How to make requests to VK API, and not duplicate information?

How to make requests to VK API and when receive the data, duplicate them, and to check there is in my application already or not?

Want to make a bot for Telegram to parse posts from the VC through its API. But I don't know how to do so, that would not be duplicates.
How to get data only when they are updated?
Like on the wall I have a new post here only to pick it up.
How this is done in VC clients for iOS and Android?
How can that be done?
March 23rd 20 at 19:36
1 answer
March 23rd 20 at 19:38
VK Callback API you need. Subscribe to events, and your app receives the data only when events.
The Callback API is a tool for tracking user activity in Your community Vkontakte.

Et is not what you need - isobel81 commented on March 23rd 20 at 19:41
There is a direct api and reverse, the other is not given. - javier.Tromp commented on March 23rd 20 at 19:44
@javier.Tromp, that is impossible from your news feed anywhere only new posts to? - isobel81 commented on March 23rd 20 at 19:47
@isobel81, or by wall.get to all the posts to save itself in the database (and then to check id and keep only new one), or when creating a post to call the callback. In the first case, it is reversed to constantly pull the VC. In the second VC pulls your app when a new post (or another event). - javier.Tromp commented on March 23rd 20 at 19:50

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