diff --git a/packages/engine/src/getContext.js b/packages/engine/src/getContext.js
index 414d78624..7774b55af 100644
--- a/packages/engine/src/getContext.js
+++ b/packages/engine/src/getContext.js
@@ -30,6 +30,7 @@ const blockData = ({
   id,
   layout,
   meta,
+  operators,
   pageId,
   properties,
   requests,
@@ -47,6 +48,7 @@ const blockData = ({
   id,
   layout,
   meta,
+  operators,
   pageId,
   properties,
   requests,
@@ -69,12 +71,13 @@ const getContext = async ({ block, contextId, lowdefy }) => {
   if (!lowdefy.inputs[contextId]) {
     lowdefy.inputs[contextId] = {};
   }
+  const operatorsSet = new Set([...block.operators, '_not', '_type']);
   lowdefy.contexts[contextId] = {
     id: contextId,
     blockId: block.blockId,
     eventLog: [],
     requests: {},
-    operators: block.operators || [],
+    operators: [...operatorsSet],
     lowdefy,
     pageId: lowdefy.pageId,
     rootBlock: blockData(block), // filter block to prevent circular structure
diff --git a/packages/engine/test/Actions/Validate.test.js b/packages/engine/test/Actions/Validate.test.js
index 724f72a97..7a812281b 100644
--- a/packages/engine/test/Actions/Validate.test.js
+++ b/packages/engine/test/Actions/Validate.test.js
@@ -46,6 +46,116 @@ afterAll(() => {
   global.Date = RealDate;
 });
 
+test('Validate required field', async () => {
+  const rootBlock = {
+    blockId: 'root',
+    meta: {
+      category: 'context',
+    },
+    areas: {
+      content: {
+        blocks: [
+          {
+            blockId: 'text1',
+            type: 'TextInput',
+            meta: {
+              category: 'input',
+              valueType: 'string',
+            },
+            required: true,
+          },
+          {
+            blockId: 'button',
+            type: 'Button',
+            meta: {
+              category: 'display',
+            },
+            events: {
+              onClick: [
+                {
+                  id: 'validate',
+                  type: 'Validate',
+                },
+              ],
+            },
+          },
+        ],
+      },
+    },
+  };
+  const context = await testContext({
+    lowdefy,
+    rootBlock,
+  });
+  const { button, text1 } = context.RootBlocks.map;
+  expect(text1.validationEval.output).toEqual({
+    errors: ['This field is required'],
+    status: null,
+    warnings: [],
+  });
+  await button.triggerEvent({ name: 'onClick' });
+  expect(button.Events.events.onClick.history[0]).toEqual({
+    blockId: 'button',
+    event: undefined,
+    eventName: 'onClick',
+    responses: [
+      {
+        actionId: 'validate',
+        actionType: 'Validate',
+        error: new Error('Your input has 1 validation error.'),
+      },
+    ],
+    success: false,
+    timestamp: {
+      date: 0,
+    },
+  });
+  expect(text1.validationEval.output).toEqual({
+    errors: ['This field is required'],
+    status: 'error',
+    warnings: [],
+  });
+  expect(displayMessage.mock.calls).toMatchInlineSnapshot(`
+    Array [
+      Array [
+        Object {
+          "content": "Your input has 1 validation error.",
+          "duration": 6,
+          "status": "error",
+        },
+      ],
+    ]
+  `);
+  displayMessage.mockReset();
+  displayMessage.mockImplementation(() => closeLoader);
+  text1.setValue('text1');
+  await button.triggerEvent({ name: 'onClick' });
+  expect(button.Events.events.onClick.history[0]).toEqual({
+    blockId: 'button',
+    event: undefined,
+    eventName: 'onClick',
+    responses: [
+      {
+        actionId: 'validate',
+        actionType: 'Validate',
+        response: undefined,
+      },
+    ],
+    success: true,
+    timestamp: {
+      date: 0,
+    },
+  });
+  expect(text1.validationEval.output).toEqual({
+    errors: [],
+    status: 'success',
+    warnings: [],
+  });
+  expect(displayMessage.mock.calls).toEqual([]);
+  displayMessage.mockReset();
+  displayMessage.mockImplementation(() => closeLoader);
+});
+
 test('Validate all fields', async () => {
   const rootBlock = {
     blockId: 'root',
diff --git a/packages/engine/test/getContext.test.js b/packages/engine/test/getContext.test.js
index 30dc1cb5d..5ca401964 100644
--- a/packages/engine/test/getContext.test.js
+++ b/packages/engine/test/getContext.test.js
@@ -46,6 +46,7 @@ test('memoize context', async () => {
     meta: {
       type: 'context',
     },
+    operators: [],
   };
   const c1 = await getContext({ block, contextId: 'c1', lowdefy });
   const c2 = await getContext({ block, contextId: 'c1', lowdefy });
@@ -71,6 +72,7 @@ test('create context', async () => {
     meta: {
       type: 'context',
     },
+    operators: [],
   };
   const context = await getContext({ block, contextId: 'contextId', lowdefy });
   expect(context.Actions).toBeDefined();
@@ -81,6 +83,7 @@ test('create context', async () => {
   expect(context.lowdefy).toEqual(lowdefy);
   expect(context.eventLog).toEqual([]);
   expect(context.id).toEqual('contextId');
+  expect(context.operators).toBeInstanceOf(Array);
   expect(context.lowdefy.pageId).toEqual('pageId');
   expect(context.parser).toBeDefined();
   expect(context.requests).toEqual({});
@@ -111,6 +114,7 @@ test('create context, initialize input', async () => {
     meta: {
       type: 'context',
     },
+    operators: [],
   };
   const context = await getContext({ block, contextId: 'contextId', lowdefy });
   expect(context.lowdefy.inputs.contextId).toEqual({});
@@ -129,12 +133,14 @@ test('call update for listening contexts', async () => {
     meta: {
       type: 'context',
     },
+    operators: [],
   };
   const block2 = {
     blockId: 'block2',
     meta: {
       type: 'context',
     },
+    operators: [],
   };
   const mockUpdate = jest.fn();
   const c1 = await getContext({ block: block1, contextId: 'c1', lowdefy });
@@ -158,6 +164,7 @@ test('remove contextId from updateListeners if not found', async () => {
     meta: {
       type: 'context',
     },
+    operators: [],
   };
   const c1 = await getContext({ block, contextId: 'c1', lowdefy });
 
@@ -180,6 +187,7 @@ test('remove contextId from updateListeners if equal to own contextId', async ()
     meta: {
       type: 'context',
     },
+    operators: [],
   };
   const c1 = await getContext({ block, contextId: 'c1', lowdefy });
 
@@ -202,6 +210,7 @@ test('update memoized context', async () => {
     meta: {
       type: 'context',
     },
+    operators: [],
   };
   const mockUpdate = jest.fn();
   const c1 = await getContext({ block, contextId: 'c1', lowdefy });
@@ -223,6 +232,7 @@ test('call update for nested contexts and prevent circular loop structure', asyn
     meta: {
       type: 'context',
     },
+    operators: [],
   };
   const block1 = {
     blockId: 'block1',
@@ -234,6 +244,7 @@ test('call update for nested contexts and prevent circular loop structure', asyn
         blocks: block2,
       },
     },
+    operators: [],
   };
   const c1 = await getContext({ block: block1, contextId: 'c1', lowdefy });
   const getC2 = () =>
@@ -244,3 +255,22 @@ test('call update for nested contexts and prevent circular loop structure', asyn
     });
   await expect(getC2()).resolves.not.toThrow();
 });
+
+test('Add operators for required validation', async () => {
+  const lowdefy = {
+    client,
+    contexts: {},
+    inputs: {},
+    pageId,
+    updateBlock,
+  };
+  const block = {
+    blockId: 'blockId',
+    meta: {
+      type: 'context',
+    },
+    operators: [],
+  };
+  const context = await getContext({ block, contextId: 'contextId', lowdefy });
+  expect(context.operators).toEqual(expect.arrayContaining(['_not', '_type']));
+});