Could you give more details on what is it you're trying to build though?
If you're planning to build something so that the user could past a TXID and in exchange, he would receive the amount, addresses involved, fees, etc. of that transactions, then the easiest way to achieve that would be to simply use the API of a blockexplorer like Blockchain.com, Blockchair, etc. There are a few options for you out there.
Sorry, i cant. But im looking for a API to help me generate and validate adresses and transactions. Im a programmer but not familiar to blockchain, so im not secure on what tool to use.
Do you guys know any tools that can help me with a faster validation of the transactions?
On what coin are you using, if bitcoin you can you it using Mempool.space api like this one below,
https://mempool.space/api/address/btc_address/txs
Get the latest transaction of the address, make sure you only give unique address to each user, you can check the status of the tx (true or false).
But if you're talking about using other crpyto, i guess you need crypto payment gateways api instead which usually are paid.
im looking at first to receive only in BTC, but in the future others coins would be accepted. Do you think, even with taxes, would be better to use a gateway?