fix(mcp): expand home paths for local stdio server commands

cmd/picoclaw/internal/mcp/add.go

@@ -223,6 +223,9 @@ func buildServerConfig(target string, args []string, opts addOptions) (config.MC
 	if err := validateLocalCommandPath(target); err != nil {
 		return config.MCPServerConfig{}, err
 	}
+	if isLocalCommandPath(command) {
+		command = expandHomePath(command)
+	}
 
 	server.Command = command
 	server.Args = commandArgs

cmd/picoclaw/internal/mcp/command_test.go

@@ -152,6 +152,28 @@ func TestMCPAddRejectsNonExecutableLocalCommand(t *testing.T) {
 	assert.Contains(t, err.Error(), "not executable")
 }
 
+func TestMCPAddExpandsHomeInSavedLocalCommand(t *testing.T) {
+	configPath := setupMCPConfigEnv(t)
+
+	homeDir := t.TempDir()
+	t.Setenv("HOME", homeDir)
+	t.Setenv("USERPROFILE", homeDir)
+
+	localCmd := filepath.Join(homeDir, "bin", "my-mcp")
+	require.NoError(t, os.MkdirAll(filepath.Dir(localCmd), 0o755))
+	require.NoError(t, os.WriteFile(localCmd, []byte("#!/bin/sh\nexit 0\n"), 0o755))
+
+	tildeCmd := "~" + string(os.PathSeparator) + filepath.Join("bin", "my-mcp")
+
+	cmd := NewMCPCommand()
+	_, err := executeCommand(cmd, []string{"add", "local-home", tildeCmd}, "")
+	require.NoError(t, err)
+
+	cfg := readMCPConfig(t, configPath)
+	server := cfg.Tools.MCP.Servers["local-home"]
+	assert.Equal(t, localCmd, server.Command)
+}
+
 func TestMCPAddShowsClearErrorForRemoteURLWithoutTransport(t *testing.T) {
 	setupMCPConfigEnv(t)
 

pkg/mcp/manager.go

@@ -25,6 +25,24 @@ type headerTransport struct {
 	headers map[string]string
 }
 
+func expandHomeCommandPath(command string) string {
+	if command == "" || command[0] != '~' {
+		return command
+	}
+
+	home, err := os.UserHomeDir()
+	if err != nil {
+		return command
+	}
+	if command == "~" {
+		return home
+	}
+	if strings.HasPrefix(command, "~/") || strings.HasPrefix(command, "~\\") {
+		return filepath.Join(home, command[2:])
+	}
+	return command
+}
+
 func (t *headerTransport) RoundTrip(req *http.Request) (*http.Response, error) {
 	// Clone the request to avoid modifying the original
 	req = req.Clone(req.Context())
@@ -324,7 +342,7 @@ func (m *Manager) ConnectServer(
 				"command": cfg.Command,
 			})
 		// Create command with context
-		cmd := exec.CommandContext(ctx, cfg.Command, cfg.Args...)
+		cmd := exec.CommandContext(ctx, expandHomeCommandPath(cfg.Command), cfg.Args...)
 
 		// Build environment variables with proper override semantics
 		// Use a map to ensure config variables override file variables

pkg/mcp/manager_test.go

@@ -136,6 +136,22 @@ func TestLoadEnvFileNotFound(t *testing.T) {
 	}
 }
 
+func TestExpandHomeCommandPath(t *testing.T) {
+	homeDir := t.TempDir()
+	t.Setenv("HOME", homeDir)
+	t.Setenv("USERPROFILE", homeDir)
+
+	want := filepath.Join(homeDir, "bin", "my-mcp")
+	got := expandHomeCommandPath("~" + string(os.PathSeparator) + filepath.Join("bin", "my-mcp"))
+	if got != want {
+		t.Fatalf("expandHomeCommandPath() = %q, want %q", got, want)
+	}
+
+	if got := expandHomeCommandPath("npx"); got != "npx" {
+		t.Fatalf("expandHomeCommandPath() should leave bare commands unchanged, got %q", got)
+	}
+}
+
 func TestEnvFilePriority(t *testing.T) {
 	// Create a temporary .env file
 	tmpDir := t.TempDir()