feat(cli): enable skill activation via slash commands (#21758)

Co-authored-by: matt korwel <matt.korwel@gmail.com>

packages/cli/src/services/SkillCommandLoader.ts

@@ -0,0 +1,53 @@
+/**
+ * @license
+ * Copyright 2026 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { type Config, ACTIVATE_SKILL_TOOL_NAME } from '@google/gemini-cli-core';
+import { CommandKind, type SlashCommand } from '../ui/commands/types.js';
+import { type ICommandLoader } from './types.js';
+
+/**
+ * Loads Agent Skills as slash commands.
+ */
+export class SkillCommandLoader implements ICommandLoader {
+  constructor(private config: Config | null) {}
+
+  /**
+   * Discovers all available skills from the SkillManager and converts
+   * them into executable slash commands.
+   *
+   * @param _signal An AbortSignal (unused for this synchronous loader).
+   * @returns A promise that resolves to an array of `SlashCommand` objects.
+   */
+  async loadCommands(_signal: AbortSignal): Promise<SlashCommand[]> {
+    if (!this.config || !this.config.isSkillsSupportEnabled()) {
+      return [];
+    }
+
+    const skillManager = this.config.getSkillManager();
+    if (!skillManager || !skillManager.isAdminEnabled()) {
+      return [];
+    }
+
+    // Convert all displayable skills into slash commands.
+    const skills = skillManager.getDisplayableSkills();
+
+    return skills.map((skill) => {
+      const commandName = skill.name.trim().replace(/\s+/g, '-');
+      return {
+        name: commandName,
+        description: skill.description || `Activate the ${skill.name} skill`,
+        kind: CommandKind.SKILL,
+        autoExecute: true,
+        action: async (_context, args) => ({
+          type: 'tool',
+          toolName: ACTIVATE_SKILL_TOOL_NAME,
+          toolArgs: { name: skill.name },
+          postSubmitPrompt: args.trim().length > 0 ? args.trim() : undefined,
+        }),
+      };
+    });
+  }
+}