diff --git a/packages/backend/src/misc/cache.ts b/packages/backend/src/misc/cache.ts
index 22201e243f..3145550a44 100644
--- a/packages/backend/src/misc/cache.ts
+++ b/packages/backend/src/misc/cache.ts
@@ -565,6 +565,28 @@ export class QuantumKVCache<T> implements Iterable<[key: string, value: T]> {
 		}
 	}
 
+	/**
+	 * Adds a value to the local memory cache without notifying other process.
+	 * Neither a Redis event nor onSet callback will be fired, as the value has not actually changed.
+	 * This should only be used when the value is known to be current, like after fetching from the database.
+	 */
+	@bindThis
+	public add(key: string, value: T): void {
+		this.memoryCache.set(key, value);
+	}
+
+	/**
+	 * Adds multiple values to the local memory cache without notifying other process.
+	 * Neither a Redis event nor onSet callback will be fired, as the value has not actually changed.
+	 * This should only be used when the value is known to be current, like after fetching from the database.
+	 */
+	@bindThis
+	public addMany(items: Iterable<[key: string, value: T]>): void {
+		for (const [key, value] of items) {
+			this.memoryCache.set(key, value);
+		}
+	}
+
 	/**
 	 * Gets a value from the local memory cache, or returns undefined if not found.
 	 */
diff --git a/packages/backend/test/unit/misc/cache.ts b/packages/backend/test/unit/misc/cache.ts
index 0b658618e6..e24f6d4dcc 100644
--- a/packages/backend/test/unit/misc/cache.ts
+++ b/packages/backend/test/unit/misc/cache.ts
@@ -417,6 +417,68 @@ describe(QuantumKVCache, () => {
 		});
 	});
 
+	describe('add', () => {
+		it('should add the item', () => {
+			const cache = makeCache();
+			cache.add('foo', 'bar');
+			expect(cache.has('foo')).toBe(true);
+		});
+
+		it('should not emit event', () => {
+			const cache = makeCache({
+				name: 'fake',
+			});
+
+			cache.add('foo', 'bar');
+
+			expect(fakeInternalEventService._calls.filter(c => c[0] === 'emit')).toHaveLength(0);
+		});
+
+		it('should not call onSet', () => {
+			const fakeOnSet = jest.fn(() => Promise.resolve());
+			const cache = makeCache({
+				onSet: fakeOnSet,
+			});
+
+			cache.add('foo', 'bar');
+
+			expect(fakeOnSet).not.toHaveBeenCalled();
+		});
+	});
+
+	describe('addMany', () => {
+		it('should add all items', () => {
+			const cache = makeCache();
+
+			cache.addMany([['foo', 'bar'], ['alpha', 'omega']]);
+
+			expect(cache.has('foo')).toBe(true);
+			expect(cache.has('alpha')).toBe(true);
+		});
+
+
+		it('should not emit event', () => {
+			const cache = makeCache({
+				name: 'fake',
+			});
+
+			cache.addMany([['foo', 'bar'], ['alpha', 'omega']]);
+
+			expect(fakeInternalEventService._calls.filter(c => c[0] === 'emit')).toHaveLength(0);
+		});
+
+		it('should not call onSet', () => {
+			const fakeOnSet = jest.fn(() => Promise.resolve());
+			const cache = makeCache({
+				onSet: fakeOnSet,
+			});
+
+			cache.addMany([['foo', 'bar'], ['alpha', 'omega']]);
+
+			expect(fakeOnSet).not.toHaveBeenCalled();
+		});
+	});
+
 	describe('has', () => {
 		it('should return false when empty', () => {
 			const cache = makeCache();