diff --git a/api/src/event.rs b/api/src/event.rs
index 7628a5c..c97692d 100644
--- a/api/src/event.rs
+++ b/api/src/event.rs
@@ -5,6 +5,9 @@ use crate::state::SwapDirection;
 #[repr(C)]
 #[derive(Clone, Copy, Debug, Default, PartialEq, Pod, Zeroable)]
 pub struct SwapEvent {
+    /// The authority of the swap.
+    pub authority: [u8; 32],
+
     /// The block id.
     pub block_id: u64,
 
diff --git a/api/src/state/market/buy_exact_in.rs b/api/src/state/market/buy_exact_in.rs
index 4456c17..d2c878a 100644
--- a/api/src/state/market/buy_exact_in.rs
+++ b/api/src/state/market/buy_exact_in.rs
@@ -1,3 +1,5 @@
+use steel::Pubkey;
+
 use crate::error::OreError;
 
 use super::{Market, SwapDirection, TokenType, VirtualLimitOrder};
@@ -52,6 +54,7 @@ impl Market {
         // Produce swap result.
         let base_out = base_via_ask + base_via_curve;
         let swap_event = SwapEvent {
+            authority: [0; 32],
             block_id: 0,
             direction: SwapDirection::Buy as u64,
             base_to_transfer: base_out as u64,
diff --git a/api/src/state/market/buy_exact_out.rs b/api/src/state/market/buy_exact_out.rs
index eed021d..4414aff 100644
--- a/api/src/state/market/buy_exact_out.rs
+++ b/api/src/state/market/buy_exact_out.rs
@@ -57,6 +57,7 @@ impl Market {
 
         // Produce swap result.
         let swap_event = SwapEvent {
+            authority: [0; 32],
             block_id: 0,
             direction: SwapDirection::Buy as u64,
             base_to_transfer: base_out as u64,
diff --git a/api/src/state/market/sell_exact_in.rs b/api/src/state/market/sell_exact_in.rs
index 04c2f4a..70447de 100644
--- a/api/src/state/market/sell_exact_in.rs
+++ b/api/src/state/market/sell_exact_in.rs
@@ -61,6 +61,7 @@ impl Market {
         // Produce swap result.
         let quote_out = quote_via_bid + quote_via_curve;
         let swap_event = SwapEvent {
+            authority: [0; 32],
             block_id: 0,
             direction: SwapDirection::Sell as u64,
             base_to_transfer: base_in as u64,
diff --git a/api/src/state/market/sell_exact_out.rs b/api/src/state/market/sell_exact_out.rs
index fbdb945..e947641 100644
--- a/api/src/state/market/sell_exact_out.rs
+++ b/api/src/state/market/sell_exact_out.rs
@@ -59,6 +59,7 @@ impl Market {
 
         // Produce swap result.
         let swap_event = SwapEvent {
+            authority: [0; 32],
             block_id: 0,
             direction: SwapDirection::Sell as u64,
             base_to_transfer: base_in as u64,
diff --git a/program/src/swap.rs b/program/src/swap.rs
index 4c73059..a1a0a9b 100644
--- a/program/src/swap.rs
+++ b/program/src/swap.rs
@@ -100,6 +100,7 @@ pub fn process_swap(accounts: &[AccountInfo<'_>], data: &[u8]) -> ProgramResult
 
     // Update market state.
     let mut swap_result = market.swap(amount, direction, precision, clock)?;
+    swap_result.authority = signer_info.key.to_bytes();
     swap_result.block_id = block.id;
     swap_result.log_return();