feat(coding-agent): add resources_discover hook

packages/coding-agent/src/core/extensions/index.ts

@@ -83,6 +83,9 @@ export type {
 	// Commands
 	RegisteredCommand,
 	RegisteredTool,
+	// Events - Resources
+	ResourcesDiscoverEvent,
+	ResourcesDiscoverResult,
 	SendMessageHandler,
 	SendUserMessageHandler,
 	SessionBeforeCompactEvent,

packages/coding-agent/src/core/extensions/runner.ts

@@ -35,6 +35,8 @@ import type {
 	MessageRenderer,
 	RegisteredCommand,
 	RegisteredTool,
+	ResourcesDiscoverEvent,
+	ResourcesDiscoverResult,
 	SessionBeforeCompactResult,
 	SessionBeforeTreeResult,
 	ToolCallEvent,
@@ -629,6 +631,54 @@ export class ExtensionRunner {
 		return undefined;
 	}
 
+	async emitResourcesDiscover(
+		cwd: string,
+		reason: ResourcesDiscoverEvent["reason"],
+	): Promise<{
+		skillPaths: Array<{ path: string; extensionPath: string }>;
+		promptPaths: Array<{ path: string; extensionPath: string }>;
+		themePaths: Array<{ path: string; extensionPath: string }>;
+	}> {
+		const ctx = this.createContext();
+		const skillPaths: Array<{ path: string; extensionPath: string }> = [];
+		const promptPaths: Array<{ path: string; extensionPath: string }> = [];
+		const themePaths: Array<{ path: string; extensionPath: string }> = [];
+
+		for (const ext of this.extensions) {
+			const handlers = ext.handlers.get("resources_discover");
+			if (!handlers || handlers.length === 0) continue;
+
+			for (const handler of handlers) {
+				try {
+					const event: ResourcesDiscoverEvent = { type: "resources_discover", cwd, reason };
+					const handlerResult = await handler(event, ctx);
+					const result = handlerResult as ResourcesDiscoverResult | undefined;
+
+					if (result?.skillPaths?.length) {
+						skillPaths.push(...result.skillPaths.map((path) => ({ path, extensionPath: ext.path })));
+					}
+					if (result?.promptPaths?.length) {
+						promptPaths.push(...result.promptPaths.map((path) => ({ path, extensionPath: ext.path })));
+					}
+					if (result?.themePaths?.length) {
+						themePaths.push(...result.themePaths.map((path) => ({ path, extensionPath: ext.path })));
+					}
+				} catch (err) {
+					const message = err instanceof Error ? err.message : String(err);
+					const stack = err instanceof Error ? err.stack : undefined;
+					this.emitError({
+						extensionPath: ext.path,
+						event: "resources_discover",
+						error: message,
+						stack,
+					});
+				}
+			}
+		}
+
+		return { skillPaths, promptPaths, themePaths };
+	}
+
 	/** Emit input event. Transforms chain, "handled" short-circuits. */
 	async emitInput(text: string, images: ImageContent[] | undefined, source: InputSource): Promise<InputEventResult> {
 		const ctx = this.createContext();

packages/coding-agent/src/core/extensions/types.ts

@@ -329,6 +329,24 @@ export interface ToolDefinition<TParams extends TSchema = TSchema, TDetails = un
 	renderResult?: (result: AgentToolResult<TDetails>, options: ToolRenderResultOptions, theme: Theme) => Component;
 }
 
+// ============================================================================
+// Resource Events
+// ============================================================================
+
+/** Fired after session_start to allow extensions to provide additional resource paths. */
+export interface ResourcesDiscoverEvent {
+	type: "resources_discover";
+	cwd: string;
+	reason: "startup" | "reload";
+}
+
+/** Result from resources_discover event handler */
+export interface ResourcesDiscoverResult {
+	skillPaths?: string[];
+	promptPaths?: string[];
+	themePaths?: string[];
+}
+
 // ============================================================================
 // Session Events
 // ============================================================================
@@ -621,6 +639,7 @@ export function isLsToolResult(e: ToolResultEvent): e is LsToolResultEvent {
 
 /** Union of all event types */
 export type ExtensionEvent =
+	| ResourcesDiscoverEvent
 	| SessionEvent
 	| ContextEvent
 	| BeforeAgentStartEvent
@@ -736,6 +755,7 @@ export interface ExtensionAPI {
 	// Event Subscription
 	// =========================================================================
 
+	on(event: "resources_discover", handler: ExtensionHandler<ResourcesDiscoverEvent, ResourcesDiscoverResult>): void;
 	on(event: "session_start", handler: ExtensionHandler<SessionStartEvent>): void;
 	on(
 		event: "session_before_switch",