Add warning regarding remote fee estimators

diff --git a/lightning/src/chain/chaininterface.rs b/lightning/src/chain/chaininterface.rs
index 54cd3381209d2579667ee33e1c2de8a89c86a420..6aed834c1436860633a75cc07c95c85370fd946b 100644 (file)
--- a/lightning/src/chain/chaininterface.rs
+++ b/lightning/src/chain/chaininterface.rs
@@ -59,6 +59,11 @@ pub enum ConfirmationTarget {
 /// A trait which should be implemented to provide feerate information on a number of time
 /// horizons.
 ///
+/// If access to a local mempool is not feasible, feerate estimates should be fetched from a set of
+/// third-parties hosting them. Note that this enables them to affect the propagation of your
+/// pre-signed transactions at any time and therefore endangers the safety of channels funds. It
+/// should be considered carefully as a deployment.
+///
 /// Note that all of the functions implemented here *must* be reentrant-safe (obviously - they're
 /// called from inside the library in response to chain events, P2P events, or timer events).
 pub trait FeeEstimator {