diff --git a/noir-projects/aztec-nr/aztec/src/ephemeral/mod.nr b/noir-projects/aztec-nr/aztec/src/ephemeral/mod.nr
index 9e4efde8cd5a..35be7114e025 100644
--- a/noir-projects/aztec-nr/aztec/src/ephemeral/mod.nr
+++ b/noir-projects/aztec-nr/aztec/src/ephemeral/mod.nr
@@ -1,5 +1,6 @@
 use crate::oracle::ephemeral;
 use crate::protocol::traits::{Deserialize, Serialize};
+use crate::protocol::utils::{reader::Reader, writer::Writer};
 
 /// A dynamically sized array that exists only during a single contract call frame.
 ///
@@ -101,6 +102,34 @@ impl<T> EphemeralArray<T> {
     }
 }
 
+/// Serializes an `EphemeralArray` as its slot identifier, allowing oracle function signatures to use
+/// `EphemeralArray<T>` instead of opaque `Field` slots.
+impl<T> Serialize for EphemeralArray<T> {
+    let N: u32 = 1;
+
+    fn serialize(self) -> [Field; Self::N] {
+        [self.slot]
+    }
+
+    fn stream_serialize<let K: u32>(self, writer: &mut Writer<K>) {
+        writer.write(self.slot);
+    }
+}
+
+/// Deserializes a single Field into an `EphemeralArray` handle, treating the field value as the slot identifier.
+/// This is the inverse of [`Serialize`].
+impl<T> Deserialize for EphemeralArray<T> {
+    let N: u32 = 1;
+
+    fn deserialize(fields: [Field; Self::N]) -> Self {
+        Self { slot: fields[0] }
+    }
+
+    fn stream_deserialize<let K: u32>(reader: &mut Reader<K>) -> Self {
+        Self { slot: reader.read() }
+    }
+}
+
 mod test {
     use crate::test::helpers::test_environment::TestEnvironment;
     use crate::test::mocks::MockStruct;
diff --git a/noir-projects/aztec-nr/aztec/src/messages/processing/mod.nr b/noir-projects/aztec-nr/aztec/src/messages/processing/mod.nr
index a793fe5df64f..df716e43ccbe 100644
--- a/noir-projects/aztec-nr/aztec/src/messages/processing/mod.nr
+++ b/noir-projects/aztec-nr/aztec/src/messages/processing/mod.nr
@@ -137,8 +137,8 @@ pub unconstrained fn enqueue_event_for_validation(
 /// API (PXE::getPrivateEvents).
 pub unconstrained fn validate_and_store_enqueued_notes_and_events(scope: AztecAddress) {
     message_processing::validate_and_store_enqueued_notes_and_events(
-        NOTE_VALIDATION_REQUESTS_ARRAY_BASE_SLOT,
-        EVENT_VALIDATION_REQUESTS_ARRAY_BASE_SLOT,
+        EphemeralArray::at(NOTE_VALIDATION_REQUESTS_ARRAY_BASE_SLOT),
+        EphemeralArray::at(EVENT_VALIDATION_REQUESTS_ARRAY_BASE_SLOT),
         MAX_NOTE_PACKED_LEN as Field,
         MAX_EVENT_SERIALIZED_LEN as Field,
         scope,
diff --git a/noir-projects/aztec-nr/aztec/src/oracle/message_processing.nr b/noir-projects/aztec-nr/aztec/src/oracle/message_processing.nr
index 7a2f2f5a666d..876f55dd9e96 100644
--- a/noir-projects/aztec-nr/aztec/src/oracle/message_processing.nr
+++ b/noir-projects/aztec-nr/aztec/src/oracle/message_processing.nr
@@ -1,7 +1,8 @@
 use crate::ephemeral::EphemeralArray;
 use crate::messages::processing::{
+    event_validation_request::EventValidationRequest,
     log_retrieval_request::LogRetrievalRequest, log_retrieval_response::LogRetrievalResponse, MessageContext,
-    pending_tagged_log::PendingTaggedLog,
+    NoteValidationRequest, pending_tagged_log::PendingTaggedLog,
 };
 use crate::protocol::address::AztecAddress;
 use crate::protocol::blob_data::TxEffect;
@@ -9,24 +10,23 @@ use crate::protocol::blob_data::TxEffect;
 /// Finds new private logs that may have been sent to all registered accounts in PXE in the current contract and
 /// returns them in an ephemeral array with an oracle-allocated base slot.
 pub(crate) unconstrained fn get_pending_tagged_logs(scope: AztecAddress) -> EphemeralArray<PendingTaggedLog> {
-    let result_slot = get_pending_tagged_logs_oracle(scope);
-    EphemeralArray::at(result_slot)
+    get_pending_tagged_logs_oracle(scope)
 }
 
 #[oracle(aztec_utl_getPendingTaggedLogs)]
-unconstrained fn get_pending_tagged_logs_oracle(scope: AztecAddress) -> Field {}
+unconstrained fn get_pending_tagged_logs_oracle(scope: AztecAddress) -> EphemeralArray<PendingTaggedLog> {}
 
 /// Validates note/event requests stored in ephemeral arrays.
 pub(crate) unconstrained fn validate_and_store_enqueued_notes_and_events(
-    note_validation_requests_array_slot: Field,
-    event_validation_requests_array_slot: Field,
+    note_validation_requests: EphemeralArray<NoteValidationRequest>,
+    event_validation_requests: EphemeralArray<EventValidationRequest>,
     max_note_packed_len: Field,
     max_event_serialized_len: Field,
     scope: AztecAddress,
 ) {
     validate_and_store_enqueued_notes_and_events_oracle(
-        note_validation_requests_array_slot,
-        event_validation_requests_array_slot,
+        note_validation_requests,
+        event_validation_requests,
         max_note_packed_len,
         max_event_serialized_len,
         scope,
@@ -35,8 +35,8 @@ pub(crate) unconstrained fn validate_and_store_enqueued_notes_and_events(
 
 #[oracle(aztec_utl_validateAndStoreEnqueuedNotesAndEvents)]
 unconstrained fn validate_and_store_enqueued_notes_and_events_oracle(
-    note_validation_requests_array_slot: Field,
-    event_validation_requests_array_slot: Field,
+    note_validation_requests: EphemeralArray<NoteValidationRequest>,
+    event_validation_requests: EphemeralArray<EventValidationRequest>,
     max_note_packed_len: Field,
     max_event_serialized_len: Field,
     scope: AztecAddress,
@@ -46,23 +46,25 @@ unconstrained fn validate_and_store_enqueued_notes_and_events_oracle(
 pub(crate) unconstrained fn get_logs_by_tag(
     requests: EphemeralArray<LogRetrievalRequest>,
 ) -> EphemeralArray<Option<LogRetrievalResponse>> {
-    let response_slot = get_logs_by_tag_oracle(requests.slot);
-    EphemeralArray::at(response_slot)
+    get_logs_by_tag_oracle(requests)
 }
 
 #[oracle(aztec_utl_getLogsByTag)]
-unconstrained fn get_logs_by_tag_oracle(request_array_slot: Field) -> Field {}
+unconstrained fn get_logs_by_tag_oracle(
+    requests: EphemeralArray<LogRetrievalRequest>,
+) -> EphemeralArray<Option<LogRetrievalResponse>> {}
 
 /// Resolves message contexts for tx hashes in an ephemeral request array and returns a response ephemeral array.
 pub(crate) unconstrained fn get_message_contexts_by_tx_hash(
     requests: EphemeralArray<Field>,
 ) -> EphemeralArray<Option<MessageContext>> {
-    let response_slot = get_message_contexts_by_tx_hash_oracle(requests.slot);
-    EphemeralArray::at(response_slot)
+    get_message_contexts_by_tx_hash_oracle(requests)
 }
 
 #[oracle(aztec_utl_getMessageContextsByTxHash)]
-unconstrained fn get_message_contexts_by_tx_hash_oracle(request_array_slot: Field) -> Field {}
+unconstrained fn get_message_contexts_by_tx_hash_oracle(
+    requests: EphemeralArray<Field>,
+) -> EphemeralArray<Option<MessageContext>> {}
 
 /// Fetches all effects of a settled transaction by its hash.
 pub unconstrained fn get_tx_effect(tx_hash: Field) -> Option<TxEffect> {
diff --git a/noir-projects/aztec-nr/aztec/src/oracle/shared_secret.nr b/noir-projects/aztec-nr/aztec/src/oracle/shared_secret.nr
index 4785328f9d71..cbcd9390d71a 100644
--- a/noir-projects/aztec-nr/aztec/src/oracle/shared_secret.nr
+++ b/noir-projects/aztec-nr/aztec/src/oracle/shared_secret.nr
@@ -7,9 +7,9 @@ global GET_SHARED_SECRETS_REQUEST_SLOT: Field =
 #[oracle(aztec_utl_getSharedSecrets)]
 unconstrained fn get_shared_secrets_oracle(
     address: AztecAddress,
-    eph_pks_slot: Field,
+    eph_pks: EphemeralArray<Point>,
     contract_address: AztecAddress,
-) -> Field {}
+) -> EphemeralArray<Field> {}
 
 /// Convenience wrapper around [`get_shared_secrets`] for a single ephemeral public key.
 pub unconstrained fn get_shared_secret(
@@ -48,8 +48,7 @@ pub unconstrained fn get_shared_secrets<let N: u32>(
         EphemeralArray::at(GET_SHARED_SECRETS_REQUEST_SLOT).clear();
     eph_pks.for_each(|pk| request_array.push(pk));
 
-    let response_slot = get_shared_secrets_oracle(address, request_array.slot, contract_address);
-    let response_array: EphemeralArray<Field> = EphemeralArray::at(response_slot);
+    let response_array = get_shared_secrets_oracle(address, request_array, contract_address);
     assert(
         response_array.len() == eph_pks.len(),
         "get_shared_secrets: response length does not match request length",