Wallets with RPC services

[Lancelight]

I am looking for a wallet that has RPC Services to it similar to what the Electrum wallets offer.  Something like Coinomi with an RPC service would be amazing.  I'm trying to avoid having to install a crap ton of wallet apps on a server with limited disk space and I would absolutely never use a 3rd party hosted custodial wallet (not your keys not your coins is in full effect here).  I know about the "prune" configurations of most wallets but thats not a solution since it's more than 1 wallet app.  The idea is to use it as a "hot wallet" on a webserver.  I like Electrum a lot as a headless interface to the Bitcoin network with wallet capabilities, but thats all it does, it doesnt do any other cryptos by default and I dont think it can be easily configured for others with just the config file (or if it can,  docs to that would be cool).  I'm also not interested in "payment gateways" like Bitpay (or should I rephrase to BitFraud since Clown Ver has it's paws all over it).  My ideal solution would be Electrum with a config file that setup in a way to support other BTC like cryptos (Monero, Dash, LTC,  etc) since I already have a working API for Electrum and like it.

What are others using as multi-coin hot wallets on their webservers?  A read-only feature to a cold wallet would be cool to but not really a requirement for what I have in mind.

[BitMaxz]

I think there is no other wallet that supports RPC calls except Electrum without downloading the full blockchain.
I don't know exactly what you want to achieve and another thing is you are not looking for a payment gateway but it seems that you want to develop a payment solution on your own without using any 3rd party like Bitpay but I still think that you want a payment gateway that doesn't need any 3rd party.

How about check the  BTCpayserver it's not a custodial 3rd party wallet it's a payment gateway that you need to host with your own it means no 3rd parties.

However, it still needs Electrum to connect it to the hosted BTCpayserver through uploading the wallet file or through a master public key(For safety master public key would be the best).
This doesn't need so much data so it won't be a problem compared to installing Bitcoin core with full node. But the problem is if you are going to add more other cryptos as you mention above then you will need to host a full node of those coins.

All you need for guide and development of this you can find here https://docs.btcpayserver.org/

[Lancelight]

I think there is no other wallet that supports RPC calls except Electrum without downloading the full blockchain.
I don't know exactly what you want to achieve and another thing is you are not looking for a payment gateway but it seems that you want to develop a payment solution on your own without using any 3rd party like Bitpay but I still think that you want a payment gateway that doesn't need any 3rd party.

How about check the  BTCpayserver it's not a custodial 3rd party wallet it's a payment gateway that you need to host with your own it means no 3rd parties.

However, it still needs Electrum to connect it to the hosted BTCpayserver through uploading the wallet file or through a master public key(For safety master public key would be the best).
This doesn't need so much data so it won't be a problem compared to installing Bitcoin core with full node. But the problem is if you are going to add more other cryptos as you mention above then you will need to host a full node of those coins.

All you need for guide and development of this you can find here https://docs.btcpayserver.org/

You're right in that I'm looking for similar functionality to a payment gateway, I just dont want to use a 3rd party for it for multiple reasons.  One is I dont trust them,  another is I have no need for a USD offramp, and I also have a need to send out payments as well as receive them.  The payment gateways I have seen so far have all been 3rd party hosted.  I have not seen/heard of btcpayserver but I'll check into it,  I like the self hosted nature and wasnt aware there were self hosted options available.  So maybe I can amend my original ask to include self-hosted payment gateways if they have a "Refund" option as well.  I dont think this btcpayserver will satisfy the need for multiple cryptos given it's name though :/  

EDIT:  I have discovered this which is exactly what I was looking for:  https://docs.btcpayserver.org/Development/Altcoins/#how-can-i-add-an-altcoin-to-btcpayserver  I should be able to add cryptos that I need to it as I see fit if a contrib plugin doesnt yet exist (it did have a good handful listed already, among them was Dash, Monero and LTC, 3 of the cryptos I was looking to add).  So thanks for the link to this.  It's more of an option than I first thought.

[n0nce]

Yeah, BTCPayServer is the way to go here. It's not a third party, because you host it yourself. And you're less likely to fuck something up, since it's been 'tried and tested' a lot already - compared to hacking something together on your own.

BitMaxz quickly found out that your question here was essentially an XY-Problem. I would recommend next time to better explain what you actually want to do from the get go, it will be much simpler that way. Of course you can also sketch out what you plan to do and what component you think you're missing, but it's best to also draw the bigger picture, because sometimes a completely different solution makes more sense than what you had in mind (like in this case implementing everything on your own).