diff --git a/contracts/src/emergency/sequencer_uptime_feed.cairo b/contracts/src/emergency/sequencer_uptime_feed.cairo
index c1784298c..1a2c75c25 100644
--- a/contracts/src/emergency/sequencer_uptime_feed.cairo
+++ b/contracts/src/emergency/sequencer_uptime_feed.cairo
@@ -79,11 +79,13 @@ mod SequencerUptimeFeed {
     #[derive(Drop, starknet::Event)]
     struct RoundUpdated {
         status: u128,
+        #[key]
         updated_at: u64
     }
 
     #[derive(Drop, starknet::Event)]
     struct NewRound {
+        #[key]
         round_id: u128,
         #[key]
         started_by: EthAddress,
@@ -93,21 +95,27 @@ mod SequencerUptimeFeed {
     #[derive(Drop, starknet::Event)]
     struct AnswerUpdated {
         current: u128,
+        #[key]
         round_id: u128,
+        #[key]
         timestamp: u64
     }
 
     #[derive(Drop, starknet::Event)]
     struct UpdateIgnored {
         latest_status: u128,
+        #[key]
         latest_timestamp: u64,
         incoming_status: u128,
+        #[key]
         incoming_timestamp: u64
     }
 
     #[derive(Drop, starknet::Event)]
     struct L1SenderTransferred {
+        #[key]
         from_address: EthAddress,
+        #[key]
         to_address: EthAddress
     }
 
diff --git a/contracts/src/libraries/access_control.cairo b/contracts/src/libraries/access_control.cairo
index d9d872bb9..b0a910d55 100644
--- a/contracts/src/libraries/access_control.cairo
+++ b/contracts/src/libraries/access_control.cairo
@@ -37,11 +37,13 @@ mod AccessControlComponent {
 
     #[derive(Drop, starknet::Event)]
     struct AddedAccess {
+        #[key]
         user: ContractAddress
     }
 
     #[derive(Drop, starknet::Event)]
     struct RemovedAccess {
+        #[key]
         user: ContractAddress
     }
 
diff --git a/contracts/src/libraries/token/erc677.cairo b/contracts/src/libraries/token/erc677.cairo
index 6b23abc77..20fd6c54a 100644
--- a/contracts/src/libraries/token/erc677.cairo
+++ b/contracts/src/libraries/token/erc677.cairo
@@ -42,7 +42,9 @@ mod ERC677Component {
 
     #[derive(Drop, starknet::Event)]
     struct TransferAndCall {
+        #[key]
         from: ContractAddress,
+        #[key]
         to: ContractAddress,
         value: u256,
         data: Array<felt252>
diff --git a/contracts/src/libraries/upgradeable.cairo b/contracts/src/libraries/upgradeable.cairo
index 388581be6..6b9e6af73 100644
--- a/contracts/src/libraries/upgradeable.cairo
+++ b/contracts/src/libraries/upgradeable.cairo
@@ -10,6 +10,7 @@ trait IUpgradeable<TContractState> {
 
 #[derive(Drop, starknet::Event)]
 struct Upgraded {
+    #[key]
     new_impl: ClassHash
 }
 
diff --git a/contracts/src/multisig.cairo b/contracts/src/multisig.cairo
index 5f78e4796..b1422df45 100644
--- a/contracts/src/multisig.cairo
+++ b/contracts/src/multisig.cairo
@@ -107,36 +107,47 @@ mod Multisig {
 
     #[derive(Drop, starknet::Event)]
     struct TransactionSubmitted {
+        #[key]
         signer: ContractAddress,
+        #[key]
         nonce: u128,
+        #[key]
         to: ContractAddress
     }
 
     #[derive(Drop, starknet::Event)]
     struct TransactionConfirmed {
+        #[key]
         signer: ContractAddress,
+        #[key]
         nonce: u128
     }
 
     #[derive(Drop, starknet::Event)]
     struct ConfirmationRevoked {
+        #[key]
         signer: ContractAddress,
+        #[key]
         nonce: u128
     }
 
     #[derive(Drop, starknet::Event)]
     struct TransactionExecuted {
+        #[key]
         executor: ContractAddress,
+        #[key]
         nonce: u128
     }
 
     #[derive(Drop, starknet::Event)]
     struct SignersSet {
+        #[key]
         signers: Array<ContractAddress>
     }
 
     #[derive(Drop, starknet::Event)]
     struct ThresholdSet {
+        #[key]
         threshold: usize
     }
 
diff --git a/contracts/src/ocr2/aggregator.cairo b/contracts/src/ocr2/aggregator.cairo
index 00456383f..f5ca342cb 100644
--- a/contracts/src/ocr2/aggregator.cairo
+++ b/contracts/src/ocr2/aggregator.cairo
@@ -244,8 +244,10 @@ mod Aggregator {
 
     #[derive(Drop, starknet::Event)]
     struct NewTransmission {
+        #[key]
         round_id: u128,
         answer: u128,
+        #[key]
         transmitter: ContractAddress,
         observation_timestamp: u64,
         observers: felt252,
@@ -418,7 +420,9 @@ mod Aggregator {
 
     #[derive(Drop, starknet::Event)]
     struct ConfigSet {
+        #[key]
         previous_config_block_number: u64,
+        #[key]
         latest_config_digest: felt252,
         config_count: u64,
         oracles: Array<OracleConfig>,
@@ -848,7 +852,9 @@ mod Aggregator {
 
     #[derive(Drop, starknet::Event)]
     struct BillingAccessControllerSet {
+        #[key]
         old_controller: ContractAddress,
+        #[key]
         new_controller: ContractAddress,
     }
 
@@ -859,6 +865,7 @@ mod Aggregator {
 
     #[derive(Drop, starknet::Event)]
     struct OraclePaid {
+        #[key]
         transmitter: ContractAddress,
         payee: ContractAddress,
         amount: u256,
@@ -867,7 +874,9 @@ mod Aggregator {
 
     #[derive(Drop, starknet::Event)]
     struct LinkTokenSet {
+        #[key]
         old_link_token: ContractAddress,
+        #[key]
         new_link_token: ContractAddress
     }
 
@@ -1150,15 +1159,21 @@ mod Aggregator {
 
     #[derive(Drop, starknet::Event)]
     struct PayeeshipTransferRequested {
+        #[key]
         transmitter: ContractAddress,
+        #[key]
         current: ContractAddress,
+        #[key]
         proposed: ContractAddress,
     }
 
     #[derive(Drop, starknet::Event)]
     struct PayeeshipTransferred {
+        #[key]
         transmitter: ContractAddress,
+        #[key]
         previous: ContractAddress,
+        #[key]
         current: ContractAddress,
     }