[Agent Builder] Agent skills implementation

x-pack/platform/packages/shared/agent-builder/agent-builder-common/chat/conversation.ts

@@ -262,6 +262,11 @@ export interface Conversation {
  */
 export interface ConversationInternalState {
   prompt?: PromptStorageState;
+  /**
+   * Dynamic tool IDs that were added during conversation rounds.
+   * These tools are persisted across rounds so they remain available.
+   */
+  dynamic_tool_ids?: string[];
 }
 
 export type ConversationWithoutRounds = Omit<Conversation, 'rounds'>;

x-pack/platform/packages/shared/agent-builder/agent-builder-common/tools/constants.ts

@@ -8,7 +8,9 @@
 import { ToolType } from './definition';
 import { internalNamespaces } from '../base/namespaces';
 
-const platformCoreTool = (toolName: string) => {
+const platformCoreTool = <TName extends string>(
+  toolName: TName
+): `${typeof internalNamespaces.platformCore}.${TName}` => {
   return `${internalNamespaces.platformCore}.${toolName}`;
 };
 

x-pack/platform/packages/shared/agent-builder/agent-builder-genai-utils/langchain/tools.ts

@@ -178,7 +178,7 @@ export const toolIdentifierFromToolCall = (toolCall: ToolCall, mapping: ToolIdMa
   return mapping.get(toolCall.toolName) ?? toolCall.toolName;
 };
 
-function reverseMap<K, V>(map: Map<K, V>): Map<V, K> {
+export function reverseMap<K, V>(map: Map<K, V>): Map<V, K> {
   const reversed = new Map<V, K>();
   for (const [key, value] of map.entries()) {
     if (reversed.has(value)) {

x-pack/platform/packages/shared/agent-builder/agent-builder-server/agents/provider.ts

@@ -26,6 +26,8 @@ import type {
   AttachmentsService,
   PromptManager,
   ConversationStateManager,
+  SkillsService,
+  ToolManager,
 } from '../runner';
 import type { IFileStore } from '../runner/filestore';
 import type { AttachmentStateManager } from '../attachments';
@@ -91,6 +93,14 @@ export interface AgentHandlerContext {
    * Attachment service to interact with attachments.
    */
   attachments: AttachmentsService;
+  /**
+   * Skills service to interact with skills.
+   */
+  skills: SkillsService;
+  /**
+   * Tool manager to manage active tools for the agent.
+   */
+  toolManager: ToolManager;
   /**
    * Result store to access and add tool results during execution.
    */

x-pack/platform/packages/shared/agent-builder/agent-builder-server/allow_lists.ts

@@ -12,7 +12,7 @@ import { internalNamespaces } from '@kbn/agent-builder-common/base/namespaces';
  * This is a manually maintained list of all built-in tools registered in Agent Builder.
  * The intention is to force a code review from the Agent Builder team when any team adds a new tool.
  */
-export const AGENT_BUILDER_BUILTIN_TOOLS: string[] = [
+export const AGENT_BUILDER_BUILTIN_TOOLS = [
   // platform core tools are registered from the agent builder plugin so will trigger a review anyway
   ...Object.values(platformCoreTools),
 
@@ -40,22 +40,26 @@ export const AGENT_BUILDER_BUILTIN_TOOLS: string[] = [
   `${internalNamespaces.security}.attack_discovery_search`,
   `${internalNamespaces.security}.security_labs_search`,
   `${internalNamespaces.security}.alerts`,
-];
+] as const;
+
+export type AgentBuilderBuiltinTool = (typeof AGENT_BUILDER_BUILTIN_TOOLS)[number];
 
 /**
  * This is a manually maintained list of all built-in agents registered in Agent Builder.
  * The intention is to force a code review from the Agent Builder team when any team adds a new agent.
  */
-export const AGENT_BUILDER_BUILTIN_AGENTS: string[] = [
+export const AGENT_BUILDER_BUILTIN_AGENTS = [
   `${internalNamespaces.observability}.agent`,
   'platform.dashboard.dashboard_agent',
   `${internalNamespaces.security}.agent`,
-];
+] as const;
+
+export type AgentBuilderBuiltinAgent = (typeof AGENT_BUILDER_BUILTIN_AGENTS)[number];
 
 export const isAllowedBuiltinTool = (toolName: string) => {
-  return AGENT_BUILDER_BUILTIN_TOOLS.includes(toolName);
+  return (AGENT_BUILDER_BUILTIN_TOOLS as readonly string[]).includes(toolName);
 };
 
 export const isAllowedBuiltinAgent = (agentName: string) => {
-  return AGENT_BUILDER_BUILTIN_AGENTS.includes(agentName);
+  return (AGENT_BUILDER_BUILTIN_AGENTS as readonly string[]).includes(agentName);
 };

x-pack/platform/packages/shared/agent-builder/agent-builder-server/runner/filestore/filesystem.ts

@@ -11,6 +11,8 @@
 export enum FileEntryType {
   toolResult = 'tool_result',
   attachment = 'attachment',
+  skill = 'skill',
+  skillReferenceContent = 'skill_reference_content',
 }
 
 export type FileEntryMetadata<TExtraMeta extends object = {}> = {

x-pack/platform/packages/shared/agent-builder/agent-builder-server/runner/index.ts

@@ -45,6 +45,10 @@ export type {
 } from './model_provider';
 export type { ToolResultStore, WritableToolResultStore, ToolResultWithMeta } from './result_store';
 export type { AttachmentsService } from './attachments_service';
+export type { SkillsService } from './skills_service';
+export type { ToolManager } from './tool_manager';
+export { ToolManagerToolType } from './tool_manager';
+export type { SkillsStore, WritableSkillsStore } from './skills_store';
 export type { PromptManager, ToolPromptManager, ConfirmationInfo } from './prompt_manager';
 export type { ConversationStateManager, ToolStateManager } from './state_manager';
 export { FileEntryType } from './filestore';

x-pack/platform/packages/shared/agent-builder/agent-builder-server/runner/skills_service.ts

@@ -0,0 +1,27 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0; you may not use this file except in compliance with the Elastic License
+ * 2.0.
+ */
+
+import type { SkillDefinition, SkillBoundedTool } from '../skills';
+import type { ExecutableTool } from './tool_provider';
+
+/**
+ * Service to access skill type definitions.
+ */
+export interface SkillsService {
+  /**
+   * Returns the list of skill type definitions
+   */
+  list(): SkillDefinition[];
+  /**
+   * Returns the skill type definition for a given skill id
+   */
+  getSkillDefinition(skillId: string): SkillDefinition | undefined;
+  /**
+   * Convert a skill-scoped tool to a generic executable tool
+   */
+  convertSkillTool(tool: SkillBoundedTool): ExecutableTool;
+}

x-pack/platform/packages/shared/agent-builder/agent-builder-server/runner/skills_store.ts

@@ -0,0 +1,25 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0; you may not use this file except in compliance with the Elastic License
+ * 2.0.
+ */
+
+import type { SkillDefinition } from '../skills';
+
+/**
+ * Store to access skills during execution
+ */
+export interface SkillsStore {
+  has(skillId: string): boolean;
+  get(resultId: string): SkillDefinition;
+}
+
+/**
+ * Writable version of SkillsStore, used internally by the runner/agent
+ */
+export interface WritableSkillsStore extends SkillsStore {
+  add(result: SkillDefinition): void;
+  delete(skillId: string): boolean;
+  asReadonly(): SkillsStore;
+}

x-pack/platform/packages/shared/agent-builder/agent-builder-server/runner/tool_manager.ts

@@ -0,0 +1,81 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0; you may not use this file except in compliance with the Elastic License
+ * 2.0.
+ */
+
+import type { StructuredTool } from '@langchain/core/tools';
+import type { BrowserApiToolMetadata } from '@kbn/agent-builder-common';
+import type { Logger } from '@kbn/logging';
+import type { AgentEventEmitterFn, ExecutableTool } from '..';
+
+export interface ToolManagerParams {
+  dynamicToolCapacity: number;
+}
+
+export type ToolName = string;
+
+export interface AddToolOptions {
+  dynamic?: boolean;
+}
+
+export enum ToolManagerToolType {
+  executable = 'executable',
+  browser = 'browser',
+}
+
+export interface ExecutableToolInput {
+  type: ToolManagerToolType.executable;
+  tools: ExecutableTool | ExecutableTool[];
+  logger: Logger;
+  eventEmitter?: AgentEventEmitterFn;
+}
+
+export interface BrowserToolInput {
+  type: ToolManagerToolType.browser;
+  tools: BrowserApiToolMetadata | BrowserApiToolMetadata[];
+}
+
+export type AddToolInput = ExecutableToolInput | BrowserToolInput;
+
+/**
+ * Interface for managing tools in the agent system.
+ * Handles both static and dynamic tools with LRU eviction for dynamic tools.
+ */
+export interface ToolManager {
+  /**
+   * Adds tools to the tool manager.
+   * Supports both executable tools and browser API tools.
+   * @param input - The tool input configuration (executable or browser)
+   * @param options - Optional configuration for tool storage (static vs dynamic)
+   */
+  addTools(input: AddToolInput, options?: AddToolOptions): Promise<void>;
+
+  /**
+   * Lists all tools in the tool manager.
+   * @returns an array of all tools (static and dynamic)
+   */
+  list(): StructuredTool[];
+
+  /**
+   * Records the use of a tool, marking it as recently used.
+   * This affects LRU eviction for dynamic tools.
+   * @param name - the name of the tool to record usage for
+   */
+  recordToolUse(langchainToolName: ToolName): void;
+
+  /**
+   * Gets the tool id mapping.
+   * Maps LangChain tool names to internal tool IDs.
+   * @returns the tool id mapping
+   */
+  getToolIdMapping(): Map<string, string>;
+
+  /**
+   * Gets the internal tool IDs of all dynamic tools currently in the tool manager.
+   * Returns internal tool IDs (not LangChain names) for persistence.
+   * @returns array of internal tool IDs
+   */
+  getDynamicToolIds(): string[];
+}

x-pack/platform/packages/shared/agent-builder/agent-builder-server/skills/index.ts

@@ -0,0 +1,16 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0; you may not use this file except in compliance with the Elastic License
+ * 2.0.
+ */
+
+export type { SkillDefinition } from './type_definition';
+export { validateSkillDefinition } from './type_definition';
+export type {
+  SkillBoundedTool,
+  BuiltinSkillBoundedTool,
+  IndexSearchSkillBoundedTool,
+  WorkflowSkillBoundedTool,
+  StaticEsqlSkillBoundedTool,
+} from './tools';

x-pack/platform/packages/shared/agent-builder/agent-builder-server/skills/tools.ts

@@ -0,0 +1,34 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0; you may not use this file except in compliance with the Elastic License
+ * 2.0.
+ */
+
+import type { ZodObject } from '@kbn/zod';
+import type { EsqlToolDefinition, ToolDefinition } from '@kbn/agent-builder-common';
+import type {
+  IndexSearchToolDefinition,
+  WorkflowToolDefinition,
+} from '@kbn/agent-builder-common/tools';
+import type { BuiltinToolDefinition } from '../tools/builtin';
+
+export type BuiltinSkillBoundedTool<RunInput extends ZodObject<any> = ZodObject<any>> = Omit<
+  BuiltinToolDefinition<RunInput>,
+  'tags' | 'availability'
+>;
+
+type SkillBoundToolMixin<T extends ToolDefinition> = Omit<T, 'readonly' | 'tags'>;
+
+export type StaticEsqlSkillBoundedTool = SkillBoundToolMixin<EsqlToolDefinition>;
+export type IndexSearchSkillBoundedTool = SkillBoundToolMixin<IndexSearchToolDefinition>;
+export type WorkflowSkillBoundedTool = SkillBoundToolMixin<WorkflowToolDefinition>;
+
+/**
+ * Definition of a tool which is bounded to a skill instance.
+ */
+export type SkillBoundedTool<RunInput extends ZodObject<any> = ZodObject<any>> =
+  | BuiltinSkillBoundedTool<RunInput>
+  | StaticEsqlSkillBoundedTool
+  | IndexSearchSkillBoundedTool
+  | WorkflowSkillBoundedTool;