feat(tools): add exec tool enhancement with background execution and PTY support

Merge #1869: Unified exec tool with actions (run/list/poll/read/write/send-keys/kill), PTY support, background execution, process session management.

Makefile

@@ -47,6 +47,13 @@ define PATCH_MIPS_FLAGS
 	fi
 endef
 
+# Patch creack/pty for loong64 support (upstream doesn't have ztypes_loong64.go)
+PTY_PATCH_LOONG64=pty_dir=$$(go env GOMODCACHE)/github.com/creack/pty@v1.1.9; \
+	if [ -d "$$pty_dir" ] && [ ! -f "$$pty_dir/ztypes_loong64.go" ]; then \
+		chmod +w "$$pty_dir" 2>/dev/null || true; \
+		printf '//go:build linux && loong64\npackage pty\ntype (_C_int int32; _C_uint uint32)\n' > "$$pty_dir/ztypes_loong64.go"; \
+	fi
+
 # Golangci-lint
 GOLANGCI_LINT?=golangci-lint
 
@@ -190,6 +197,7 @@ build-all: generate
 	GOOS=linux GOARCH=amd64 $(GO) build $(GOFLAGS) -ldflags "$(LDFLAGS)" -o $(BUILD_DIR)/$(BINARY_NAME)-linux-amd64 ./$(CMD_DIR)
 	GOOS=linux GOARCH=arm GOARM=7 $(GO) build $(GOFLAGS) -ldflags "$(LDFLAGS)" -o $(BUILD_DIR)/$(BINARY_NAME)-linux-arm ./$(CMD_DIR)
 	GOOS=linux GOARCH=arm64 $(GO) build $(GOFLAGS) -ldflags "$(LDFLAGS)" -o $(BUILD_DIR)/$(BINARY_NAME)-linux-arm64 ./$(CMD_DIR)
+	@$(PTY_PATCH_LOONG64)
 	GOOS=linux GOARCH=loong64 $(GO) build $(GOFLAGS) -ldflags "$(LDFLAGS)" -o $(BUILD_DIR)/$(BINARY_NAME)-linux-loong64 ./$(CMD_DIR)
 	GOOS=linux GOARCH=riscv64 $(GO) build $(GOFLAGS) -ldflags "$(LDFLAGS)" -o $(BUILD_DIR)/$(BINARY_NAME)-linux-riscv64 ./$(CMD_DIR)
 	GOOS=linux GOARCH=mipsle GOMIPS=softfloat $(GO) build $(GOFLAGS_NO_GOOLM) -ldflags "$(LDFLAGS)" -o $(BUILD_DIR)/$(BINARY_NAME)-linux-mipsle ./$(CMD_DIR)

go.mod

@@ -12,6 +12,7 @@ require (
 	github.com/aws/aws-sdk-go-v2/service/bedrockruntime v1.50.2
 	github.com/bwmarrin/discordgo v0.29.0
 	github.com/caarlos0/env/v11 v11.4.0
+	github.com/creack/pty v1.1.9
 	github.com/ergochat/irc-go v0.6.0
 	github.com/ergochat/readline v0.1.3
 	github.com/gdamore/tcell/v2 v2.13.8

go.sum

@@ -69,6 +69,7 @@ github.com/coder/websocket v1.8.14 h1:9L0p0iKiNOibykf283eHkKUHHrpG7f65OE3BhhO7v9
 github.com/coder/websocket v1.8.14/go.mod h1:NX3SzP+inril6yawo5CQXx8+fk145lPDC6pumgx0mVg=
 github.com/coreos/go-systemd/v22 v22.5.0/go.mod h1:Y58oyj3AT4RCenI/lSvhwexgC+NSVTIJ3seZv2GcEnc=
 github.com/cpuguy83/go-md2man/v2 v2.0.6/go.mod h1:oOW0eioCTA6cOiMLiUPZOpcVxMig6NIQQ7OS05n1F4g=
+github.com/creack/pty v1.1.9 h1:uDmaGzcdjhF4i/plgjmEsriH11Y0o7RKapEf/LDaM3w=
 github.com/creack/pty v1.1.9/go.mod h1:oKZEueFk5CKHvIhNR5MUki03XCEU+Q6VDXinZuGJ33E=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=

pkg/agent/instance_test.go

@@ -236,8 +236,9 @@ func TestNewAgentInstance_AllowsMediaTempDirForReadListAndExec(t *testing.T) {
 		t.Fatal("exec tool not registered")
 	}
 	execResult := execTool.Execute(context.Background(), map[string]any{
-		"command":     "cat " + filepath.Base(mediaPath),
+		"action":  "run",
-		"working_dir": mediaDir,
+		"command": "cat " + filepath.Base(mediaPath),
+		"cwd":     mediaDir,
 	})
 	if execResult.IsError {
 		t.Fatalf("exec should allow media temp dir, got: %s", execResult.ForLLM)

pkg/tools/session.go

@@ -0,0 +1,252 @@
+package tools
+
+import (
+	"bytes"
+	"errors"
+	"io"
+	"os"
+	"sync"
+	"time"
+
+	"github.com/google/uuid"
+)
+
+const maxOutputBufferSize = 1 * 1024 * 1024 // 1MB
+
+const outputTruncateMarker = "\n... [output truncated, exceeded 1MB]\n"
+
+// PtyKeyMode represents arrow key encoding mode for PTY sessions.
+// Programs send smkx/rmkx sequences to switch between CSI and SS3 modes.
+type PtyKeyMode uint8
+
+const (
+	PtyKeyModeCSI PtyKeyMode = iota // triggered by rmkx (\x1b[?1l)
+	PtyKeyModeSS3                   // triggered by smkx (\x1b[?1h)
+)
+
+const PtyKeyModeNotFound PtyKeyMode = 255
+
+var (
+	ErrSessionNotFound = errors.New("session not found")
+	ErrSessionDone     = errors.New("session already completed")
+	ErrPTYNotSupported = errors.New("PTY is not supported on this platform")
+	ErrNoStdin         = errors.New("no stdin available")
+)
+
+type ProcessSession struct {
+	mu              sync.Mutex
+	ID              string
+	PID             int
+	Command         string
+	PTY             bool
+	Background      bool
+	StartTime       int64
+	ExitCode        int
+	Status          string
+	stdinWriter     io.Writer
+	stdoutPipe      io.Reader
+	outputBuffer    *bytes.Buffer
+	outputTruncated bool
+	ptyMaster       *os.File
+
+	// ptyKeyMode tracks arrow key encoding mode (CSI vs SS3)
+	ptyKeyMode PtyKeyMode
+}
+
+func (s *ProcessSession) IsDone() bool {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	return s.Status == "done" || s.Status == "exited"
+}
+
+func (s *ProcessSession) GetPtyKeyMode() PtyKeyMode {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	return s.ptyKeyMode
+}
+
+func (s *ProcessSession) SetPtyKeyMode(mode PtyKeyMode) {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	s.ptyKeyMode = mode
+}
+
+func (s *ProcessSession) GetStatus() string {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	return s.Status
+}
+
+func (s *ProcessSession) SetStatus(status string) {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	s.Status = status
+}
+
+func (s *ProcessSession) GetExitCode() int {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	return s.ExitCode
+}
+
+func (s *ProcessSession) SetExitCode(code int) {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	s.ExitCode = code
+}
+
+func (s *ProcessSession) killProcess() error {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+
+	if s.Status != "running" {
+		return ErrSessionDone
+	}
+
+	pid := s.PID
+	if pid <= 0 {
+		return ErrSessionNotFound
+	}
+
+	if err := killProcessGroup(pid); err != nil {
+		return err
+	}
+
+	s.Status = "done"
+	s.ExitCode = -1
+	return nil
+}
+
+func (s *ProcessSession) Kill() error {
+	return s.killProcess()
+}
+
+func (s *ProcessSession) Write(data string) error {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+
+	if s.Status != "running" {
+		return ErrSessionDone
+	}
+
+	var writer io.Writer
+	if s.PTY && s.ptyMaster != nil {
+		writer = s.ptyMaster
+	} else if s.stdinWriter != nil {
+		writer = s.stdinWriter
+	} else {
+		return ErrNoStdin
+	}
+
+	_, err := writer.Write([]byte(data))
+	return err
+}
+
+func (s *ProcessSession) Read() string {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+
+	if s.outputBuffer.Len() == 0 {
+		return ""
+	}
+
+	data := s.outputBuffer.String()
+	s.outputBuffer.Reset()
+	return data
+}
+
+func (s *ProcessSession) ToSessionInfo() SessionInfo {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+
+	return SessionInfo{
+		ID:        s.ID,
+		Command:   s.Command,
+		Status:    s.Status,
+		PID:       s.PID,
+		StartedAt: s.StartTime,
+	}
+}
+
+type SessionManager struct {
+	mu       sync.RWMutex
+	sessions map[string]*ProcessSession
+}
+
+func NewSessionManager() *SessionManager {
+	sm := &SessionManager{
+		sessions: make(map[string]*ProcessSession),
+	}
+
+	// Start cleaner goroutine - runs every 5 minutes, cleans up sessions done for >30 minutes
+	go func() {
+		ticker := time.NewTicker(5 * time.Minute)
+		defer ticker.Stop()
+		for range ticker.C {
+			sm.cleanupOldSessions()
+		}
+	}()
+
+	return sm
+}
+
+// cleanupOldSessions removes sessions that are done and older than 30 minutes
+func (sm *SessionManager) cleanupOldSessions() {
+	sm.mu.Lock()
+	defer sm.mu.Unlock()
+
+	cutoff := time.Now().Add(-30 * time.Minute)
+	for id, session := range sm.sessions {
+		if session.IsDone() && session.StartTime < cutoff.Unix() {
+			delete(sm.sessions, id)
+		}
+	}
+}
+
+func (sm *SessionManager) Add(session *ProcessSession) {
+	sm.mu.Lock()
+	defer sm.mu.Unlock()
+	sm.sessions[session.ID] = session
+}
+
+func (sm *SessionManager) Get(sessionID string) (*ProcessSession, error) {
+	sm.mu.RLock()
+	defer sm.mu.RUnlock()
+
+	session, ok := sm.sessions[sessionID]
+	if !ok {
+		return nil, ErrSessionNotFound
+	}
+
+	return session, nil
+}
+
+func (sm *SessionManager) Remove(sessionID string) {
+	sm.mu.Lock()
+	defer sm.mu.Unlock()
+	delete(sm.sessions, sessionID)
+}
+
+func (sm *SessionManager) List() []SessionInfo {
+	sm.mu.RLock()
+	defer sm.mu.RUnlock()
+
+	result := make([]SessionInfo, 0, len(sm.sessions))
+	for _, session := range sm.sessions {
+		result = append(result, session.ToSessionInfo())
+	}
+
+	return result
+}
+
+func generateSessionID() string {
+	return uuid.New().String()[:8]
+}
+
+type SessionInfo struct {
+	ID        string `json:"id"`
+	Command   string `json:"command"`
+	Status    string `json:"status"`
+	PID       int    `json:"pid"`
+	StartedAt int64  `json:"startedAt"`
+}

pkg/tools/session_process_unix.go

@@ -0,0 +1,14 @@
+//go:build !windows
+
+package tools
+
+import (
+	"syscall"
+)
+
+func killProcessGroup(pid int) error {
+	if err := syscall.Kill(-pid, syscall.SIGKILL); err != nil {
+		_ = syscall.Kill(pid, syscall.SIGKILL)
+	}
+	return nil
+}

pkg/tools/session_process_windows.go

@@ -0,0 +1,13 @@
+//go:build windows
+
+package tools
+
+import (
+	"os/exec"
+	"strconv"
+)
+
+func killProcessGroup(pid int) error {
+	_ = exec.Command("taskkill", "/T", "/F", "/PID", strconv.Itoa(pid)).Run()
+	return nil
+}

pkg/tools/session_test.go

@@ -0,0 +1,99 @@
+package tools
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestSessionManager_AddGet(t *testing.T) {
+	sm := NewSessionManager()
+	session := &ProcessSession{
+		ID:        "test-1",
+		Command:   "echo hello",
+		Status:    "running",
+		StartTime: 1000,
+	}
+
+	sm.Add(session)
+
+	got, err := sm.Get("test-1")
+	require.NoError(t, err)
+	require.Equal(t, "test-1", got.ID)
+}
+
+func TestSessionManager_Remove(t *testing.T) {
+	sm := NewSessionManager()
+	session := &ProcessSession{
+		ID:        "test-1",
+		Command:   "echo hello",
+		Status:    "running",
+		StartTime: 1000,
+	}
+	sm.Add(session)
+	sm.Remove("test-1")
+
+	_, err := sm.Get("test-1")
+	require.ErrorIs(t, err, ErrSessionNotFound)
+}
+
+func TestSessionManager_List(t *testing.T) {
+	sm := NewSessionManager()
+	sm.Add(&ProcessSession{
+		ID:        "test-1",
+		Command:   "echo hello",
+		Status:    "running",
+		StartTime: 1000,
+	})
+	sm.Add(&ProcessSession{
+		ID:        "test-2",
+		Command:   "echo world",
+		Status:    "running",
+		StartTime: 1001,
+	})
+	sm.Add(&ProcessSession{
+		ID:        "test-3",
+		Command:   "echo done",
+		Status:    "done",
+		StartTime: 1002,
+	})
+
+	sessions := sm.List()
+	require.Len(t, sessions, 3)
+
+	ids := make(map[string]bool)
+	for _, s := range sessions {
+		ids[s.ID] = true
+	}
+	require.True(t, ids["test-1"])
+	require.True(t, ids["test-2"])
+	require.True(t, ids["test-3"])
+}
+
+func TestProcessSession_IsDone(t *testing.T) {
+	session := &ProcessSession{Status: "running"}
+	require.False(t, session.IsDone())
+
+	session.Status = "done"
+	require.True(t, session.IsDone())
+
+	session.Status = "exited"
+	require.True(t, session.IsDone())
+}
+
+func TestProcessSession_ToSessionInfo(t *testing.T) {
+	session := &ProcessSession{
+		ID:        "test-1",
+		PID:       12345,
+		Command:   "echo hello",
+		Status:    "running",
+		StartTime: 1000,
+	}
+
+	info := session.ToSessionInfo()
+	require.Equal(t, "test-1", info.ID)
+	require.Equal(t, "echo hello", info.Command)
+	require.Equal(t, "running", info.Status)
+	require.Equal(t, 12345, info.PID)
+	require.Equal(t, int64(1000), info.StartedAt)
+}

pkg/tools/shell.go

@@ -3,20 +3,36 @@ package tools
 import (
 	"bytes"
 	"context"
+	"encoding/json"
 	"errors"
 	"fmt"
+	"io"
 	"os"
 	"os/exec"
 	"path/filepath"
 	"regexp"
 	"runtime"
 	"strings"
+	"sync"
 	"time"
 
+	"github.com/creack/pty"
+
 	"github.com/sipeed/picoclaw/pkg/config"
 	"github.com/sipeed/picoclaw/pkg/constants"
 )
 
+var (
+	globalSessionManager = NewSessionManager()
+	sessionManagerMu     sync.RWMutex
+)
+
+func getSessionManager() *SessionManager {
+	sessionManagerMu.RLock()
+	defer sessionManagerMu.RUnlock()
+	return globalSessionManager
+}
+
 type ExecTool struct {
 	workingDir          string
 	timeout             time.Duration
@@ -26,6 +42,7 @@ type ExecTool struct {
 	allowedPathPatterns []*regexp.Regexp
 	restrictToWorkspace bool
 	allowRemote         bool
+	sessionManager      *SessionManager
 }
 
 var (
@@ -145,7 +162,7 @@ func NewExecToolWithConfig(
 		denyPatterns = append(denyPatterns, defaultDenyPatterns...)
 	}
 
-	timeout := 60 * time.Second
+	var timeout time.Duration
 	if config != nil && config.Tools.Exec.TimeoutSeconds > 0 {
 		timeout = time.Duration(config.Tools.Exec.TimeoutSeconds) * time.Second
 	}
@@ -159,6 +176,7 @@ func NewExecToolWithConfig(
 		allowedPathPatterns: allowedPathPatterns,
 		restrictToWorkspace: restrict,
 		allowRemote:         allowRemote,
+		sessionManager:      getSessionManager(),
 	}, nil
 }
 
@@ -167,27 +185,82 @@ func (t *ExecTool) Name() string {
 }
 
 func (t *ExecTool) Description() string {
-	return "Execute a shell command and return its output. Use with caution."
+	return `Execute shell commands. Use background=true for long-running commands (returns sessionId). Use pty=true for interactive commands (can combine with background=true). Use poll/read/write/send-keys/kill with sessionId to manage background sessions. Sessions auto-cleanup 30 minutes after process exits; use kill to terminate early. Output buffer limit: 1MB.`
 }
 
 func (t *ExecTool) Parameters() map[string]any {
 	return map[string]any{
 		"type": "object",
 		"properties": map[string]any{
+			"action": map[string]any{
+				"type":        "string",
+				"enum":        []string{"run", "list", "poll", "read", "write", "kill", "send-keys"},
+				"description": "Action: run (execute command), list (show sessions), poll (check status), read (get output), write (send input), kill (terminate), send-keys (send keys to PTY)",
+			},
 			"command": map[string]any{
 				"type":        "string",
-				"description": "The shell command to execute",
+				"description": "Shell command to execute (required for run)",
 			},
-			"working_dir": map[string]any{
+			"sessionId": map[string]any{
 				"type":        "string",
-				"description": "Optional working directory for the command",
+				"description": "Session ID (required for poll/read/write/kill/send-keys)",
+			},
+			"keys": map[string]any{
+				"type":        "string",
+				"description": "Key names for send-keys: up, down, left, right, enter, tab, escape, backspace, ctrl-c, ctrl-d, home, end, pageup, pagedown, f1-f12",
+			},
+			"data": map[string]any{
+				"type":        "string",
+				"description": "Data to write to stdin (required for write)",
+			},
+			"background": map[string]any{
+				"type":        "string",
+				"description": "Run in background immediately",
+			},
+			"pty": map[string]any{
+				"type":        "string",
+				"description": "Run in a pseudo-terminal (PTY) when available",
+			},
+			"cwd": map[string]any{
+				"type":        "string",
+				"description": "Working directory for the command",
+			},
+			"timeout": map[string]any{
+				"type":        "integer",
+				"description": "Timeout in seconds (0 = no timeout)",
 			},
 		},
-		"required": []string{"command"},
+		"required": []string{"action"},
 	}
 }
 
 func (t *ExecTool) Execute(ctx context.Context, args map[string]any) *ToolResult {
+	action, _ := args["action"].(string)
+	if action == "" {
+		return ErrorResult("action is required")
+	}
+
+	switch action {
+	case "run":
+		return t.executeRun(ctx, args)
+	case "list":
+		return t.executeList()
+	case "poll":
+		return t.executePoll(args)
+	case "read":
+		return t.executeRead(args)
+	case "write":
+		return t.executeWrite(args)
+	case "kill":
+		return t.executeKill(args)
+	case "send-keys":
+		return t.executeSendKeys(args)
+	default:
+		return ErrorResult(fmt.Sprintf("unknown action: %s", action))
+	}
+}
+
+func (t *ExecTool) executeRun(ctx context.Context, args map[string]any) *ToolResult {
 	command, ok := args["command"].(string)
 	if !ok {
 		return ErrorResult("command is required")
@@ -206,8 +279,26 @@ func (t *ExecTool) Execute(ctx context.Context, args map[string]any) *ToolResult
 		}
 	}
 
+	getBoolArg := func(key string) bool {
+		switch v := args[key].(type) {
+		case bool:
+			return v
+		case string:
+			return v == "true"
+		}
+		return false
+	}
+	isPty := getBoolArg("pty")
+	isBackground := getBoolArg("background")
+
+	if isPty {
+		if runtime.GOOS == "windows" {
+			return ErrorResult("PTY is not supported on Windows. Use background=true without pty.")
+		}
+	}
+
 	cwd := t.workingDir
-	if wd, ok := args["working_dir"].(string); ok && wd != "" {
+	if wd, ok := args["cwd"].(string); ok && wd != "" {
 		if t.restrictToWorkspace && t.workingDir != "" {
 			resolvedWD, err := validatePathWithAllowPaths(wd, t.workingDir, true, t.allowedPathPatterns)
 			if err != nil {
@@ -253,6 +344,14 @@ func (t *ExecTool) Execute(ctx context.Context, args map[string]any) *ToolResult
 		}
 	}
 
+	if isBackground {
+		return t.runBackground(ctx, command, cwd, isPty)
+	}
+
+	return t.runSync(ctx, command, cwd)
+}
+
+func (t *ExecTool) runSync(ctx context.Context, command, cwd string) *ToolResult {
 	// timeout == 0 means no timeout
 	var cmdCtx context.Context
 	var cancel context.CancelFunc
@@ -361,6 +460,560 @@ func (t *ExecTool) Execute(ctx context.Context, args map[string]any) *ToolResult
 	}
 }
 
+func (t *ExecTool) runBackground(ctx context.Context, command, cwd string, ptyEnabled bool) *ToolResult {
+	sessionID := generateSessionID()
+	session := &ProcessSession{
+		ID:         sessionID,
+		Command:    command,
+		PTY:        ptyEnabled,
+		Background: true,
+		StartTime:  time.Now().Unix(),
+		Status:     "running",
+		ptyKeyMode: PtyKeyModeCSI,
+	}
+
+	var cmd *exec.Cmd
+	if runtime.GOOS == "windows" {
+		cmd = exec.Command("powershell", "-NoProfile", "-NonInteractive", "-Command", command)
+	} else {
+		cmd = exec.Command("sh", "-c", command)
+	}
+	if cwd != "" {
+		cmd.Dir = cwd
+	}
+
+	prepareCommandForTermination(cmd)
+
+	var stdoutReader io.ReadCloser
+	var stderrReader io.ReadCloser
+	var stdinWriter io.WriteCloser
+
+	if ptyEnabled {
+		ptmx, tty, err := pty.Open()
+		if err != nil {
+			return ErrorResult(fmt.Sprintf("failed to create PTY: %v", err))
+		}
+
+		cmd.Stdin = tty
+		cmd.Stdout = tty
+		cmd.Stderr = tty
+
+		// For PTY, we need Setsid to create a new session.
+		// Note: Setsid and Setpgid conflict, so we must replace SysProcAttr entirely.
+		setSysProcAttrForPty(cmd)
+
+		session.ptyMaster = ptmx
+	} else {
+		var err error
+		stdoutReader, err = cmd.StdoutPipe()
+		if err != nil {
+			return ErrorResult(fmt.Sprintf("failed to create stdout pipe: %v", err))
+		}
+		stderrReader, err = cmd.StderrPipe()
+		if err != nil {
+			return ErrorResult(fmt.Sprintf("failed to create stderr pipe: %v", err))
+		}
+		stdinWriter, err = cmd.StdinPipe()
+		if err != nil {
+			return ErrorResult(fmt.Sprintf("failed to create stdin pipe: %v", err))
+		}
+		session.stdoutPipe = io.MultiReader(stdoutReader, stderrReader)
+		session.stdinWriter = stdinWriter
+	}
+
+	if err := cmd.Start(); err != nil {
+		if session.ptyMaster != nil {
+			session.ptyMaster.Close()
+		}
+		return ErrorResult(fmt.Sprintf("failed to start command: %v", err))
+	}
+
+	session.PID = cmd.Process.Pid
+	t.sessionManager.Add(session)
+
+	session.outputBuffer = &bytes.Buffer{}
+
+	// PTY mode: read from ptyMaster and wait for process
+	// Note: On Linux, closing ptyMaster doesn't interrupt blocking Read() calls,
+	// so we need cmd.Wait() in a separate goroutine to detect process exit.
+	if session.PTY && session.ptyMaster != nil {
+		go func() {
+			cmd.Wait() // Wait for process to exit
+			session.mu.Lock()
+			if cmd.ProcessState != nil {
+				session.ExitCode = cmd.ProcessState.ExitCode()
+			}
+			session.Status = "done"
+			session.mu.Unlock()
+		}()
+
+		go func() {
+			buf := make([]byte, 4096)
+			for {
+				n, err := session.ptyMaster.Read(buf)
+				if n > 0 {
+					raw := string(buf[:n])
+					if mode := detectPtyKeyMode(raw); mode != PtyKeyModeNotFound && mode != session.GetPtyKeyMode() {
+						session.SetPtyKeyMode(mode)
+					}
+
+					session.mu.Lock()
+					if session.outputBuffer.Len() >= maxOutputBufferSize {
+						if !session.outputTruncated {
+							session.outputBuffer.WriteString(outputTruncateMarker)
+							session.outputTruncated = true
+						}
+					} else {
+						session.outputBuffer.Write(buf[:n])
+					}
+					session.mu.Unlock()
+				}
+				if err != nil {
+					break
+				}
+			}
+		}()
+	} else {
+		// Non-PTY mode: single goroutine reads pipes.
+		// When Read() returns EOF (pipe closed), we break.
+		// When process exits, OS closes pipe write end → Read() returns EOF → we exit.
+		go func() {
+			buf := make([]byte, 4096)
+
+			// Read stdout
+			for {
+				n, err := stdoutReader.Read(buf)
+				if n > 0 {
+					session.mu.Lock()
+					if session.outputBuffer.Len() >= maxOutputBufferSize {
+						if !session.outputTruncated {
+							session.outputBuffer.WriteString(outputTruncateMarker)
+							session.outputTruncated = true
+						}
+					} else {
+						session.outputBuffer.Write(buf[:n])
+					}
+					session.mu.Unlock()
+				}
+				if err != nil {
+					break
+				}
+			}
+
+			// Read stderr
+			for {
+				n, err := stderrReader.Read(buf)
+				if n > 0 {
+					session.mu.Lock()
+					if session.outputBuffer.Len() >= maxOutputBufferSize {
+						if !session.outputTruncated {
+							session.outputBuffer.WriteString(outputTruncateMarker)
+							session.outputTruncated = true
+						}
+					} else {
+						session.outputBuffer.Write(buf[:n])
+					}
+					session.mu.Unlock()
+				}
+				if err != nil {
+					break
+				}
+			}
+
+			// All pipes closed, get exit status
+			if stdinWriter != nil {
+				stdinWriter.Close()
+			}
+			cmd.Wait()
+
+			session.mu.Lock()
+			if cmd.ProcessState != nil {
+				session.ExitCode = cmd.ProcessState.ExitCode()
+			}
+			session.Status = "done"
+			session.mu.Unlock()
+		}()
+	}
+
+	resp := ExecResponse{
+		SessionID: sessionID,
+		Status:    "running",
+	}
+	data, _ := json.Marshal(resp)
+	return &ToolResult{
+		ForLLM:  string(data),
+		ForUser: fmt.Sprintf("Session %s started", sessionID),
+		IsError: false,
+	}
+}
+
+func (t *ExecTool) executeList() *ToolResult {
+	sessions := t.sessionManager.List()
+	resp := ExecResponse{
+		Sessions: sessions,
+	}
+	data, _ := json.Marshal(resp)
+	return &ToolResult{
+		ForLLM:  string(data),
+		ForUser: fmt.Sprintf("%d active sessions", len(sessions)),
+		IsError: false,
+	}
+}
+
+func (t *ExecTool) executePoll(args map[string]any) *ToolResult {
+	sessionID, ok := args["sessionId"].(string)
+	if !ok {
+		return ErrorResult("sessionId is required")
+	}
+
+	session, err := t.sessionManager.Get(sessionID)
+	if err != nil {
+		if errors.Is(err, ErrSessionNotFound) {
+			return ErrorResult(fmt.Sprintf("session not found: %s", sessionID))
+		}
+		return ErrorResult(err.Error())
+	}
+
+	resp := ExecResponse{
+		SessionID: sessionID,
+		Status:    session.GetStatus(),
+		ExitCode:  session.GetExitCode(),
+	}
+	data, _ := json.Marshal(resp)
+	return &ToolResult{
+		ForLLM:  string(data),
+		IsError: false,
+	}
+}
+
+func (t *ExecTool) executeRead(args map[string]any) *ToolResult {
+	sessionID, ok := args["sessionId"].(string)
+	if !ok {
+		return ErrorResult("sessionId is required")
+	}
+
+	session, err := t.sessionManager.Get(sessionID)
+	if err != nil {
+		if errors.Is(err, ErrSessionNotFound) {
+			return ErrorResult(fmt.Sprintf("session not found: %s", sessionID))
+		}
+		return ErrorResult(err.Error())
+	}
+
+	output := session.Read()
+
+	resp := ExecResponse{
+		SessionID: sessionID,
+		Output:    output,
+		Status:    session.GetStatus(),
+	}
+	data, _ := json.Marshal(resp)
+	return &ToolResult{
+		ForLLM:  string(data),
+		IsError: false,
+	}
+}
+
+func (t *ExecTool) executeWrite(args map[string]any) *ToolResult {
+	sessionID, ok := args["sessionId"].(string)
+	if !ok {
+		return ErrorResult("sessionId is required")
+	}
+
+	data, ok := args["data"].(string)
+	if !ok {
+		return ErrorResult("data is required")
+	}
+
+	session, err := t.sessionManager.Get(sessionID)
+	if err != nil {
+		if errors.Is(err, ErrSessionNotFound) {
+			return ErrorResult(fmt.Sprintf("session not found: %s", sessionID))
+		}
+		return ErrorResult(err.Error())
+	}
+
+	if session.IsDone() {
+		return ErrorResult(fmt.Sprintf("process already exited with code %d", session.GetExitCode()))
+	}
+
+	if err := session.Write(data); err != nil {
+		if errors.Is(err, ErrSessionDone) {
+			return ErrorResult(fmt.Sprintf("process already exited with code %d", session.GetExitCode()))
+		}
+		return ErrorResult(fmt.Sprintf("failed to write to session: %v", err))
+	}
+
+	resp := ExecResponse{
+		SessionID: sessionID,
+		Status:    session.GetStatus(),
+	}
+	respData, _ := json.Marshal(resp)
+	return &ToolResult{
+		ForLLM:  string(respData),
+		IsError: false,
+	}
+}
+
+func (t *ExecTool) executeKill(args map[string]any) *ToolResult {
+	sessionID, ok := args["sessionId"].(string)
+	if !ok {
+		return ErrorResult("sessionId is required")
+	}
+
+	session, err := t.sessionManager.Get(sessionID)
+	if err != nil {
+		if errors.Is(err, ErrSessionNotFound) {
+			return ErrorResult(fmt.Sprintf("session not found: %s", sessionID))
+		}
+		return ErrorResult(err.Error())
+	}
+
+	if session.IsDone() {
+		return ErrorResult(fmt.Sprintf("process already exited with code %d", session.GetExitCode()))
+	}
+
+	if err := session.Kill(); err != nil {
+		return ErrorResult(fmt.Sprintf("failed to kill session: %v", err))
+	}
+
+	t.sessionManager.Remove(sessionID)
+
+	resp := ExecResponse{
+		SessionID: sessionID,
+		Status:    "done",
+	}
+	data, _ := json.Marshal(resp)
+	return &ToolResult{
+		ForLLM:  string(data),
+		ForUser: fmt.Sprintf("Session %s killed", sessionID),
+		IsError: false,
+	}
+}
+
+// keyMap maps key names to their escape sequences.
+var keyMap = map[string]string{
+	"enter":     "\r",
+	"return":    "\r",
+	"tab":       "\t",
+	"escape":    "\x1b",
+	"esc":       "\x1b",
+	"space":     " ",
+	"backspace": "\x7f",
+	"bspace":    "\x7f",
+	"up":        "\x1b[A",
+	"down":      "\x1b[B",
+	"right":     "\x1b[C",
+	"left":      "\x1b[D",
+	"home":      "\x1b[1~",
+	"end":       "\x1b[4~",
+	"pageup":    "\x1b[5~",
+	"pagedown":  "\x1b[6~",
+	"pgup":      "\x1b[5~",
+	"pgdn":      "\x1b[6~",
+	"insert":    "\x1b[2~",
+	"ic":        "\x1b[2~",
+	"delete":    "\x1b[3~",
+	"del":       "\x1b[3~",
+	"dc":        "\x1b[3~",
+	"btab":      "\x1b[Z",
+	"f1":        "\x1bOP",
+	"f2":        "\x1bOQ",
+	"f3":        "\x1bOR",
+	"f4":        "\x1bOS",
+	"f5":        "\x1b[15~",
+	"f6":        "\x1b[17~",
+	"f7":        "\x1b[18~",
+	"f8":        "\x1b[19~",
+	"f9":        "\x1b[20~",
+	"f10":       "\x1b[21~",
+	"f11":       "\x1b[23~",
+	"f12":       "\x1b[24~",
+}
+
+// ss3KeysMap maps key names to SS3 escape sequences
+var ss3KeysMap = map[string]string{
+	"up":    "\x1bOA",
+	"down":  "\x1bOB",
+	"right": "\x1bOC",
+	"left":  "\x1bOD",
+	"home":  "\x1bOH",
+	"end":   "\x1bOF",
+}
+
+func detectPtyKeyMode(raw string) PtyKeyMode {
+	const SMKX = "\x1b[?1h"
+	const RMKX = "\x1b[?1l"
+
+	lastSmkx := strings.LastIndex(raw, SMKX)
+	lastRmkx := strings.LastIndex(raw, RMKX)
+
+	if lastSmkx == -1 && lastRmkx == -1 {
+		return PtyKeyModeNotFound
+	}
+
+	if lastSmkx > lastRmkx {
+		return PtyKeyModeSS3
+	}
+	return PtyKeyModeCSI
+}
+
+// encodeKeyToken encodes a single key token into its escape sequence.
+// Supports:
+//   - Named keys: "enter", "tab", "up", "ctrl-c", "alt-x", etc.
+//   - Ctrl modifier: "ctrl-c" or "c-c" (sends Ctrl+char)
+//   - Alt modifier: "alt-x" or "m-x" (sends ESC+char)
+func encodeKeyToken(token string, ptyKeyMode PtyKeyMode) (string, error) {
+	token = strings.ToLower(strings.TrimSpace(token))
+	if token == "" {
+		return "", nil
+	}
+
+	// Handle ctrl-X format (c-x)
+	if strings.HasPrefix(token, "c-") {
+		char := token[2]
+		if char >= 'a' && char <= 'z' {
+			return string(rune(char) & 0x1f), nil // ctrl-a through ctrl-z
+		}
+		return "", fmt.Errorf("invalid ctrl key: %s", token)
+	}
+
+	// Handle ctrl-X format (ctrl-x)
+	if strings.HasPrefix(token, "ctrl-") {
+		char := token[5]
+		if char >= 'a' && char <= 'z' {
+			return string(rune(char) & 0x1f), nil
+		}
+		return "", fmt.Errorf("invalid ctrl key: %s", token)
+	}
+
+	// Handle alt-X format (m-x or alt-x)
+	if strings.HasPrefix(token, "m-") || strings.HasPrefix(token, "alt-") {
+		var char string
+		if strings.HasPrefix(token, "m-") {
+			char = token[2:]
+		} else {
+			char = token[4:]
+		}
+		if len(char) == 1 {
+			return "\x1b" + char, nil
+		}
+		return "", fmt.Errorf("invalid alt key: %s", token)
+	}
+
+	// Handle shift modifier for special keys (shift-up, shift-down, etc.)
+	if strings.HasPrefix(token, "s-") || strings.HasPrefix(token, "shift-") {
+		var key string
+		if strings.HasPrefix(token, "s-") {
+			key = token[2:]
+		} else {
+			key = token[6:]
+		}
+		// Apply shift modifier: for single-char keys, return uppercase
+		if seq, ok := keyMap[key]; ok {
+			// For escape sequences, we can't easily add shift
+			// For single-char keys (letters), return uppercase
+			if len(seq) == 1 {
+				return strings.ToUpper(seq), nil
+			}
+			return seq, nil
+		}
+		return "", fmt.Errorf("unknown key with shift: %s", key)
+	}
+
+	if ptyKeyMode == PtyKeyModeSS3 {
+		if seq, ok := ss3KeysMap[token]; ok {
+			return seq, nil
+		}
+	}
+
+	if seq, ok := keyMap[token]; ok {
+		return seq, nil
+	}
+
+	return "", fmt.Errorf("unknown key: %s (use write action for text input)", token)
+}
+
+// encodeKeySequence encodes a slice of key tokens into a single string.
+func encodeKeySequence(tokens []string, ptyKeyMode PtyKeyMode) (string, error) {
+	var result string
+	for _, token := range tokens {
+		seq, err := encodeKeyToken(token, ptyKeyMode)
+		if err != nil {
+			return "", err
+		}
+		result += seq
+	}
+	return result, nil
+}
+
+func (t *ExecTool) executeSendKeys(args map[string]any) *ToolResult {
+	sessionID, ok := args["sessionId"].(string)
+	if !ok {
+		return ErrorResult("sessionId is required")
+	}
+
+	keysStr, ok := args["keys"].(string)
+	if !ok {
+		return ErrorResult("keys must be a string")
+	}
+
+	if keysStr == "" {
+		return ErrorResult("keys cannot be empty")
+	}
+
+	// Parse comma-separated key names
+	keyNames := strings.Split(keysStr, ",")
+	var keys []string
+	for _, k := range keyNames {
+		k = strings.TrimSpace(k)
+		if k != "" {
+			keys = append(keys, k)
+		}
+	}
+
+	if len(keys) == 0 {
+		return ErrorResult("keys cannot be empty")
+	}
+
+	session, err := t.sessionManager.Get(sessionID)
+	if err != nil {
+		if errors.Is(err, ErrSessionNotFound) {
+			return ErrorResult(fmt.Sprintf("session not found: %s", sessionID))
+		}
+		return ErrorResult(err.Error())
+	}
+
+	ptyKeyMode := session.GetPtyKeyMode()
+
+	data, err := encodeKeySequence(keys, ptyKeyMode)
+	if err != nil {
+		return ErrorResult(fmt.Sprintf("invalid key: %v", err))
+	}
+
+	if session.IsDone() {
+		return ErrorResult(fmt.Sprintf("process already exited with code %d", session.GetExitCode()))
+	}
+
+	if err := session.Write(data); err != nil {
+		if errors.Is(err, ErrSessionDone) {
+			return ErrorResult(fmt.Sprintf("process already exited with code %d", session.GetExitCode()))
+		}
+		return ErrorResult(fmt.Sprintf("failed to send keys: %v", err))
+	}
+
+	resp := ExecResponse{
+		SessionID: sessionID,
+		Status:    "running",
+		Output:    fmt.Sprintf("Sent keys: %v", keys),
+	}
+	respData, _ := json.Marshal(resp)
+	return &ToolResult{
+		ForLLM:  string(respData),
+		IsError: false,
+	}
+}
+
 func (t *ExecTool) guardCommand(command, cwd string) string {
 	cmd := strings.TrimSpace(command)
 	lower := strings.ToLower(cmd)

pkg/tools/shell_timeout_unix_test.go

@@ -30,6 +30,7 @@ func TestShellTool_TimeoutKillsChildProcess(t *testing.T) {
 	tool.SetTimeout(500 * time.Millisecond)
 
 	args := map[string]any{
+		"action": "run",
 		// Spawn a child process that would outlive the shell unless process-group kill is used.
 		"command": "sleep 60 & echo $! > child.pid; wait",
 	}

pkg/tools/sysproc_unix.go

@@ -0,0 +1,12 @@
+//go:build !windows
+
+package tools
+
+import (
+	"os/exec"
+	"syscall"
+)
+
+func setSysProcAttrForPty(cmd *exec.Cmd) {
+	cmd.SysProcAttr = &syscall.SysProcAttr{Setsid: true}
+}

pkg/tools/sysproc_windows.go

@@ -0,0 +1,10 @@
+//go:build windows
+
+package tools
+
+import "os/exec"
+
+func setSysProcAttrForPty(cmd *exec.Cmd) {
+	// Windows doesn't support Setsid, and PTY is not available on Windows anyway.
+	// This function is a no-op for Windows builds.
+}

pkg/tools/types.go

@@ -56,3 +56,24 @@ type ToolFunctionDefinition struct {
 	Description string         `json:"description"`
 	Parameters  map[string]any `json:"parameters"`
 }
+
+type ExecRequest struct {
+	Action     string            `json:"action"`
+	Command    string            `json:"command,omitempty"`
+	PTY        bool              `json:"pty,omitempty"`
+	Background bool              `json:"background,omitempty"`
+	Timeout    int               `json:"timeout,omitempty"`
+	Env        map[string]string `json:"env,omitempty"`
+	Cwd        string            `json:"cwd,omitempty"`
+	SessionID  string            `json:"sessionId,omitempty"`
+	Data       string            `json:"data,omitempty"`
+}
+
+type ExecResponse struct {
+	SessionID string        `json:"sessionId,omitempty"`
+	Status    string        `json:"status,omitempty"`
+	ExitCode  int           `json:"exitCode,omitempty"`
+	Output    string        `json:"output,omitempty"`
+	Error     string        `json:"error,omitempty"`
+	Sessions  []SessionInfo `json:"sessions,omitempty"`
+}