# Transaction Filtering
Clients running a light client may wish to filter for transactions on a separate server, in which case LDK will tell them about transactions to filter for.
More information is available in the Blockchain Data guide.
# Fee Estimation
LDK let's you decide your source for fee estimation. This could be Bitcoin Core's fee estimation through
estimatesmartfee RPC method or third-party fee-estimators (opens new window).
LDK's sample node implementation uses Bitcoin Core's fee estimation API here. (opens new window)
# Transaction Broadcasting
You can broadcast transactions in a few ways, using Bitcoin core or other external API's (opens new window)
LDK's sample node implementation uses Bitcoin Core's transaction broadcasting API here. (opens new window)