersionInfo() systemVersionResponse {
+	return launcherBuildInfoForVersion()
+}
+
+func fallbackSystemVersionInfoFromConfig() systemVersionResponse {
+	buildTime, goVer := config.FormatBuildInfo()
+	return systemVersionResponse{
+		Version:   config.GetVersion(),
+		GitCommit: config.GitCommit,
+		BuildTime: buildTime,
+		GoVersion: goVer,
+	}
+}
+
+// resolveGatewayBinaryForVersionInfo uses the same executable as the launcher
+// gateway start path when available, then falls back to launcher binary lookup.
+// This keeps version probing aligned with the actual gateway startup behavior,
+// so web and gateway do not drift onto different binaries.
+func resolveGatewayBinaryForVersionInfo() string {
+	gateway.mu.Lock()
+	cmd := gateway.cmd
+	gateway.mu.Unlock()
+
+	if cmd != nil {
+		if execPath := strings.TrimSpace(cmd.Path); execPath != "" {
+			return execPath
+		}
+	}
+
+	return utils.FindPicoclawBinary()
+}
+
+func gatewayVersionState() (int, bool) {
+	gateway.mu.Lock()
+	defer gateway.mu.Unlock()
+
+	if gateway.cmd == nil || gateway.cmd.Process == nil {
+		return 0, false
+	}
+	pid := gateway.cmd.Process.Pid
+	if pid <= 0 {
+		return 0, false
+	}
+
+	return pid, isCmdProcessAliveLocked(gateway.cmd)
+}
+
+func (c *systemVersionCache) get(gatewayPID int, gatewayAlive bool) (systemVersionResponse, bool) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	if c.hasCurrent && (!gatewayAlive || gatewayPID <= 0 || gatewayPID != c.current.gatewayPID) {
+		c.clearCurrentLocked()
+	}
+
+	if c.hasCurrent {
+		return c.current.value, true
+	}
+
+	return systemVersionResponse{}, false
+}
+
+func (c *systemVersionCache) waitOrStart(ctx context.Context) (bool, bool) {
+	if ctx == nil {
+		ctx = context.Background()
+	}
+	if ctx.Err() != nil {
+		return false, false
+	}
+
+	c.mu.Lock()
+	if c.inflightCh == nil {
+		c.inflightCh = make(chan struct{})
+		c.mu.Unlock()
+		return true, true
+	}
+	waitCh := c.inflightCh
+	c.mu.Unlock()
+
+	select {
+	case <-waitCh:
+		return false, true
+	case <-ctx.Done():
+		return false, false
+	}
+}
+
+func (c *systemVersionCache) finishResolve(value systemVersionResponse, gatewayPID int, gatewayAlive bool) {
+	c.mu.Lock()
+	if gatewayAlive && gatewayPID > 0 {
+		c.current = cachedSystemVersion{value: value, gatewayPID: gatewayPID}
+		c.hasCurrent = true
+	} else {
+		c.clearCurrentLocked()
+	}
+
+	inflightCh := c.inflightCh
+	c.inflightCh = nil
+	c.mu.Unlock()
+
+	if inflightCh != nil {
+		close(inflightCh)
+	}
+}
+
+func (c *systemVersionCache) clearCurrentLocked() {
+	c.hasCurrent = false
+	c.current = cachedSystemVersion{}
+}
+
+func (c *systemVersionCache) resetForTest() {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	c.current = cachedSystemVersion{}
+	c.hasCurrent = false
+	if c.inflightCh != nil {
+		close(c.inflightCh)
+		c.inflightCh = nil
+	}
+}
+
+// executePicoclawVersion runs the version subcommand against the
+// discovered picoclaw executable.
+func executePicoclawVersion(ctx context.Context, execPath string) (string, error) {
+	out, err := exec.CommandContext(ctx, execPath, "version").CombinedOutput()
+	if err == nil {
+		return string(out), nil
+	}
+
+	return string(out), fmt.Errorf("failed to execute version command: %w", err)
+}
+
+// parsePicoclawVersionOutput extracts version/build/go fields from CLI output.
+// It accepts banner/ANSI-decorated output and only requires the version line.
+func parsePicoclawVersionOutput(raw string) (systemVersionResponse, bool) {
+	var result systemVersionResponse
+
+	scanner := bufio.NewScanner(strings.NewReader(raw))
+	for scanner.Scan() {
+		line := strings.TrimSpace(ansiEscapePattern.ReplaceAllString(scanner.Text(), ""))
+		if line == "" {
+			continue
+		}
+
+		if match := versionLinePattern.FindStringSubmatch(line); len(match) > 0 {
+			candidateVersion := strings.TrimSpace(match[1])
+			if !isLikelyVersionValue(candidateVersion) {
+				continue
+			}
+			result.Version = candidateVersion
+			if len(match) > 2 {
+				result.GitCommit = strings.TrimSpace(match[2])
+			}
+			continue
+		}
+
+		if buildValue, ok := strings.CutPrefix(line, "Build:"); ok {
+			result.BuildTime = strings.TrimSpace(buildValue)
+			continue
+		}
+
+		if goValue, ok := strings.CutPrefix(line, "Go:"); ok {
+			result.GoVersion = strings.TrimSpace(goValue)
+		}
+	}
+
+	if err := scanner.Err(); err != nil {
+		return systemVersionResponse{}, false
+	}
+
+	if result.Version == "" {
+		return systemVersionResponse{}, false
+	}
+
+	return result, true
+}
+
+func isLikelyVersionValue(value string) bool {
+	v := strings.TrimSpace(strings.ToLower(value))
+	if v == "" {
+		return false
+	}
+	if v == "dev" {
+		return true
+	}
+
+	// Accept git-like short/long hashes even when they contain only letters (a-f).
+	if len(v) >= 7 && len(v) <= 40 {
+		allHex := true
+		for _, ch := range v {
+			if (ch >= '0' && ch <= '9') || (ch >= 'a' && ch <= 'f') {
+				continue
+			}
+			allHex = false
+			break
+		}
+		if allHex {
+			return true
+		}
+	}
+
+	for _, ch := range v {
+		if ch >= '0' && ch <= '9' {
+			return true
+		}
+	}
+	return false
+}
diff --git a/web/backend/api/version_test.go b/web/backend/api/version_test.go
new file mode 100644
index 000000000..31c5366ab
--- /dev/null
+++ b/web/backend/api/version_test.go
@@ -0,0 +1,317 @@
+package api
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"net/http"
+	"net/http/httptest"
+	"os/exec"
+	"runtime"
+	"testing"
+)
+
+func setupVersionTestIsolation(t *testing.T) {
+	t.Helper()
+
+	originalGatewayState := currentGatewayVersionState
+	originalFinder := findPicoclawBinaryForInfo
+	originalRunner := runPicoclawVersionOutput
+	originalFallback := launcherBuildInfoForVersion
+	t.Cleanup(func() {
+		currentGatewayVersionState = originalGatewayState
+		findPicoclawBinaryForInfo = originalFinder
+		runPicoclawVersionOutput = originalRunner
+		launcherBuildInfoForVersion = originalFallback
+		versionInfoCache.resetForTest()
+	})
+
+	currentGatewayVersionState = func() (int, bool) { return 0, false }
+	versionInfoCache.resetForTest()
+}
+
+func TestGetSystemVersionUsesPicoclawBinaryInfo(t *testing.T) {
+	setupVersionTestIsolation(t)
+
+	launcherBuildInfoForVersion = func() systemVersionResponse {
+		return systemVersionResponse{Version: "fallback", GoVersion: "go-fallback"}
+	}
+
+	findPicoclawBinaryForInfo = func() string { return "picoclaw" }
+	runPicoclawVersionOutput = func(_ context.Context, _ string) (string, error) {
+		return "🦞 picoclaw v1.2.3 (git: deadbeef)\n  Build: 2026-03-27T12:34:56Z\n  Go: go1.25.8\n", nil
+	}
+
+	h := NewHandler("")
+	mux := http.NewServeMux()
+	h.RegisterRoutes(mux)
+
+	rec := httptest.NewRecorder()
+	req := httptest.NewRequest(http.MethodGet, "/api/system/version", nil)
+	mux.ServeHTTP(rec, req)
+
+	if rec.Code != http.StatusOK {
+		t.Fatalf("status = %d, want %d, body=%s", rec.Code, http.StatusOK, rec.Body.String())
+	}
+
+	var got systemVersionResponse
+	if err := json.Unmarshal(rec.Body.Bytes(), &got); err != nil {
+		t.Fatalf("unmarshal response: %v", err)
+	}
+
+	if got.Version != "v1.2.3" {
+		t.Fatalf("version = %q, want %q", got.Version, "v1.2.3")
+	}
+	if got.GitCommit != "deadbeef" {
+		t.Fatalf("git_commit = %q, want %q", got.GitCommit, "deadbeef")
+	}
+	if got.BuildTime != "2026-03-27T12:34:56Z" {
+		t.Fatalf("build_time = %q, want %q", got.BuildTime, "2026-03-27T12:34:56Z")
+	}
+	if got.GoVersion != "go1.25.8" {
+		t.Fatalf("go_version = %q, want %q", got.GoVersion, "go1.25.8")
+	}
+}
+
+func TestGetSystemVersionFallsBackToLauncherInfoWhenCommandFails(t *testing.T) {
+	setupVersionTestIsolation(t)
+
+	expected := systemVersionResponse{
+		Version:   "v9.9.9",
+		GitCommit: "cafebabe",
+		BuildTime: "2026-03-27T10:43:34+0000",
+		GoVersion: "go1.25.8",
+	}
+	launcherBuildInfoForVersion = func() systemVersionResponse { return expected }
+
+	findPicoclawBinaryForInfo = func() string { return "picoclaw" }
+	runPicoclawVersionOutput = func(_ context.Context, _ string) (string, error) {
+		return "", errors.New("binary unavailable")
+	}
+
+	h := NewHandler("")
+	mux := http.NewServeMux()
+	h.RegisterRoutes(mux)
+
+	rec := httptest.NewRecorder()
+	req := httptest.NewRequest(http.MethodGet, "/api/system/version", nil)
+	mux.ServeHTTP(rec, req)
+
+	if rec.Code != http.StatusOK {
+		t.Fatalf("status = %d, want %d, body=%s", rec.Code, http.StatusOK, rec.Body.String())
+	}
+
+	var got systemVersionResponse
+	if err := json.Unmarshal(rec.Body.Bytes(), &got); err != nil {
+		t.Fatalf("unmarshal response: %v", err)
+	}
+
+	if got.Version != expected.Version {
+		t.Fatalf("version = %q, want %q", got.Version, expected.Version)
+	}
+	if got.GitCommit != expected.GitCommit {
+		t.Fatalf("git_commit = %q, want %q", got.GitCommit, expected.GitCommit)
+	}
+	if got.BuildTime != expected.BuildTime {
+		t.Fatalf("build_time = %q, want %q", got.BuildTime, expected.BuildTime)
+	}
+	if got.GoVersion != expected.GoVersion {
+		t.Fatalf("go_version = %q, want %q", got.GoVersion, expected.GoVersion)
+	}
+}
+
+func TestParsePicoclawVersionOutput(t *testing.T) {
+	setupVersionTestIsolation(t)
+
+	raw := "\u001b[1;31m████\u001b[0m\n🦞 picoclaw 18ec263 (git: 18ec2631)\n  Build: 2026-03-27T10:43:34+0000\n  Go: go1.25.8\n"
+	got, ok := parsePicoclawVersionOutput(raw)
+	if !ok {
+		t.Fatal("parsePicoclawVersionOutput() should parse valid output")
+	}
+	if got.Version != "18ec263" {
+		t.Fatalf("version = %q, want %q", got.Version, "18ec263")
+	}
+	if got.GitCommit != "18ec2631" {
+		t.Fatalf("git_commit = %q, want %q", got.GitCommit, "18ec2631")
+	}
+	if got.BuildTime != "2026-03-27T10:43:34+0000" {
+		t.Fatalf("build_time = %q, want %q", got.BuildTime, "2026-03-27T10:43:34+0000")
+	}
+	if got.GoVersion != "go1.25.8" {
+		t.Fatalf("go_version = %q, want %q", got.GoVersion, "go1.25.8")
+	}
+}
+
+func TestParsePicoclawVersionOutputIgnoresUsageLine(t *testing.T) {
+	setupVersionTestIsolation(t)
+
+	raw := "Usage: picoclaw version [flags]\n"
+	got, ok := parsePicoclawVersionOutput(raw)
+	if ok {
+		t.Fatalf("parsePicoclawVersionOutput() parsed usage line unexpectedly: %#v", got)
+	}
+}
+
+func TestParsePicoclawVersionOutputAcceptsLetterOnlyHashVersion(t *testing.T) {
+	setupVersionTestIsolation(t)
+
+	raw := "picoclaw abcdefa (git: abcdefabcdefabcdefabcdefabcdefabcdefabcd)\n"
+	got, ok := parsePicoclawVersionOutput(raw)
+	if !ok {
+		t.Fatal("parsePicoclawVersionOutput() should parse letter-only hash version")
+	}
+	if got.Version != "abcdefa" {
+		t.Fatalf("version = %q, want %q", got.Version, "abcdefa")
+	}
+	if got.GitCommit != "abcdefabcdefabcdefabcdefabcdefabcdefabcd" {
+		t.Fatalf("git_commit = %q, want %q", got.GitCommit, "abcdefabcdefabcdefabcdefabcdefabcdefabcd")
+	}
+}
+
+func TestResolveSystemVersionInfoFallsBackRuntimeGoVersion(t *testing.T) {
+	setupVersionTestIsolation(t)
+
+	launcherBuildInfoForVersion = func() systemVersionResponse {
+		return systemVersionResponse{Version: "dev", GoVersion: ""}
+	}
+
+	findPicoclawBinaryForInfo = func() string { return "picoclaw" }
+	runPicoclawVersionOutput = func(_ context.Context, _ string) (string, error) {
+		return "picoclaw v1.0.0\n", nil
+	}
+
+	h := NewHandler("")
+	got := h.resolveSystemVersionInfo(context.Background())
+	if got.GoVersion != runtime.Version() {
+		t.Fatalf("go_version = %q, want runtime version %q", got.GoVersion, runtime.Version())
+	}
+}
+
+func TestResolveSystemVersionInfoCachesWhileGatewayAlive(t *testing.T) {
+	setupVersionTestIsolation(t)
+
+	launcherBuildInfoForVersion = func() systemVersionResponse {
+		return systemVersionResponse{Version: "dev", GoVersion: "go-fallback"}
+	}
+	findPicoclawBinaryForInfo = func() string { return "picoclaw" }
+
+	pid := 4321
+	currentGatewayVersionState = func() (int, bool) { return pid, true }
+
+	runCount := 0
+	runPicoclawVersionOutput = func(_ context.Context, _ string) (string, error) {
+		runCount++
+		return fmt.Sprintf("picoclaw v1.2.%d\n", runCount), nil
+	}
+
+	h := NewHandler("")
+	first := h.resolveSystemVersionInfo(context.Background())
+	second := h.resolveSystemVersionInfo(context.Background())
+
+	if first.Version != "v1.2.1" {
+		t.Fatalf("first version = %q, want %q", first.Version, "v1.2.1")
+	}
+	if second.Version != "v1.2.1" {
+		t.Fatalf("second version = %q, want cached %q", second.Version, "v1.2.1")
+	}
+	if runCount != 1 {
+		t.Fatalf("run count = %d, want %d", runCount, 1)
+	}
+}
+
+func TestResolveSystemVersionInfoInvalidatesCacheWhenGatewayStops(t *testing.T) {
+	setupVersionTestIsolation(t)
+
+	launcherBuildInfoForVersion = func() systemVersionResponse {
+		return systemVersionResponse{Version: "dev", GoVersion: "go-fallback"}
+	}
+	findPicoclawBinaryForInfo = func() string { return "picoclaw" }
+
+	alive := true
+	pid := 9876
+	currentGatewayVersionState = func() (int, bool) {
+		if !alive {
+			return 0, false
+		}
+		return pid, true
+	}
+
+	runCount := 0
+	runPicoclawVersionOutput = func(_ context.Context, _ string) (string, error) {
+		runCount++
+		return fmt.Sprintf("picoclaw v2.0.%d\n", runCount), nil
+	}
+
+	h := NewHandler("")
+	first := h.resolveSystemVersionInfo(context.Background())
+	second := h.resolveSystemVersionInfo(context.Background())
+
+	if first.Version != "v2.0.1" || second.Version != "v2.0.1" {
+		t.Fatalf("expected cached version v2.0.1, got first=%q second=%q", first.Version, second.Version)
+	}
+	if runCount != 1 {
+		t.Fatalf("run count after cache hit = %d, want %d", runCount, 1)
+	}
+
+	alive = false
+	third := h.resolveSystemVersionInfo(context.Background())
+	if third.Version != "v2.0.2" {
+		t.Fatalf("third version = %q, want refreshed %q", third.Version, "v2.0.2")
+	}
+	if runCount != 2 {
+		t.Fatalf("run count after invalidation = %d, want %d", runCount, 2)
+	}
+}
+
+func TestResolveSystemVersionInfoSkipsCommandWhenContextCanceled(t *testing.T) {
+	setupVersionTestIsolation(t)
+
+	launcherBuildInfoForVersion = func() systemVersionResponse {
+		return systemVersionResponse{Version: "v3.0.0", GoVersion: "go-fallback"}
+	}
+	findPicoclawBinaryForInfo = func() string { return "picoclaw" }
+
+	runCount := 0
+	runPicoclawVersionOutput = func(_ context.Context, _ string) (string, error) {
+		runCount++
+		return "picoclaw v9.9.9\n", nil
+	}
+
+	canceledCtx, cancel := context.WithCancel(context.Background())
+	cancel()
+
+	h := NewHandler("")
+	got := h.resolveSystemVersionInfo(canceledCtx)
+
+	if runCount != 0 {
+		t.Fatalf("run count = %d, want %d", runCount, 0)
+	}
+	if got.Version != "v3.0.0" {
+		t.Fatalf("version = %q, want fallback %q", got.Version, "v3.0.0")
+	}
+}
+
+func TestResolveGatewayBinaryForVersionInfoPrefersGatewayCommandPath(t *testing.T) {
+	setupVersionTestIsolation(t)
+
+	originalFinder := findPicoclawBinaryForInfo
+	t.Cleanup(func() {
+		findPicoclawBinaryForInfo = originalFinder
+	})
+
+	gateway.mu.Lock()
+	originalCmd := gateway.cmd
+	gateway.cmd = &exec.Cmd{Path: "/tmp/picoclaw-from-gateway"}
+	gateway.mu.Unlock()
+	t.Cleanup(func() {
+		gateway.mu.Lock()
+		gateway.cmd = originalCmd
+		gateway.mu.Unlock()
+	})
+
+	got := resolveGatewayBinaryForVersionInfo()
+	if got != "/tmp/picoclaw-from-gateway" {
+		t.Fatalf("exec path = %q, want %q", got, "/tmp/picoclaw-from-gateway")
+	}
+}
diff --git a/web/frontend/src/api/system.ts b/web/frontend/src/api/system.ts
index 2e2f36f15..dfc48b6b8 100644
--- a/web/frontend/src/api/system.ts
+++ b/web/frontend/src/api/system.ts
@@ -13,6 +13,13 @@ export interface LauncherConfig {
   allowed_cidrs: string[]
 }
 
+export interface SystemVersionInfo {
+  version: string
+  git_commit?: string
+  build_time?: string
+  go_version: string
+}
+
 async function request<T>(path: string, options?: RequestInit): Promise<T> {
   const res = await launcherFetch(path, options)
   if (!res.ok) {
@@ -62,3 +69,7 @@ export async function setLauncherConfig(
     body: JSON.stringify(payload),
   })
 }
+
+export async function getSystemVersionInfo(): Promise<SystemVersionInfo> {
+  return request<SystemVersionInfo>("/api/system/version")
+}
diff --git a/web/frontend/src/components/app-sidebar.tsx b/web/frontend/src/components/app-sidebar.tsx
index 0e135c0c1..18bc9f092 100644
--- a/web/frontend/src/components/app-sidebar.tsx
+++ b/web/frontend/src/components/app-sidebar.tsx
@@ -10,10 +10,12 @@ import {
   IconSparkles,
   IconTools,
 } from "@tabler/icons-react"
+import { useQuery } from "@tanstack/react-query"
 import { Link, useRouterState } from "@tanstack/react-router"
 import * as React from "react"
 import { useTranslation } from "react-i18next"
 
+import { getSystemVersionInfo } from "@/api/system"
 import {
   Collapsible,
   CollapsibleContent,
@@ -27,6 +29,7 @@ import {
   SidebarGroupLabel,
   SidebarMenu,
   SidebarMenuButton,
+  SidebarFooter,
   SidebarMenuItem,
   SidebarRail,
 } from "@/components/ui/sidebar"
@@ -78,6 +81,13 @@ export function AppSidebar({ ...props }: React.ComponentProps<typeof Sidebar>) {
     language: (i18n.resolvedLanguage ?? i18n.language ?? "").toLowerCase(),
     t,
   })
+  const { data: versionInfo } = useQuery({
+    queryKey: ["system", "version"],
+    queryFn: getSystemVersionInfo,
+    staleTime: 5 * 60 * 1000,
+  })
+
+  const versionText = versionInfo?.version ?? t("footer.version_unknown")
 
   const navGroups: NavGroup[] = React.useMemo(() => {
     return [
@@ -235,6 +245,26 @@ export function AppSidebar({ ...props }: React.ComponentProps<typeof Sidebar>) {
           </Collapsible>
         ))}
       </SidebarContent>
+      <SidebarFooter className="border-t-border/30 group-data-[collapsible=icon]:hidden border-t px-3 py-2">
+        <div className="text-muted-foreground flex flex-col gap-0.5 text-[11px] leading-4">
+          <div className="truncate" title={versionText}>
+            <span className="text-foreground/80">{t("footer.version")}:</span>{" "}
+            {versionText}
+          </div>
+          {versionInfo?.git_commit && (
+            <div className="truncate" title={versionInfo.git_commit}>
+              <span className="text-foreground/80">{t("footer.commit")}:</span>{" "}
+              {versionInfo.git_commit}
+            </div>
+          )}
+          {versionInfo?.build_time && (
+            <div className="truncate" title={versionInfo.build_time}>
+              <span className="text-foreground/80">{t("footer.build")}:</span>{" "}
+              {versionInfo.build_time}
+            </div>
+          )}
+        </div>
+      </SidebarFooter>
       <SidebarRail />
     </Sidebar>
   )
diff --git a/web/frontend/src/i18n/locales/en.json b/web/frontend/src/i18n/locales/en.json
index 38cdeb324..9d170a4c8 100644
--- a/web/frontend/src/i18n/locales/en.json
+++ b/web/frontend/src/i18n/locales/en.json
@@ -93,6 +93,12 @@
   "labels": {
     "loading": "Loading..."
   },
+  "footer": {
+    "version": "Version",
+    "commit": "Commit",
+    "build": "Build",
+    "version_unknown": "Unknown"
+  },
   "credentials": {
     "description": "Manage OAuth and token-based credentials for supported providers.",
     "loading": "Loading credentials...",
diff --git a/web/frontend/src/i18n/locales/zh.json b/web/frontend/src/i18n/locales/zh.json
index 9ec4ec967..b214753ca 100644
--- a/web/frontend/src/i18n/locales/zh.json
+++ b/web/frontend/src/i18n/locales/zh.json
@@ -93,6 +93,12 @@
   "labels": {
     "loading": "加载中..."
   },
+  "footer": {
+    "version": "版本",
+    "commit": "提交",
+    "build": "构建",
+    "version_unknown": "未知"
+  },
   "credentials": {
     "description": "管理已支持服务商的 OAuth 与 Token 凭据。",
     "loading": "正在加载凭据...",