diff --git a/plugins/catalog-backend/src/catalog/types.ts b/plugins/catalog-backend/src/catalog/types.ts
index d00c38f536..1fbf337986 100644
--- a/plugins/catalog-backend/src/catalog/types.ts
+++ b/plugins/catalog-backend/src/catalog/types.ts
@@ -58,7 +58,7 @@ export type EntitiesRequest = {
  */
 export type EntitiesResponseItems =
   | {
-      type: 'objects';
+      type: 'object';
       entities: (Entity | null)[];
     }
   | {
diff --git a/plugins/catalog-backend/src/service/AuthorizedEntitiesCatalog.ts b/plugins/catalog-backend/src/service/AuthorizedEntitiesCatalog.ts
index 225c87cae9..073e153dcc 100644
--- a/plugins/catalog-backend/src/service/AuthorizedEntitiesCatalog.ts
+++ b/plugins/catalog-backend/src/service/AuthorizedEntitiesCatalog.ts
@@ -60,7 +60,7 @@ export class AuthorizedEntitiesCatalog implements EntitiesCatalog {
 
     if (authorizeDecision.result === AuthorizeResult.DENY) {
       return {
-        entities: { type: 'objects', entities: [] },
+        entities: { type: 'object', entities: [] },
         pageInfo: { hasNextPage: false },
       };
     }
@@ -93,7 +93,7 @@ export class AuthorizedEntitiesCatalog implements EntitiesCatalog {
     if (authorizeDecision.result === AuthorizeResult.DENY) {
       return {
         items: {
-          type: 'objects',
+          type: 'object',
           entities: new Array(request.entityRefs.length).fill(null),
         },
       };
@@ -126,7 +126,7 @@ export class AuthorizedEntitiesCatalog implements EntitiesCatalog {
 
     if (authorizeDecision.result === AuthorizeResult.DENY) {
       return {
-        items: { type: 'objects', entities: [] },
+        items: { type: 'object', entities: [] },
         pageInfo: {},
         totalItems: 0,
       };
diff --git a/plugins/catalog-backend/src/service/createRouter.test.ts b/plugins/catalog-backend/src/service/createRouter.test.ts
index 8efb6543a3..d4940e4a35 100644
--- a/plugins/catalog-backend/src/service/createRouter.test.ts
+++ b/plugins/catalog-backend/src/service/createRouter.test.ts
@@ -136,7 +136,7 @@ describe('createRouter readonly disabled', () => {
       ];
 
       entitiesCatalog.queryEntities.mockResolvedValueOnce({
-        items: { type: 'objects', entities: [entities[0]] },
+        items: { type: 'object', entities: [entities[0]] },
         pageInfo: {},
         totalItems: 1,
       });
@@ -149,7 +149,7 @@ describe('createRouter readonly disabled', () => {
 
     it('parses single and multiple request parameters and passes them down', async () => {
       entitiesCatalog.queryEntities.mockResolvedValueOnce({
-        items: { type: 'objects', entities: [] },
+        items: { type: 'object', entities: [] },
         pageInfo: {},
         totalItems: 0,
       });
@@ -185,7 +185,7 @@ describe('createRouter readonly disabled', () => {
       ];
 
       entitiesCatalog.queryEntities.mockResolvedValueOnce({
-        items: { type: 'objects', entities: items },
+        items: { type: 'object', entities: items },
         totalItems: 100,
         pageInfo: { nextCursor: mockCursor() },
       });
@@ -203,7 +203,7 @@ describe('createRouter readonly disabled', () => {
 
     it('parses initial request', async () => {
       entitiesCatalog.queryEntities.mockResolvedValueOnce({
-        items: { type: 'objects', entities: [] },
+        items: { type: 'object', entities: [] },
         pageInfo: {},
         totalItems: 0,
       });
@@ -239,7 +239,7 @@ describe('createRouter readonly disabled', () => {
 
     it('parses encoded params request', async () => {
       entitiesCatalog.queryEntities.mockResolvedValueOnce({
-        items: { type: 'objects', entities: [] },
+        items: { type: 'object', entities: [] },
         pageInfo: {},
         totalItems: 0,
       });
@@ -283,7 +283,7 @@ describe('createRouter readonly disabled', () => {
       ];
 
       entitiesCatalog.queryEntities.mockResolvedValueOnce({
-        items: { type: 'objects', entities: items },
+        items: { type: 'object', entities: items },
         totalItems: 100,
         pageInfo: { nextCursor: mockCursor() },
       });
@@ -312,7 +312,7 @@ describe('createRouter readonly disabled', () => {
       ];
 
       entitiesCatalog.queryEntities.mockResolvedValueOnce({
-        items: { type: 'objects', entities: items },
+        items: { type: 'object', entities: items },
         totalItems: 100,
         pageInfo: {
           nextCursor: mockCursor({ fullTextFilter: { term: 'mySearch' } }),
@@ -354,7 +354,7 @@ describe('createRouter readonly disabled', () => {
       ];
 
       entitiesCatalog.queryEntities.mockResolvedValueOnce({
-        items: { type: 'objects', entities: items },
+        items: { type: 'object', entities: items },
         totalItems: 100,
         pageInfo: { nextCursor: mockCursor() },
       });
@@ -379,7 +379,7 @@ describe('createRouter readonly disabled', () => {
       ];
 
       entitiesCatalog.queryEntities.mockResolvedValueOnce({
-        items: { type: 'objects', entities: items },
+        items: { type: 'object', entities: items },
         totalItems: 100,
         pageInfo: { nextCursor: mockCursor() },
       });
@@ -402,7 +402,7 @@ describe('createRouter readonly disabled', () => {
         },
       };
       entitiesCatalog.entities.mockResolvedValue({
-        entities: { type: 'objects', entities: [entity] },
+        entities: { type: 'object', entities: [entity] },
         pageInfo: { hasNextPage: false },
       });
 
@@ -419,7 +419,7 @@ describe('createRouter readonly disabled', () => {
 
     it('responds with a 404 for missing entities', async () => {
       entitiesCatalog.entities.mockResolvedValue({
-        entities: { type: 'objects', entities: [] },
+        entities: { type: 'object', entities: [] },
         pageInfo: { hasNextPage: false },
       });
 
@@ -446,7 +446,7 @@ describe('createRouter readonly disabled', () => {
         },
       };
       entitiesCatalog.entitiesBatch.mockResolvedValue({
-        items: { type: 'objects', entities: [entity] },
+        items: { type: 'object', entities: [entity] },
       });
 
       const response = await request(app).get('/entities/by-name/k/ns/n');
@@ -462,7 +462,7 @@ describe('createRouter readonly disabled', () => {
 
     it('responds with a 404 for missing entities', async () => {
       entitiesCatalog.entitiesBatch.mockResolvedValue({
-        items: { type: 'objects', entities: [null] },
+        items: { type: 'object', entities: [null] },
       });
 
       const response = await request(app).get('/entities/by-name/b/d/c');
@@ -534,7 +534,7 @@ describe('createRouter readonly disabled', () => {
       };
       const entityRef = stringifyEntityRef(entity);
       entitiesCatalog.entitiesBatch.mockResolvedValue({
-        items: { type: 'objects', entities: [entity] },
+        items: { type: 'object', entities: [entity] },
       });
       const response = await request(app)
         .post('/entities/by-refs?filter=kind=Component')
@@ -910,7 +910,7 @@ describe('createRouter readonly enabled', () => {
       ];
 
       entitiesCatalog.queryEntities.mockResolvedValueOnce({
-        items: { type: 'objects', entities: [entities[0]] },
+        items: { type: 'object', entities: [entities[0]] },
         pageInfo: {},
         totalItems: 1,
       });
@@ -1130,7 +1130,7 @@ describe('NextRouter permissioning', () => {
       },
     };
     entitiesCatalog.entities.mockResolvedValueOnce({
-      entities: { type: 'objects', entities: [spideySense] },
+      entities: { type: 'object', entities: [spideySense] },
       pageInfo: { hasNextPage: false },
     });
 
diff --git a/plugins/catalog-backend/src/service/createRouter.ts b/plugins/catalog-backend/src/service/createRouter.ts
index b670253089..7208c29a89 100644
--- a/plugins/catalog-backend/src/service/createRouter.ts
+++ b/plugins/catalog-backend/src/service/createRouter.ts
@@ -23,7 +23,7 @@ import {
   stringifyEntityRef,
 } from '@backstage/catalog-model';
 import { Config } from '@backstage/config';
-import { InputError, NotFoundError, serializeError } from '@backstage/errors';
+import { InputError, serializeError } from '@backstage/errors';
 import express from 'express';
 import yn from 'yn';
 import { z } from 'zod';
@@ -272,9 +272,7 @@ export async function createRouter(
           filter: basicEntityFilter({ 'metadata.uid': uid }),
           credentials: await httpAuth.credentials(req),
         });
-        if (!writeSingleEntityResponse(res, entities)) {
-          throw new NotFoundError(`No entity with uid ${uid}`);
-        }
+        writeSingleEntityResponse(res, entities, `No entity with uid ${uid}`);
       })
       .delete('/entities/by-uid/:uid', async (req, res) => {
         const { uid } = req.params;
@@ -289,11 +287,11 @@ export async function createRouter(
           entityRefs: [stringifyEntityRef({ kind, namespace, name })],
           credentials: await httpAuth.credentials(req),
         });
-        if (!writeSingleEntityResponse(res, items)) {
-          throw new NotFoundError(
-            `No entity named '${name}' found, with kind '${kind}' in namespace '${namespace}'`,
-          );
-        }
+        writeSingleEntityResponse(
+          res,
+          items,
+          `No entity named '${name}' found, with kind '${kind}' in namespace '${namespace}'`,
+        );
       })
       .get(
         '/entities/by-name/:kind/:namespace/:name/ancestry',
diff --git a/plugins/catalog-backend/src/service/response/process.ts b/plugins/catalog-backend/src/service/response/process.ts
index 26ab544a4d..7e7730d697 100644
--- a/plugins/catalog-backend/src/service/response/process.ts
+++ b/plugins/catalog-backend/src/service/response/process.ts
@@ -23,7 +23,7 @@ export function processRawEntitiesResult(
 ): EntitiesResponseItems {
   if (transform) {
     return {
-      type: 'objects',
+      type: 'object',
       entities: serializedEntities.map(e =>
         e !== null ? transform(JSON.parse(e)) : e,
       ),
@@ -47,7 +47,7 @@ export function processEntitiesResponseItems(
     return processRawEntitiesResult(response.entities, transform);
   }
   return {
-    type: 'objects',
+    type: 'object',
     entities: response.entities.map(e => (e !== null ? transform(e) : e)),
   };
 }
@@ -55,7 +55,7 @@ export function processEntitiesResponseItems(
 export function entitiesResponseToObjects(
   response: EntitiesResponseItems,
 ): (Entity | null)[] {
-  if (response.type === 'objects') {
+  if (response.type === 'object') {
     return response.entities;
   }
   return response.entities.map(e => (e !== null ? JSON.parse(e) : e));
diff --git a/plugins/catalog-backend/src/service/response/write.test.ts b/plugins/catalog-backend/src/service/response/write.test.ts
new file mode 100644
index 0000000000..412aefe404
--- /dev/null
+++ b/plugins/catalog-backend/src/service/response/write.test.ts
@@ -0,0 +1,125 @@
+/*
+ * Copyright 2024 The Backstage Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import express from 'express';
+import { mockErrorHandler } from '@backstage/backend-test-utils';
+import request from 'supertest';
+import { writeSingleEntityResponse } from './write';
+
+describe('writeSingleEntityResponse', () => {
+  const app = express();
+  app.use(express.json());
+  app.get('/echo', (req, res) => {
+    writeSingleEntityResponse(res, req.body, 'not found');
+  });
+  app.use(mockErrorHandler());
+
+  describe('in object form', () => {
+    it('should write a single entity', async () => {
+      const res = await request(app)
+        .get('/echo')
+        .send({
+          type: 'object',
+          entities: [{ kind: 'Component' }, { kind: 'User' }],
+        });
+
+      expect(res.status).toBe(200);
+      expect(res.type).toBe('application/json');
+      expect(res.header['content-type']).toBe(
+        'application/json; charset=utf-8',
+      );
+      expect(res.body).toEqual({ kind: 'Component' });
+    });
+
+    it('should write a missing entity', async () => {
+      const res = await request(app)
+        .get('/echo')
+        .send({ type: 'object', entities: [null] });
+
+      expect(res.status).toBe(404);
+      expect(res.type).toBe('application/json');
+      expect(res.header['content-type']).toBe(
+        'application/json; charset=utf-8',
+      );
+      expect(res.body).toMatchObject({
+        error: { name: 'NotFoundError', message: 'not found' },
+      });
+    });
+
+    it('should write no entities', async () => {
+      const res = await request(app)
+        .get('/echo')
+        .send({ type: 'object', entities: [] });
+
+      expect(res.status).toBe(404);
+      expect(res.type).toBe('application/json');
+      expect(res.header['content-type']).toBe(
+        'application/json; charset=utf-8',
+      );
+      expect(res.body).toMatchObject({
+        error: { name: 'NotFoundError', message: 'not found' },
+      });
+    });
+  });
+
+  describe('in raw form', () => {
+    it('should write a single entity', async () => {
+      const res = await request(app)
+        .get('/echo')
+        .send({
+          type: 'raw',
+          entities: ['{"kind":"Component"}', '{"kind":"User"}'],
+        });
+
+      expect(res.status).toBe(200);
+      expect(res.type).toBe('application/json');
+      expect(res.header['content-type']).toBe(
+        'application/json; charset=utf-8',
+      );
+      expect(res.body).toEqual({ kind: 'Component' });
+    });
+
+    it('should write a missing entity', async () => {
+      const res = await request(app)
+        .get('/echo')
+        .send({ type: 'raw', entities: [null] });
+
+      expect(res.status).toBe(404);
+      expect(res.type).toBe('application/json');
+      expect(res.header['content-type']).toBe(
+        'application/json; charset=utf-8',
+      );
+      expect(res.body).toMatchObject({
+        error: { name: 'NotFoundError', message: 'not found' },
+      });
+    });
+
+    it('should write no entities', async () => {
+      const res = await request(app)
+        .get('/echo')
+        .send({ type: 'raw', entities: [] });
+
+      expect(res.status).toBe(404);
+      expect(res.type).toBe('application/json');
+      expect(res.header['content-type']).toBe(
+        'application/json; charset=utf-8',
+      );
+      expect(res.body).toMatchObject({
+        error: { name: 'NotFoundError', message: 'not found' },
+      });
+    });
+  });
+});
diff --git a/plugins/catalog-backend/src/service/response/write.ts b/plugins/catalog-backend/src/service/response/write.ts
index 1f9392e3a9..1dac8d3ce4 100644
--- a/plugins/catalog-backend/src/service/response/write.ts
+++ b/plugins/catalog-backend/src/service/response/write.ts
@@ -17,27 +17,29 @@
 import { Response } from 'express';
 import { EntitiesResponseItems } from '../../catalog/types';
 import { JsonValue } from '@backstage/types';
+import { NotFoundError } from '@backstage/errors';
 
 const JSON_CONTENT_TYPE = 'application/json; charset=utf-8';
 
 export function writeSingleEntityResponse(
   res: Response,
   response: EntitiesResponseItems,
-): boolean {
-  const entity = response.entities[0];
-  if (!entity) {
-    return false;
-  }
+  notFoundMessage: string,
+) {
+  if (response.type === 'object') {
+    if (!response.entities[0]) {
+      throw new NotFoundError(notFoundMessage);
+    }
 
-  if (typeof entity === 'string') {
-    res.setHeader('Content-Type', JSON_CONTENT_TYPE);
-    res.status(200);
-    res.write(entity);
+    res.json(response.entities[0]);
   } else {
-    res.json(entity);
-  }
+    if (!response.entities[0]) {
+      throw new NotFoundError(notFoundMessage);
+    }
 
-  return true;
+    res.setHeader('Content-Type', JSON_CONTENT_TYPE);
+    res.end(response.entities[0]);
+  }
 }
 
 export function writeEntitiesResponse(
@@ -45,7 +47,7 @@ export function writeEntitiesResponse(
   response: EntitiesResponseItems,
   responseWrapper?: (entities: JsonValue) => JsonValue,
 ) {
-  if (response.type === 'objects') {
+  if (response.type === 'object') {
     res.json(
       responseWrapper
         ? responseWrapper?.(response.entities)
@@ -55,7 +57,6 @@ export function writeEntitiesResponse(
   }
 
   res.setHeader('Content-Type', JSON_CONTENT_TYPE);
-  res.status(200);
 
   // responseWrapper allows the caller to render the entities within an object
   let trailing = '';