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

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

packages/cli/src/services/SkillCommandLoader.test.ts

@@ -0,0 +1,125 @@
+/**
+ * @license
+ * Copyright 2026 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { vi, describe, it, expect, beforeEach } from 'vitest';
+import { SkillCommandLoader } from './SkillCommandLoader.js';
+import { CommandKind } from '../ui/commands/types.js';
+import { ACTIVATE_SKILL_TOOL_NAME } from '@google/gemini-cli-core';
+
+describe('SkillCommandLoader', () => {
+  // eslint-disable-next-line @typescript-eslint/no-explicit-any
+  let mockConfig: any;
+  // eslint-disable-next-line @typescript-eslint/no-explicit-any
+  let mockSkillManager: any;
+
+  beforeEach(() => {
+    mockSkillManager = {
+      getDisplayableSkills: vi.fn(),
+      isAdminEnabled: vi.fn().mockReturnValue(true),
+    };
+
+    mockConfig = {
+      isSkillsSupportEnabled: vi.fn().mockReturnValue(true),
+      getSkillManager: vi.fn().mockReturnValue(mockSkillManager),
+    };
+  });
+
+  it('should return an empty array if skills support is disabled', async () => {
+    mockConfig.isSkillsSupportEnabled.mockReturnValue(false);
+    const loader = new SkillCommandLoader(mockConfig);
+    const commands = await loader.loadCommands(new AbortController().signal);
+    expect(commands).toEqual([]);
+  });
+
+  it('should return an empty array if SkillManager is missing', async () => {
+    mockConfig.getSkillManager.mockReturnValue(null);
+    const loader = new SkillCommandLoader(mockConfig);
+    const commands = await loader.loadCommands(new AbortController().signal);
+    expect(commands).toEqual([]);
+  });
+
+  it('should return an empty array if skills are admin-disabled', async () => {
+    mockSkillManager.isAdminEnabled.mockReturnValue(false);
+    const loader = new SkillCommandLoader(mockConfig);
+    const commands = await loader.loadCommands(new AbortController().signal);
+    expect(commands).toEqual([]);
+  });
+
+  it('should load skills as slash commands', async () => {
+    const mockSkills = [
+      { name: 'skill1', description: 'Description 1' },
+      { name: 'skill2', description: '' },
+    ];
+    mockSkillManager.getDisplayableSkills.mockReturnValue(mockSkills);
+
+    const loader = new SkillCommandLoader(mockConfig);
+    const commands = await loader.loadCommands(new AbortController().signal);
+
+    expect(commands).toHaveLength(2);
+
+    expect(commands[0]).toMatchObject({
+      name: 'skill1',
+      description: 'Description 1',
+      kind: CommandKind.SKILL,
+      autoExecute: true,
+    });
+
+    expect(commands[1]).toMatchObject({
+      name: 'skill2',
+      description: 'Activate the skill2 skill',
+      kind: CommandKind.SKILL,
+      autoExecute: true,
+    });
+  });
+
+  it('should return a tool action when a skill command is executed', async () => {
+    const mockSkills = [{ name: 'test-skill', description: 'Test skill' }];
+    mockSkillManager.getDisplayableSkills.mockReturnValue(mockSkills);
+
+    const loader = new SkillCommandLoader(mockConfig);
+    const commands = await loader.loadCommands(new AbortController().signal);
+
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    const actionResult = await commands[0].action!({} as any, '');
+    expect(actionResult).toEqual({
+      type: 'tool',
+      toolName: ACTIVATE_SKILL_TOOL_NAME,
+      toolArgs: { name: 'test-skill' },
+      postSubmitPrompt: undefined,
+    });
+  });
+
+  it('should return a tool action with postSubmitPrompt when args are provided', async () => {
+    const mockSkills = [{ name: 'test-skill', description: 'Test skill' }];
+    mockSkillManager.getDisplayableSkills.mockReturnValue(mockSkills);
+
+    const loader = new SkillCommandLoader(mockConfig);
+    const commands = await loader.loadCommands(new AbortController().signal);
+
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    const actionResult = await commands[0].action!({} as any, 'hello world');
+    expect(actionResult).toEqual({
+      type: 'tool',
+      toolName: ACTIVATE_SKILL_TOOL_NAME,
+      toolArgs: { name: 'test-skill' },
+      postSubmitPrompt: 'hello world',
+    });
+  });
+
+  it('should sanitize skill names with spaces', async () => {
+    const mockSkills = [{ name: 'my awesome skill', description: 'Desc' }];
+    mockSkillManager.getDisplayableSkills.mockReturnValue(mockSkills);
+
+    const loader = new SkillCommandLoader(mockConfig);
+    const commands = await loader.loadCommands(new AbortController().signal);
+
+    expect(commands[0].name).toBe('my-awesome-skill');
+
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    const actionResult = (await commands[0].action!({} as any, '')) as any;
+    expect(actionResult.toolArgs).toEqual({ name: 'my awesome skill' });
+  });
+});

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,
+        }),
+      };
+    });
+  }
+}

packages/cli/src/ui/commands/types.ts

@@ -182,6 +182,7 @@ export enum CommandKind {
   EXTENSION_FILE = 'extension-file',
   MCP_PROMPT = 'mcp-prompt',
   AGENT = 'agent',
+  SKILL = 'skill',
 }
 
 // The standardized contract for any command in the system.

packages/cli/src/ui/hooks/slashCommandProcessor.ts

@@ -52,6 +52,7 @@ import { CommandService } from '../../services/CommandService.js';
 import { BuiltinCommandLoader } from '../../services/BuiltinCommandLoader.js';
 import { FileCommandLoader } from '../../services/FileCommandLoader.js';
 import { McpPromptLoader } from '../../services/McpPromptLoader.js';
+import { SkillCommandLoader } from '../../services/SkillCommandLoader.js';
 import { parseSlashCommand } from '../../utils/commands.js';
 import {
   type ExtensionUpdateAction,
@@ -324,6 +325,7 @@ export const useSlashCommandProcessor = (
     (async () => {
       const commandService = await CommandService.create(
         [
+          new SkillCommandLoader(config),
           new McpPromptLoader(config),
           new BuiltinCommandLoader(config),
           new FileCommandLoader(config),
@@ -445,6 +447,7 @@ export const useSlashCommandProcessor = (
                     type: 'schedule_tool',
                     toolName: result.toolName,
                     toolArgs: result.toolArgs,
+                    postSubmitPrompt: result.postSubmitPrompt,
                   };
                 case 'message':
                   addItem(

packages/cli/src/ui/hooks/useGeminiStream.ts

@@ -759,7 +759,8 @@ export const useGeminiStream = (
           if (slashCommandResult) {
             switch (slashCommandResult.type) {
               case 'schedule_tool': {
-                const { toolName, toolArgs } = slashCommandResult;
+                const { toolName, toolArgs, postSubmitPrompt } =
+                  slashCommandResult;
                 const toolCallRequest: ToolCallRequestInfo = {
                   callId: `${toolName}-${Date.now()}-${Math.random().toString(16).slice(2)}`,
                   name: toolName,
@@ -768,6 +769,15 @@ export const useGeminiStream = (
                   prompt_id,
                 };
                 await scheduleToolCalls([toolCallRequest], abortSignal);
+
+                if (postSubmitPrompt) {
+                  localQueryToSendToGemini = postSubmitPrompt;
+                  return {
+                    queryToSend: localQueryToSendToGemini,
+                    shouldProceed: true,
+                  };
+                }
+
                 return { queryToSend: null, shouldProceed: false };
               }
               case 'submit_prompt': {

packages/cli/src/ui/types.ts

@@ -483,6 +483,7 @@ export type SlashCommandProcessorResult =
       type: 'schedule_tool';
       toolName: string;
       toolArgs: Record<string, unknown>;
+      postSubmitPrompt?: PartListUnion;
     }
   | {
       type: 'handled'; // Indicates the command was processed and no further action is needed.

packages/core/src/commands/types.ts

@@ -12,6 +12,11 @@ export interface ToolActionReturn {
   type: 'tool';
   toolName: string;
   toolArgs: Record<string, unknown>;
+  /**
+   * Optional content to be submitted as a prompt to the Gemini model
+   * after the tool call completes.
+   */
+  postSubmitPrompt?: PartListUnion;
 }
 
 /**

packages/core/src/scheduler/policy.test.ts

@@ -164,6 +164,43 @@ describe('policy.ts', () => {
       const result = await checkPolicy(toolCall, mockConfig);
       expect(result.decision).toBe(PolicyDecision.ASK_USER);
     });
+
+    it('should return ALLOW if decision is ASK_USER and request is client-initiated', async () => {
+      const mockPolicyEngine = {
+        check: vi.fn().mockResolvedValue({ decision: PolicyDecision.ASK_USER }),
+      } as unknown as Mocked<PolicyEngine>;
+
+      const mockConfig = {
+        getPolicyEngine: vi.fn().mockReturnValue(mockPolicyEngine),
+        isInteractive: vi.fn().mockReturnValue(true),
+      } as unknown as Mocked<Config>;
+
+      const toolCall = {
+        request: { name: 'test-tool', args: {}, isClientInitiated: true },
+        tool: { name: 'test-tool' },
+      } as ValidatingToolCall;
+
+      const result = await checkPolicy(toolCall, mockConfig);
+      expect(result.decision).toBe(PolicyDecision.ALLOW);
+    });
+
+    it('should still return DENY if request is client-initiated but policy says DENY', async () => {
+      const mockPolicyEngine = {
+        check: vi.fn().mockResolvedValue({ decision: PolicyDecision.DENY }),
+      } as unknown as Mocked<PolicyEngine>;
+
+      const mockConfig = {
+        getPolicyEngine: vi.fn().mockReturnValue(mockPolicyEngine),
+      } as unknown as Mocked<Config>;
+
+      const toolCall = {
+        request: { name: 'test-tool', args: {}, isClientInitiated: true },
+        tool: { name: 'test-tool' },
+      } as ValidatingToolCall;
+
+      const result = await checkPolicy(toolCall, mockConfig);
+      expect(result.decision).toBe(PolicyDecision.DENY);
+    });
   });
 
   describe('updatePolicy', () => {

packages/core/src/scheduler/policy.ts

@@ -69,6 +69,19 @@ export async function checkPolicy(
 
   const { decision } = result;
 
+  // If the tool call was initiated by the client (e.g. via a slash command),
+  // we treat it as implicitly confirmed by the user and bypass the
+  // confirmation prompt if the policy engine's decision is 'ASK_USER'.
+  if (
+    decision === PolicyDecision.ASK_USER &&
+    toolCall.request.isClientInitiated
+  ) {
+    return {
+      decision: PolicyDecision.ALLOW,
+      rule: result.rule,
+    };
+  }
+
   /*
    * Return the full check result including the rule that matched.
    * This is necessary to access metadata like custom deny messages.