@@ -222,7 +222,7 @@ export interface ProviderResponse {
 export function isVendorJsonForbidden(response: ProviderResponse): boolean {
   return (
     response.status === 403 &&
-    (response.headers.get('content-type') ?? '').includes('application/json')
+    (response.headers.get('content-type') ?? '').toLowerCase().includes('application/json')
   )
 }
 
 
@@ -156,6 +156,14 @@ describe('validateHubspotServiceAccount', () => {
       'lacks the contacts scope',
       () => jsonResponse({ status: 'error', category: 'MISSING_SCOPES' }, 403),
     ],
+    [
+      'lacks the contacts scope, answered with a mixed-case JSON media type',
+      () =>
+        new Response(JSON.stringify({ status: 'error', category: 'MISSING_SCOPES' }), {
+          status: 403,
+          headers: { 'Content-Type': 'Application/JSON; charset=UTF-8' },
+        }),
+    ],
   ])(
     'accepts a service key that account-info refuses but that %s',
     async (_case, contactsAnswer) => {
 
@@ -37,6 +37,26 @@ describe('ZoomInfo requests', () => {
     expect(mockSecureFetchWithValidation).not.toHaveBeenCalled()
   })
 
+  it.each([
+    ['a blank', '   ', 'client-blank-token'],
+    ['a non-string', 123, 'client-numeric-token'],
+  ])(
+    'refuses %s access token in the token response before calling the API',
+    async (_case, token, clientId) => {
+      mockSecureFetchWithValidation.mockResolvedValue(
+        Response.json({ access_token: token, expires_in: 3600 })
+      )
+
+      await expect(
+        requestZoomInfo({ ...REQUEST, clientId, clientSecret: 'secret' }, 'request-4')
+      ).rejects.toMatchObject({
+        message: 'ZoomInfo token response missing access_token',
+        status: 500,
+      })
+      expect(mockSecureFetchWithValidation).toHaveBeenCalledTimes(1)
+    }
+  )
+
   it('keeps reporting an inline token refusal exactly as before', async () => {
     mockSecureFetchWithValidation.mockResolvedValue(
       Response.json({ error: 'invalid_client' }, { status: 401 })
 
@@ -1,5 +1,6 @@
 import { createHash } from 'node:crypto'
 import { createLogger } from '@sim/logger'
+import { isRecordLike } from '@sim/utils/object'
 import {
   MAX_JSON_API_RESPONSE_BYTES,
   secureFetchWithValidation,
@@ -130,12 +131,8 @@ export async function requestZoomInfoToken(
     logger.warn('ZoomInfo token fetch failed', { requestId, status: response.status, error: text })
     throw new ZoomInfoTokenError(response.status)
   }
-  const data = (await response.json()) as {
-    access_token?: string
-    expires_in?: number
-    scope?: string
-  }
-  if (!data.access_token) {
+  const data: unknown = await response.json()
+  if (!isRecordLike(data) || typeof data.access_token !== 'string' || !data.access_token.trim()) {
     throw new ZoomInfoOperationError('ZoomInfo token response missing access_token', 500)
   }
   return {
Original file line number	Diff line number	Diff line change
`@@ -222,7 +222,7 @@ export interface ProviderResponse {`
`222`	`222`	`export function isVendorJsonForbidden(response: ProviderResponse): boolean {`
`223`	`223`	`return (`
`224`	`224`	`response.status === 403 &&`
`225`		`- (response.headers.get('content-type') ?? '').includes('application/json')`
	`225`	`+ (response.headers.get('content-type') ?? '').toLowerCase().includes('application/json')`
`226`	`226`	`)`
`227`	`227`	`}`
`228`	`228`