diff --git a/src/main/services/agents/BaseService.ts b/src/main/services/agents/BaseService.ts
index 40a3d059dc..65d326465b 100644
--- a/src/main/services/agents/BaseService.ts
+++ b/src/main/services/agents/BaseService.ts
@@ -1,5 +1,6 @@
 import { type Client, createClient } from '@libsql/client'
 import { loggerService } from '@logger'
+import { objectKeys } from '@types'
 import { drizzle, type LibSQLDatabase } from 'drizzle-orm/libsql'
 import fs from 'fs'
 import path from 'path'
@@ -150,6 +151,13 @@ export abstract class BaseService {
       }
     }
 
+    // convert null from db to undefined to satisfy type definition
+    for (const key of objectKeys(data)) {
+      if (deserialized[key] === null) {
+        deserialized[key] = undefined
+      }
+    }
+
     return deserialized
   }
 
diff --git a/src/renderer/src/types/agent.ts b/src/renderer/src/types/agent.ts
index 58e7e5e7cb..d477a6f59c 100644
--- a/src/renderer/src/types/agent.ts
+++ b/src/renderer/src/types/agent.ts
@@ -1,6 +1,8 @@
 /**
  * Database entity types for Agent, Session, and SessionMessage
  * Shared between main and renderer processes
+ *
+ * WARNING: Any null value will be converted to undefined from api.
  */
 import { ModelMessage, modelMessageSchema, TextStreamPart } from 'ai'
 import { z } from 'zod'