Types for the Telegram Bot API
Please consider contributing to @grammyjs/types instead.
typegram
is legacy and will not be updated directly anymore.
Instead, @grammyjs/types is maintained and kept in sync with the Bot API specification.
Changes are backported to typegram
periodically to keep older projects running.
This project provides TypeScript types for the entire Telegram Bot API in version 5.5.
It contains zero bytes of executable code.
Installation
npm install --save-dev typegram
Available Types
Generally this package just exposes a huge load of interface
s that correspond to the types used throughout the Telegram Bot API.
Note that the API specification sometimes only has one name for multiple variants of a type, e.g. there is a number of different Update
s you can receive, but they're all just called Update
.
This package represents such types as large unions of all possible options of what an Update
could be, such that type narrowing can work as expected on your side.
If you need to access the individual variants of an Update
, refer to Update.MessageUpdate
and its siblings.
In fact, this pattern is used for various types, namely:
CallbackQuery
Chat
ChatFromGetChat
InlineKeyboardButton
KeyboardButton
Message
MessageEntity
Location
Update
(Naturally, when the API specification is actually modelling types to be unions (e.g. InlineQueryResult
), this is reflected here as a union type, too.)
Available Methods
In addition to the types, this package provides you with another type Telegram
which contains all available methods of the API.
There is no further structure applied to this, but if you can come up with something reasonable, please suggest it in an issue or directly open a PR.
Each method takes just a single argument with a structure that corresponds to the object expected by Telegram.
If you need to directly access that type, consider using Opts<M>
where M
is the method name (e.g. Opts<'getMe'>
).
Note that Opts<M>
will give you an empty object type (i.e. {}
) for methods that do not take any parameters.
That is to say, it will not give you a type error or undefined
(as opposed to something like Parameters<Telegram['getMe']>[0]
).
Caveat with JSON-Serialized Objects
Some methods of the Telegram Bot API are expected to be called with JSON-serialized objects contained in a property of the payload, rather than an actual JSON payload.
In other words, the objects are serialized twice—the first time in order to conform with the docs, and the second time when the payload is actually sent in the POST body to the API server.
The most prominent example is the reply_markup
property that appears in a number of different methods, but more than a dozen other properties like this can be found throughout the API.
Strictly speaking, the typegram
types do not reflect this accurately.
Instead of using string
(representing a serialized object) as the type, typegram
uses the type of the object itself, thus ignoring the serialization step.
For instance, instead of declaring reply_markup: string
, it declares the property as reply_markup: InlineKeyboardMarkup | ReplyKeyboardMarkup | ReplyKeyboardRemove | ForceReply
because that is what is supposed to be serialized to string
before calling the respective method.
This makes sense for two reasons.
- The goal of this library is to provide type safety.
However, the contents of a string cannot be typechecked for being valid JSON of the correct object.
As a result, we would be missing type safety if we would only model the properties as
string
. - A common use case for this library is to pull the types into some wrapper code around the Telegram Bot API.
This wrapper code often does the necessary JSON serialization automatically for the required properties.
The consumer then does not need to care about which properties to serialize and which not.
Given that
typegram
refers to the objects themselves instead of their serialized strings, the wrapper code can now simply expose the typegram
types to its consumers without having to transform them before.
Using Promises
All of the methods are specified with the actual return type of the Telegram Bot API.
If you need them to return Promise
s instead, consider using TelegramP
.
This type maps all methods of Telegram
to a promisified version.
Using API Response Objects
The Telegram Bot API does not return just the requested data in the body of the response objects.
Instead, they are wrapped inside an object that has an ok: boolean
status flag, indicating success or failure of the preceding API request.
This outer object is modelled in typegram
by the ApiResponse
type.
If you need the methods of Telegram
to return ApiResponse
objects instead of the raw data, consider using TelegramR
.
This works analogously to TelegramP
.
The type maps all methods of Telegram
to a version where they return ApiResponse
objects of the data, instead of the data themselves.
Using Both Promises and API Response Objects
Yes.
TelegramPR
.
Customizing InputFile
The Telegram Bot API lets bots send files in three different ways.
Two of those ways are by specifying a string
—either a file_id
or a URL.
The third option, however, is by uploading files to the server using multipart/form-data.
The first two means to send a file are already covered by the type annotations across the library.
In all places where a file_id
or a URL is permitted, the corresponding property allows a string
.
We will now look at the type declarations that are relevant for uploading files directly.
Depending on the code you're using the typegram
types for, you may want to support different ways to specify the file to be uploaded.
As an example, you may want to be able to make calls to sendDocument
with an object that conforms to { path: string }
in order to specify the location of a local file.
(Your code is then assumed to able to translate calls to sendDocument
and the like to multipart/form-data uploads when supplied with an object alike { path: '/tmp/file.txt' }
in the document
property of the argument object.)
typegram
cannot possibly know what objects you want to support as InputFile
s.
Consequently, the exposed type InputFile
is merely an alias for never
.
However, you can specify your own version of what an InputFile
is, hence effectively creating a completely new version of typegram
with your custom InputFile
type used throughout all affected methods and interfaces.
This is possible by what we call a proxy type.
For instance, let's stick with our example and say that you want to support InputFile
s of the following type.
interface MyInputFile {
path: string;
}
You can then customize typegram
to fit your needs by
- importing the magical
Typegram
proxy type and - setting this alias:
import { Typegram } from "typegram";
type MyTypegram = Typegram<MyInputFile>;
You can now access all types that must respect MyInputFile
through the MyTypegram
type:
type Telegram = MyTypegram["Telegram"];
type Opts<M extends keyof Telegram> = MyTypegram["Opts"][M];
type InputMedia = MyTypegram["InputMedia"];
type InputMediaPhoto = MyTypegram["InputMediaPhoto"];
type InputMediaVideo = MyTypegram["InputMediaVideo"];
type InputMediaAnimation = MyTypegram["InputMediaAnimation"];
type InputMediaAudio = MyTypegram["InputMediaAudio"];
type InputMediaDocument = MyTypegram["InputMediaDocument"];
In fact, if you are using the type annotations of typegram
without relying on the Typegram
proxy type, you are actually still using a default proxy type under the hood.
The declaration of this default proxy type may help you to define your own version.
Check out the default.d.ts file.
Note that interfaces other than the ones mentioned above are unaffected by the customization through MyInputFile
.
They can simply continue to be imported directly from typegram
.
Where Do the Types Come from
They're handwritten.
That is, they're of course not entirely handwritten.
The initial version of them were produced in one afternoon by a combination of copying and pasting from the website, VIM magic, regular expressions, and VSCode auto-formatting the rest.
After that, some more work and a few community contributions did the polishing.
Subsequent updates to the API were integrated manually in a similar fashion.
Other people's previous attempts to harvest the types directly from the website using a script failed due to the required effort of handling special cases about the layout of the website.
The grammY bot framework was orginally based on typegram
which served as the starting point for the grammY types package.
Starting after the upgrade to Bot API 5.0, most changes and updates to typegram
were simply git cherry-pick
ed from this repository.
If you want to contribute to typegram
, it may makes sense to add them to grammY first and then can easily be backported to typegram
.