diff --git a/crates/topos-tce-api/tests/grpc/certificate_precedence.rs b/crates/topos-tce-api/tests/grpc/certificate_precedence.rs
new file mode 100644
index 000000000..676bf4dcc
--- /dev/null
+++ b/crates/topos-tce-api/tests/grpc/certificate_precedence.rs
@@ -0,0 +1,122 @@
+use base64ct::{Base64, Encoding};
+use rstest::rstest;
+use std::sync::Arc;
+use test_log::test;
+use tokio_stream::Stream;
+use topos_api::grpc::tce::v1::{GetLastPendingCertificatesRequest, LastPendingCertificate};
+use topos_core::uci::Certificate;
+use topos_tce_api::RuntimeEvent;
+use topos_test_sdk::{
+    certificates::create_certificate_chain,
+    constants::{SOURCE_SUBNET_ID_1, TARGET_SUBNET_ID_1},
+    storage::{create_fullnode_store, create_validator_store, storage_client},
+    tce::public_api::{broadcast_stream, create_public_api, PublicApiContext},
+};
+
+use topos_tce_storage::{types::CertificateDeliveredWithPositions, validator::ValidatorStore};
+
+#[rstest]
+#[test(tokio::test)]
+async fn fetch_latest_pending_certificates() {
+    let fullnode_store = create_fullnode_store(vec![]).await;
+    let validator_store: Arc<ValidatorStore> =
+        create_validator_store(vec![], futures::future::ready(fullnode_store.clone())).await;
+
+    let (tx, rx): (
+        _,
+        tokio::sync::broadcast::Receiver<CertificateDeliveredWithPositions>,
+    ) = tokio::sync::broadcast::channel(10);
+
+    let (mut api_context, _) = create_public_api(
+        storage_client(vec![]),
+        broadcast_stream(),
+        futures::future::ready(validator_store.clone()),
+    )
+    .await;
+    let mut client = api_context.api_client;
+    let certificates = create_certificate_chain(SOURCE_SUBNET_ID_1, &[TARGET_SUBNET_ID_1], 2);
+
+    let expected = certificates[1].certificate.clone();
+
+    assert!(validator_store
+        .insert_pending_certificate(&certificates[1].certificate)
+        .unwrap()
+        .is_none());
+
+    assert!(validator_store
+        .insert_pending_certificate(&certificates[0].certificate)
+        .unwrap()
+        .is_some());
+
+    let mut res = client
+        .get_last_pending_certificates(GetLastPendingCertificatesRequest {
+            subnet_ids: vec![SOURCE_SUBNET_ID_1.into()],
+        })
+        .await
+        .unwrap()
+        .into_inner();
+
+    let res: LastPendingCertificate = res
+        .last_pending_certificate
+        .remove(&Base64::encode_string(SOURCE_SUBNET_ID_1.as_array()))
+        .unwrap();
+
+    let res: Certificate = res.value.unwrap().try_into().unwrap();
+
+    assert_eq!(res, expected);
+}
+
+#[rstest]
+#[test(tokio::test)]
+async fn fetch_latest_pending_certificates_with_conflicts() {
+    let fullnode_store = create_fullnode_store(vec![]).await;
+    let validator_store: Arc<ValidatorStore> =
+        create_validator_store(vec![], futures::future::ready(fullnode_store.clone())).await;
+
+    let (tx, rx): (
+        _,
+        tokio::sync::broadcast::Receiver<CertificateDeliveredWithPositions>,
+    ) = tokio::sync::broadcast::channel(10);
+
+    let (mut api_context, _) = create_public_api(
+        storage_client(vec![]),
+        broadcast_stream(),
+        futures::future::ready(validator_store.clone()),
+    )
+    .await;
+    let mut client = api_context.api_client;
+    let mut certificates = create_certificate_chain(SOURCE_SUBNET_ID_1, &[TARGET_SUBNET_ID_1], 3);
+
+    certificates[2].certificate.prev_id = certificates[1].certificate.prev_id;
+
+    let expected = certificates[2].certificate.clone();
+
+    for certificate in certificates.iter().skip(1) {
+        assert!(validator_store
+            .insert_pending_certificate(&certificate.certificate)
+            .unwrap()
+            .is_none());
+    }
+
+    assert!(validator_store
+        .insert_pending_certificate(&certificates[0].certificate)
+        .unwrap()
+        .is_some());
+
+    let mut res = client
+        .get_last_pending_certificates(GetLastPendingCertificatesRequest {
+            subnet_ids: vec![SOURCE_SUBNET_ID_1.into()],
+        })
+        .await
+        .unwrap()
+        .into_inner();
+
+    let res: LastPendingCertificate = res
+        .last_pending_certificate
+        .remove(&Base64::encode_string(SOURCE_SUBNET_ID_1.as_array()))
+        .unwrap();
+
+    let res: Certificate = res.value.unwrap().try_into().unwrap();
+
+    assert_eq!(res, expected);
+}
diff --git a/crates/topos-tce-api/tests/grpc/mod.rs b/crates/topos-tce-api/tests/grpc/mod.rs
new file mode 100644
index 000000000..769ba1e4e
--- /dev/null
+++ b/crates/topos-tce-api/tests/grpc/mod.rs
@@ -0,0 +1 @@
+mod certificate_precedence;
diff --git a/crates/topos-tce-api/tests/runtime.rs b/crates/topos-tce-api/tests/runtime.rs
index 2b2e294be..0357e8811 100644
--- a/crates/topos-tce-api/tests/runtime.rs
+++ b/crates/topos-tce-api/tests/runtime.rs
@@ -29,6 +29,8 @@ use topos_test_sdk::networking::get_available_addr;
 use topos_test_sdk::storage::{create_fullnode_store, create_validator_store, storage_client};
 use topos_test_sdk::tce::public_api::{broadcast_stream, create_public_api, PublicApiContext};
 
+mod grpc;
+
 #[rstest]
 #[timeout(Duration::from_secs(4))]
 #[test(tokio::test)]