import { Context } from "https://deno.land/x/grammy@v1.10.1/mod.ts";
When your bot receives a message, Telegram sends an update object to your bot. The update contains information about the chat, the user, and of course the message itself. There are numerous other updates, too: https://core.telegram.org/bots/api#update
When grammY receives an update, it wraps this update into a context object
for you. Context objects are commonly named ctx
. A context object does two
things:
ctx.update
holds the update object that you can use to process the message. This includes providing useful shortcuts for the update, for instance,ctx.msg
is a shortcut that gives you the message object from the update—no matter whether it is contained inctx.update.message
, orctx.update.edited_message
, orctx.update.channel_post
, orctx.update.edited_channel_post
.ctx.api
gives you access to the full Telegram Bot API so that you can directly call any method, such as responding viactx.api.sendMessage
. Also here, the context objects has some useful shortcuts for you. For instance, if you want to send a message to the same chat that a message comes from (i.e. just respond to a user) you can callctx.reply
. This is nothing but a wrapper forctx.api.sendMessage
with the rightchat_id
pre-filled for you. Almost all methods of the Telegram Bot API have their own shortcut directly on the context object, so you probably never really have to usectx.api
at all.
This context object is then passed to all of the listeners (called
middleware) that you register on your bot. Because this is so useful, the
context object is often used to hold more information. One example are
sessions (a chat-specific data storage that is stored in a database), and
another example is ctx.match
that is used by bot.command
and other
methods to keep information about how a regular expression was matched.
Read up about middleware on the website if you want to know more about the powerful opportunities that lie in context objects, and about how grammY implements them.
Properties
Get chat object from wherever possible. Alias for (ctx.msg ?? ctx.myChatMember ?? ctx.chatMember ?? ctx.chatJoinRequest)?.chat
Get message author from wherever possible. Alias for
(ctx.callbackQuery?? ctx.inlineQuery ?? ctx.shippingQuery ?? ctx.preCheckoutQuery ?? ctx.chosenInlineResult ?? ctx.msg ?? ctx.myChatMember ?? ctx.chatMember ?? ctx.chatJoinRequest)?.from
Get inline message ID from wherever possible. Alias for
(ctx.callbackQuery ?? ctx.chosenInlineResult)?.inline_message_id
Used by some middleware to store information about how a certain string or regular expression was matched.
Get message object from wherever possible. Alias for ctx.message ?? ctx.editedMessage ?? ctx.callbackQuery?.message ?? ctx.channelPost ?? ctx.editedChannelPost
Get sender chat object from wherever possible. Alias for
ctx.msg?.sender_chat
.
Methods
Context-aware alias for api.answerCallbackQuery
. Use this method to send answers to callback queries sent from inline keyboards. The answer will be displayed to the user as a notification at the top of the chat screen or as an alert. On success, True is returned.
Alternatively, the user can be redirected to the specified Game URL. For this option to work, you must first create a game for your bot via @Botfather and accept the terms. Otherwise, you may use links like t.me/your_bot?start=XXXX that open your bot with a parameter.
Context-aware alias for api.answerInlineQuery
. Use this method to send answers to an inline query. On success, True is returned.
No more than 50 results per query are allowed.
Example: An inline bot that sends YouTube videos can ask the user to connect the bot to their YouTube account to adapt search results accordingly. To do this, it displays a 'Connect your YouTube account' button above the results, or even before showing any. The user presses the button, switches to a private chat with the bot and, in doing so, passes a start parameter that instructs the bot to return an OAuth link. Once done, the bot can offer a switch_inline button so that the user can easily return to the chat where they wanted to use the bot's inline capabilities.
Context-aware alias for api.answerPreCheckoutQuery
. Once the user has confirmed their payment and shipping details, the Bot API sends the final confirmation in the form of an Update with the field pre_checkout_query. Use this method to respond to such pre-checkout queries. On success, True is returned. Note: The Bot API must receive an answer within 10 seconds after the pre-checkout query was sent.
Context-aware alias for api.answerShippingQuery
. If you sent an invoice requesting a shipping address and the parameter is_flexible was specified, the Bot API will send an Update with a shipping_query field to the bot. Use this method to reply to shipping queries. On success, True is returned.
Context-aware alias for api.approveChatJoinRequest
. Use this method to approve a chat join request. The bot must be an administrator in the chat for this to work and must have the can_invite_users administrator right. Returns True on success.
Context-aware alias for api.banChatMember
. Use this method to ban a user in a group, a supergroup or a channel. In the case of supergroups and channels, the user will not be able to return to the chat on their own using invite links, etc., unless unbanned first. The bot must be an administrator in the chat for this to work and must have the appropriate administrator rights. Returns True on success.
Context-aware alias for api.banChatMember
. Use this method to ban a user in a group, a supergroup or a channel. In the case of supergroups and channels, the user will not be able to return to the chat on their own using invite links, etc., unless unbanned first. The bot must be an administrator in the chat for this to work and must have the appropriate administrator rights. Returns True on success.
Context-aware alias for api.banChatSenderChat
. Use this method to ban a channel chat in a supergroup or a channel. Until the chat is unbanned, the owner of the banned chat won't be able to send messages on behalf of any of their channels. The bot must be an administrator in the supergroup or channel for this to work and must have the appropriate administrator rights. Returns True on success.
Context-aware alias for api.copyMessage
. Use this method to copy messages of any kind. Service messages and invoice messages can't be copied. The method is analogous to the method forwardMessage, but the copied message doesn't have a link to the original message. Returns the MessageId of the sent message on success.
Context-aware alias for api.createChatInviteLink
. Use this method to create an additional invite link for a chat. The bot must be an administrator in the chat for this to work and must have the appropriate administrator rights. The link can be revoked using the method revokeChatInviteLink. Returns the new invite link as ChatInviteLink object.
Context-aware alias for api.declineChatJoinRequest
. Use this method to decline a chat join request. The bot must be an administrator in the chat for this to work and must have the can_invite_users administrator right. Returns True on success.
Context-aware alias for api.deleteChatPhoto
. Use this method to delete a chat photo. Photos can't be changed for private chats. The bot must be an administrator in the chat for this to work and must have the appropriate administrator rights. Returns True on success.
Context-aware alias for api.deleteChatStickerSet
. Use this method to delete a group sticker set from a supergroup. The bot must be an administrator in the chat for this to work and must have the appropriate administrator rights. Use the field can_set_sticker_set ly returned in getChat requests to check if the bot can use this method. Returns True on success.
Context-aware alias for api.deleteMessage
. Use this method to delete a message, including service messages, with the following limitations:
- A message can only be deleted if it was sent less than 48 hours ago.
- A dice message in a private chat can only be deleted if it was sent more than 24 hours ago.
- Bots can delete outgoing messages in private chats, groups, and supergroups.
- Bots can delete incoming messages in private chats.
- Bots granted can_post_messages permissions can delete outgoing messages in channels.
- If the bot is an administrator of a group, it can delete any message there.
- If the bot has can_delete_messages permission in a supergroup or a channel, it can delete any message there. Returns True on success.
Context-aware alias for api.editChatInviteLink
. Use this method to edit a non-primary invite link created by the bot. The bot must be an administrator in the chat for this to work and must have the appropriate administrator rights. Returns the edited invite link as a ChatInviteLink object.
Context-aware alias for api.editMessageCaption
. Use this method to edit captions of messages. On success, if the edited message is not an inline message, the edited Message is returned, otherwise True is returned.
Context-aware alias for api.editMessageLiveLocation
. Use this method to edit live location messages. A location can be edited until its live_period expires or editing is explicitly disabled by a call to stopMessageLiveLocation. On success, if the edited message is not an inline message, the edited Message is returned, otherwise True is returned.
Context-aware alias for api.editMessageMedia
. Use this method to edit animation, audio, document, photo, or video messages. If a message is part of a message album, then it can be edited only to an audio for audio albums, only to a document for document albums and to a photo or a video otherwise. When an inline message is edited, a new file can't be uploaded; use a previously uploaded file via its file_id or specify a URL. On success, if the edited message is not an inline message, the edited Message is returned, otherwise True is returned.
Context-aware alias for api.editMessageReplyMarkup
. Use this method to edit only the reply markup of messages. On success, if the edited message is not an inline message, the edited Message is returned, otherwise True is returned.
Context-aware alias for api.editMessageText
. Use this method to edit text and game messages. On success, if the edited message is not an inline message, the edited Message is returned, otherwise True is returned.
Context-aware alias for api.exportChatInviteLink
. Use this method to generate a new primary invite link for a chat; any previously generated primary link is revoked. The bot must be an administrator in the chat for this to work and must have the appropriate administrator rights. Returns the new invite link as String on success.
Note: Each administrator in a chat generates their own invite links. Bots can't use invite links generated by other administrators. If you want your bot to work with invite links, it will need to generate its own link using exportChatInviteLink or by calling the getChat method. If your bot needs to generate a new primary invite link replacing its previous one, use exportChatInviteLink again.
Context-aware alias for api.forwardMessage
. Use this method to forward messages of any kind. Service messages can't be forwarded. On success, the sent Message is returned.
Context-aware alias for api.getChatMember
. Use this method to get information about a member of a chat. Returns a ChatMember object on success.
Context-aware alias for api.getChat
. Use this method to get up to date information about the chat (current name of the user for one-on-one conversations, current username of a user, group or channel, etc.). Returns a Chat object on success.
Context-aware alias for api.getChatAdministrators
. Use this method to get a list of administrators in a chat. On success, returns an Array of ChatMember objects that contains information about all chat administrators except other bots. If the chat is a group or a supergroup and no administrators were appointed, only the creator will be returned.
Context-aware alias for api.getChatMember
. Use this method to get information about a member of a chat. Returns a ChatMember object on success.
Context-aware alias for api.getChatMemberCount
. Use this method to get the number of members in a chat. Returns Int on success.
Context-aware alias for api.getChatMenuButton
. Use this method to get the current value of the bot's menu button in a private chat, or the default menu button. Returns MenuButton on success.
Context-aware alias for api.getFile
. Use this method to get basic info about a file and prepare it for downloading. For the moment, bots can download files of up to 20MB in size. On success, a File object is returned. The file can then be downloaded via the link https://api.telegram.org/file/bot/<file_path>, where <file_path> is taken from the response. It is guaranteed that the link will be valid for at least 1 hour. When the link expires, a new one can be requested by calling getFile again.
Note: This function may not preserve the original file name and MIME type. You should save the file's MIME type and name (if available) when the File object is received.
Context-aware alias for api.getMyDefaultAdministratorRights
. Use this method to get the current default administrator rights of the bot. Returns ChatAdministratorRights on success.
Context-aware alias for api.getUserProfilePhotos
. Use this method to get a list of profile pictures for a user. Returns a UserProfilePhotos object.
Returns true
if this context object matches the given filter query, and
false
otherwise. This uses the same logic as bot.on
.
Returns true
if this context object contains the given callback query,
or if the contained callback query data matches the given regular
expression. It returns false
otherwise. This uses the same logic as
bot.callbackQuery
.
Returns true
if this context object belongs to a chat with the given
chat type, and false
otherwise. This uses the same logic as
bot.chatType
.
Returns true
if this context object contains the given command, and
false
otherwise. This uses the same logic as bot.command
.
Returns true
if this context object contains the given game query, or
if the contained game query matches the given regular expression. It
returns false
otherwise. This uses the same logic as bot.gameQuery
.
Returns true
if this context object contains the given inline query, or
if the contained inline query matches the given regular expression. It
returns false
otherwise. This uses the same logic as bot.inlineQuery
.
Returns true
if this context object contains the given text, or if it
contains text that matches the given regular expression. It returns
false
otherwise. This uses the same logic as bot.hears
.
Context-aware alias for api.leaveChat
. Use this method for your bot to leave a group, supergroup or channel. Returns True on success.
Context-aware alias for api.pinChatMessage
. Use this method to add a message to the list of pinned messages in a chat. If the chat is not a private chat, the bot must be an administrator in the chat for this to work and must have the 'can_pin_messages' administrator right in a supergroup or 'can_edit_messages' administrator right in a channel. Returns True on success.
Context-aware alias for api.promoteChatMember
. Use this method to promote or demote a user in a supergroup or a channel. The bot must be an administrator in the chat for this to work and must have the appropriate administrator rights. Pass False for all boolean parameters to demote a user. Returns True on success.
Context-aware alias for api.promoteChatMember
. Use this method to promote or demote a user in a supergroup or a channel. The bot must be an administrator in the chat for this to work and must have the appropriate administrator rights. Pass False for all boolean parameters to demote a user. Returns True on success.
Context-aware alias for api.sendMessage
. Use this method to send text messages. On success, the sent Message is returned.
Context-aware alias for api.sendAnimation
. Use this method to send animation files (GIF or H.264/MPEG-4 AVC video without sound). On success, the sent Message is returned. Bots can currently send animation files of up to 50 MB in size, this limit may be changed in the future.
Context-aware alias for api.sendAudio
. Use this method to send audio files, if you want Telegram clients to display them in the music player. Your audio must be in the .MP3 or .M4A format. On success, the sent Message is returned. Bots can currently send audio files of up to 50 MB in size, this limit may be changed in the future.
For sending voice messages, use the sendVoice method instead.
Context-aware alias for api.sendChatAction
. Use this method when you need to tell the user that something is happening on the bot's side. The status is set for 5 seconds or less (when a message arrives from your bot, Telegram clients clear its typing status). Returns True on success.
Example: The ImageBot needs some time to process a request and upload the image. Instead of sending a text message along the lines of “Retrieving image, please wait…”, the bot may use sendChatAction with action = upload_photo. The user will see a “sending photo” status for the bot.
We only recommend using this method when a response from the bot will take a noticeable amount of time to arrive.
Context-aware alias for api.sendContact
. Use this method to send phone contacts. On success, the sent Message is returned.
Context-aware alias for api.sendDice
. Use this method to send an animated emoji that will display a random value. On success, the sent Message is returned.
Context-aware alias for api.sendDocument
. Use this method to send general files. On success, the sent Message is returned. Bots can currently send files of any type of up to 50 MB in size, this limit may be changed in the future.
Context-aware alias for api.sendGame
. Use this method to send a game. On success, the sent Message is returned.
Context-aware alias for api.sendInvoice
. Use this method to send invoices. On success, the sent Message is returned.
Context-aware alias for api.sendLocation
. Use this method to send point on the map. On success, the sent Message is returned.
Context-aware alias for api.sendMediaGroup
. Use this method to send a group of photos, videos, documents or audios as an album. Documents and audio files can be only grouped in an album with messages of the same type. On success, an array of Messages that were sent is returned.
Context-aware alias for api.sendPhoto
. Use this method to send photos. On success, the sent Message is returned.
Context-aware alias for api.sendPoll
. Use this method to send a native poll. On success, the sent Message is returned.
Context-aware alias for api.sendSticker
. Use this method to send static .WEBP, animated .TGS, or video .WEBM stickers. On success, the sent Message is returned.
Context-aware alias for api.sendVenue
. Use this method to send information about a venue. On success, the sent Message is returned.
Context-aware alias for api.sendVideo
. Use this method to send video files, Telegram clients support mp4 videos (other formats may be sent as Document). On success, the sent Message is returned. Bots can currently send video files of up to 50 MB in size, this limit may be changed in the future.
Context-aware alias for api.sendVideoNote
. Use this method to send video messages. On success, the sent Message is returned.
As of v.4.0, Telegram clients support rounded square mp4 videos of up to 1 minute long.
Context-aware alias for api.sendVoice
. Use this method to send audio files, if you want Telegram clients to display the file as a playable voice message. For this to work, your audio must be in an .OGG file encoded with OPUS (other formats may be sent as Audio or Document). On success, the sent Message is returned. Bots can currently send voice messages of up to 50 MB in size, this limit may be changed in the future.
Context-aware alias for api.restrictChatMember
. Use this method to restrict a user in a supergroup. The bot must be an administrator in the supergroup for this to work and must have the appropriate administrator rights. Pass True for all permissions to lift restrictions from a user. Returns True on success.
Context-aware alias for api.restrictChatMember
. Use this method to restrict a user in a supergroup. The bot must be an administrator in the supergroup for this to work and must have the appropriate administrator rights. Pass True for all permissions to lift restrictions from a user. Returns True on success.
Context-aware alias for api.revokeChatInviteLink
. Use this method to revoke an invite link created by the bot. If the primary link is revoked, a new link is automatically generated. The bot must be an administrator in the chat for this to work and must have the appropriate administrator rights. Returns the revoked invite link as ChatInviteLink object.
Context-aware alias for api.setChatAdministratorCustomTitle
. Use this method to set a custom title for an administrator in a supergroup promoted by the bot. Returns True on success.
Context-aware alias for api.setChatAdministratorCustomTitle
. Use this method to set a custom title for an administrator in a supergroup promoted by the bot. Returns True on success.
Context-aware alias for api.setChatDescription
. Use this method to change the description of a group, a supergroup or a channel. The bot must be an administrator in the chat for this to work and must have the appropriate administrator rights. Returns True on success.
Context-aware alias for api.setChatMenuButton
. Use this method to change the bot's menu button in a private chat, or the default menu button. Returns True on success.
Context-aware alias for api.setChatPermissions
. Use this method to set default chat permissions for all members. The bot must be an administrator in the group or a supergroup for this to work and must have the can_restrict_members administrator rights. Returns True on success.
Context-aware alias for api.setChatPhoto
. Use this method to set a new profile photo for the chat. Photos can't be changed for private chats. The bot must be an administrator in the chat for this to work and must have the appropriate administrator rights. Returns True on success.
Context-aware alias for api.setChatStickerSet
. Use this method to set a new group sticker set for a supergroup. The bot must be an administrator in the chat for this to work and must have the appropriate administrator rights. Use the field can_set_sticker_set ly returned in getChat requests to check if the bot can use this method. Returns True on success.
Context-aware alias for api.setChatTitle
. Use this method to change the title of a chat. Titles can't be changed for private chats. The bot must be an administrator in the chat for this to work and must have the appropriate administrator rights. Returns True on success.
Context-aware alias for api.setMyDefaultAdministratorRights
. Use this method to the change the default administrator rights requested by the bot when it's added as an administrator to groups or channels. These rights will be suggested to users, but they are are free to modify the list before adding the bot. Returns True on success.
Context-aware alias for api.setPassportDataErrors
. Informs a user that some of the Telegram Passport elements they provided contains errors. The user will not be able to re-submit their Passport to you until the errors are fixed (the contents of the field for which you returned the error must change). Returns True on success.
Use this if the data submitted by the user doesn't satisfy the standards your service requires for any reason. For example, if a birthday date seems invalid, a submitted document is blurry, a scan shows evidence of tampering, etc. Supply some details in the error message to make sure the user knows how to correct the issues.
Context-aware alias for api.stopMessageLiveLocation
. Use this method to stop updating a live location message before live_period expires. On success, if the message is not an inline message, the edited Message is returned, otherwise True is returned.
Context-aware alias for api.stopPoll
. Use this method to stop a poll which was sent by the bot. On success, the stopped Poll is returned.
Context-aware alias for api.unbanChatMember
. Use this method to unban a previously banned user in a supergroup or channel. The user will not return to the group or channel automatically, but will be able to join via link, etc. The bot must be an administrator for this to work. By default, this method guarantees that after the call the user is not a member of the chat, but will be able to join it. So if the user is a member of the chat they will also be removed from the chat. If you don't want this, use the parameter only_if_banned. Returns True on success.
Context-aware alias for api.unbanChatSenderChat
. Use this method to unban a previously banned channel chat in a supergroup or channel. The bot must be an administrator for this to work and must have the appropriate administrator rights. Returns True on success.
Context-aware alias for api.unpinAllChatMessages
. Use this method to clear the list of pinned messages in a chat. If the chat is not a private chat, the bot must be an administrator in the chat for this to work and must have the 'can_pin_messages' administrator right in a supergroup or 'can_edit_messages' administrator right in a channel. Returns True on success.
Context-aware alias for api.unpinChatMessage
. Use this method to remove a message from the list of pinned messages in a chat. If the chat is not a private chat, the bot must be an administrator in the chat for this to work and must have the 'can_pin_messages' administrator right in a supergroup or 'can_edit_messages' administrator right in a channel. Returns True on success.
Static Properties
Context.has
is an object that contains a number of useful functions for
probing context objects. Each of these functions can generate a predicate
function, to which you can pass context objects in order to check if a
condition holds for the respective context object.
For example, you can call Context.has.filterQuery(":text")
to generate
a predicate function that tests context objects for containing text:
const hasText = Context.has.filterQuery(":text");
if (hasText(ctx0)) {} // `ctx0` matches the filter query `:text`
if (hasText(ctx1)) {} // `ctx1` matches the filter query `:text`
if (hasText(ctx2)) {} // `ctx2` matches the filter query `:text`
These predicate funtions are used internally by the has-methods that are
installed on every context object. This means that calling
ctx.has(":text")
is equivalent to
Context.has.filterQuery(":text")(ctx)
.