How to import an existing extended private key to bcoin? I´m searching for a way to import an existing extended private key, exported from electrum, into a bcoin node. Reading https://bcoin.io/api-docs/ I can´t find a description to do this. 

Am I missing a part or does someone have a solution for this?
What exactly do you have from Electrum? Is it an xprv... ?

What you need to do is create a wallet and assign the master private key:

https://bcoin.io/api-docs/#create-a-wallet

bwallet-cli mkwallet --id=WALLETNAME --master=xprv...

Note that Electrum's address derivation scheme may not match bcoin's exactly (since bip32/bip44 don't provide metadata like address type). Therefore you may also need to include the flag --witness=true which will derive bech32 addresses along the bip44 path. If Electrum is using bip49 or bip84 derivation schemes, you will have to run a modified branch of bcoin to recover the same addresses.

If you want to chat about this the developers are usually available on slack or IRC #bcoin