Conversion of ERC-20 Custom ETHEREUM Tokens to Wrapped ETH (WETH)

[DDCT]

There must be a programmable way (using Solidity or whatever programming language) to convert custom built ERC-20 tokens (Smart contracts on the Ethereum blockchain) to WETH (Wrapped Ether) OR through the service of an interactive website that provide this feature.  Any idea or help is welcome. Thanks.

[logfiles]

Not sure what exactly you want.
Are you asking for exchanges that provide the service of converting tokens listed in there to WETH and vice versa like the ones in the list below?
https://www.coingecko.com/en/coins/weth

[shinratensei_]

Weth mostly used by the swap service and it looks like you can make it available by using the API that already created by those swap services. Do you wanna put that feature on your site or what?
You should connect it to the swap service to make it able to swap custom ethereum token to the WETH but again when your coin doesn't have pooled WETH and you cant do that.

[cryptoaddictchie]

There must be a programmable way (using Solidity or whatever programming language) to convert custom built ERC-20 tokens (Smart contracts on the Ethereum blockchain) to WETH (Wrapped Ether) OR through the service of an interactive website that provide this feature.  Any idea or help is welcome. Thanks.

You can convert it using uniswap. Erc20 smart tokens are compatible with weth it's just a wrapped eth but technically it's still eth. Uniswap does the conversion directly from tokens to weth even their pairing or liquidity is eth or usdt. But you just add some fees higher than normal one since it will convert it for you from eth to weth or usdt to weth.

I've always directing my trades to usdt so whichever liquidity they had is no problem at all on uniswap trading.