feat(community): add whatsapp chat loader

libs/langchain-community/package.json

@@ -3406,6 +3406,17 @@
         "default": "./dist/experimental/llms/chrome_ai.cjs"
       }
     },
+    "./chat_loaders/whatsapp": {
+      "input": "./src/chat_loaders/whatsapp.ts",
+      "import": {
+        "types": "./dist/chat_loaders/whatsapp.d.ts",
+        "default": "./dist/chat_loaders/whatsapp.js"
+      },
+      "require": {
+        "types": "./dist/chat_loaders/whatsapp.d.cts",
+        "default": "./dist/chat_loaders/whatsapp.cjs"
+      }
+    },
     "./experimental/tools/pyinterpreter": {
       "input": "./src/experimental/tools/pyinterpreter.ts",
       "import": {

libs/langchain-community/src/chat_loaders/tests/example_data/whatsapp/whatsapp_chat.txt

@@ -0,0 +1,13 @@
+[8/15/23, 9:12:33 AM] Dr. Feather: ‎Messages and calls are end-to-end encrypted. No one outside of this chat, not even WhatsApp, can read or listen to them.
+[8/15/23, 9:12:43 AM] Dr. Feather: I spotted a rare Hyacinth Macaw yesterday in the Amazon Rainforest. Such a magnificent creature!
+‎[8/15/23, 9:12:48 AM] Dr. Feather: ‎image omitted
+[8/15/23, 9:13:15 AM] Jungle Jane: That's stunning! Were you able to observe its behavior?
+‎[8/15/23, 9:13:23 AM] Dr. Feather: ‎image omitted
+[8/15/23, 9:14:02 AM] Dr. Feather: Yes, it seemed quite social with other macaws. They're known for their playful nature.
+[8/15/23, 9:14:15 AM] Jungle Jane: How's the research going on parrot communication?
+‎[8/15/23, 9:14:30 AM] Dr. Feather: ‎image omitted
+[8/15/23, 9:14:50 AM] Dr. Feather: It's progressing well. We're learning so much about how they use sound and color to communicate.
+[8/15/23, 9:15:10 AM] Jungle Jane: That's fascinating! Can't wait to read your paper on it.
+[8/15/23, 9:15:20 AM] Dr. Feather: Thank you! I'll send you a draft soon.
+[8/15/23, 9:25:16 PM] Jungle Jane: Looking forward to it! Keep up the great work.
+

libs/langchain-community/src/chat_loaders/tests/whatsapp.test.ts

@@ -0,0 +1,22 @@
+import * as url from "node:url";
+import * as path from "node:path";
+import { test, expect } from "@jest/globals";
+import { WhatsAppChatLoader } from "../whatsapp.js";
+
+test("WhatsAppChatLoader parses WhatsApp export preserving timestamps and senders", async () => {
+  const filePath = path.resolve(
+    path.dirname(url.fileURLToPath(import.meta.url)),
+    "./example_data/whatsapp/whatsapp_chat.txt"
+  );
+
+  const loader = new WhatsAppChatLoader(filePath);
+  const sessions = await loader.load();
+  expect(sessions.length).toBe(1);
+  const { messages } = sessions[0];
+  expect(messages.length).toBeGreaterThan(0);
+  // Mirror Python assertion: content contains the macaw sentence
+  const first = messages[0];
+  expect(first.text).toContain(
+    "I spotted a rare Hyacinth Macaw yesterday in the Amazon Rainforest. Such a magnificent creature!"
+  );
+});

libs/langchain-community/src/chat_loaders/whatsapp.ts

@@ -0,0 +1,126 @@
+import type { readFile as ReadFileT } from "node:fs/promises";
+import { BaseMessage, HumanMessage } from "@langchain/core/messages";
+import { getEnv } from "@langchain/core/utils/env";
+
+export type ChatSession = {
+  messages: BaseMessage[];
+  // Reserved for future parity with Python ChatSession
+  // functions?: Array<Record<string, unknown>>;
+};
+
+/**
+ * Loader for WhatsApp chat export .txt files (without media).
+ *
+ * Parity with Python implementation:
+ * - Single regex with optional brackets and leading LRM
+ * - Slash-separated dates, 12-hour times with seconds and AM/PM
+ * - Multi-line messages joined with a single space
+ * - Exact ignore list and LRM-tolerant matching
+ */
+export class WhatsAppChatLoader {
+  constructor(public filePathOrBlob: string | Blob) {}
+
+  async load(): Promise<ChatSession[]> {
+    const sessions: ChatSession[] = [];
+    for await (const session of this.lazyLoad()) {
+      sessions.push(session);
+    }
+    return sessions;
+  }
+
+  async *lazyLoad(): AsyncGenerator<ChatSession> {
+    const text = await this.readAllText();
+    yield this.parse(text);
+  }
+
+  protected parse(raw: string): ChatSession {
+    const messages: BaseMessage[] = [];
+
+    const ignoreLines = [
+      "This message was deleted",
+      "<Media omitted>",
+      "image omitted",
+      "Messages and calls are end-to-end encrypted. No one outside of this chat, not even WhatsApp, can read or listen to them.",
+    ];
+    const escapeRe = (s: string) => s.replace(/[.*+?^${}()|[\]\\]/g, "\\$&");
+    const ignoreRe = new RegExp(
+      `(${ignoreLines.map((s) => `\\u200E*${escapeRe(s)}`).join("|")})`,
+      "i"
+    );
+
+    const messageLineRe = new RegExp(
+      String.raw`^\u200E*\[?(\d{1,2}\/\d{1,2}\/\d{2,4}, \d{1,2}:\d{2}:\d{2} (?:AM|PM))\]?[ \u200E]*([^:]+): (.+)$`,
+      "i"
+    );
+
+    // Split messages by newlines but keep multi-line messages grouped
+    const chatLines: string[] = [];
+    let currentMessage = "";
+    for (const line of raw.split("\n")) {
+      if (messageLineRe.test(line)) {
+        if (currentMessage) chatLines.push(currentMessage);
+        currentMessage = line;
+      } else {
+        currentMessage += ` ${line.trim()}`;
+      }
+    }
+    if (currentMessage) chatLines.push(currentMessage);
+
+    for (const line of chatLines) {
+      const result = messageLineRe.exec(line.trim());
+      if (result) {
+        const [, timestamp, sender, text] = result;
+        if (!ignoreRe.test(text.trim())) {
+          messages.push(
+            new HumanMessage({
+              content: text,
+              name: sender,
+              additional_kwargs: {
+                sender,
+                events: [{ message_time: timestamp }],
+              },
+            })
+          );
+        }
+      } else {
+        // Mirror Python's debug logging for unparsable lines
+        console.debug(`Could not parse line: ${line}`);
+      }
+    }
+
+    return { messages };
+  }
+
+  protected async readAllText(): Promise<string> {
+    if (typeof this.filePathOrBlob === "string") {
+      const { readFile } = await WhatsAppChatLoader.imports();
+      try {
+        return await readFile(this.filePathOrBlob, "utf8");
+      } catch (e) {
+        console.error(e);
+        throw new Error("Failed to read file");
+      }
+    } else {
+      try {
+        return await this.filePathOrBlob.text();
+      } catch (e) {
+        console.error(e);
+        throw new Error("Failed to read blob");
+      }
+    }
+  }
+
+  static async imports(): Promise<{
+    readFile: typeof ReadFileT;
+  }> {
+    try {
+      const { readFile } = await import("node:fs/promises");
+      return { readFile };
+    } catch (e) {
+      console.error(e);
+      throw new Error(
+        `Failed to load fs/promises. WhatsAppChatLoader available only on environment 'node'. It appears you are running environment '${getEnv()}'.`
+      );
+    }
+  }
+}

libs/langchain-community/src/load/import_map.ts

@@ -247,5 +247,6 @@ export * as experimental__callbacks__handlers__datadog from "../experimental/cal
 export * as experimental__graph_transformers__llm from "../experimental/graph_transformers/llm.js";
 export * as experimental__multimodal_embeddings__googlevertexai from "../experimental/multimodal_embeddings/googlevertexai.js";
 export * as experimental__llms__chrome_ai from "../experimental/llms/chrome_ai.js";
+export * as chat_loaders__whatsapp from "../chat_loaders/whatsapp.js";
 export * as experimental__tools__pyinterpreter from "../experimental/tools/pyinterpreter.js";
 export * as chains__graph_qa__cypher from "../chains/graph_qa/cypher.js";