diff --git a/apps/server/src/migrations/mikro-orm/Migration20241022205656.ts b/apps/server/src/migrations/mikro-orm/Migration20241022205656.ts
new file mode 100644
index 00000000000..072c8f0711c
--- /dev/null
+++ b/apps/server/src/migrations/mikro-orm/Migration20241022205656.ts
@@ -0,0 +1,37 @@
+import { Migration } from '@mikro-orm/migrations-mongodb';
+
+export class Migration20241022205656 extends Migration {
+	async up(): Promise<void> {
+		await this.getCollection('context-external-tools').updateMany(
+			{
+				contextId: { $type: 'string' },
+			},
+			[
+				{
+					$set: {
+						contextId: {
+							$toObjectId: '$contextId',
+						},
+					},
+				},
+			]
+		);
+	}
+
+	async down(): Promise<void> {
+		await this.getCollection('context-external-tools').updateMany(
+			{
+				contextId: { $type: 'objectId' },
+			},
+			[
+				{
+					$set: {
+						contextId: {
+							$toString: '$contextId',
+						},
+					},
+				},
+			]
+		);
+	}
+}
diff --git a/apps/server/src/modules/tool/context-external-tool/controller/api-test/tool-context.api.spec.ts b/apps/server/src/modules/tool/context-external-tool/controller/api-test/tool-context.api.spec.ts
index 54a366a5f25..0af81812244 100644
--- a/apps/server/src/modules/tool/context-external-tool/controller/api-test/tool-context.api.spec.ts
+++ b/apps/server/src/modules/tool/context-external-tool/controller/api-test/tool-context.api.spec.ts
@@ -310,7 +310,7 @@ describe('ToolContextController (API)', () => {
 				expect(result.statusCode).toEqual(HttpStatus.NO_CONTENT);
 
 				const deleted: ContextExternalToolEntity | null = await em.findOne(ContextExternalToolEntity, {
-					contextId: contextExternalToolEntity.id,
+					contextId: new ObjectId(contextExternalToolEntity.id),
 				});
 
 				expect(deleted).toBeNull();
@@ -433,7 +433,7 @@ describe('ToolContextController (API)', () => {
 					await setup();
 
 				const response = await loggedInClient.get(
-					`${contextExternalTool1.contextType}/${contextExternalTool1.contextId}`
+					`${contextExternalTool1.contextType}/${contextExternalTool1.contextId.toHexString()}`
 				);
 
 				expect(response.status).toEqual(HttpStatus.OK);
@@ -448,7 +448,7 @@ describe('ToolContextController (API)', () => {
 							],
 							id: contextExternalTool1.id,
 							schoolToolId: contextExternalTool1.schoolTool.id,
-							contextId: contextExternalTool1.contextId,
+							contextId: contextExternalTool1.contextId.toHexString(),
 							contextType: ToolContextType.COURSE,
 							displayName: contextExternalTool1.displayName,
 						},
@@ -461,7 +461,7 @@ describe('ToolContextController (API)', () => {
 							],
 							id: contextExternalTool2.id,
 							schoolToolId: contextExternalTool2.schoolTool.id,
-							contextId: contextExternalTool2.contextId,
+							contextId: contextExternalTool2.contextId.toHexString(),
 							contextType: ToolContextType.COURSE,
 							displayName: contextExternalTool2.displayName,
 						},
@@ -478,7 +478,7 @@ describe('ToolContextController (API)', () => {
 							],
 							id: contextExternalToolFromOtherSchool.id,
 							schoolToolId: contextExternalToolFromOtherSchool.schoolTool.id,
-							contextId: contextExternalToolFromOtherSchool.contextId,
+							contextId: contextExternalToolFromOtherSchool.contextId.toHexString(),
 							contextType: ToolContextType.COURSE,
 							displayName: contextExternalToolFromOtherSchool.displayName,
 						},
@@ -491,7 +491,7 @@ describe('ToolContextController (API)', () => {
 					const { contextExternalTool1 } = await setup();
 
 					const response = await testApiClient.get(
-						`${contextExternalTool1.contextType}/${contextExternalTool1.contextId}`
+						`${contextExternalTool1.contextType}/${contextExternalTool1.contextId.toHexString()}`
 					);
 
 					expect(response.statusCode).toEqual(HttpStatus.UNAUTHORIZED);
@@ -503,7 +503,7 @@ describe('ToolContextController (API)', () => {
 					const { contextExternalTool1, otherLoggedInClient } = await setup();
 
 					const response = await otherLoggedInClient.get(
-						`${contextExternalTool1.contextType}/${contextExternalTool1.contextId}`
+						`${contextExternalTool1.contextType}/${contextExternalTool1.contextId.toHexString()}`
 					);
 
 					expect(response.status).toEqual(HttpStatus.OK);
@@ -568,7 +568,7 @@ describe('ToolContextController (API)', () => {
 				expect(response.status).toEqual(HttpStatus.OK);
 				expect(response.body).toEqual({
 					schoolToolId: contextExternalTool.schoolTool.id,
-					contextId: contextExternalTool.contextId,
+					contextId: contextExternalTool.contextId.toHexString(),
 					contextType: ToolContextType.COURSE,
 					id: contextExternalTool.id,
 					displayName: contextExternalTool.displayName,
@@ -638,7 +638,9 @@ describe('ToolContextController (API)', () => {
 			it('should return unauthorized', async () => {
 				const { contextExternalTool } = await setup();
 
-				const response = await testApiClient.get(`${contextExternalTool.contextType}/${contextExternalTool.contextId}`);
+				const response = await testApiClient.get(
+					`${contextExternalTool.contextType}/${contextExternalTool.contextId.toHexString()}`
+				);
 
 				expect(response.status).toEqual(HttpStatus.UNAUTHORIZED);
 			});
diff --git a/apps/server/src/modules/tool/context-external-tool/entity/context-external-tool.entity.spec.ts b/apps/server/src/modules/tool/context-external-tool/entity/context-external-tool.entity.spec.ts
index b04b7c1ee10..7ffec395d88 100644
--- a/apps/server/src/modules/tool/context-external-tool/entity/context-external-tool.entity.spec.ts
+++ b/apps/server/src/modules/tool/context-external-tool/entity/context-external-tool.entity.spec.ts
@@ -33,7 +33,7 @@ describe(ExternalToolEntity.name, () => {
 				const contextExternalToolEntity: ContextExternalToolEntity = new ContextExternalToolEntity({
 					id: new ObjectId().toHexString(),
 					schoolTool: schoolExternalToolEntityFactory.buildWithId(),
-					contextId: 'mockContextId',
+					contextId: new ObjectId(),
 					contextType: ContextExternalToolType.MEDIA_BOARD,
 					parameters: [],
 				});
diff --git a/apps/server/src/modules/tool/context-external-tool/entity/context-external-tool.entity.ts b/apps/server/src/modules/tool/context-external-tool/entity/context-external-tool.entity.ts
index 0077295ce8c..b43b30b4cbe 100644
--- a/apps/server/src/modules/tool/context-external-tool/entity/context-external-tool.entity.ts
+++ b/apps/server/src/modules/tool/context-external-tool/entity/context-external-tool.entity.ts
@@ -1,6 +1,7 @@
 import { Embedded, Entity, ManyToOne, Property } from '@mikro-orm/core';
 import { BaseEntityWithTimestamps } from '@shared/domain/entity/base.entity';
 import { EntityId } from '@shared/domain/types';
+import { ObjectId } from '@mikro-orm/mongodb';
 import { CustomParameterEntryEntity } from '../../common/entity';
 import { SchoolExternalToolEntity } from '../../school-external-tool/entity';
 import { ContextExternalToolType } from './context-external-tool-type.enum';
@@ -10,7 +11,7 @@ export interface ContextExternalToolEntityProps {
 
 	schoolTool: SchoolExternalToolEntity;
 
-	contextId: string;
+	contextId: EntityId | ObjectId;
 
 	contextType: ContextExternalToolType;
 
@@ -25,7 +26,7 @@ export class ContextExternalToolEntity extends BaseEntityWithTimestamps {
 	schoolTool: SchoolExternalToolEntity;
 
 	@Property()
-	contextId: string;
+	contextId: ObjectId;
 
 	@Property()
 	contextType: ContextExternalToolType;
@@ -42,7 +43,7 @@ export class ContextExternalToolEntity extends BaseEntityWithTimestamps {
 			this.id = props.id;
 		}
 		this.schoolTool = props.schoolTool;
-		this.contextId = props.contextId;
+		this.contextId = new ObjectId(props.contextId);
 		this.contextType = props.contextType;
 		this.displayName = props.displayName;
 		this.parameters = props.parameters ?? [];
diff --git a/apps/server/src/shared/repo/contextexternaltool/context-external-tool.repo.spec.ts b/apps/server/src/shared/repo/contextexternaltool/context-external-tool.repo.spec.ts
index 1334823da8a..a17efc3df59 100644
--- a/apps/server/src/shared/repo/contextexternaltool/context-external-tool.repo.spec.ts
+++ b/apps/server/src/shared/repo/contextexternaltool/context-external-tool.repo.spec.ts
@@ -258,13 +258,13 @@ describe(ContextExternalToolRepo.name, () => {
 
 				const query: ContextExternalToolQuery = {
 					context: {
-						id: contextExternalTool1.contextId,
+						id: contextExternalTool1.contextId.toHexString(),
 					},
 				};
 
 				const result: ContextExternalTool[] = await repo.find(query);
 
-				expect(result[0].contextRef.id).toEqual(contextExternalTool1.contextId);
+				expect(result[0].contextRef.id).toEqual(contextExternalTool1.contextId.toHexString());
 			});
 		});
 
@@ -303,7 +303,7 @@ describe(ContextExternalToolRepo.name, () => {
 
 				const query: ContextExternalToolQuery = {
 					context: {
-						id: contextExternalTool1.contextId,
+						id: contextExternalTool1.contextId.toHexString(),
 					},
 				};
 
@@ -373,7 +373,7 @@ describe(ContextExternalToolRepo.name, () => {
 				expect(result.getProps()).toEqual<ContextExternalToolProps>({
 					id: contextExternalTool.id,
 					contextRef: {
-						id: contextExternalTool.contextId,
+						id: contextExternalTool.contextId.toHexString(),
 						type: ToolContextType.COURSE,
 					},
 					displayName: contextExternalTool.displayName,
@@ -417,7 +417,7 @@ describe(ContextExternalToolRepo.name, () => {
 				expect(result?.getProps()).toEqual<ContextExternalToolProps>({
 					id: contextExternalTool.id,
 					contextRef: {
-						id: contextExternalTool.contextId,
+						id: contextExternalTool.contextId.toHexString(),
 						type: ToolContextType.COURSE,
 					},
 					displayName: contextExternalTool.displayName,
diff --git a/apps/server/src/shared/repo/contextexternaltool/context-external-tool.repo.ts b/apps/server/src/shared/repo/contextexternaltool/context-external-tool.repo.ts
index 2b3b0a7a551..a5bd792ca85 100644
--- a/apps/server/src/shared/repo/contextexternaltool/context-external-tool.repo.ts
+++ b/apps/server/src/shared/repo/contextexternaltool/context-external-tool.repo.ts
@@ -136,7 +136,7 @@ export class ContextExternalToolRepo {
 		});
 
 		const contextRef: ContextRef = new ContextRef({
-			id: entity.contextId,
+			id: entity.contextId.toHexString(),
 			type: this.mapContextTypeToDomainObjectType(entity.contextType),
 		});
 
diff --git a/apps/server/src/shared/repo/contextexternaltool/context-external-tool.scope.spec.ts b/apps/server/src/shared/repo/contextexternaltool/context-external-tool.scope.spec.ts
index 1083e3a85df..4143a6da892 100644
--- a/apps/server/src/shared/repo/contextexternaltool/context-external-tool.scope.spec.ts
+++ b/apps/server/src/shared/repo/contextexternaltool/context-external-tool.scope.spec.ts
@@ -1,6 +1,7 @@
 import { ToolContextType } from '@modules/tool/common/enum';
 import { SchoolExternalToolEntity } from '@modules/tool/school-external-tool/entity';
 import { schoolExternalToolEntityFactory } from '@modules/tool/school-external-tool/testing';
+import { ObjectId } from '@mikro-orm/mongodb';
 import { ContextExternalToolScope } from './context-external-tool.scope';
 
 describe('CourseExternalToolScope', () => {
@@ -63,7 +64,7 @@ describe('CourseExternalToolScope', () => {
 
 				scope.byContextId(schoolExternalToolEntity.id);
 
-				expect(scope.query).toEqual({ contextId: schoolExternalToolEntity.id });
+				expect(scope.query).toEqual({ contextId: new ObjectId(schoolExternalToolEntity.id) });
 			});
 		});
 	});
diff --git a/apps/server/src/shared/repo/contextexternaltool/context-external-tool.scope.ts b/apps/server/src/shared/repo/contextexternaltool/context-external-tool.scope.ts
index b481f31b458..6b3eaa09037 100644
--- a/apps/server/src/shared/repo/contextexternaltool/context-external-tool.scope.ts
+++ b/apps/server/src/shared/repo/contextexternaltool/context-external-tool.scope.ts
@@ -2,6 +2,7 @@ import { ToolContextType } from '@modules/tool/common/enum';
 import { ContextExternalToolEntity } from '@modules/tool/context-external-tool/entity';
 import { EntityId } from '@shared/domain/types';
 import { Scope } from '@shared/repo';
+import { ObjectId } from '@mikro-orm/mongodb';
 
 export class ContextExternalToolScope extends Scope<ContextExternalToolEntity> {
 	byId(id: EntityId | undefined): ContextExternalToolScope {
@@ -21,7 +22,7 @@ export class ContextExternalToolScope extends Scope<ContextExternalToolEntity> {
 
 	byContextId(contextId: EntityId | undefined): ContextExternalToolScope {
 		if (contextId !== undefined) {
-			this.addQuery({ contextId });
+			this.addQuery({ contextId: new ObjectId(contextId) });
 		}
 
 		return this;
diff --git a/backup/setup/context-external-tools.json b/backup/setup/context-external-tools.json
index 1c1c03b942f..2b6ed119fbe 100644
--- a/backup/setup/context-external-tools.json
+++ b/backup/setup/context-external-tools.json
@@ -12,7 +12,7 @@
 		"schoolTool": {
 			"$oid": "644a46e5d0a8301e6cf25d86"
 		},
-		"contextId": "0000dcfbfb5c7a3f00bf21ab",
+		"contextId": { "$oid" : "0000dcfbfb5c7a3f00bf21ab" },
 		"contextType": "course",
 		"displayName": "Google-Suche",
 		"parameters": [
@@ -26,7 +26,7 @@
 		"_id": {
 			"$oid": "647de3cfab79fd5bd57e68f4"
 		},
-		"contextId": "0000dcfbfb5c7a3f00bf21ab",
+		"contextId": { "$oid" : "0000dcfbfb5c7a3f00bf21ab" },
 		"contextType": "course",
 		"parameters": [],
 		"schoolTool": {
diff --git a/backup/setup/migrations.json b/backup/setup/migrations.json
index 225324cd518..d8778bc0d98 100644
--- a/backup/setup/migrations.json
+++ b/backup/setup/migrations.json
@@ -232,5 +232,14 @@
 		"created_at": {
 			"$date": "2024-10-02T20:12:54.209Z"
 		}
+	},
+	{
+		"_id": {
+			"$oid": "6717bba2b08d6ccb1dd5db60"
+		},
+		"name": "Migration20241022205656",
+		"created_at": {
+			"$date": "2024-10-22T14:50:10.445Z"
+		}
 	}
 ]