feat: add custom system prompt configuration

packages/core/src/PageAgentCore.ts

@@ -413,6 +413,10 @@ export class PageAgentCore extends EventTarget {
 	 * Get system prompt, dynamically replace language settings based on configured language
 	 */
 	#getSystemPrompt(): string {
+		if (this.config.customSystemPrompt) {
+			return this.config.customSystemPrompt
+		}
+
 		let systemPrompt = SYSTEM_PROMPT
 
 		const targetLanguage = this.config.language === 'zh-CN' ? '中文' : 'English'

packages/core/src/config/index.ts

@@ -141,6 +141,12 @@ export interface AgentConfig {
 	 * }
 	 */
 	transformPageContent?: (content: string) => Promise<string> | string
+
+	/**
+	 * Completely override the default system prompt.
+	 * @experimental Use with caution - incorrect prompts may break agent behavior.
+	 */
+	customSystemPrompt?: string
 }
 
 export type PageAgentConfig = LLMConfig & AgentConfig & PageControllerConfig