diff --git a/packages/backend/server/src/base/storage/providers/r2.ts b/packages/backend/server/src/base/storage/providers/r2.ts
index b7f08d0d4..71d511e46 100644
--- a/packages/backend/server/src/base/storage/providers/r2.ts
+++ b/packages/backend/server/src/base/storage/providers/r2.ts
@@ -175,7 +175,7 @@ export class R2StorageProvider extends S3StorageProvider {
     body: Readable | Buffer | Uint8Array | string,
     options: { contentType?: string; contentLength?: number } = {}
   ) {
-    return this.client.putObject(key, body as any, {
+    return this.client.putObject(key, this.normalizeBody(body), {
       contentType: options.contentType,
       contentLength: options.contentLength,
     });
@@ -192,13 +192,24 @@ export class R2StorageProvider extends S3StorageProvider {
       key,
       uploadId,
       partNumber,
-      body as any,
+      this.normalizeBody(body),
       { contentLength: options.contentLength }
     );
 
     return result.etag;
   }
 
+  private normalizeBody(body: Readable | Buffer | Uint8Array | string) {
+    // s3mini does not accept Node.js Readable directly.
+    // Convert it to Web ReadableStream for compatibility.
+    if (body instanceof Readable) {
+      return Readable.toWeb(body);
+    } else if (typeof body === 'string') {
+      return this.encoder.encode(body);
+    }
+    return body;
+  }
+
   override async get(
     key: string,
     signedUrl?: boolean
diff --git a/packages/backend/server/src/base/storage/providers/s3.ts b/packages/backend/server/src/base/storage/providers/s3.ts
index 1bafcb395..0759dbc5d 100644
--- a/packages/backend/server/src/base/storage/providers/s3.ts
+++ b/packages/backend/server/src/base/storage/providers/s3.ts
@@ -281,7 +281,7 @@ export class S3StorageProvider implements StorageProvider {
 
       this.logger.verbose(`Read object \`${key}\``);
       return {
-        body: Readable.fromWeb(obj.body as any),
+        body: Readable.fromWeb(obj.body),
         metadata: {
           contentType: contentType ?? 'application/octet-stream',
           contentLength: contentLength ?? 0,
diff --git a/packages/backend/server/src/plugins/copilot/controller.ts b/packages/backend/server/src/plugins/copilot/controller.ts
index 88e931389..a9885c8f3 100644
--- a/packages/backend/server/src/plugins/copilot/controller.ts
+++ b/packages/backend/server/src/plugins/copilot/controller.ts
@@ -560,7 +560,7 @@ export class CopilotController implements BeforeApplicationShutdown {
                         status: data.status,
                         id: data.node.id,
                         type: data.node.config.nodeType,
-                      } as any,
+                      },
                     };
                 }
               })