--- a/pallets/evm-contract-helpers/src/eth.rs
+++ b/pallets/evm-contract-helpers/src/eth.rs
@@ -46,10 +46,18 @@
 where
 	T::AccountId: AsRef<[u8]>,
 {
+	/// Get contract ovner
+	/// 
+	/// @param Contract_address contract for which the owner is being determined.
+	/// @return Contract owner.
 	fn contract_owner(&self, contract_address: address) -> Result<address> {
 		Ok(<Owner<T>>::get(contract_address))
 	}
 
+	/// Set sponsor.
+	/// 
+	/// @param contract_address Contract for which a sponsor is being established.
+	/// @param sponsor User address who set as pending sponsor.
 	fn set_sponsor(
 		&mut self,
 		caller: caller,
@@ -65,12 +73,21 @@
 		Ok(())
 	}
 
+	/// Confirm sponsorship.
+	/// 
+	/// @dev Caller must be same that set via [`set_sponsor`].
+	/// 
+	/// @param contract_address Сontract for which need to confirm sponsorship.
 	fn confirm_sponsorship(&mut self, caller: caller, contract_address: address) -> Result<void> {
 		Pallet::<T>::confirm_sponsorship(&T::CrossAccountId::from_eth(caller), contract_address)
 			.map_err(dispatch_to_evm::<T>)?;
 		Ok(())
 	}
 
+	/// Get current sponsor.
+	/// 
+	/// @param contract_address The contract for which a sponsor is requested.
+	/// @return Tuble with sponsor address and his substrate mirror. If there is no confirmed sponsor error "Contract has no sponsor" throw.
 	fn get_sponsor(&self, contract_address: address) -> Result<(address, uint256)> {
 		let sponsor =
 			Pallet::<T>::get_sponsor(contract_address).ok_or("Contract has no sponsor")?;
@@ -78,10 +95,18 @@
 		Ok((*sponsor.as_eth(), sponsor_sub))
 	}
 
+	/// Check tat contract has confirmed sponsor.
+	/// 
+	/// @param contract_address The contract for which the presence of a confirmed sponsor is checked.
+	/// @return **true** if contract has confirmed sponsor.
 	fn has_sponsor(&self, contract_address: address) -> Result<bool> {
 		Ok(Pallet::<T>::get_sponsor(contract_address).is_some())
 	}
 
+	/// Check tat contract has pending sponsor.
+	/// 
+	/// @param contract_address The contract for which the presence of a pending sponsor is checked.
+	/// @return **true** if contract has pending sponsor.
 	fn has_pending_sponsor(&self, contract_address: address) -> Result<bool> {
 		Ok(match Sponsoring::<T>::get(contract_address) {
 			SponsorshipState::Disabled | SponsorshipState::Confirmed(_) => false,
--- a/pallets/evm-contract-helpers/src/lib.rs
+++ b/pallets/evm-contract-helpers/src/lib.rs
@@ -101,6 +101,11 @@
 		OnEmpty = T::DefaultSponsoringRateLimit,
 	>;
 
+	/// Storage for last sponsored block.
+	/// 
+	/// * **Key1** - contract address.
+	/// * **Key2** - sponsored user address.
+	/// * **Value** - last sponsored block number.
 	#[pallet::storage]
 	pub(super) type SponsorBasket<T: Config> = StorageDoubleMap<
 		Hasher1 = Twox128,
@@ -151,6 +156,14 @@
 	}
 
 	impl<T: Config> Pallet<T> {
+		/// Get contract owner.
+		pub fn contract_owner(contract: H160) -> H160 {
+			<Owner<T>>::get(contract)
+		}
+		
+		/// Set `sponsor` for `contract`. 
+		/// 
+		/// `sender` must be owner of contract.
 		pub fn set_sponsor(
 			sender: &T::CrossAccountId,
 			contract: H160,
@@ -164,6 +177,9 @@
 			Ok(())
 		}
 
+		/// Confirm sponsorship.
+		/// 
+		/// `sender` must be same that set via [`set_sponsor`].
 		pub fn confirm_sponsorship(sender: &T::CrossAccountId, contract: H160) -> DispatchResult {
 			match Sponsoring::<T>::get(contract) {
 				SponsorshipState::Unconfirmed(sponsor) => {
@@ -181,6 +197,7 @@
 			}
 		}
 
+		/// Get sponsor.
 		pub fn get_sponsor(contract: H160) -> Option<T::CrossAccountId> {
 			match Sponsoring::<T>::get(contract) {
 				SponsorshipState::Disabled | SponsorshipState::Unconfirmed(_) => None,
@@ -224,12 +241,6 @@
 		pub fn ensure_owner(contract: H160, user: H160) -> DispatchResult {
 			ensure!(<Owner<T>>::get(&contract) == user, Error::<T>::NoPermission);
 			Ok(())
-		}
-	}
-
-	impl<T: Config> Pallet<T> {
-		pub fn contract_owner(contract: H160) -> H160 {
-			<Owner<T>>::get(contract)
 		}
 	}
 }