diff --git a/app/src/core/events/Event.ts b/app/src/core/events/Event.ts
index 9defb4c4..009556b6 100644
--- a/app/src/core/events/Event.ts
+++ b/app/src/core/events/Event.ts
@@ -14,6 +14,10 @@ export abstract class Event<Params = any, Returning = void> {
    params: Params;
    returned: boolean = false;
 
+   /**
+    * Shallow validation of the event return
+    * It'll be deeply validated on the place where it is called
+    */
    validate(value: Returning): Event<Params, Returning> | void {
       throw new EventReturnedWithoutValidation(this as any, value);
    }
diff --git a/app/src/core/index.ts b/app/src/core/index.ts
index 5c63a4b7..c1bce4db 100644
--- a/app/src/core/index.ts
+++ b/app/src/core/index.ts
@@ -27,6 +27,7 @@ export {
 export { Registry, type Constructor } from "./registry/Registry";
 
 export * from "./console";
+export * from "./events";
 
 // compatibility
 export type Middleware = MiddlewareHandler<any, any, any>;
diff --git a/app/src/data/entities/Entity.ts b/app/src/data/entities/Entity.ts
index a59672fa..aade33f4 100644
--- a/app/src/data/entities/Entity.ts
+++ b/app/src/data/entities/Entity.ts
@@ -232,7 +232,7 @@ export class Entity<
       }
 
       for (const field of fields) {
-         if (!field.isValid(data[field.name], context)) {
+         if (!field.isValid(data?.[field.name], context)) {
             $console.warn(
                "invalid data given for",
                this.name,
diff --git a/app/src/data/events/index.ts b/app/src/data/events/index.ts
index b9d75599..85497506 100644
--- a/app/src/data/events/index.ts
+++ b/app/src/data/events/index.ts
@@ -1,4 +1,4 @@
-import type { PrimaryFieldType } from "core";
+import { $console, type PrimaryFieldType } from "core";
 import { Event, InvalidEventReturn } from "core/events";
 import type { Entity, EntityData } from "../entities";
 import type { RepoQuery } from "../server/data-query-impl";
@@ -9,6 +9,10 @@ export class MutatorInsertBefore extends Event<{ entity: Entity; data: EntityDat
    override validate(data: EntityData) {
       const { entity } = this.params;
       if (!entity.isValidData(data, "create")) {
+         $console.warn("MutatorInsertBefore.validate: invalid", {
+            entity: entity.name,
+            data,
+         });
          throw new InvalidEventReturn("EntityData", "invalid");
       }
 
@@ -36,13 +40,18 @@ export class MutatorUpdateBefore extends Event<
    static override slug = "mutator-update-before";
 
    override validate(data: EntityData) {
-      const { entity, ...rest } = this.params;
+      const { entity, entityId } = this.params;
       if (!entity.isValidData(data, "update")) {
+         $console.warn("MutatorUpdateBefore.validate: invalid", {
+            entity: entity.name,
+            entityId,
+            data,
+         });
          throw new InvalidEventReturn("EntityData", "invalid");
       }
 
       return this.clone({
-         ...rest,
+         entityId,
          entity,
          data,
       });
diff --git a/app/src/data/fields/Field.ts b/app/src/data/fields/Field.ts
index 2b51edfb..cb1e47d3 100644
--- a/app/src/data/fields/Field.ts
+++ b/app/src/data/fields/Field.ts
@@ -185,12 +185,14 @@ export abstract class Field<
       };
    }
 
+   // @todo: add field level validation
    isValid(value: any, context: TActionContext): boolean {
-      if (value) {
+      if (typeof value !== "undefined") {
          return this.isFillable(context);
-      } else {
+      } else if (context === "create") {
          return !this.isRequired();
       }
+      return true;
    }
 
    /**