This plugin watches for chat_member
updates and stores a list of users, their statuses and permissions for each chat
in which they and the bot are a member.
You can use a valid grammY storage adapter or an
instance of any class that implements the StorageAdapter
interface.
import { Bot, Context, MemorySessionStorage } from "grammy";
import type { ChatMember } from "@grammyjs/types";
import { chatMembers, ChatMembersFlavor } from "@grammyjs/chat-members";
type MyContext = Context & ChatMembersFlavor;
const adapter = new MemorySessionStorage<ChatMember>();
const bot = new Bot<MyContext>("<your bot token>");
bot.use(chatMembers(adapter));
bot.start({
allowed_updates: ["chat_member", "message"],
onStart: ({ username }) => console.log(`Listening as ${username}`),
});
This plugin also adds a new ctx.chatMembers.getChatMember
function that will check the storage for information about a
chat member before querying telegram for it. If the chat member exists in the storage, it will be returned. Otherwise,
ctx.api.getChatMember
will be called and the result will be saved to the storage, making subsequent calls faster and
removing the need to call telegram again for that user and chat in the future.
Here's an example:
bot.on("message", async (ctx) => {
const chatMember = await ctx.chatMembers.getChatMember();
return ctx.reply(`Hello, ${chatMember.user.first_name}! I see you are a ${chatMember.status} of this chat!`);
});
The second parameter, which is the chat id, is optional; if you don't provide it, ctx.chat.id
will be used instead.
Please notice that, if you don't provide a chat id and there's no chat
property inside the context (for example: on
inline query updates), this will throw an error.
The enableAggressiveStorage
config option will install middleware to cache chat members without depending on the
chat_member
event. For every update, the middleware checks if ctx.chat
and ctx.from
exist. If they both do, it
then proceeds to call ctx.chatMembers.getChatMember
to add the chat member information to the storage in case it
doesn't exist.
Please note that this means the storage will be called for every update, which may be a lot, depending on how many updates your bot receives. This also has the potential to impact the performance of your bot drastically. Only use this if you really know what you're doing and are ok with the risks and consequences.