📎 fix: Allow Message Attachments for Users with Viewer Permission on Agents (#11210)

* fix: allow message attachments for users with viewer permission on agents

Fixes regression introduced by the agent file upload access control fix
(SBA-ADV-20251204-01). The original fix was too restrictive - it blocked
ALL file uploads with agent_id + tool_resource, including temporary
message attachments used during chat.

## Problem

Users with VIEWER permission on a shared agent could not attach files to
their chat messages. The permission check blocked any upload request that
included both `agent_id` and `tool_resource`, but message attachments
legitimately include both fields since files need to be added to the
agent's context for processing within that conversation.

* test: Add permission check for file uploads with message_file set to false

Introduced a new test case to ensure that file uploads are denied when the `message_file` flag is false, reinforcing permission checks for users with VIEW access on agents. This change enhances security by preventing unauthorized file uploads while maintaining functionality for legitimate message attachments.

* fix: Update BadgeRow to handle undefined endpoint in ChatForm

Modified the `showEphemeralBadges` prop in the `BadgeRow` component to ensure it correctly handles cases where the `endpoint` is undefined. This change improves the robustness of the chat input functionality by preventing potential errors related to endpoint checks.

api/server/routes/files/files.agents.test.js

@@ -608,5 +608,114 @@ describe('File Routes - Agent Files Endpoint', () => {
       expect(response.status).toBe(200);
       expect(processAgentFileUpload).toHaveBeenCalled();
     });
+
+    it('should allow message_file attachment to agent even without EDIT permission', async () => {
+      // Create an agent owned by authorId
+      const agent = await createAgent({
+        id: agentCustomId,
+        name: 'Test Agent',
+        provider: 'openai',
+        model: 'gpt-4',
+        author: authorId,
+      });
+
+      // Grant only VIEW permission to otherUserId
+      const { grantPermission } = require('~/server/services/PermissionService');
+      await grantPermission({
+        principalType: PrincipalType.USER,
+        principalId: otherUserId,
+        resourceType: ResourceType.AGENT,
+        resourceId: agent._id,
+        accessRoleId: AccessRoleIds.AGENT_VIEWER,
+        grantedBy: authorId,
+      });
+
+      const testApp = createAppWithUser(otherUserId);
+
+      // message_file: true indicates this is a chat message attachment, not a permanent file upload
+      const response = await request(testApp).post('/files').send({
+        endpoint: 'agents',
+        agent_id: agentCustomId,
+        tool_resource: 'context',
+        message_file: true,
+        file_id: uuidv4(),
+      });
+
+      expect(response.status).toBe(200);
+      expect(processAgentFileUpload).toHaveBeenCalled();
+    });
+
+    it('should allow message_file attachment (string "true") to agent even without EDIT permission', async () => {
+      // Create an agent owned by authorId
+      const agent = await createAgent({
+        id: agentCustomId,
+        name: 'Test Agent',
+        provider: 'openai',
+        model: 'gpt-4',
+        author: authorId,
+      });
+
+      // Grant only VIEW permission to otherUserId
+      const { grantPermission } = require('~/server/services/PermissionService');
+      await grantPermission({
+        principalType: PrincipalType.USER,
+        principalId: otherUserId,
+        resourceType: ResourceType.AGENT,
+        resourceId: agent._id,
+        accessRoleId: AccessRoleIds.AGENT_VIEWER,
+        grantedBy: authorId,
+      });
+
+      const testApp = createAppWithUser(otherUserId);
+
+      // message_file as string "true" (from form data) should also be allowed
+      const response = await request(testApp).post('/files').send({
+        endpoint: 'agents',
+        agent_id: agentCustomId,
+        tool_resource: 'context',
+        message_file: 'true',
+        file_id: uuidv4(),
+      });
+
+      expect(response.status).toBe(200);
+      expect(processAgentFileUpload).toHaveBeenCalled();
+    });
+
+    it('should deny file upload when message_file is false (not a message attachment)', async () => {
+      // Create an agent owned by authorId
+      const agent = await createAgent({
+        id: agentCustomId,
+        name: 'Test Agent',
+        provider: 'openai',
+        model: 'gpt-4',
+        author: authorId,
+      });
+
+      // Grant only VIEW permission to otherUserId
+      const { grantPermission } = require('~/server/services/PermissionService');
+      await grantPermission({
+        principalType: PrincipalType.USER,
+        principalId: otherUserId,
+        resourceType: ResourceType.AGENT,
+        resourceId: agent._id,
+        accessRoleId: AccessRoleIds.AGENT_VIEWER,
+        grantedBy: authorId,
+      });
+
+      const testApp = createAppWithUser(otherUserId);
+
+      // message_file: false should NOT bypass permission check
+      const response = await request(testApp).post('/files').send({
+        endpoint: 'agents',
+        agent_id: agentCustomId,
+        tool_resource: 'context',
+        message_file: false,
+        file_id: uuidv4(),
+      });
+
+      expect(response.status).toBe(403);
+      expect(response.body.error).toBe('Forbidden');
+      expect(processAgentFileUpload).not.toHaveBeenCalled();
+    });
   });
 });

api/server/routes/files/files.js

@@ -381,8 +381,14 @@ router.post('/', async (req, res) => {
       return await processFileUpload({ req, res, metadata });
     }
 
-    /** Check agent permissions for agent file uploads (not message attachments) */
-    if (metadata.agent_id && metadata.tool_resource) {
+    /**
+     * Check agent permissions for permanent agent file uploads (not message attachments).
+     * Message attachments (message_file=true) are temporary files for a single conversation
+     * and should be allowed for users who can chat with the agent.
+     * Permanent file uploads to tool_resources require EDIT permission.
+     */
+    const isMessageAttachment = metadata.message_file === true || metadata.message_file === 'true';
+    if (metadata.agent_id && metadata.tool_resource && !isMessageAttachment) {
       const userId = req.user.id;
 
       /** Admin users bypass permission checks */