diff --git a/packages/backend/native/src/backend_runtime/blob_complete.rs b/packages/backend/native/src/backend_runtime/blob_complete.rs
index 140561b19d..4c8c0edbf3 100644
--- a/packages/backend/native/src/backend_runtime/blob_complete.rs
+++ b/packages/backend/native/src/backend_runtime/blob_complete.rs
@@ -10,6 +10,8 @@ use sha2::{Digest, Sha256};
 
 use super::{BackendRuntime, error::napi_error, types::RuntimeBlobCompleteResult};
 
+const MAX_BLOB_SIZE: i64 = i32::MAX as i64;
+
 fn object_missing_error(err: &napi::Error) -> bool {
   let message = err.to_string();
   message.contains("NoSuchKey") || message.contains("NotFound") || message.contains("not found")
@@ -110,6 +112,11 @@ async fn upsert_completed_blob(
   mime: &str,
   size: i64,
 ) -> Result<()> {
+  if !(0..=MAX_BLOB_SIZE).contains(&size) {
+    return Err(napi_error("BlobComplete size exceeds limit"));
+  }
+  let size = i32::try_from(size).map_err(|_| napi_error("BlobComplete size exceeds limit"))?;
+
   sqlx::query(
     r#"
     INSERT INTO blobs (workspace_id, key, mime, size, status, upload_id)
@@ -125,7 +132,7 @@ async fn upsert_completed_blob(
   .bind(workspace_id)
   .bind(key)
   .bind(mime)
-  .bind(size as i32)
+  .bind(size)
   .execute(&runtime.pool().await?)
   .await
   .map_err(|err| napi_error(format!("BlobComplete upsert metadata failed: {err}")))?;
@@ -143,6 +150,10 @@ impl BackendRuntime {
     expected_size: i64,
     expected_mime: String,
   ) -> Result<RuntimeBlobCompleteResult> {
+    if !(0..=MAX_BLOB_SIZE).contains(&expected_size) {
+      return Ok(blob_complete_failure("size_too_large"));
+    }
+
     let object_key = format!("{workspace_id}/{key}");
     let object = match self.object_storage_get(object_key.clone()).await {
       Ok(Some(object)) => object,
@@ -151,6 +162,14 @@ impl BackendRuntime {
       Err(err) => return Err(err),
     };
 
+    if !(0..=MAX_BLOB_SIZE).contains(&object.metadata.content_length) {
+      match self.object_storage_delete(object_key).await {
+        Ok(()) => {}
+        Err(err) if object_missing_error(&err) => {}
+        Err(err) => return Err(err),
+      }
+      return Ok(blob_complete_failure("size_too_large"));
+    }
     if object.metadata.content_length != expected_size {
       return Ok(blob_complete_failure("size_mismatch"));
     }
@@ -194,6 +213,10 @@ impl BackendRuntime {
     expected_size: i64,
     expected_mime: String,
   ) -> Result<RuntimeBlobCompleteResult> {
+    if !(0..=MAX_BLOB_SIZE).contains(&expected_size) {
+      return Ok(blob_complete_failure("size_too_large"));
+    }
+
     let storage_key = format!("{workspace_id}/{key}");
     let path = fs_object_path(&root, &bucket, &storage_key)?;
     let metadata = match read_fs_metadata(&path)? {
@@ -201,6 +224,11 @@ impl BackendRuntime {
       None => return Ok(blob_complete_failure("not_found")),
     };
 
+    if !(0..=MAX_BLOB_SIZE).contains(&metadata.content_length) {
+      let _ = fs::remove_file(&path);
+      let _ = fs::remove_file(PathBuf::from(format!("{}.metadata.json", path.display())));
+      return Ok(blob_complete_failure("size_too_large"));
+    }
     if metadata.content_length != expected_size {
       return Ok(blob_complete_failure("size_mismatch"));
     }
diff --git a/packages/backend/native/src/backend_runtime/tests.rs b/packages/backend/native/src/backend_runtime/tests.rs
index 86a692b95b..a734259ab9 100644
--- a/packages/backend/native/src/backend_runtime/tests.rs
+++ b/packages/backend/native/src/backend_runtime/tests.rs
@@ -1,7 +1,7 @@
-use super::{runtime_state::*, *};
-
 use anyhow::{Context, Result as AnyResult, anyhow};
 
+use super::{runtime_state::*, *};
+
 static PG_TEST_LOCK: std::sync::OnceLock<tokio::sync::Mutex<()>> = std::sync::OnceLock::new();
 const TEST_VERIFICATION_TOKEN_TYPE: i32 = 99_999;
 
diff --git a/packages/backend/server/src/native.ts b/packages/backend/server/src/native.ts
index 9a012f62d5..8675ebbbf9 100644
--- a/packages/backend/server/src/native.ts
+++ b/packages/backend/server/src/native.ts
@@ -2,6 +2,7 @@ import serverNativeModule, {
   type ActionEvent as NativeActionEventContract,
   type ActionRuntimeInput as NativeActionRuntimeInputContract,
   type AssertSafeUrlRequest,
+  type BackendRuntimeHealth,
   type BuiltInPromptRenderContract,
   type BuiltInPromptSessionContract,
   type BuiltInPromptSpec,
@@ -45,6 +46,22 @@ import serverNativeModule, {
   type RequestedModelMatchResponse,
   type ResolvedEntitlement,
   type ResolveEntitlementInput,
+  type RuntimeBlobCleanupResult,
+  type RuntimeBlobCompleteResult,
+  type RuntimeByokLocalLeaseRecord,
+  type RuntimeDocCompactionResult,
+  type RuntimeMagicLinkOtpConsumeResult,
+  type RuntimeMultipartUploadInit,
+  type RuntimeMultipartUploadPart,
+  type RuntimeObjectGetResult,
+  type RuntimeObjectListEntry,
+  type RuntimeObjectMetadata,
+  type RuntimeObjectStorageHealth,
+  type RuntimeObjectStoragePutOptions,
+  type RuntimePresignedObjectRequest,
+  type RuntimeVerificationTokenRecord,
+  type RuntimeWorkspaceInviteLinkRecord,
+  type RuntimeWorkspaceStatsDailyRecalibrationResult,
   type SafeFetchRequest,
   type SafeFetchResponse,
   type Tokenizer,
@@ -52,6 +69,7 @@ import serverNativeModule, {
 
 export type {
   AssertSafeUrlRequest,
+  BackendRuntimeHealth,
   CapabilityAttachmentContract,
   CapabilityModelCapability,
   CommandResponse,
@@ -73,6 +91,22 @@ export type {
   RemoteMimeTypeRequest,
   ResolvedEntitlement,
   ResolveEntitlementInput,
+  RuntimeBlobCleanupResult,
+  RuntimeBlobCompleteResult,
+  RuntimeByokLocalLeaseRecord,
+  RuntimeDocCompactionResult,
+  RuntimeMagicLinkOtpConsumeResult,
+  RuntimeMultipartUploadInit,
+  RuntimeMultipartUploadPart,
+  RuntimeObjectGetResult,
+  RuntimeObjectListEntry,
+  RuntimeObjectMetadata,
+  RuntimeObjectStorageHealth,
+  RuntimeObjectStoragePutOptions,
+  RuntimePresignedObjectRequest,
+  RuntimeVerificationTokenRecord,
+  RuntimeWorkspaceInviteLinkRecord,
+  RuntimeWorkspaceStatsDailyRecalibrationResult,
   SafeFetchRequest,
   SafeFetchResponse,
 };
@@ -180,6 +214,7 @@ export const readAllDocIdsFromRootDoc =
 export const AFFINE_PRO_PUBLIC_KEY = serverNativeModule.AFFINE_PRO_PUBLIC_KEY;
 export const AFFINE_PRO_LICENSE_AES_KEY =
   serverNativeModule.AFFINE_PRO_LICENSE_AES_KEY;
+export const BackendRuntime = serverNativeModule.BackendRuntime;
 
 export type PermissionWorkspaceRole = 'external' | 'member' | 'admin' | 'owner';
 export type PermissionDocRole =