humanlayer · crdant · Nov 5, 2025 · Nov 5, 2025 · Nov 5, 2025
diff --git a/hld/api/handlers/plugins.go b/hld/api/handlers/plugins.go
@@ -0,0 +1,202 @@
+package handlers
+
+import (
+	"encoding/json"
+	"fmt"
+	"log/slog"
+	"os"
+	"path/filepath"
+	"strings"
+	"time"
+
+	api "github.com/humanlayer/humanlayer/hld/api"
+)
+
+// InstalledPluginsJSON represents the installed_plugins.json file structure
+type InstalledPluginsJSON struct {
+	Version int                        `json:"version"`
+	Plugins map[string]InstalledPlugin `json:"plugins"`
+}
+
+// InstalledPlugin represents a single plugin's metadata
+type InstalledPlugin struct {
+	Version      string    `json:"version"`
+	InstalledAt  time.Time `json:"installedAt"`
+	LastUpdated  time.Time `json:"lastUpdated"`
+	InstallPath  string    `json:"installPath"`
+	GitCommitSha string    `json:"gitCommitSha"`
+	IsLocal      bool      `json:"isLocal"`
+}
+
+// SettingsJSON represents the settings.json file structure
+type SettingsJSON struct {
+	EnabledPlugins map[string]bool `json:"enabledPlugins"`
+	// Other settings fields are ignored
+}
+
+// discoverPluginCommands discovers slash commands from installed Claude Code plugins
+// This function encapsulates all plugin-specific logic to isolate it from the main flow
+func discoverPluginCommands(configDir string) ([]api.SlashCommand, error) {
+	var pluginCommands []api.SlashCommand
+
+	// Expand tilde in config directory
+	configDir = expandTilde(configDir)
+
+	// Plugin files are in a subdirectory
+	pluginsDir := filepath.Join(configDir, "plugins")
+
+	// 1. Read installed plugins metadata
+	installedPluginsPath := filepath.Join(pluginsDir, "installed_plugins.json")
+	installedData, err := os.ReadFile(installedPluginsPath)
+	if err != nil {
+		if os.IsNotExist(err) {
+			// No plugins installed, return empty list
+			slog.Debug("No installed_plugins.json found",
+				"path", installedPluginsPath,
+				"operation", "discoverPluginCommands")
+			return pluginCommands, nil
+		}
+		// Other error (permissions, etc.)
+		return nil, fmt.Errorf("failed to read installed_plugins.json: %w", err)
+	}
+
+	var installed InstalledPluginsJSON
+	if err := json.Unmarshal(installedData, &installed); err != nil {
+		slog.Warn("Failed to parse installed_plugins.json",
+			"path", installedPluginsPath,
+			"error", err.Error(),
+			"operation", "discoverPluginCommands")
+		// Return empty rather than failing entirely
+		return pluginCommands, nil
+	}
+
+	// 2. Read enabled plugins state
+	settingsPath := filepath.Join(configDir, "settings.json")
+	settingsData, err := os.ReadFile(settingsPath)
+	if err != nil {
+		if os.IsNotExist(err) {
+			// No settings file, assume all plugins are enabled
+			slog.Debug("No settings.json found, treating all plugins as enabled",
+				"path", settingsPath,
+				"operation", "discoverPluginCommands")
+		} else {
+			// Log but don't fail
+			slog.Warn("Failed to read settings.json",
+				"path", settingsPath,
+				"error", err.Error(),
+				"operation", "discoverPluginCommands")
+		}
+		// Continue with all plugins enabled
+		settingsData = []byte("{}")
+	}
+
+	var settings SettingsJSON
+	if err := json.Unmarshal(settingsData, &settings); err != nil {
+		slog.Warn("Failed to parse settings.json",
+			"path", settingsPath,
+			"error", err.Error(),
+			"operation", "discoverPluginCommands")
+		// Continue with empty settings (all plugins enabled)
+		settings = SettingsJSON{EnabledPlugins: make(map[string]bool)}
+	}
+
+	// 3. For each plugin, check if enabled and scan commands
+	for pluginID, plugin := range installed.Plugins {
+		// Check if plugin is explicitly disabled
+		if enabled, exists := settings.EnabledPlugins[pluginID]; exists && !enabled {
+			slog.Debug("Skipping disabled plugin",
+				"plugin_id", pluginID,
+				"operation", "discoverPluginCommands")
+			continue
+		}
+
+		// Extract plugin name from "plugin-name@marketplace-name" format
+		pluginName := strings.Split(pluginID, "@")[0]
+
+		// Scan plugin commands directory
+		commandsDir := filepath.Join(plugin.InstallPath, "commands")
+		commands, err := scanPluginCommandsDir(commandsDir, pluginName)
+		if err != nil {
+			slog.Warn("Failed to scan plugin commands",
+				"plugin", pluginName,
+				"commands_dir", commandsDir,
+				"error", err.Error(),
+				"operation", "discoverPluginCommands")
+			// Continue with other plugins
+			continue
+		}
+
+		slog.Debug("Discovered plugin commands",
+			"plugin", pluginName,
+			"count", len(commands),
+			"operation", "discoverPluginCommands")
+
+		pluginCommands = append(pluginCommands, commands...)
+	}
+
+	return pluginCommands, nil
+}
+
+// scanPluginCommandsDir scans a single plugin's commands directory
+func scanPluginCommandsDir(dir string, pluginName string) ([]api.SlashCommand, error) {
+	var commands []api.SlashCommand
+
+	// Check if directory exists
+	if _, err := os.Stat(dir); os.IsNotExist(err) {
+		// Commands directory doesn't exist, return empty
+		return commands, nil
+	}
+
+	err := filepath.WalkDir(dir, func(path string, d os.DirEntry, err error) error {
+		if err != nil {
+			// Log but don't fail the entire scan
+			slog.Debug("Error walking directory",
+				"path", path,
+				"error", err.Error(),
+				"operation", "scanPluginCommandsDir")
+			return nil
+		}
+
+		if d.IsDir() {
+			return nil
+		}
+
+		// Only process .md files
+		if !strings.HasSuffix(path, ".md") {
+			return nil
+		}
+
+		// Get relative path from commands directory
+		relPath, err := filepath.Rel(dir, path)
+		if err != nil {
+			slog.Debug("Failed to get relative path",
+				"path", path,
+				"base", dir,
+				"error", err.Error(),
+				"operation", "scanPluginCommandsDir")
+			return nil
+		}
+
+		// Convert to command name
+		commandName := strings.TrimSuffix(relPath, ".md")
+
+		// Convert path separators to colons for nested commands
+		commandName = strings.ReplaceAll(commandName, string(filepath.Separator), ":")
+
+		// Create namespaced command: /plugin-name:command-name
+		fullCommandName := "/" + pluginName + ":" + commandName
+
+		commands = append(commands, api.SlashCommand{
+			Name:   fullCommandName,
+			Source: api.SlashCommandSourcePlugin,
+		})
+
+		return nil
+	})
+
+	if err != nil {
+		return nil, fmt.Errorf("failed to walk directory %s: %w", dir, err)
+	}
+
+	return commands, nil
+}