diff --git a/proto/executionapis/astria/bundle/v1alpha1/bundle.proto b/proto/executionapis/astria/bundle/v1alpha1/bundle.proto
index f4d350803f..08c8b461ea 100644
--- a/proto/executionapis/astria/bundle/v1alpha1/bundle.proto
+++ b/proto/executionapis/astria/bundle/v1alpha1/bundle.proto
@@ -24,6 +24,22 @@ message Bundle {
   bytes prev_rollup_block_hash = 4;
 }
 
+// The AuctionResult message is submitted by the Auctioneer to the rollup as a
+// `RollupDataSubmission` on the sequencer.
+// The rollup will verify the signature and public key against its configuration,
+// then unbundle the body into rollup transactions and execute them first in the
+// block.
+message AuctionResult {
+    // The Ed25519 signature of the Auctioneer, to be verified against config by the
+    // rollup.
+    bytes signature = 1;
+    // The Ed25519 public key of the Auctioneer, to be verified against config by the
+    // rollup.
+    bytes public_key = 2;
+    // The bundle that was allocated the winning slot by the Auctioneer.
+    Bundle allocation = 3;
+}
+
 message GetBundleStreamResponse {
   Bundle bundle = 1;
 }