add memory store

Author: seratch

packages/agents-core/src/index.ts

@@ -167,6 +167,7 @@ export type {
 } from './types';
 export { Usage } from './usage';
 export type { Session, SessionInputCallback } from './memory/session';
+export { MemorySession } from './memory/memorySession';
 
 /**
  * Exporting the whole protocol as an object here. This contains both the types

packages/agents-core/src/memory/memorySession.ts

@@ -0,0 +1,58 @@
+import { randomUUID } from '@openai/agents-core/_shims';
+
+import type { AgentInputItem } from '../types';
+import type { Session } from './session';
+
+export type MemorySessionOptions = {
+  sessionId?: string;
+  initialItems?: AgentInputItem[];
+};
+
+/**
+ * Simple in-memory session store intended for demos or tests. Not recommended for production use.
+ */
+export class MemorySession implements Session {
+  private readonly sessionId: string;
+
+  private items: AgentInputItem[];
+
+  constructor(options: MemorySessionOptions = {}) {
+    this.sessionId = options.sessionId ?? randomUUID();
+    this.items = options.initialItems ? [...options.initialItems] : [];
+  }
+
+  async getSessionId(): Promise<string> {
+    return this.sessionId;
+  }
+
+  async getItems(limit?: number): Promise<AgentInputItem[]> {
+    if (limit === undefined) {
+      return [...this.items];
+    }
+    if (limit <= 0) {
+      return [];
+    }
+    const start = Math.max(this.items.length - limit, 0);
+    return this.items.slice(start);
+  }
+
+  async addItems(items: AgentInputItem[]): Promise<void> {
+    if (items.length === 0) {
+      return;
+    }
+    this.items = [...this.items, ...items];
+  }
+
+  async popItem(): Promise<AgentInputItem | undefined> {
+    if (this.items.length === 0) {
+      return undefined;
+    }
+    const item = this.items[this.items.length - 1];
+    this.items = this.items.slice(0, -1);
+    return item;
+  }
+
+  async clearSession(): Promise<void> {
+    this.items = [];
+  }
+}

packages/agents-core/test/memorySession.test.ts

@@ -0,0 +1,41 @@
+import { describe, expect, test } from 'vitest';
+
+import { MemorySession } from '../src/memory/memorySession';
+import type { AgentInputItem } from '../src/types';
+
+const createUserMessage = (text: string): AgentInputItem => ({
+  role: 'user',
+  content: [
+    {
+      type: 'input_text',
+      text,
+    },
+  ],
+});
+
+describe('MemorySession', () => {
+  test('stores and retrieves items in memory', async () => {
+    const initialItems = [createUserMessage('hello')];
+    const session = new MemorySession({
+      sessionId: 'session-1',
+      initialItems,
+    });
+
+    expect(await session.getSessionId()).toBe('session-1');
+    expect(await session.getItems()).toEqual(initialItems);
+
+    const newItems = [createUserMessage('one'), createUserMessage('two')];
+    await session.addItems(newItems);
+    expect(await session.getItems()).toEqual([...initialItems, ...newItems]);
+
+    expect(await session.getItems(2)).toEqual(newItems);
+
+    expect(await session.popItem()).toEqual(newItems[1]);
+    expect(await session.getItems()).toEqual([...initialItems, newItems[0]]);
+
+    await session.clearSession();
+    expect(await session.getItems()).toEqual([]);
+    expect(await session.getItems(3)).toEqual([]);
+    expect(await session.popItem()).toBeUndefined();
+  });
+});