diff --git a/package.json b/package.json
index f9b32ca1..dd90aca0 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "hawk.api",
-  "version": "1.1.29",
+  "version": "1.1.30",
   "main": "index.ts",
   "license": "UNLICENSED",
   "scripts": {
@@ -21,6 +21,8 @@
   "devDependencies": {
     "@shelf/jest-mongodb": "^1.2.2",
     "@types/jest": "^26.0.8",
+    "@types/lodash.clonedeep": "^4.5.9",
+    "@types/lodash.mergewith": "^4.6.9",
     "eslint": "^6.7.2",
     "eslint-config-codex": "1.2.4",
     "eslint-plugin-import": "^2.19.1",
@@ -37,7 +39,8 @@
     "@graphql-tools/schema": "^8.5.1",
     "@graphql-tools/utils": "^8.9.0",
     "@hawk.so/nodejs": "^3.1.1",
-    "@hawk.so/types": "^0.1.31",
+    "@hawk.so/types": "^0.1.33",
+    "@n1ru4l/json-patch-plus": "^0.2.0",
     "@types/amqp-connection-manager": "^2.0.4",
     "@types/bson": "^4.0.5",
     "@types/debug": "^4.1.5",
@@ -70,6 +73,8 @@
     "graphql-upload": "^13",
     "jsonwebtoken": "^8.5.1",
     "lodash": "^4.17.15",
+    "lodash.clonedeep": "^4.5.0",
+    "lodash.mergewith": "^4.6.2",
     "migrate-mongo": "^7.0.1",
     "mime-types": "^2.1.25",
     "mongodb": "^3.7.3",
diff --git a/src/utils/merge.ts b/src/utils/merge.ts
new file mode 100644
index 00000000..090ada79
--- /dev/null
+++ b/src/utils/merge.ts
@@ -0,0 +1,130 @@
+import mergeWith from 'lodash.mergewith';
+import cloneDeep from 'lodash.clonedeep';
+import { patch } from '@n1ru4l/json-patch-plus';
+import { GroupedEventDBScheme, RepetitionDBScheme } from '@hawk.so/types';
+
+/**
+ * One of the features of the events is that their repetition is the difference
+ * between the original, which greatly optimizes storage. So we need to restore
+ * the original repetition payload using the very first event and its difference
+ * between its repetition
+ *
+ * @deprecated remove after 6 september 2025
+ * @param originalEvent - the very first event we received
+ * @param repetition - the difference with its repetition, for the repetition we want to display
+ * @returns fully assembled payload of the current repetition
+ */
+export function repetitionAssembler(originalEvent: GroupedEventDBScheme['payload'], repetition: GroupedEventDBScheme['payload']): GroupedEventDBScheme['payload'] {
+  const customizer = (originalParam: any, repetitionParam: any): any => {
+    if (repetitionParam === null) {
+      return originalParam;
+    }
+
+    if (typeof repetitionParam === 'object' && typeof originalParam === 'object') {
+      /**
+       * If original event has null but repetition has some value, we need to return repetition value
+       */
+      if (originalParam === null) {
+        return repetitionParam;
+        /**
+         * Otherwise, we need to recursively merge original and repetition values
+         */
+      } else {
+        return repetitionAssembler(originalParam, repetitionParam);
+      }
+    }
+
+    return repetitionParam;
+  };
+
+  return mergeWith(cloneDeep(originalEvent), cloneDeep(repetition), customizer);
+}
+
+/**
+ * Parse addons and context fields from string to object, in db it stores as string
+ *
+ * @param payload - the payload of the event
+ * @param field - the field to parse, can be 'addons' or 'context'
+ * @returns the payload with parsed field
+ */
+function parsePayloadField(payload: GroupedEventDBScheme['payload'], field: 'addons' | 'context') {
+  if (payload && payload[field] && typeof payload[field] === 'string') {
+    payload[field] = JSON.parse(payload[field] as string);
+  }
+
+  return payload;
+}
+
+/**
+ * Stringify addons and context fields from object to string, in db it stores as string
+ *
+ * @param payload - the payload of the event
+ * @param field - the field to stringify, can be 'addons' or 'context'
+ * @returns the payload with stringified field
+ */
+function stringifyPayloadField(payload: GroupedEventDBScheme['payload'], field: 'addons' | 'context') {
+  if (payload && payload[field]) {
+    payload[field] = JSON.stringify(payload[field]);
+  }
+
+  return payload;
+}
+
+/**
+ * Helps to merge original event and repetition due to delta format,
+ * in case of old delta format, we need to patch the payload
+ * in case of new delta format, we need to assemble the payload
+ *
+ * @param originalEvent {HawkEvent} - The original event
+ * @param repetition {HawkEventRepetition} - The repetition to process
+ * @returns {HawkEvent} Updated event with processed repetition payload
+ */
+export function composeFullRepetitionEvent(originalEvent: GroupedEventDBScheme, repetition: RepetitionDBScheme | undefined): GroupedEventDBScheme {
+  /**
+   * Make a deep copy of the original event, because we need to avoid mutating the original event
+   */
+  const event = cloneDeep(originalEvent);
+
+  if (!repetition) {
+    return event;
+  }
+
+  /**
+   * New delta format (repetition.delta is not null)
+   */
+  if (repetition.delta) {
+    /**
+     * Parse addons and context fields from string to object before patching
+     */
+    event.payload = parsePayloadField(event.payload, 'addons');
+    event.payload = parsePayloadField(event.payload, 'context');
+
+    event.payload = patch({
+      left: event.payload,
+      delta: JSON.parse(repetition.delta),
+    });
+
+    /**
+     * Stringify addons and context fields from object to string after patching
+     */
+    event.payload = stringifyPayloadField(event.payload, 'addons');
+    event.payload = stringifyPayloadField(event.payload, 'context');
+
+    return event;
+  }
+
+  /**
+   * New delta format (repetition.payload is null) and repetition.delta is null (there is no delta between original and repetition)
+   */
+  if (!repetition.payload) {
+    return event;
+  }
+
+  /**
+   * Old delta format (repetition.payload is not null)
+   * @todo remove after 6 september 2025
+   */
+  event.payload = repetitionAssembler(event.payload, repetition.payload);
+
+  return event;
+}
diff --git a/test/utils/merge.test.ts b/test/utils/merge.test.ts
new file mode 100644
index 00000000..c065d338
--- /dev/null
+++ b/test/utils/merge.test.ts
@@ -0,0 +1,366 @@
+import { composeFullRepetitionEvent } from '../../src/utils/merge';
+import { GroupedEventDBScheme, RepetitionDBScheme } from '@hawk.so/types';
+
+import { diff } from '@n1ru4l/json-patch-plus';
+
+describe('composeFullRepetitionEvent', () => {
+    const mockOriginalEvent: GroupedEventDBScheme = {
+        groupHash: 'original-event-1',
+        totalCount: 1,
+        catcherType: 'javascript',
+        payload: {
+            title: 'Original message',
+            type: 'error',
+            addons: JSON.stringify({ userId: 123 }),
+            context: JSON.stringify({ sessionId: 'abc' }),
+        },
+        usersAffected: 1,
+        visitedBy: [],
+        timestamp: 1640995200, // 2023-01-01T00:00:00Z
+    };
+
+    beforeEach(() => {
+        jest.clearAllMocks();
+    });
+
+    describe('when repetition is undefined', () => {
+        it('should return a deep copy of the original event', () => {
+            /**
+             * Arrange
+             */
+            const repetition = undefined;
+
+            /**
+             * Act
+             */
+            const result = composeFullRepetitionEvent(mockOriginalEvent, repetition);
+
+            /**
+             * Assert
+             */
+            expect(result).toEqual(mockOriginalEvent);
+            expect(result).toMatchObject(mockOriginalEvent);
+            expect(result.payload).toMatchObject(mockOriginalEvent.payload);
+        });
+    });
+
+    describe('when repetition.delta is provided (new delta format)', () => {
+        it('should parse addons and context, apply patch, and stringify fields back', () => {
+            /**
+             * Arrange
+             */
+            const delta = diff({
+                left: mockOriginalEvent.payload,
+                right: {
+                    ...mockOriginalEvent.payload,
+                    title: 'Updated message',
+                    type: 'warning',
+                },
+            });
+
+            const repetition: RepetitionDBScheme = {
+                groupHash: 'original-event-1',
+                timestamp: 1640995200,
+                delta: JSON.stringify(delta),
+            };
+
+            /**
+             * Act
+             */
+            const result = composeFullRepetitionEvent(mockOriginalEvent, repetition);
+
+            /**
+             * Assert
+             */
+            expect(result.payload).toEqual({
+                title: 'Updated message',
+                type: 'warning',
+                addons: JSON.stringify({ userId: 123 }),
+                context: JSON.stringify({ sessionId: 'abc' }),
+            });
+        });
+
+        it('should handle delta with new fields', () => {
+            /**
+             * Arrange
+             */
+            const delta = diff({
+                left: mockOriginalEvent.payload,
+                right: {
+                    ...mockOriginalEvent.payload,
+                    release: 'v1.0.0',
+                    catcherVersion: '2.0.0',
+                },
+            });
+
+            const repetition: RepetitionDBScheme = {
+                groupHash: 'original-event-1',
+                timestamp: 1640995200,
+                delta: JSON.stringify(delta),
+            };
+
+            /**
+             * Act
+             */
+            const result = composeFullRepetitionEvent(mockOriginalEvent, repetition);
+
+            /**
+             * Assert
+             */
+            expect(result.payload).toEqual({
+                title: 'Original message',
+                type: 'error',
+                release: 'v1.0.0',
+                catcherVersion: '2.0.0',
+                addons: JSON.stringify({ userId: 123 }),
+                context: JSON.stringify({ sessionId: 'abc' }),
+            });
+        });
+    });
+
+    describe('when repetition.delta is undefined and repetition.payload is undefined', () => {
+        it('should return the original event unchanged', () => {
+            /**
+             * Arrange
+             */
+            const repetition: RepetitionDBScheme = {
+                groupHash: 'original-event-1',
+                timestamp: 1640995200,
+                delta: undefined,
+                payload: undefined,
+            };
+
+            /**
+             * Act
+             */
+            const result = composeFullRepetitionEvent(mockOriginalEvent, repetition);
+
+            /**
+             * Assert
+             */
+            expect(result).toEqual(mockOriginalEvent);
+            expect(result).not.toBe(mockOriginalEvent); // Должна быть глубокая копия
+        });
+    });
+
+    describe('when repetition.delta is undefined and repetition.payload is provided (old delta format)', () => {
+        it('should use repetitionAssembler to merge payloads', () => {
+            /**
+             * Arrange
+             */
+            const repetition: RepetitionDBScheme = {
+                groupHash: 'original-event-1',
+                timestamp: 1640995200,
+                delta: undefined,
+                payload: {
+                    title: 'Updated message',
+                    type: 'warning',
+                    release: 'v1.0.0',
+                },
+            };
+
+            /**
+             * Act
+             */
+            const result = composeFullRepetitionEvent(mockOriginalEvent, repetition);
+
+            /**
+             * Assert
+             */
+            expect(result.payload).toEqual({
+                title: 'Updated message',
+                type: 'warning',
+                release: 'v1.0.0',
+                // Addons and context should be, because old format doesn't remove fields
+                addons: JSON.stringify({ userId: 123 }),
+                context: JSON.stringify({ sessionId: 'abc' }),
+            });
+        });
+
+        it('should handle null values in repetition payload', () => {
+            /**
+             * Arrange
+             */
+            const repetition: RepetitionDBScheme = {
+                groupHash: 'original-event-1',
+                timestamp: 1640995200,
+                delta: undefined,
+                payload: {
+                    title: 'Updated title',
+                    type: 'info',
+                },
+            };
+
+            /**
+             * Act
+             */
+            const result = composeFullRepetitionEvent(mockOriginalEvent, repetition);
+
+            /**
+             * Assert
+             */
+            expect(result.payload).toEqual({
+                title: 'Updated title', // repetition value replaces original
+                type: 'info',
+                // Addons and context should be, because old format doesn't remove fields
+                addons: JSON.stringify({ userId: 123 }),
+                context: JSON.stringify({ sessionId: 'abc' }),
+            });
+        });
+
+        it('should preserve original value when repetition payload has null', () => {
+            /**
+             * Arrange
+             */
+            const repetition: RepetitionDBScheme = {
+                groupHash: 'original-event-1',
+                timestamp: 1640995200,
+                delta: undefined,
+                payload: {
+                    title: null as any,
+                    type: 'info',
+                },
+            };
+
+            /**
+             * Act
+             */
+            const result = composeFullRepetitionEvent(mockOriginalEvent, repetition);
+
+            /**
+             * Assert
+             */
+            expect(result.payload).toEqual({
+                title: 'Original message', // null в repetition должно сохранить оригинальное значение
+                type: 'info',
+                addons: JSON.stringify({ userId: 123 }),
+                context: JSON.stringify({ sessionId: 'abc' }),
+            });
+        });
+    });
+
+    describe('edge cases', () => {
+        it('should handle empty payload in original event', () => {
+            /**
+             * Arrange
+             */
+            const eventWithEmptyPayload: GroupedEventDBScheme = {
+                groupHash: 'event-4',
+                totalCount: 1,
+                catcherType: 'javascript',
+                payload: {
+                    title: 'Empty event',
+                },
+                usersAffected: 1,
+                visitedBy: [],
+                timestamp: 1640995200,
+            };
+
+            const delta = diff({
+                left: eventWithEmptyPayload.payload,
+                right: {
+                    ...eventWithEmptyPayload.payload,
+                    title: 'New message',
+                },
+            });
+
+            const repetition: RepetitionDBScheme = {
+                groupHash: 'event-4',
+                timestamp: 1640995200,
+                delta: JSON.stringify(delta),
+            };
+
+            /**
+             * Act
+             */
+            const result = composeFullRepetitionEvent(eventWithEmptyPayload, repetition);
+
+            /**
+             * Assert
+             */
+            expect(result.payload).toEqual({
+                title: 'New message',
+            });
+        });
+
+        it('should handle null payload in original event', () => {
+            /**
+             * Arrange
+             */
+            const eventWithNullPayload: GroupedEventDBScheme = {
+                groupHash: 'event-5',
+                totalCount: 1,
+                catcherType: 'javascript',
+                payload: null as any,
+                usersAffected: 1,
+                visitedBy: [],
+                timestamp: 1640995200,
+            };
+
+            const delta = diff({
+                left: eventWithNullPayload.payload,
+                right: {
+                    title: 'New message',
+                },
+            });
+
+            const repetition: RepetitionDBScheme = {
+                groupHash: 'event-5',
+                timestamp: 1640995200,
+                delta: JSON.stringify(delta),
+            };
+
+            /**
+             * Act
+             */
+            const result = composeFullRepetitionEvent(eventWithNullPayload, repetition);
+
+            /**
+             * Assert
+             */
+            expect(result.payload).toEqual({
+                title: 'New message',
+            });
+        });
+
+        it('should handle invalid JSON in addons or context', () => {
+            /**
+             * Arrange
+             */
+            const eventWithInvalidJSON: GroupedEventDBScheme = {
+                groupHash: 'event-6',
+                totalCount: 1,
+                catcherType: 'javascript',
+                payload: {
+                    title: 'Test',
+                    addons: 'invalid json',
+                    context: 'also invalid',
+                },
+                usersAffected: 1,
+                visitedBy: [],
+                timestamp: 1640995200,
+            };
+
+            const delta = diff({
+                left: eventWithInvalidJSON.payload,
+                right: {
+                    ...eventWithInvalidJSON.payload,
+                    title: 'Updated',
+                },
+            });
+
+            const repetition: RepetitionDBScheme = {
+                groupHash: 'event-6',
+                timestamp: 1640995200,
+                delta: JSON.stringify(delta),
+            };
+
+            /**
+             * Act & Assert
+             */
+            expect(() => {
+                composeFullRepetitionEvent(eventWithInvalidJSON, repetition);
+            }).toThrow(); // Должно выбросить ошибку при парсинге невалидного JSON
+        });
+    });
+}); 
\ No newline at end of file
diff --git a/yarn.lock b/yarn.lock
index 9d2d9361..80a104ae 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -458,10 +458,10 @@
   dependencies:
     "@types/mongodb" "^3.5.34"
 
-"@hawk.so/types@^0.1.31":
-  version "0.1.31"
-  resolved "https://registry.yarnpkg.com/@hawk.so/types/-/types-0.1.31.tgz#fba2c3451e927558bfcc3b1d942baaf8e72ad214"
-  integrity sha512-o1LeA3JVIUPRSIZegKwAdl4noQ1KYxwr80eisJMlghP9knu6PbYw20rIMyan5qQ3epOWs8gO1CU3iwHZprFiCg==
+"@hawk.so/types@^0.1.33":
+  version "0.1.33"
+  resolved "https://registry.yarnpkg.com/@hawk.so/types/-/types-0.1.33.tgz#feb077b699b3e0001552588a372e1efe6cd58f40"
+  integrity sha512-q3AdVxzQ8Qk8qyYiAcAacxNZXWTG/oLmVpjQlcLm2Eh5OJgpaZvH8hQCeRQ/ml1cqbYW8gUrRbMMCS2QOcwxEw==
   dependencies:
     "@types/mongodb" "^3.5.34"
 
@@ -720,6 +720,11 @@
     semver "^7.3.5"
     tar "^6.1.11"
 
+"@n1ru4l/json-patch-plus@^0.2.0":
+  version "0.2.0"
+  resolved "https://registry.yarnpkg.com/@n1ru4l/json-patch-plus/-/json-patch-plus-0.2.0.tgz#b8fa09fd980c3460dfdc109a7c4cc5590157aa6b"
+  integrity sha512-pLkJy83/rVfDTyQgDSC8GeXAHEdXNHGNJrB1b7wAyGQu0iv7tpMXntKVSqj0+XKNVQbco40SZffNfVALzIt0SQ==
+
 "@phc/format@^1.0.0":
   version "1.0.0"
   resolved "https://registry.yarnpkg.com/@phc/format/-/format-1.0.0.tgz#b5627003b3216dc4362125b13f48a4daa76680e4"
@@ -1077,6 +1082,25 @@
     "@types/koa-compose" "*"
     "@types/node" "*"
 
+"@types/lodash.clonedeep@^4.5.9":
+  version "4.5.9"
+  resolved "https://registry.yarnpkg.com/@types/lodash.clonedeep/-/lodash.clonedeep-4.5.9.tgz#ea48276c7cc18d080e00bb56cf965bcceb3f0fc1"
+  integrity sha512-19429mWC+FyaAhOLzsS8kZUsI+/GmBAQ0HFiCPsKGU+7pBXOQWhyrY6xNNDwUSX8SMZMJvuFVMF9O5dQOlQK9Q==
+  dependencies:
+    "@types/lodash" "*"
+
+"@types/lodash.mergewith@^4.6.9":
+  version "4.6.9"
+  resolved "https://registry.yarnpkg.com/@types/lodash.mergewith/-/lodash.mergewith-4.6.9.tgz#7093028a36de3cae4495d03b9d92c351cab1f8bf"
+  integrity sha512-fgkoCAOF47K7sxrQ7Mlud2TH023itugZs2bUg8h/KzT+BnZNrR2jAOmaokbLunHNnobXVWOezAeNn/lZqwxkcw==
+  dependencies:
+    "@types/lodash" "*"
+
+"@types/lodash@*":
+  version "4.17.20"
+  resolved "https://registry.yarnpkg.com/@types/lodash/-/lodash-4.17.20.tgz#1ca77361d7363432d29f5e55950d9ec1e1c6ea93"
+  integrity sha512-H3MHACvFUEiujabxhaI/ImO6gUrd8oOurg7LQtS7mbwIXA/cUqWrvBsaeJ23aZEPk1TAYkurjfMbSELfoCXlGA==
+
 "@types/long@^4.0.0":
   version "4.0.2"
   resolved "https://registry.yarnpkg.com/@types/long/-/long-4.0.2.tgz#b74129719fc8d11c01868010082d483b7545591a"
@@ -4616,6 +4640,11 @@ lockfile@^1.0.4:
   dependencies:
     signal-exit "^3.0.2"
 
+lodash.clonedeep@^4.5.0:
+  version "4.5.0"
+  resolved "https://registry.yarnpkg.com/lodash.clonedeep/-/lodash.clonedeep-4.5.0.tgz#e23f3f9c4f8fbdde872529c1071857a086e5ccef"
+  integrity sha512-H5ZhCF25riFd9uB5UCkVKo61m3S/xZk1x4wA6yp/L3RFP6Z/eHH1ymQcGLo7J3GMPfm0V/7m1tryHuGVxpqEBQ==
+
 lodash.includes@^4.3.0:
   version "4.3.0"
   resolved "https://registry.yarnpkg.com/lodash.includes/-/lodash.includes-4.3.0.tgz#60bb98a87cb923c68ca1e51325483314849f553f"
@@ -4646,6 +4675,11 @@ lodash.isstring@^4.0.1:
   resolved "https://registry.yarnpkg.com/lodash.isstring/-/lodash.isstring-4.0.1.tgz#d527dfb5456eca7cc9bb95d5daeaf88ba54a5451"
   integrity sha512-0wJxfxH1wgO3GrbuP+dTTk7op+6L41QCXbGINEmD+ny/G/eCqGzxyCsh7159S+mgDDcoarnBw6PC1PS5+wUGgw==
 
+lodash.mergewith@^4.6.2:
+  version "4.6.2"
+  resolved "https://registry.yarnpkg.com/lodash.mergewith/-/lodash.mergewith-4.6.2.tgz#617121f89ac55f59047c7aec1ccd6654c6590f55"
+  integrity sha512-GK3g5RPZWTRSeLSpgP8Xhra+pnjBC56q9FZYe1d5RN3TJ35dbkGy3YqBSMbyCrlbi+CM9Z3Jk5yTL7RCsqboyQ==
+
 lodash.once@^4.0.0:
   version "4.1.1"
   resolved "https://registry.yarnpkg.com/lodash.once/-/lodash.once-4.1.1.tgz#0dd3971213c7c56df880977d504c88fb471a97ac"