feat: add custom system prompt functionality to agent system prompt

Author: NoOne7135

agent/systemPrompt.ts

@@ -35,10 +35,21 @@ export const DEFAULT_AGENT_SYSTEM_PROMPT = [
   "If the confirmed plan has multiple steps, you may execute the whole confirmed plan without asking again between those steps.",
   "If the plan changes, expands, or you want to do anything beyond the confirmed plan, ask for confirmation again.",
   "Do not reuse an old confirmation for a new mutation plan.",
-
-  
 ].join(" ");
 
+export function appendCustomSystemPrompt(
+  systemPrompt: string,
+  customSystemPrompt?: string,
+) {
+  const normalizedCustomSystemPrompt = customSystemPrompt?.trim();
+
+  if (!normalizedCustomSystemPrompt) {
+    return systemPrompt;
+  }
+
+  return `${systemPrompt}\n\n${normalizedCustomSystemPrompt}`;
+}
+
 function formatResources(resources: AdminForthResource[]) {
   return resources
     .map((resource) => `- resourceId: ${resource.resourceId}\n  label: ${resource.label}`)

index.ts

@@ -16,6 +16,7 @@ import {
 } from './apiBasedTools.js';
 import type { ApiBasedTool } from './apiBasedTools.js';
 import {
+  appendCustomSystemPrompt,
   buildAgentSystemPrompt,
   DEFAULT_AGENT_SYSTEM_PROMPT,
 } from "./agent/systemPrompt.js";
@@ -67,7 +68,7 @@ function assertRequiredApiTool(
 export default class AdminForthAgentPlugin extends AdminForthPlugin {
   options: PluginOptions;
   apiBasedTools: Record<string, ApiBasedTool> = {};
-  agentSystemPromptPromise = Promise.resolve(DEFAULT_AGENT_SYSTEM_PROMPT);
+  agentSystemPromptPromise: Promise<string>;
 
   private async createNewTurn(sessionId: string, prompt: string, response?: string) {
     const turnId = randomUUID();
@@ -109,6 +110,9 @@ export default class AdminForthAgentPlugin extends AdminForthPlugin {
   constructor(options: PluginOptions) {
     super(options, import.meta.url);
     this.options = options;
+    this.agentSystemPromptPromise = Promise.resolve(
+      appendCustomSystemPrompt(DEFAULT_AGENT_SYSTEM_PROMPT, this.options.systemPrompt),
+    );
     this.shouldHaveSingleInstancePerWholeApp = () => false;
   }
 
@@ -139,7 +143,8 @@ export default class AdminForthAgentPlugin extends AdminForthPlugin {
       assertRequiredApiTool(this.apiBasedTools, toolName);
     }
     assertRequiredApiTool(this.apiBasedTools, "update_record");
-    this.agentSystemPromptPromise = buildAgentSystemPrompt(adminforth);
+    this.agentSystemPromptPromise = buildAgentSystemPrompt(adminforth)
+      .then((systemPrompt) => appendCustomSystemPrompt(systemPrompt, this.options.systemPrompt));
   }
 
   instanceUniqueRepresentation(pluginOptions: any) : string {

types.ts

@@ -36,6 +36,11 @@ export interface PluginOptions extends PluginsCommonOptions {
    */
   maxTokens?: number;
 
+  /**
+   * Optional custom system prompt appended to the built-in agent system prompt.
+   */
+  systemPrompt?: string;
+
   /**
    * Response generation level.
    * Default is low