How to parse data from the blockchain?

Question

RPC

Good afternoon, I would like to know a little information about where the data comes from on sites such as coinmarketcap.com, coingecko.com, etc. I know that there are many blockchains like Etherium , binance smart chain etc. There is not enough information on Google about data parsing, using ready-made APIs from current sites is not an option, hunting to create your own service, tell me where to dig, and where to get all the data about transaction tokens, etc. without affecting third-party services.

Answer 1

See what kind of information you need.
If you take coinmarketcap, you first need to create a list of coins.
It can be taken from the API of exchanges + one of the ways to generate a list of coins is to add them manually, through the application https://support.coinmarketcap.com/hc/en-us/article... .
If you need to know the prices of coins, the volume of trading, you need to make requests to the API of the exchanges that have these coins (they are free with reasonable limits).
If you need to find out the emission - there are also many options here, for example, for ERC20 standard tokens on the ether blockchain - you can call the totalSupply contract method.
If you need some data about movements within blockchains, then you need to analyze the transaction logs of each specific blockchain.
At the same time, if you do not use other people's APIs, you will have to put the nodes of the necessary blockchains on your server and analyze them with their own libraries.