Entities

The library widely uses the concept of “entities”. An entity will refer to any User, Chat or Channel object that the API may return in response to certain methods, such as GetUsersRequest.

Note

When something “entity-like” is required, it means that you need to provide something that can be turned into an entity. These things include, but are not limited to, usernames, exact titles, IDs, Peer objects, or even entire User, Chat and Channel objects and even phone numbers from people you have in your contact list.

To “encounter” an ID, you would have to “find it” like you would in the normal app. If the peer is in your dialogs, you would need to client.get_dialogs(). If the peer is someone in a group, you would similarly client.get_participants(group).

Once you have encountered an ID, the library will (by default) have saved their access_hash for you, which is needed to invoke most methods. This is why sometimes you might encounter this error when working with the library. You should except ValueError and run code that you know should work to find the entity.

What is an Entity?

A lot of methods and requests require entities to work. For example, you send a message to an entity, get the username of an entity, and so on.

There are a lot of things that work as entities: usernames, phone numbers, chat links, invite links, IDs, and the types themselves. That is, you can use any of those when you see an “entity” is needed.

Note

Remember that the phone number must be in your contact list before you can use it.

You should use, from better to worse:

  1. Input entities. For example, event.input_chat, message.input_sender, or caching an entity you will use a lot with entity = await client.get_input_entity(...).
  2. Entities. For example, if you had to get someone’s username, you can just use user or channel. It will work. Only use this option if you already have the entity!
  3. IDs. This will always look the entity up from the cache (the *.session file caches seen entities).
  4. Usernames, phone numbers and links. The cache will be used too (unless you force a client.get_entity()), but may make a request if the username, phone or link has not been found yet.

In recent versions of the library, the following two are equivalent:

async def handler(event):
    await client.send_message(event.sender_id, 'Hi')
    await client.send_message(event.input_sender, 'Hi')

If you need to be 99% sure that the code will work (sometimes it’s simply impossible for the library to find the input entity), or if you will reuse the chat a lot, consider using the following instead:

async def handler(event):
    # This method may make a network request to find the input sender.
    # Properties can't make network requests, so we need a method.
    sender = await event.get_input_sender()
    await client.send_message(sender, 'Hi')
    await client.send_message(sender, 'Hi')

Getting Entities

Through the use of the Session Files, the library will automatically remember the ID and hash pair, along with some extra information, so you’re able to just do this:

# (These examples assume you are inside an "async def")
#
# Dialogs are the "conversations you have open".
# This method returns a list of Dialog, which
# has the .entity attribute and other information.
#
# This part is IMPORTANT, because it feels the entity cache.
dialogs = await client.get_dialogs()

# All of these work and do the same.
lonami = await client.get_entity('lonami')
lonami = await client.get_entity('t.me/lonami')
lonami = await client.get_entity('https://telegram.dog/lonami')

# Other kind of entities.
channel = await client.get_entity('telegram.me/joinchat/AAAAAEkk2WdoDrB4-Q8-gg')
contact = await client.get_entity('+34xxxxxxxxx')
friend  = await client.get_entity(friend_id)

# Getting entities through their ID (User, Chat or Channel)
entity = await client.get_entity(some_id)

# You can be more explicit about the type for said ID by wrapping
# it inside a Peer instance. This is recommended but not necessary.
from telethon.tl.types import PeerUser, PeerChat, PeerChannel

my_user    = await client.get_entity(PeerUser(some_id))
my_chat    = await client.get_entity(PeerChat(some_id))
my_channel = await client.get_entity(PeerChannel(some_id))

Note

You don’t need to get the entity before using it! Just let the library do its job. Use a phone from your contacts, username, ID or input entity (preferred but not necessary), whatever you already have.

All methods in the TelegramClient call .get_input_entity() prior to sending the request to save you from the hassle of doing so manually. That way, convenience calls such as client.send_message('lonami', 'hi!') become possible.

Every entity the library encounters (in any response to any call) will by default be cached in the .session file (an SQLite database), to avoid performing unnecessary API calls. If the entity cannot be found, additonal calls like ResolveUsernameRequest or GetContactsRequest may be made to obtain the required information.

Entities vs. Input Entities

Note

This section is informative, but worth reading. The library will transparently handle all of these details for you.

On top of the normal types, the API also make use of what they call their Input* versions of objects. The input version of an entity (e.g. InputPeerUser, InputChat, etc.) only contains the minimum information that’s required from Telegram to be able to identify who you’re referring to: a Peer’s ID and hash. They are named like this because they are input parameters in the requests.

Entities’ ID are the same for all user and bot accounts, however, the access hash is different for each account, so trying to reuse the access hash from one account in another will not work.

Sometimes, Telegram only needs to indicate the type of the entity along with their ID. For this purpose, Peer versions of the entities also exist, which just have the ID. You cannot get the hash out of them since you should not be needing it. The library probably has cached it before.

Peers are enough to identify an entity, but they are not enough to make a request with them use them. You need to know their hash before you can “use them”, and to know the hash you need to “encounter” them, let it be in your dialogs, participants, message forwards, etc.

Note

You can use peers with the library. Behind the scenes, they are replaced with the input variant. Peers “aren’t enough” on their own but the library will do some more work to use the right type.

As we just mentioned, API calls don’t need to know the whole information about the entities, only their ID and hash. For this reason, another method, client.get_input_entity() is available. This will always use the cache while possible, making zero API calls most of the time. When a request is made, if you provided the full entity, e.g. an User, the library will convert it to the required InputPeer automatically for you.

You should always favour client.get_input_entity() over client.get_entity() for this reason! Calling the latter will always make an API call to get the most recent information about said entity, but invoking requests don’t need this information, just the InputPeer. Only use client.get_entity() if you need to get actual information, like the username, name, title, etc. of the entity.

To further simplify the workflow, since the version 0.16.2 of the library, the raw requests you make to the API are also able to call client.get_input_entity() wherever needed, so you can even do things like:

await client(SendMessageRequest('username', 'hello'))

The library will call the .resolve() method of the request, which will resolve 'username' with the appropriated InputPeer. Don’t worry if you don’t get this yet, but remember some of the details here are important.

Full Entities

In addition to PeerUser, InputPeerUser, User (and its variants for chats and channels), there is also the concept of UserFull.

This full variant has additional information such as whether the user is blocked, its notification settings, the bio or about of the user, etc.

There is also messages.ChatFull which is the equivalent of full entities for chats and channels, with also the about section of the channel. Note that the users field only contains bots for the channel (so that clients can suggest commands to use).

You can get both of these by invoking GetFullUser, GetFullChat and GetFullChannel respectively.

Accessing Entities

Although it’s explicitly noted in the documentation that messages subclass ChatGetter and SenderGetter, some people still don’t get inheritance.

When the documentation says “Bases: telethon.tl.custom.chatgetter.ChatGetter” it means that the class you’re looking at, also can act as the class it bases. In this case, ChatGetter knows how to get the chat where a thing belongs to.

So, a Message is a ChatGetter. That means you can do this:

message.is_private
message.chat_id
await message.get_chat()
# ...etc

SenderGetter is similar:

message.user_id
await message.get_input_user()
message.user
# ...etc

Quite a few things implement them, so it makes sense to reuse the code. For example, all events (except raw updates) implement ChatGetter since all events occur in some chat.

Summary

TL;DR; If you’re here because of “Could not find the input entity for”, you must ask yourself “how did I find this entity through official applications”? Now do the same with the library. Use what applies:

# (These examples assume you are inside an "async def")
async with client:
    # Does it have an username? Use it!
    entity = await client.get_entity(username)

    # Do you have a conversation open with them? Get dialogs.
    await client.get_dialogs()

    # Are they participant of some group? Get them.
    await client.get_participants('TelethonChat')

    # Is the entity the original sender of a forwarded message? Get it.
    await client.get_messages('TelethonChat', 100)

    # NOW you can use the ID, anywhere!
    await client.send_message(123456, 'Hi!')

    entity = await client.get_entity(123456)
    print(entity)

Once the library has “seen” the entity, you can use their integer ID. You can’t use entities from IDs the library hasn’t seen. You must make the library see them at least once and disconnect properly. You know where the entities are and you must tell the library. It won’t guess for you.