feat: create langchain agent

apps/dojo/e2e/tests/langchainTests/agenticChatPage.spec.ts

@@ -0,0 +1,115 @@
+import {
+  test,
+  expect,
+  waitForAIResponse,
+  retryOnAIFailure,
+} from "../../test-isolation-helper";
+import { AgenticChatPage } from "../../featurePages/AgenticChatPage";
+
+test("[LangChain] Agentic Chat sends and receives a message", async ({
+  page,
+}) => {
+  await retryOnAIFailure(async () => {
+    await page.goto(
+      "/langchain/feature/agentic_chat"
+    );
+
+    const chat = new AgenticChatPage(page);
+
+    await chat.openChat();
+    await chat.agentGreeting.isVisible;
+    await chat.sendMessage("Hi, I am duaa");
+
+    await waitForAIResponse(page);
+    await chat.assertUserMessageVisible("Hi, I am duaa");
+    await chat.assertAgentReplyVisible(/Hello/i);
+  });
+});
+
+test("[LangChain] Agentic Chat changes background on message and reset", async ({
+  page,
+}) => {
+  await retryOnAIFailure(async () => {
+    await page.goto(
+      "/langchain/feature/agentic_chat"
+    );
+
+    const chat = new AgenticChatPage(page);
+
+    await chat.openChat();
+    await chat.agentGreeting.waitFor({ state: "visible" });
+
+    // Store initial background color
+    const backgroundContainer = page.locator('[data-testid="background-container"]')
+    const initialBackground = await backgroundContainer.evaluate(el => getComputedStyle(el).backgroundColor);
+    console.log("Initial background color:", initialBackground);
+
+    // 1. Send message to change background to blue
+    await chat.sendMessage("Hi change the background color to blue");
+    await chat.assertUserMessageVisible(
+      "Hi change the background color to blue"
+    );
+    await waitForAIResponse(page);
+
+    await expect(backgroundContainer).not.toHaveCSS('background-color', initialBackground, { timeout: 7000 });
+    const backgroundBlue = await backgroundContainer.evaluate(el => getComputedStyle(el).backgroundColor);
+    // Check if background is blue (string color name or contains blue)
+    expect(backgroundBlue.toLowerCase()).toMatch(/blue|rgb\(.*,.*,.*\)|#[0-9a-f]{6}/);
+
+    // 2. Change to pink
+    await chat.sendMessage("Hi change the background color to pink");
+    await chat.assertUserMessageVisible(
+      "Hi change the background color to pink"
+    );
+    await waitForAIResponse(page);
+
+    await expect(backgroundContainer).not.toHaveCSS('background-color', backgroundBlue, { timeout: 7000 });
+    const backgroundPink = await backgroundContainer.evaluate(el => getComputedStyle(el).backgroundColor);
+    // Check if background is pink (string color name or contains pink)
+    expect(backgroundPink.toLowerCase()).toMatch(/pink|rgb\(.*,.*,.*\)|#[0-9a-f]{6}/);
+  });
+});
+
+test("[LangChain] Agentic Chat retains memory of user messages during a conversation", async ({
+  page,
+}) => {
+  await retryOnAIFailure(async () => {
+    await page.goto(
+      "/langchain/feature/agentic_chat"
+    );
+
+    const chat = new AgenticChatPage(page);
+    await chat.openChat();
+    await chat.agentGreeting.click();
+
+    await chat.sendMessage("Hey there");
+    await chat.assertUserMessageVisible("Hey there");
+    await waitForAIResponse(page);
+    await chat.assertAgentReplyVisible(/how can I assist you/i);
+
+    const favFruit = "Mango";
+    await chat.sendMessage(`My favorite fruit is ${favFruit}`);
+    await chat.assertUserMessageVisible(`My favorite fruit is ${favFruit}`);
+    await waitForAIResponse(page);
+    await chat.assertAgentReplyVisible(new RegExp(favFruit, "i"));
+
+    await chat.sendMessage("and I love listening to Kaavish");
+    await chat.assertUserMessageVisible("and I love listening to Kaavish");
+    await waitForAIResponse(page);
+    await chat.assertAgentReplyVisible(/Kaavish/i);
+
+    await chat.sendMessage("tell me an interesting fact about Moon");
+    await chat.assertUserMessageVisible(
+      "tell me an interesting fact about Moon"
+    );
+    await waitForAIResponse(page);
+    await chat.assertAgentReplyVisible(/Moon/i);
+
+    await chat.sendMessage("Can you remind me what my favorite fruit is?");
+    await chat.assertUserMessageVisible(
+      "Can you remind me what my favorite fruit is?"
+    );
+    await waitForAIResponse(page);
+    await chat.assertAgentReplyVisible(new RegExp(favFruit, "i"));
+  });
+});

apps/dojo/e2e/tests/langchainTests/toolBasedGenUIPage.spec.ts

@@ -0,0 +1,38 @@
+import { test, expect } from "@playwright/test";
+import { ToolBaseGenUIPage } from "../../featurePages/ToolBaseGenUIPage";
+
+const pageURL =
+  "/langchain/feature/tool_based_generative_ui";
+
+test('[LangChain] Haiku generation and display verification', async ({
+  page,
+}) => {
+  await page.goto(pageURL);
+
+  const genAIAgent = new ToolBaseGenUIPage(page);
+
+  await expect(genAIAgent.haikuAgentIntro).toBeVisible();
+  await genAIAgent.generateHaiku('Generate Haiku for "I will always win"');
+  await genAIAgent.checkGeneratedHaiku();
+  await genAIAgent.checkHaikuDisplay(page);
+});
+
+test('[LangChain] Haiku generation and UI consistency for two different prompts', async ({
+  page,
+}) => {
+  await page.goto(pageURL);
+
+  const genAIAgent = new ToolBaseGenUIPage(page);
+
+  await expect(genAIAgent.haikuAgentIntro).toBeVisible();
+
+  const prompt1 = 'Generate Haiku for "I will always win"';
+  await genAIAgent.generateHaiku(prompt1);
+  await genAIAgent.checkGeneratedHaiku();
+  await genAIAgent.checkHaikuDisplay(page);
+
+  const prompt2 = 'Generate Haiku for "The moon shines bright"';
+  await genAIAgent.generateHaiku(prompt2);
+  await genAIAgent.checkGeneratedHaiku();
+  await genAIAgent.checkHaikuDisplay(page);
+});

apps/dojo/package.json

@@ -19,6 +19,7 @@
     "@ag-ui/agno": "workspace:*",
     "@ag-ui/crewai": "workspace:*",
     "@ag-ui/langgraph": "workspace:*",
+    "@ag-ui/langchain": "workspace:*",
     "@ag-ui/llamaindex": "workspace:*",
     "@ag-ui/mastra": "workspace:*",
     "@ag-ui/middleware-starter": "workspace:*",

apps/dojo/src/agents.ts

@@ -21,6 +21,7 @@ import { HttpAgent } from "@ag-ui/client";
 import { A2AMiddlewareAgent } from "@ag-ui/a2a-middleware";
 import { A2AAgent } from "@ag-ui/a2a";
 import { A2AClient } from "@a2a-js/sdk/client";
+import { LangChainAgent } from "@ag-ui/langchain";
 
 const envVars = getEnvVars();
 export const agentsIntegrations: AgentIntegrationConfig[] = [
@@ -260,6 +261,35 @@ export const agentsIntegrations: AgentIntegrationConfig[] = [
       };
     },
   },
+  {
+    id: "langchain",
+    agents: async () => {
+      return {
+        agentic_chat: new LangChainAgent({
+          chainFn: async ({ messages, tools, threadId }) => {
+            // @ts-ignore
+            const { ChatOpenAI } = await import("@langchain/openai");
+            const chatOpenAI = new ChatOpenAI({ model: "gpt-4o" });
+            const model = chatOpenAI.bindTools(tools, {
+              strict: true,
+            });
+            return model.stream(messages, { tools, metadata: { conversation_id: threadId } });
+          },
+        }),
+        tool_based_generative_ui: new LangChainAgent({
+          chainFn: async ({ messages, tools, threadId }) => {
+            // @ts-ignore
+            const { ChatOpenAI } = await import("@langchain/openai");
+            const chatOpenAI = new ChatOpenAI({ model: "gpt-4o" });
+            const model = chatOpenAI.bindTools(tools, {
+              strict: true,
+            });
+            return model.stream(messages, { tools, metadata: { conversation_id: threadId } });
+          },
+        }),
+      }
+    },
+  },
   {
     id: "agno",
     agents: async () => {

apps/dojo/src/menu.ts

@@ -44,6 +44,14 @@ export const menuIntegrations: MenuIntegrationConfig[] = [
       "subgraphs",
     ],
   },
+  {
+    id: "langchain",
+    name: "LangChain",
+    features: [
+      "agentic_chat",
+      "tool_based_generative_ui",
+    ],
+  },
   {
     id: "mastra",
     name: "Mastra",

integrations/langchain/typescript/.gitignore

@@ -0,0 +1,141 @@
+# Logs
+logs
+*.log
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+lerna-debug.log*
+
+# Diagnostic reports (https://nodejs.org/api/report.html)
+report.[0-9]*.[0-9]*.[0-9]*.[0-9]*.json
+
+# Runtime data
+pids
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+*.seed
+*.pid.lock
+
+# Directory for instrumented libs generated by jscoverage/JSCover
+lib-cov
+
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+coverage
+*.lcov
+
+# nyc test coverage
+.nyc_output
+
+# Grunt intermediate storage (https://gruntjs.com/creating-plugins#storing-task-files)
+.grunt
+
+# Bower dependency directory (https://bower.io/)
+bower_components
+
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+
+# Compiled binary addons (https://nodejs.org/api/addons.html)
+build/Release
+
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+node_modules/
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+
+# Snowpack dependency directory (https://snowpack.dev/)
+web_modules/
+
+# TypeScript cache
+*.tsbuildinfo
+
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+.npm
+
+# Optional eslint cache
+.eslintcache
+
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+.stylelintcache
+
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+.node_repl_history
+
+# Output of 'npm pack'
+*.tgz
+
+# Yarn Integrity file
+.yarn-integrity
+
+# dotenv environment variable files
+.env
+.env.*
+!.env.example
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+.cache
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+.next
+out
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+# Nuxt.js build / generate output
+.nuxt
+dist
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+# Gatsby files
+.cache/
+# Comment in the public line in if your project uses Gatsby and not Next.js
+# https://nextjs.org/blog/next-9-1#public-directory-support
+# public
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+.vuepress/dist
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+.temp
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+**/.vitepress/dist
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+**/.vitepress/cache
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+.docusaurus
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+.serverless/
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+.dynamodb/
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+# Firebase cache directory
+.firebase/
+
+# TernJS port file
+.tern-port
+
+# Stores VSCode versions used for testing VSCode extensions
+.vscode-test
+
+# yarn v3
+.pnp.*
+.yarn/*
+!.yarn/patches
+!.yarn/plugins
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+!.yarn/versions
+
+# Vite files
+vite.config.js.timestamp-*
+vite.config.ts.timestamp-*
+.vite/

integrations/langchain/typescript/.npmignore

@@ -0,0 +1,13 @@
+.turbo
+.DS_Store
+.git
+.gitignore
+.idea
+.vscode
+.env
+__tests__
+src
+tsup.config.ts
+tsconfig.json
+jest.config.js
+example