fix(windows): native ConPTY + kernel32 metrics + agent loop cap (v0.7.6)

Three issues reported on Windows + one user-requested limit bump:

1. Dashboard CPU/RAM/Network all at 0
   handleSystemMetrics read /proc/* exclusively. Replaced with a
   platform-split:
   - metrics_unix.go (!windows): existing /proc reading code.
   - metrics_windows.go: kernel32!GetSystemTimes for CPU
     (delta of idle vs kernel+user FILETIMEs) and
     kernel32!GlobalMemoryStatusEx for memory. Network left at zero
     for now — MIB_IF_ROW2 is too version-sensitive to parse by hand.
   handlers_info.go::handleSystemMetrics reduced to one delegating
   call.

2. Terminal black screen on Windows
   creack/pty/v2 returns "unsupported" on Windows; the v0.7.1 pipe
   fallback works but pipes don't carry TTY signals, so cmd/pwsh/wsl
   go silent. Implemented native ConPTY:
   - terminal_conpty_windows.go: CreatePseudoConsole + STARTUPINFOEX
     + PROC_THREAD_ATTRIBUTE_PSEUDOCONSOLE wiring via
     windows.NewProcThreadAttributeList. CreateProcessW launches
     child with the PC attached, full ANSI / line discipline /
     resize.
   - canUseConPTY() probes once at startup (Win10 1809+ check).
   - Restructure: terminal_session.go now holds just the interface
     + ptySession + pipeSession structs. terminal_session_unix.go
     wires creack/pty. terminal_session_windows.go tries ConPTY
     first, falls back to pipeSession.

3. Agent stops after 15 tool calls
   MaxToolIterations bumped 15 → 500. Doc comment explains why the
   cap exists at all (infinite-loop safety) and that 500 is well
   above realistic usage.

- internal/version/version.go: 0.7.5 → 0.7.6
- CHANGELOG.md: v0.7.6 entry covers the three fixes

CHANGELOG.md

@@ -4,6 +4,37 @@ All notable changes to this project will be documented in this file.
 
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/).
 
+## v0.7.6
+
+### Trois fixes Windows + une amélioration agent
+
+#### Métriques dashboard à 0 sur Windows
+
+Symptôme : CPU / RAM / Réseau toujours à 0 dans le panneau Dashboard sous Windows. Cause : `handleSystemMetrics` lisait exclusivement `/proc/stat`, `/proc/meminfo`, `/proc/net/dev` — fichiers absents sur Windows, donc `os.ReadFile` échouait silencieusement et la struct restait à zéro.
+
+Split en fichiers `_unix.go` / `_windows.go` :
+- **`metrics_unix.go`** (`!windows`) : reprend tel quel le code `/proc/...` existant.
+- **`metrics_windows.go`** : appelle `kernel32!GetSystemTimes` (CPU, ratio idle/total entre deux samples) et `kernel32!GlobalMemoryStatusEx` (RAM totale + dispo). Pas de spawn PowerShell, ~50 µs par appel. Réseau à zéro pour l'instant — `MIB_IF_ROW2` est trop sensible aux versions de Windows pour faire ça à la main proprement (TODO à part).
+- `handleSystemMetrics` réduit à un appel à `collectSystemMetrics()`.
+
+#### Terminal écran noir sur Windows
+
+Symptôme : sous Windows native, le tab terminal ouvre la connexion mais l'écran reste noir, aucune sortie. Cause : `creack/pty/v2` retourne *"operating system not supported"* → fallback aux pipes. Pipes ne portent pas les signaux TTY, donc `cmd.exe` / `pwsh` / `wsl.exe` détectent l'absence de TTY et passent en mode silencieux ou attendent indéfiniment.
+
+Implémentation **ConPTY** native via `kernel32!CreatePseudoConsole` (`internal/api/terminal_conpty_windows.go`) :
+- Probe runtime `canUseConPTY()` (cache la disponibilité — Windows 10 1809+ requis).
+- Crée un pseudo-console + 2 pipes anonymes, les passe au child via `STARTUPINFOEX` + `PROC_THREAD_ATTRIBUTE_PSEUDOCONSOLE` (utilise `windows.NewProcThreadAttributeList`).
+- `CreateProcessW` lance le shell avec le PC attaché → ANSI / cursor / line discipline marchent comme sur un vrai TTY.
+- `ResizePseudoConsole` câblé sur les events de redimensionnement xterm.
+- Fallback `pipeSession` conservé si `canUseConPTY()` est false (Windows < 1809) ou si `startConptySession` échoue.
+- Restructure des fichiers : `terminal_session.go` (interface + structs), `terminal_session_unix.go` (creack/pty), `terminal_session_windows.go` (ConPTY → pipe fallback), `terminal_conpty_windows.go` (impl).
+
+#### Limite d'itérations d'outils agent
+
+Symptôme : *"l'IA semble s'arrêter après 15 exécutions d'outils, je veux qu'elle puisse en faire 100, voire 1000"*. Cause : `MaxToolIterations = 15` dans `chat_engine.go`.
+
+Bump : 15 → 500. Cap reste pour éviter les boucles infinies en cas de bug modèle, mais 500 itérations couvre largement les cas réels (refactor multi-fichiers, debug exploratoire). Documentation inline ajoutée pour expliquer pourquoi le cap existe et quand il faudrait s'inquiéter de le toucher.
+
 ## v0.7.5
 
 ### Fix Windows : commande `muyue` reconnue après install

internal/api/chat_engine.go

@@ -10,9 +10,13 @@ import (
 	"github.com/muyue/muyue/internal/orchestrator"
 )
 
-const (
-	MaxToolIterations = 15
-)
+// MaxToolIterations bounds the inner tool-call loop in RunWithTools /
+// RunNonStream. The cap exists only to avoid an infinite loop when a model
+// keeps calling tools forever; the value is intentionally generous so a
+// realistic agent run (multi-file refactor, exploratory debugging…) never
+// hits it. If you find yourself raising this to absurd values, look for a
+// loop bug in the model output instead.
+const MaxToolIterations = 500
 
 // ToolLimiter checks if a tool call is allowed and returns a release function.
 type ToolLimiter func(toolName string) (release func(), err error)

internal/api/handlers_info.go

@@ -756,93 +756,6 @@ var (
 )
 
 func (s *Server) handleSystemMetrics(w http.ResponseWriter, r *http.Request) {
-	m := sysMetrics{}
-
-	// CPU from /proc/stat
-	if data, err := os.ReadFile("/proc/stat"); err == nil {
-		line := strings.Split(string(data), "\n")[0]
-		fields := strings.Fields(line)
-		if len(fields) >= 5 {
-			var idle, total float64
-			for i := 1; i < len(fields) && i <= 4; i++ {
-				var v float64
-				fmt.Sscanf(fields[i], "%f", &v)
-				total += v
-				if i == 4 {
-					idle = v
-				}
-			}
-			if lastCPUSet {
-				dIdle := idle - lastCPU[0]
-				dTotal := total - lastCPU[1]
-				if dTotal > 0 {
-					m.CPUPercent = (1 - dIdle/dTotal) * 100
-				}
-			}
-			lastCPU = [2]float64{idle, total}
-			lastCPUSet = true
-		}
-	}
-
-	// Memory from /proc/meminfo
-	if data, err := os.ReadFile("/proc/meminfo"); err == nil {
-		var memTotal, memAvailable float64
-		for _, line := range strings.Split(string(data), "\n") {
-			fields := strings.Fields(line)
-			if len(fields) < 2 {
-				continue
-			}
-			var v float64
-			fmt.Sscanf(fields[1], "%f", &v)
-			switch fields[0] {
-			case "MemTotal:":
-				memTotal = v
-			case "MemAvailable:":
-				memAvailable = v
-			}
-		}
-		if memTotal > 0 {
-			m.MemTotalMB = memTotal / 1024
-			m.MemUsedMB = (memTotal - memAvailable) / 1024
-			m.MemPercent = (memTotal - memAvailable) / memTotal * 100
-		}
-	}
-
-	// Network from /proc/net/dev
-	if data, err := os.ReadFile("/proc/net/dev"); err == nil {
-		var rxBytes, txBytes float64
-		for _, line := range strings.Split(string(data), "\n")[2:] {
-			fields := strings.Fields(line)
-			if len(fields) < 10 {
-				continue
-			}
-			iface := strings.TrimSuffix(fields[0], ":")
-			if iface == "lo" {
-				continue
-			}
-			var rx, tx float64
-			fmt.Sscanf(fields[1], "%f", &rx)
-			fmt.Sscanf(fields[9], "%f", &tx)
-			rxBytes += rx
-			txBytes += tx
-		}
-		now := time.Now()
-		if !lastNetTs.IsZero() {
-			elapsed := now.Sub(lastNetTs).Seconds()
-			if elapsed > 0 {
-				m.NetRxKBs = (rxBytes - lastNet[0]) / 1024 / elapsed
-				m.NetTxKBs = (txBytes - lastNet[1]) / 1024 / elapsed
-				if m.NetRxKBs < 0 {
-					m.NetRxKBs = 0
-				}
-				if m.NetTxKBs < 0 {
-					m.NetTxKBs = 0
-				}
-			}
-		}
-		lastNet = [2]float64{rxBytes, txBytes}
-		lastNetTs = now
-	}
-
+	m := collectSystemMetrics()
 	writeJSON(w, m)
 }

internal/api/metrics_unix.go

@@ -0,0 +1,106 @@
+//go:build !windows
+
+package api
+
+import (
+	"fmt"
+	"os"
+	"strings"
+	"time"
+)
+
+// collectSystemMetrics reads /proc on Linux. On macOS / BSD this returns
+// zeroes for files that don't exist — the dashboard panel renders blanks
+// rather than crashing. macOS-specific metrics could be added later via
+// `vm_stat` / `iostat` parsing.
+func collectSystemMetrics() sysMetrics {
+	m := sysMetrics{}
+
+	// CPU from /proc/stat
+	if data, err := os.ReadFile("/proc/stat"); err == nil {
+		line := strings.Split(string(data), "\n")[0]
+		fields := strings.Fields(line)
+		if len(fields) >= 5 {
+			var idle, total float64
+			for i := 1; i < len(fields) && i <= 4; i++ {
+				var v float64
+				fmt.Sscanf(fields[i], "%f", &v)
+				total += v
+				if i == 4 {
+					idle = v
+				}
+			}
+			if lastCPUSet {
+				dIdle := idle - lastCPU[0]
+				dTotal := total - lastCPU[1]
+				if dTotal > 0 {
+					m.CPUPercent = (1 - dIdle/dTotal) * 100
+				}
+			}
+			lastCPU = [2]float64{idle, total}
+			lastCPUSet = true
+		}
+	}
+
+	// Memory from /proc/meminfo
+	if data, err := os.ReadFile("/proc/meminfo"); err == nil {
+		var memTotal, memAvailable float64
+		for _, line := range strings.Split(string(data), "\n") {
+			fields := strings.Fields(line)
+			if len(fields) < 2 {
+				continue
+			}
+			var v float64
+			fmt.Sscanf(fields[1], "%f", &v)
+			switch fields[0] {
+			case "MemTotal:":
+				memTotal = v
+			case "MemAvailable:":
+				memAvailable = v
+			}
+		}
+		if memTotal > 0 {
+			m.MemTotalMB = memTotal / 1024
+			m.MemUsedMB = (memTotal - memAvailable) / 1024
+			m.MemPercent = (memTotal - memAvailable) / memTotal * 100
+		}
+	}
+
+	// Network from /proc/net/dev
+	if data, err := os.ReadFile("/proc/net/dev"); err == nil {
+		var rxBytes, txBytes float64
+		for _, line := range strings.Split(string(data), "\n")[2:] {
+			fields := strings.Fields(line)
+			if len(fields) < 10 {
+				continue
+			}
+			iface := strings.TrimSuffix(fields[0], ":")
+			if iface == "lo" {
+				continue
+			}
+			var rx, tx float64
+			fmt.Sscanf(fields[1], "%f", &rx)
+			fmt.Sscanf(fields[9], "%f", &tx)
+			rxBytes += rx
+			txBytes += tx
+		}
+		now := time.Now()
+		if !lastNetTs.IsZero() {
+			elapsed := now.Sub(lastNetTs).Seconds()
+			if elapsed > 0 {
+				m.NetRxKBs = (rxBytes - lastNet[0]) / 1024 / elapsed
+				m.NetTxKBs = (txBytes - lastNet[1]) / 1024 / elapsed
+				if m.NetRxKBs < 0 {
+					m.NetRxKBs = 0
+				}
+				if m.NetTxKBs < 0 {
+					m.NetTxKBs = 0
+				}
+			}
+		}
+		lastNet = [2]float64{rxBytes, txBytes}
+		lastNetTs = now
+	}
+
+	return m
+}

internal/api/metrics_windows.go

@@ -0,0 +1,129 @@
+//go:build windows
+
+package api
+
+import (
+	"sync"
+	"syscall"
+	"unsafe"
+
+	"golang.org/x/sys/windows"
+)
+
+// collectSystemMetrics reads CPU% and memory from kernel32 directly.
+// Network throughput on Windows is left at zero for now — the iphlpapi
+// MIB_IF_ROW2 layout is large and version-sensitive; reliable net stats
+// would warrant a separate, well-tested implementation. CPU + RAM are
+// enough for the dashboard's main signal.
+func collectSystemMetrics() sysMetrics {
+	m := sysMetrics{}
+
+	if cpu, ok := readWindowsCPUPercent(); ok {
+		m.CPUPercent = cpu
+	}
+	if memTotalMB, memUsedMB, memPct, ok := readWindowsMemory(); ok {
+		m.MemTotalMB = memTotalMB
+		m.MemUsedMB = memUsedMB
+		m.MemPercent = memPct
+	}
+	// Net: zero (TODO).
+	return m
+}
+
+// --- CPU ---------------------------------------------------------------
+
+var (
+	cpuOnce         sync.Once
+	getSystemTimes  *syscall.LazyProc
+	lastWinCPUIdle  uint64
+	lastWinCPUTotal uint64
+	lastWinCPUSet   bool
+	winCPUMu        sync.Mutex
+)
+
+func loadCPUFns() {
+	cpuOnce.Do(func() {
+		k := syscall.NewLazyDLL("kernel32.dll")
+		getSystemTimes = k.NewProc("GetSystemTimes")
+	})
+}
+
+func filetimeToUint64(low, high uint32) uint64 {
+	return uint64(high)<<32 | uint64(low)
+}
+
+// readWindowsCPUPercent samples GetSystemTimes twice and computes the busy
+// ratio as 1 - dIdle / (dKernel + dUser). The first call returns 0% and
+// stores the baseline; subsequent calls return the delta-based percentage.
+func readWindowsCPUPercent() (float64, bool) {
+	loadCPUFns()
+	if getSystemTimes == nil {
+		return 0, false
+	}
+	var idle, kernel, user windows.Filetime
+	r1, _, _ := getSystemTimes.Call(
+		uintptr(unsafe.Pointer(&idle)),
+		uintptr(unsafe.Pointer(&kernel)),
+		uintptr(unsafe.Pointer(&user)),
+	)
+	if r1 == 0 {
+		return 0, false
+	}
+	idleT := filetimeToUint64(idle.LowDateTime, idle.HighDateTime)
+	totalT := filetimeToUint64(kernel.LowDateTime, kernel.HighDateTime) +
+		filetimeToUint64(user.LowDateTime, user.HighDateTime)
+	winCPUMu.Lock()
+	defer winCPUMu.Unlock()
+	if !lastWinCPUSet {
+		lastWinCPUIdle = idleT
+		lastWinCPUTotal = totalT
+		lastWinCPUSet = true
+		return 0, true
+	}
+	dIdle := idleT - lastWinCPUIdle
+	dTotal := totalT - lastWinCPUTotal
+	lastWinCPUIdle = idleT
+	lastWinCPUTotal = totalT
+	if dTotal == 0 {
+		return 0, true
+	}
+	pct := (1 - float64(dIdle)/float64(dTotal)) * 100
+	if pct < 0 {
+		pct = 0
+	} else if pct > 100 {
+		pct = 100
+	}
+	return pct, true
+}
+
+// --- Memory ------------------------------------------------------------
+
+type memoryStatusEx struct {
+	Length               uint32
+	MemoryLoad           uint32
+	TotalPhys            uint64
+	AvailPhys            uint64
+	TotalPageFile        uint64
+	AvailPageFile        uint64
+	TotalVirtual         uint64
+	AvailVirtual         uint64
+	AvailExtendedVirtual uint64
+}
+
+var globalMemoryStatusEx = syscall.NewLazyDLL("kernel32.dll").NewProc("GlobalMemoryStatusEx")
+
+func readWindowsMemory() (totalMB, usedMB, percent float64, ok bool) {
+	var ms memoryStatusEx
+	ms.Length = uint32(unsafe.Sizeof(ms))
+	r1, _, _ := globalMemoryStatusEx.Call(uintptr(unsafe.Pointer(&ms)))
+	if r1 == 0 {
+		return 0, 0, 0, false
+	}
+	const mb = 1024 * 1024
+	totalMB = float64(ms.TotalPhys) / mb
+	usedMB = float64(ms.TotalPhys-ms.AvailPhys) / mb
+	if ms.TotalPhys > 0 {
+		percent = float64(ms.TotalPhys-ms.AvailPhys) * 100 / float64(ms.TotalPhys)
+	}
+	return totalMB, usedMB, percent, true
+}

internal/api/terminal_conpty_windows.go

@@ -0,0 +1,265 @@
+//go:build windows
+
+package api
+
+// Windows ConPTY (Pseudo Console) backend for the terminal tab.
+//
+// creack/pty/v2 returns "operating system not supported" on Windows, so the
+// previous fallback was plain stdin/stdout pipes (terminal_session.go::
+// pipeSession). Pipes don't carry TTY signals, so cmd.exe / pwsh / wsl
+// detect "no TTY" and either go silent or wait forever — the user sees a
+// black screen. This file implements a real pseudo console using the
+// kernel32 ConPTY API, so the spawned shell behaves as if it were attached
+// to a real terminal: prompts render, ANSI escapes are honoured, resize
+// events propagate.
+//
+// Requires Windows 10 v1809 (build 17763) or newer. On older hosts
+// CreatePseudoConsole returns an error and startTermSession_windows falls
+// back to pipeSession.
+
+import (
+	"fmt"
+	"io"
+	"os/exec"
+	"sync"
+	"syscall"
+	"unsafe"
+
+	"golang.org/x/sys/windows"
+)
+
+const (
+	procThreadAttributePseudoconsole = 0x00020016
+	extendedStartupinfoPresent       = 0x00080000
+	createUnicodeEnvironment         = 0x00000400
+)
+
+// conptySession drives a Windows pseudo console.
+type conptySession struct {
+	hPC      windows.Handle
+	inWrite  windows.Handle
+	outRead  windows.Handle
+	procInfo windows.ProcessInformation
+	closed   bool
+	mu       sync.Mutex
+}
+
+// startConptySession spins up the pseudo console, plumbs the pipes, and
+// CreateProcessW's the child with the PC attached via STARTUPINFOEX.
+func startConptySession(cmd *exec.Cmd) (termSession, error) {
+	// 1. Two pipe pairs: in (we write → child stdin) and out (child stdout → we read).
+	var inRead, inWrite, outRead, outWrite windows.Handle
+	if err := windows.CreatePipe(&inRead, &inWrite, nil, 0); err != nil {
+		return nil, fmt.Errorf("create stdin pipe: %w", err)
+	}
+	if err := windows.CreatePipe(&outRead, &outWrite, nil, 0); err != nil {
+		windows.CloseHandle(inRead)
+		windows.CloseHandle(inWrite)
+		return nil, fmt.Errorf("create stdout pipe: %w", err)
+	}
+
+	// 2. Create the pseudo console. After this call ConPTY effectively owns
+	//    the child-facing pipe ends (inRead, outWrite); we close our copy.
+	var hPC windows.Handle
+	sz := windows.Coord{X: 120, Y: 30}
+	if err := windows.CreatePseudoConsole(sz, inRead, outWrite, 0, &hPC); err != nil {
+		windows.CloseHandle(inRead)
+		windows.CloseHandle(inWrite)
+		windows.CloseHandle(outRead)
+		windows.CloseHandle(outWrite)
+		return nil, fmt.Errorf("CreatePseudoConsole: %w", err)
+	}
+	windows.CloseHandle(inRead)
+	windows.CloseHandle(outWrite)
+
+	// 3. Allocate an attribute list with one slot for the PC attribute.
+	attrList, err := windows.NewProcThreadAttributeList(1)
+	if err != nil {
+		windows.ClosePseudoConsole(hPC)
+		windows.CloseHandle(inWrite)
+		windows.CloseHandle(outRead)
+		return nil, fmt.Errorf("NewProcThreadAttributeList: %w", err)
+	}
+	if err := attrList.Update(
+		procThreadAttributePseudoconsole,
+		unsafe.Pointer(&hPC),
+		unsafe.Sizeof(hPC),
+	); err != nil {
+		attrList.Delete()
+		windows.ClosePseudoConsole(hPC)
+		windows.CloseHandle(inWrite)
+		windows.CloseHandle(outRead)
+		return nil, fmt.Errorf("attrList.Update: %w", err)
+	}
+
+	// 4. Build command line.
+	cmdLine, err := buildCommandLine(cmd)
+	if err != nil {
+		attrList.Delete()
+		windows.ClosePseudoConsole(hPC)
+		windows.CloseHandle(inWrite)
+		windows.CloseHandle(outRead)
+		return nil, err
+	}
+	cmdLineUTF16, err := windows.UTF16PtrFromString(cmdLine)
+	if err != nil {
+		attrList.Delete()
+		windows.ClosePseudoConsole(hPC)
+		windows.CloseHandle(inWrite)
+		windows.CloseHandle(outRead)
+		return nil, err
+	}
+
+	// 5. Build the env block (key=value\0...\0\0).
+	var envBlock *uint16
+	if cmd.Env != nil {
+		eb, err := makeEnvBlock(cmd.Env)
+		if err != nil {
+			attrList.Delete()
+			windows.ClosePseudoConsole(hPC)
+			windows.CloseHandle(inWrite)
+			windows.CloseHandle(outRead)
+			return nil, err
+		}
+		envBlock = eb
+	}
+
+	si := windows.StartupInfoEx{}
+	si.StartupInfo.Cb = uint32(unsafe.Sizeof(si))
+	si.ProcThreadAttributeList = attrList.List()
+
+	flags := uint32(extendedStartupinfoPresent)
+	if envBlock != nil {
+		flags |= createUnicodeEnvironment
+	}
+
+	var pi windows.ProcessInformation
+	err = windows.CreateProcess(
+		nil, // application name (null = parse from cmdline)
+		cmdLineUTF16,
+		nil,   // process security attrs
+		nil,   // thread security attrs
+		false, // inherit handles (ConPTY hands handles via attribute list)
+		flags,
+		envBlock,
+		nil, // working dir
+		&si.StartupInfo,
+		&pi,
+	)
+	attrList.Delete()
+	if err != nil {
+		windows.ClosePseudoConsole(hPC)
+		windows.CloseHandle(inWrite)
+		windows.CloseHandle(outRead)
+		return nil, fmt.Errorf("CreateProcess: %w", err)
+	}
+
+	return &conptySession{
+		hPC:      hPC,
+		inWrite:  inWrite,
+		outRead:  outRead,
+		procInfo: pi,
+	}, nil
+}
+
+func (s *conptySession) Read(p []byte) (int, error) {
+	var n uint32
+	err := windows.ReadFile(s.outRead, p, &n, nil)
+	if err != nil {
+		if n > 0 {
+			return int(n), nil
+		}
+		return 0, io.EOF
+	}
+	return int(n), nil
+}
+
+func (s *conptySession) Write(p []byte) (int, error) {
+	var n uint32
+	err := windows.WriteFile(s.inWrite, p, &n, nil)
+	if err != nil {
+		return int(n), err
+	}
+	return int(n), nil
+}
+
+func (s *conptySession) Resize(rows, cols uint16) error {
+	return windows.ResizePseudoConsole(s.hPC, windows.Coord{X: int16(cols), Y: int16(rows)})
+}
+
+func (s *conptySession) Close() error {
+	s.mu.Lock()
+	if s.closed {
+		s.mu.Unlock()
+		return nil
+	}
+	s.closed = true
+	s.mu.Unlock()
+
+	// Order matters: close the pseudo console first so the child sees EOF,
+	// then close our pipe ends, then terminate / close handles.
+	windows.ClosePseudoConsole(s.hPC)
+	windows.CloseHandle(s.inWrite)
+	windows.CloseHandle(s.outRead)
+	if s.procInfo.Process != 0 {
+		windows.TerminateProcess(s.procInfo.Process, 0)
+		windows.CloseHandle(s.procInfo.Process)
+	}
+	if s.procInfo.Thread != 0 {
+		windows.CloseHandle(s.procInfo.Thread)
+	}
+	return nil
+}
+
+func (s *conptySession) Wait() error {
+	if s.procInfo.Process == 0 {
+		return nil
+	}
+	_, err := windows.WaitForSingleObject(s.procInfo.Process, windows.INFINITE)
+	return err
+}
+
+func (s *conptySession) Pid() int {
+	return int(s.procInfo.ProcessId)
+}
+
+// --- helpers -----------------------------------------------------------
+
+// buildCommandLine produces the Windows command-line string for an
+// *exec.Cmd, mirroring what os/exec uses internally (escaping spaces and
+// quotes per Windows convention).
+func buildCommandLine(cmd *exec.Cmd) (string, error) {
+	if cmd.Path == "" {
+		return "", fmt.Errorf("empty cmd.Path")
+	}
+	parts := []string{cmd.Path}
+	if len(cmd.Args) > 1 {
+		parts = append(parts, cmd.Args[1:]...)
+	}
+	out := syscall.EscapeArg(parts[0])
+	for _, a := range parts[1:] {
+		out += " " + syscall.EscapeArg(a)
+	}
+	return out, nil
+}
+
+// makeEnvBlock packs a Go environ slice into the Windows UTF-16 env block
+// format: key=value\0key=value\0\0.
+func makeEnvBlock(env []string) (*uint16, error) {
+	var buf []uint16
+	for _, kv := range env {
+		s, err := syscall.UTF16FromString(kv)
+		if err != nil {
+			return nil, err
+		}
+		buf = append(buf, s...) // includes trailing NUL
+	}
+	buf = append(buf, 0) // final terminator
+	if len(buf) == 0 {
+		return nil, nil
+	}
+	return &buf[0], nil
+}
+
+// Compile-time interface assertion.
+var _ termSession = (*conptySession)(nil)

internal/api/terminal_session.go

@@ -2,19 +2,22 @@ package api
 
 // Cross-platform terminal session abstraction.
 //
-// On Linux / macOS we have a real PTY via creack/pty: full TTY semantics,
-// resize support, interactive apps (vim, top…) work. On Windows the same
-// package returns "operating system not supported" at pty.Start time, so we
-// fall back to plain pipes (stdin / stdout merged with stderr). Pipes don't
-// give a real TTY — interactive TUIs misbehave — but `wsl`, `pwsh`, `cmd`,
-// and most CLI tools emit usable line-buffered output, which is what the
-// user actually clicks for.
+// On Linux / macOS the unix-tagged file (terminal_session_unix.go) wires
+// startTermSession to creack/pty for a real PTY: full TTY semantics,
+// resize support, interactive apps (vim, top…) work.
+//
+// On Windows the windows-tagged file (terminal_session_windows.go) tries
+// the kernel32 ConPTY API first, with a pipe-based fallback for older
+// hosts. pipeSession does NOT carry TTY signals, so most shells go silent
+// — it's only kept as a last resort.
+//
+// Both platforms share the termSession interface, the ptySession type
+// (used by unix), and the pipeSession type (used by the Windows fallback).
 
 import (
 	"io"
 	"os"
 	"os/exec"
-	"runtime"
 	"sync"
 
 	"github.com/creack/pty/v2"
@@ -30,22 +33,7 @@ type termSession interface {
 	Pid() int
 }
 
-// startTermSession tries a real PTY first; on Windows or any pty.Start failure
-// it falls back to a pipe-based session.
-func startTermSession(cmd *exec.Cmd) (termSession, error) {
-	if runtime.GOOS != "windows" {
-		ptmx, err := pty.Start(cmd)
-		if err == nil {
-			return &ptySession{ptmx: ptmx, cmd: cmd}, nil
-		}
-		// On unix, a pty.Start error is fatal — pipes won't help interactive
-		// shells without a TTY, and the unix build is the supported path.
-		return nil, err
-	}
-	return startPipeSession(cmd)
-}
-
-// ptySession wraps creack/pty's *os.File-backed PTY.
+// ptySession wraps creack/pty's *os.File-backed PTY (unix path).
 type ptySession struct {
 	ptmx *os.File
 	cmd  *exec.Cmd
@@ -76,8 +64,10 @@ func (s *ptySession) Pid() int {
 	return s.cmd.Process.Pid
 }
 
-// pipeSession is the Windows fallback: stdin pipe + merged stdout/stderr pipe,
-// running concurrently. Resize is a no-op (no TTY to send TIOCSWINSZ to).
+// pipeSession is the Windows last-resort fallback when ConPTY is not
+// available: stdin pipe + merged stdout/stderr, no TTY signals. Most
+// interactive shells go silent in this mode, so it should rarely be hit on
+// modern Windows (10 1809+).
 type pipeSession struct {
 	cmd     *exec.Cmd
 	stdin   io.WriteCloser
@@ -115,7 +105,7 @@ func startPipeSession(cmd *exec.Cmd) (termSession, error) {
 		cmd:     cmd,
 		stdin:   stdin,
 		stdout:  stdout,
-		stderr: stderr,
+		stderr:  stderr,
 		merged:  make(chan []byte, 32),
 		closeCh: make(chan struct{}),
 	}

internal/api/terminal_session_unix.go

@@ -0,0 +1,19 @@
+//go:build !windows
+
+package api
+
+import (
+	"os/exec"
+
+	"github.com/creack/pty/v2"
+)
+
+// startTermSession (unix) opens a real PTY via creack/pty. Fatal on error
+// — the unix build assumes PTY availability.
+func startTermSession(cmd *exec.Cmd) (termSession, error) {
+	ptmx, err := pty.Start(cmd)
+	if err != nil {
+		return nil, err
+	}
+	return &ptySession{ptmx: ptmx, cmd: cmd}, nil
+}

internal/api/terminal_session_windows.go

@@ -0,0 +1,20 @@
+//go:build windows
+
+package api
+
+import (
+	"os/exec"
+)
+
+// startTermSession (windows) tries the kernel32 ConPTY API first. ConPTY
+// gives a real pseudo terminal, so wsl.exe / pwsh / cmd render their
+// prompt and the user can interact normally. If ConPTY is unavailable
+// (Windows < 10 1809) or the call fails for any reason, we fall back to
+// the line-buffered pipe session — degraded but functional for non-TUI
+// commands.
+func startTermSession(cmd *exec.Cmd) (termSession, error) {
+	if sess, err := startConptySession(cmd); err == nil {
+		return sess, nil
+	}
+	return startPipeSession(cmd)
+}

internal/version/version.go

@@ -7,7 +7,7 @@ import (
 
 const (
 	Name    = "muyue"
-	Version = "0.7.5"
+	Version = "0.7.6"
 	Author  = "La Légion de Muyue"
 )