diff --git a/docs/use-cases/audio_upload.feature b/docs/use-cases/audio_upload.feature
index 16fcc83..13d1df8 100644
--- a/docs/use-cases/audio_upload.feature
+++ b/docs/use-cases/audio_upload.feature
@@ -214,3 +214,44 @@ Feature: Upload an audio recording, get a private Swedish transcript, discuss it
     When the model changes a word
     Then the segment containing it carries the reconciled word
     And the segment's timing is unchanged
+
+  # ADR-035 decision 8: hardening from the adversarial review
+
+  Scenario: Chat about a recording is offered with local models only
+    When I open the chat for my recording
+    Then the model list holds only models that run on the homelab
+    And a cloud model the shared chat service knows is not in it
+
+  Scenario: A forged cloud model is never sent the transcript
+    When a chat request names a cloud model
+    Then a local model answers instead, and nothing was sent to the cloud one
+
+  Scenario: A wedged engine does not use up the whole job
+    When the primary engine never answers
+    Then it fails at its own deadline while the job is still alive
+    And the fallback runs, unless the job itself was cancelled or timed out
+
+  Scenario: A file that lies about its length is refused
+    When a file claims to be short but converts to more than the limit
+    Then the job fails with a plain explanation and no engine receives the audio
+
+  Scenario: A truncated recording is refused, not half transcribed
+    When a file converts to far less audio than it claimed
+    Then the job fails and asks for the complete recording
+
+  Scenario: A full queue is a retry, not an error
+    When too many recordings are already waiting
+    Then the upload is answered as busy, its row is failed honestly and its audio is deleted
+
+  Scenario: One user cannot fill the queue for everyone
+    When one user has several recordings waiting
+    Then further uploads from that user are refused and other users are not affected
+
+  Scenario: Errors are shown as kinds, never their text
+    When a model or an engine fails
+    Then the log, the stored reason and the page carry a kind such as timeout or http_502
+    And never the provider's response, a file path or a word from the transcript
+
+  Scenario: Input that cannot be right is a client error
+    When the id is not an id, or a header or title holds control bytes
+    Then the answer is a 4xx or the title is cleaned, never a server error