Added the discord get messages tool.

langchain/package.json

@@ -1384,6 +1384,7 @@
     "@langchain/core": "^0.0.1",
     "@langchain/openai": "^0.0.1",
     "binary-extensions": "^2.2.0",
+    "discord.js": "^14.14.1",
     "expr-eval": "^2.0.2",
     "flat": "^5.0.2",
     "js-tiktoken": "^1.0.7",

langchain/src/tools/discord.ts

@@ -0,0 +1,70 @@
+import { getEnvironmentVariable } from "../util/env.js";
+import { Tool } from "./base.js";
+import { Client, TextChannel, GatewayIntentBits, Message } from "discord.js";
+
+/*
+ * A tool for retrieving messages from a discord channel using a bot.
+ * It extends the base Tool class and implements the _call method to
+ * perform the retrieve operation. Requires an bot token which can be set
+ * in the environment variables, and a limit on how many messages to retrieve.
+ * The _call method takes the discord channel ID as the input argument.
+ * The bot must have read permissions to the given channel. It returns the
+ * message content, author, and time the message was created for each message.
+ */
+
+export class DiscordGetMessagesTool extends Tool {
+  static lc_name() {
+    return "DiscordGetMessagesTool";
+  }
+
+  name = "discord-get-messages";
+
+  description = `a discord tool. useful for reading messages from a discord channel. 
+    input should be the discord channel ID. the bot should have read 
+    permissions for the channel`;
+
+  protected botToken: string;
+  protected messageLimit: number;
+
+  client = new Client({
+    intents: [GatewayIntentBits.Guilds, GatewayIntentBits.GuildMessages],
+  });
+
+  constructor(
+    botToken: string | undefined = getEnvironmentVariable("DiscordBotToken"),
+    messageLimit: number | undefined = 100
+  ) {
+    super(...arguments);
+
+    if (!botToken) {
+      throw new Error(
+        "Discord API key not set. You can set it as DiscordBotToken in your .env file."
+      );
+    }
+
+    this.botToken = botToken;
+    this.messageLimit = messageLimit;
+  }
+
+  /** @ignore */
+  async _call(input: string): Promise<string> {
+    await this.client.login(this.botToken);
+
+    const channel = (await this.client.channels.fetch(input)) as TextChannel;
+
+    if (!channel) {
+      return "Channel not found";
+    }
+
+    const messages = await channel.messages.fetch({ limit: this.messageLimit });
+    this.client.destroy();
+    const results =
+      messages.map((message: Message) => ({
+        author: message.author.tag,
+        content: message.content,
+        timestamp: message.createdAt,
+      })) ?? [];
+
+    return JSON.stringify(results);
+  }
+}

langchain/src/tools/tests/discord.test.ts

@@ -0,0 +1,12 @@
+import { test } from "@jest/globals";
+import { DiscordGetMessagesTool } from "../discord.js";
+
+test("DiscordGetMessagesTool", async () => {
+  const tool = new DiscordGetMessagesTool();
+  try {
+    const result = await tool.call('1153400523718938780')
+    console.log(result)
+  } catch (error) {
+    console.error(error);
+  }
+});