diff --git a/solana/programs/matching-engine/src/composite/mod.rs b/solana/programs/matching-engine/src/composite/mod.rs
index 9a62b0f0..1fd6ee79 100644
--- a/solana/programs/matching-engine/src/composite/mod.rs
+++ b/solana/programs/matching-engine/src/composite/mod.rs
@@ -97,7 +97,7 @@ pub struct CheckedCustodian<'info> {
         seeds = [Custodian::SEED_PREFIX],
         bump = Custodian::BUMP,
     )]
-    pub custodian: Account<'info, Custodian>,
+    pub custodian: Box<Account<'info, Custodian>>,
 }
 
 impl<'info> Deref for CheckedCustodian<'info> {
@@ -138,7 +138,7 @@ pub struct OwnerOnlyMut<'info> {
         seeds = [Custodian::SEED_PREFIX],
         bump = Custodian::BUMP,
     )]
-    pub custodian: Account<'info, Custodian>,
+    pub custodian: Box<Account<'info, Custodian>>,
 }
 
 #[derive(Accounts)]
@@ -171,7 +171,7 @@ pub struct AdminMut<'info> {
         seeds = [Custodian::SEED_PREFIX],
         bump = Custodian::BUMP,
     )]
-    pub custodian: Account<'info, Custodian>,
+    pub custodian: Box<Account<'info, Custodian>>,
 }
 
 #[derive(Accounts)]
@@ -195,7 +195,7 @@ pub struct LocalTokenRouter<'info> {
         associated_token::mint = common::USDC_MINT,
         associated_token::authority = token_router_emitter,
     )]
-    pub token_router_mint_recipient: Account<'info, token::TokenAccount>,
+    pub token_router_mint_recipient: Box<Account<'info, token::TokenAccount>>,
 }
 
 #[derive(Accounts)]
@@ -208,7 +208,7 @@ pub struct ExistingMutRouterEndpoint<'info> {
         ],
         bump = endpoint.bump,
     )]
-    pub endpoint: Account<'info, RouterEndpoint>,
+    pub endpoint: Box<Account<'info, RouterEndpoint>>,
 }
 
 impl<'info> Deref for ExistingMutRouterEndpoint<'info> {
@@ -644,7 +644,7 @@ pub struct ReserveFastFillSequence<'info> {
                 // This check makes sure that the auction account did not exist before this
                 // instruction was called.
                 require!(
-                    auction.vaa_hash == [0; 32],
+                    auction.vaa_hash == <[u8; 32]>::default(),
                     MatchingEngineError::AuctionExists,
                 );
 
diff --git a/solana/programs/matching-engine/src/events/auction_settled.rs b/solana/programs/matching-engine/src/events/auction_settled.rs
index bda0fd33..aa31d359 100644
--- a/solana/programs/matching-engine/src/events/auction_settled.rs
+++ b/solana/programs/matching-engine/src/events/auction_settled.rs
@@ -11,7 +11,7 @@ pub struct SettledTokenAccountInfo {
 #[derive(Debug)]
 pub struct AuctionSettled {
     /// The pubkey of the auction that was settled.
-    pub auction: Pubkey,
+    pub fast_vaa_hash: [u8; 32],
 
     /// If there was an active auction, this field will have the pubkey of the best offer token that
     /// was paid back and its balance after repayment.
diff --git a/solana/programs/matching-engine/src/events/auction_updated.rs b/solana/programs/matching-engine/src/events/auction_updated.rs
index 6ac2c6a9..3bd13f81 100644
--- a/solana/programs/matching-engine/src/events/auction_updated.rs
+++ b/solana/programs/matching-engine/src/events/auction_updated.rs
@@ -5,7 +5,7 @@ use anchor_lang::prelude::*;
 #[derive(Debug)]
 pub struct AuctionUpdated {
     pub config_id: u32,
-    pub auction: Pubkey,
+    pub fast_vaa_hash: [u8; 32],
     pub vaa: Option<Pubkey>,
     pub source_chain: u16,
     pub target_protocol: MessageProtocol,
diff --git a/solana/programs/matching-engine/src/events/fast_fill_redeemed.rs b/solana/programs/matching-engine/src/events/fast_fill_redeemed.rs
index 02c7057f..123b5b2d 100644
--- a/solana/programs/matching-engine/src/events/fast_fill_redeemed.rs
+++ b/solana/programs/matching-engine/src/events/fast_fill_redeemed.rs
@@ -1,7 +1,9 @@
 use anchor_lang::prelude::*;
 
+use crate::state::FastFillSeeds;
+
 #[event]
 pub struct FastFillRedeemed {
     pub prepared_by: Pubkey,
-    pub fast_fill: Pubkey,
+    pub fast_fill: FastFillSeeds,
 }
diff --git a/solana/programs/matching-engine/src/events/fast_fill_sequence_reserved.rs b/solana/programs/matching-engine/src/events/fast_fill_sequence_reserved.rs
index 41326b9f..bb07a6f2 100644
--- a/solana/programs/matching-engine/src/events/fast_fill_sequence_reserved.rs
+++ b/solana/programs/matching-engine/src/events/fast_fill_sequence_reserved.rs
@@ -4,5 +4,5 @@ use anchor_lang::prelude::*;
 #[event]
 pub struct FastFillSequenceReserved {
     pub fast_vaa_hash: [u8; 32],
-    pub fast_fill_seeds: FastFillSeeds,
+    pub fast_fill: FastFillSeeds,
 }
diff --git a/solana/programs/matching-engine/src/events/order_executed.rs b/solana/programs/matching-engine/src/events/order_executed.rs
index a5a7c07c..55edf8a6 100644
--- a/solana/programs/matching-engine/src/events/order_executed.rs
+++ b/solana/programs/matching-engine/src/events/order_executed.rs
@@ -4,7 +4,7 @@ use anchor_lang::prelude::*;
 #[event]
 #[derive(Debug)]
 pub struct OrderExecuted {
-    pub auction: Pubkey,
+    pub fast_vaa_hash: [u8; 32],
     pub vaa: Pubkey,
     pub source_chain: u16,
     pub target_protocol: MessageProtocol,
diff --git a/solana/programs/matching-engine/src/processor/auction/execute_fast_order/mod.rs b/solana/programs/matching-engine/src/processor/auction/execute_fast_order/mod.rs
index 8399d89c..935596c0 100644
--- a/solana/programs/matching-engine/src/processor/auction/execute_fast_order/mod.rs
+++ b/solana/programs/matching-engine/src/processor/auction/execute_fast_order/mod.rs
@@ -214,7 +214,7 @@ fn handle_execute_fast_order<'info>(
                 execute_penalty: if penalized { penalty.into() } else { None },
             },
             OrderExecuted {
-                auction: auction.key(),
+                fast_vaa_hash: auction.vaa_hash,
                 vaa: fast_vaa.key(),
                 source_chain: auction_info.source_chain,
                 target_protocol: auction.target_protocol,
diff --git a/solana/programs/matching-engine/src/processor/auction/offer/improve.rs b/solana/programs/matching-engine/src/processor/auction/offer/improve.rs
index a869fe8e..b99dc4d7 100644
--- a/solana/programs/matching-engine/src/processor/auction/offer/improve.rs
+++ b/solana/programs/matching-engine/src/processor/auction/offer/improve.rs
@@ -137,7 +137,7 @@ pub fn improve_offer(ctx: Context<ImproveOffer>, offer_price: u64) -> Result<()>
         // Emit event for auction participants to listen to.
         emit_cpi!(crate::utils::log_emit(crate::events::AuctionUpdated {
             config_id: info.config_id,
-            auction: auction.key(),
+            fast_vaa_hash: auction.vaa_hash,
             vaa: Default::default(),
             source_chain: info.source_chain,
             target_protocol: auction.target_protocol,
diff --git a/solana/programs/matching-engine/src/processor/auction/offer/place_initial/cctp.rs b/solana/programs/matching-engine/src/processor/auction/offer/place_initial/cctp.rs
index 9bd02637..fab8c53b 100644
--- a/solana/programs/matching-engine/src/processor/auction/offer/place_initial/cctp.rs
+++ b/solana/programs/matching-engine/src/processor/auction/offer/place_initial/cctp.rs
@@ -169,7 +169,7 @@ pub fn place_initial_offer_cctp(
     // Emit event for auction participants to listen to.
     emit_cpi!(crate::utils::log_emit(crate::events::AuctionUpdated {
         config_id: info.config_id,
-        auction: ctx.accounts.auction.key(),
+        fast_vaa_hash: ctx.accounts.auction.vaa_hash,
         vaa: ctx.accounts.fast_order_path.fast_vaa.key().into(),
         source_chain: info.source_chain,
         target_protocol: ctx.accounts.auction.target_protocol,
diff --git a/solana/programs/matching-engine/src/processor/auction/settle/complete.rs b/solana/programs/matching-engine/src/processor/auction/settle/complete.rs
index 22e680d6..f9249645 100644
--- a/solana/programs/matching-engine/src/processor/auction/settle/complete.rs
+++ b/solana/programs/matching-engine/src/processor/auction/settle/complete.rs
@@ -249,7 +249,7 @@ fn handle_settle_auction_complete(
     };
 
     emit_cpi!(crate::events::AuctionSettled {
-        auction: ctx.accounts.auction.key(),
+        fast_vaa_hash: ctx.accounts.auction.vaa_hash,
         best_offer_token: settled_best_offer_result,
         base_fee_token: settled_base_fee_result,
         with_execute: Default::default(),
diff --git a/solana/programs/matching-engine/src/processor/auction/settle/none/mod.rs b/solana/programs/matching-engine/src/processor/auction/settle/none/mod.rs
index 85acbde8..9c8233cc 100644
--- a/solana/programs/matching-engine/src/processor/auction/settle/none/mod.rs
+++ b/solana/programs/matching-engine/src/processor/auction/settle/none/mod.rs
@@ -84,7 +84,7 @@ fn settle_none_and_prepare_fill(accounts: SettleNoneAndPrepareFill<'_, '_>) -> R
     };
 
     let auction_settled_event = AuctionSettled {
-        auction: auction.key(),
+        fast_vaa_hash: auction.vaa_hash,
         best_offer_token: Default::default(),
         base_fee_token: crate::events::SettledTokenAccountInfo {
             key: fee_recipient_token.key(),
diff --git a/solana/programs/matching-engine/src/processor/fast_fill/complete.rs b/solana/programs/matching-engine/src/processor/fast_fill/complete.rs
index e27e14c2..c5afdd08 100644
--- a/solana/programs/matching-engine/src/processor/fast_fill/complete.rs
+++ b/solana/programs/matching-engine/src/processor/fast_fill/complete.rs
@@ -31,7 +31,7 @@ pub struct CompleteFastFill<'info> {
         bump = fast_fill.seeds.bump,
         constraint = !fast_fill.redeemed @ MatchingEngineError::FastFillAlreadyRedeemed,
     )]
-    fast_fill: Account<'info, FastFill>,
+    fast_fill: Box<Account<'info, FastFill>>,
 
     /// Only the registered local Token Router program can call this instruction. It is allowed to
     /// invoke this instruction by using its emitter (i.e. its Custodian account) as a signer. We
@@ -43,7 +43,7 @@ pub struct CompleteFastFill<'info> {
         mut,
         token::mint = local_custody_token.mint,
     )]
-    token_router_custody_token: Account<'info, token::TokenAccount>,
+    token_router_custody_token: Box<Account<'info, token::TokenAccount>>,
 
     #[account(
         constraint = {
@@ -84,7 +84,7 @@ pub fn complete_fast_fill(ctx: Context<CompleteFastFill>) -> Result<()> {
     // Emit event that the fast fill is redeemed. Listeners can close this account.
     emit_cpi!(crate::events::FastFillRedeemed {
         prepared_by: ctx.accounts.fast_fill.info.prepared_by,
-        fast_fill: ctx.accounts.fast_fill.key(),
+        fast_fill: ctx.accounts.fast_fill.seeds,
     });
 
     // Finally transfer to local token router's token account.
diff --git a/solana/programs/matching-engine/src/processor/fast_fill/reserve_sequence/mod.rs b/solana/programs/matching-engine/src/processor/fast_fill/reserve_sequence/mod.rs
index 4c214aeb..7cc3a906 100644
--- a/solana/programs/matching-engine/src/processor/fast_fill/reserve_sequence/mod.rs
+++ b/solana/programs/matching-engine/src/processor/fast_fill/reserve_sequence/mod.rs
@@ -81,6 +81,6 @@ fn set_reserved_sequence_data(
     // easily execute local orders.
     Ok(FastFillSequenceReserved {
         fast_vaa_hash,
-        fast_fill_seeds,
+        fast_fill: fast_fill_seeds,
     })
 }
diff --git a/solana/ts/src/idl/json/matching_engine.json b/solana/ts/src/idl/json/matching_engine.json
index 866b97b0..1900ecb7 100644
--- a/solana/ts/src/idl/json/matching_engine.json
+++ b/solana/ts/src/idl/json/matching_engine.json
@@ -3535,11 +3535,16 @@
         "kind": "struct",
         "fields": [
           {
-            "name": "auction",
+            "name": "fast_vaa_hash",
             "docs": [
               "The pubkey of the auction that was settled."
             ],
-            "type": "pubkey"
+            "type": {
+              "array": [
+                "u8",
+                32
+              ]
+            }
           },
           {
             "name": "best_offer_token",
@@ -3640,8 +3645,13 @@
             "type": "u32"
           },
           {
-            "name": "auction",
-            "type": "pubkey"
+            "name": "fast_vaa_hash",
+            "type": {
+              "array": [
+                "u8",
+                32
+              ]
+            }
           },
           {
             "name": "vaa",
@@ -3911,7 +3921,11 @@
           },
           {
             "name": "fast_fill",
-            "type": "pubkey"
+            "type": {
+              "defined": {
+                "name": "FastFillSeeds"
+              }
+            }
           }
         ]
       }
@@ -3973,7 +3987,7 @@
             }
           },
           {
-            "name": "fast_fill_seeds",
+            "name": "fast_fill",
             "type": {
               "defined": {
                 "name": "FastFillSeeds"
@@ -4115,8 +4129,13 @@
         "kind": "struct",
         "fields": [
           {
-            "name": "auction",
-            "type": "pubkey"
+            "name": "fast_vaa_hash",
+            "type": {
+              "array": [
+                "u8",
+                32
+              ]
+            }
           },
           {
             "name": "vaa",
diff --git a/solana/ts/src/idl/ts/matching_engine.ts b/solana/ts/src/idl/ts/matching_engine.ts
index 9406379e..7ccf19c6 100644
--- a/solana/ts/src/idl/ts/matching_engine.ts
+++ b/solana/ts/src/idl/ts/matching_engine.ts
@@ -3541,11 +3541,16 @@ export type MatchingEngine = {
         "kind": "struct",
         "fields": [
           {
-            "name": "auction",
+            "name": "fastVaaHash",
             "docs": [
               "The pubkey of the auction that was settled."
             ],
-            "type": "pubkey"
+            "type": {
+              "array": [
+                "u8",
+                32
+              ]
+            }
           },
           {
             "name": "bestOfferToken",
@@ -3646,8 +3651,13 @@ export type MatchingEngine = {
             "type": "u32"
           },
           {
-            "name": "auction",
-            "type": "pubkey"
+            "name": "fastVaaHash",
+            "type": {
+              "array": [
+                "u8",
+                32
+              ]
+            }
           },
           {
             "name": "vaa",
@@ -3917,7 +3927,11 @@ export type MatchingEngine = {
           },
           {
             "name": "fastFill",
-            "type": "pubkey"
+            "type": {
+              "defined": {
+                "name": "fastFillSeeds"
+              }
+            }
           }
         ]
       }
@@ -3979,7 +3993,7 @@ export type MatchingEngine = {
             }
           },
           {
-            "name": "fastFillSeeds",
+            "name": "fastFill",
             "type": {
               "defined": {
                 "name": "fastFillSeeds"
@@ -4121,8 +4135,13 @@ export type MatchingEngine = {
         "kind": "struct",
         "fields": [
           {
-            "name": "auction",
-            "type": "pubkey"
+            "name": "fastVaaHash",
+            "type": {
+              "array": [
+                "u8",
+                32
+              ]
+            }
           },
           {
             "name": "vaa",
diff --git a/solana/ts/src/matchingEngine/index.ts b/solana/ts/src/matchingEngine/index.ts
index 7c37d21d..74422e34 100644
--- a/solana/ts/src/matchingEngine/index.ts
+++ b/solana/ts/src/matchingEngine/index.ts
@@ -147,7 +147,7 @@ export type SettledTokenAccountInfo = {
 };
 
 export type AuctionSettled = {
-    auction: PublicKey;
+    fastVaaHash: Array<number>;
     bestOfferToken: SettledTokenAccountInfo | null;
     baseFeeToken: SettledTokenAccountInfo | null;
     withExecute: MessageProtocol | null;
@@ -155,7 +155,7 @@ export type AuctionSettled = {
 
 export type AuctionUpdated = {
     configId: number;
-    auction: PublicKey;
+    fastVaaHash: Array<number>;
     vaa: PublicKey | null;
     sourceChain: number;
     targetProtocol: MessageProtocol;
@@ -169,7 +169,7 @@ export type AuctionUpdated = {
 };
 
 export type OrderExecuted = {
-    auction: PublicKey;
+    fastVaaHash: Array<number>;
     vaa: PublicKey;
     targetProtocol: MessageProtocol;
 };
@@ -190,12 +190,12 @@ export type LocalFastOrderFilled = {
 
 export type FastFillSequenceReserved = {
     fastVaaHash: Array<number>;
-    fastFillSeeds: FastFillSeeds;
+    fastFill: FastFillSeeds;
 };
 
 export type FastFillRedeemed = {
     preparedBy: PublicKey;
-    fastFill: PublicKey;
+    fastFill: FastFillSeeds;
 };
 
 export type MatchingEngineEvent = {