diff --git a/src/llm_orchestration_service_api.py b/src/llm_orchestration_service_api.py
index 110c299..12cb0ed 100644
--- a/src/llm_orchestration_service_api.py
+++ b/src/llm_orchestration_service_api.py
@@ -281,6 +281,12 @@ async def orchestrate_llm_request(
         # Process the request
         response = await orchestration_service.process_orchestration_request(request)
 
+        buttons_present = bool(response.buttons)
+        buttons_count = len(response.buttons) if response.buttons else 0
+        logger.info(
+            f"[orchestrate] buttons in response for chatId {request.chatId}: "
+            f"present={buttons_present}, count={buttons_count}"
+        )
         logger.info(f"Successfully processed request for chatId: {request.chatId}")
         return response
 
@@ -364,6 +370,10 @@ async def test_orchestrate_llm_request(
 
         # If response is already TestOrchestrationResponse (when environment is testing), return it directly
         if isinstance(response, TestOrchestrationResponse):
+            buttons_count = len(response.buttons) if response.buttons else 0
+            logger.info(
+                f"[test_orchestrate] buttons present in response: {buttons_count}"
+            )
             logger.info(
                 f"Successfully processed test request for environment: {request.environment}"
             )
@@ -375,9 +385,9 @@ async def test_orchestrate_llm_request(
             questionOutOfLLMScope=response.questionOutOfLLMScope,
             inputGuardFailed=response.inputGuardFailed,
             content=response.content,
+            buttons=response.buttons,
             chunks=None,  # OrchestrationResponse doesn't have chunks
         )
-
         logger.info(
             f"Successfully processed test request for environment: {request.environment}"
         )
diff --git a/src/models/request_models.py b/src/models/request_models.py
index 689c68c..c6c58eb 100644
--- a/src/models/request_models.py
+++ b/src/models/request_models.py
@@ -138,6 +138,16 @@ class DocumentReference(BaseModel):
     relevance_score: float = Field(..., description="Relevance score (0-1)")
 
 
+class ChoiceButton(BaseModel):
+    """A single MCQ choice button returned in an orchestration response."""
+
+    title: str = Field(..., description="Button label shown to the user")
+    payload: str = Field(
+        ...,
+        description="Routing string sent when the button is clicked (e.g. '#service, /POST/...')",
+    )
+
+
 class OrchestrationResponse(BaseModel):
     """Model for LLM orchestration response."""
 
@@ -150,6 +160,10 @@ class OrchestrationResponse(BaseModel):
         ..., description="Whether input guard validation failed"
     )
     content: str = Field(..., description="Response content with citations")
+    buttons: Optional[List[ChoiceButton]] = Field(
+        default=None,
+        description="Optional list of choice buttons for MCQ step responses",
+    )
 
 
 # New models for embedding and context generation
@@ -261,6 +275,10 @@ class TestOrchestrationResponse(BaseModel):
         ..., description="Whether input guard validation failed"
     )
     content: str = Field(..., description="Response content with citations")
+    buttons: Optional[List[ChoiceButton]] = Field(
+        default=None,
+        description="Optional list of choice buttons for MCQ step responses",
+    )
     chunks: Optional[List[ChunkInfo]] = Field(
         default=None, description="Retrieved chunks with rank and content"
     )
diff --git a/src/utils/input_sanitizer.py b/src/utils/input_sanitizer.py
index 3627038..b0bd146 100644
--- a/src/utils/input_sanitizer.py
+++ b/src/utils/input_sanitizer.py
@@ -57,6 +57,8 @@ def strip_html_tags(text: str) -> str:
         if not text:
             return text
 
+        text = html.unescape(text)
+
         # First pass: Remove dangerous tags and their content
         for tag in InputSanitizer.DANGEROUS_TAGS:
             # Remove opening tag, content, and closing tag
@@ -74,9 +76,6 @@ def strip_html_tags(text: str) -> str:
         # Third pass: Remove all remaining HTML tags
         text = re.sub(r"<[^>]+>", "", text)
 
-        # Unescape HTML entities (e.g., &lt; -> <)
-        text = html.unescape(text)
-
         return text
 
     @staticmethod
diff --git a/tests/test_input_sanitizer.py b/tests/test_input_sanitizer.py
new file mode 100644
index 0000000..ad129f5
--- /dev/null
+++ b/tests/test_input_sanitizer.py
@@ -0,0 +1,125 @@
+"""Unit tests for InputSanitizer — focused on #service prefix safety.
+
+Validates that strip_html_tags() and sanitize_message() leave the
+#service, /POST/... routing prefix characters (#, comma, /) untouched,
+so that prefix detection logic in downstream handlers can always match.
+"""
+
+import pytest
+
+from src.utils.input_sanitizer import InputSanitizer
+
+
+class TestSanitizeMessageServicePrefix:
+    """Primary passthrough: #service, /METHOD/... payloads must survive sanitization unchanged."""
+
+    def test_exact_service_prefix_passthrough(self) -> None:
+        """The canonical #service prefix must survive sanitization bit-for-bit identical."""
+        msg = "#service, /POST/services/active/foo"
+        assert InputSanitizer.sanitize_message(msg) == msg
+
+    @pytest.mark.parametrize(
+        "msg",
+        [
+            "#service, /POST/services/active/foo",
+            "#service, /GET/services/list",
+            "#service, /DELETE/services/active/foo",
+            "#service, /PUT/services/active/foo",
+            "#service, /PATCH/services/active/foo",
+            "#service, /POST/services/active/foo?status=true",
+            "#service, /POST/services/active/foo?a=1&b=2",
+            "#service, /POST/services/active/foo#anchor",
+        ],
+    )
+    def test_service_prefix_variants_passthrough(self, msg: str) -> None:
+        """All #service, /METHOD/... variants must pass through unmodified."""
+        assert InputSanitizer.sanitize_message(msg) == msg
+
+
+class TestSanitizeMessageHtmlStripping:
+    """Confirms HTML IS stripped while #service prefix characters survive.
+
+    These tests prove the sanitizer is active (not a no-op) and that it
+    surgically removes only HTML constructs, leaving #, comma, and / intact.
+    """
+
+    def test_bold_tags_stripped_prefix_survives(self) -> None:
+        result = InputSanitizer.sanitize_message(
+            "#service, <b>/POST/</b>services/active/foo"
+        )
+        assert result == "#service, /POST/services/active/foo"
+
+    def test_script_tag_content_stripped_path_survives(self) -> None:
+        """Dangerous <script> tag and its content are removed; path remainder survives."""
+        result = InputSanitizer.sanitize_message(
+            "#service, /POST/<script>alert(1)</script>foo"
+        )
+        assert result == "#service, /POST/foo"
+
+    def test_entity_encoded_script_tag_stripped_path_survives(self) -> None:
+        """Entity-encoded <script> tag is decoded then stripped; path remainder survives.
+
+        If html.unescape() ran *after* tag stripping, &lt;script&gt;...&lt;/script&gt;
+        would survive all three stripping passes and be decoded into a live <script>
+        tag in the output.  The sanitizer must unescape *before* stripping to close
+        this bypass.
+        """
+        result = InputSanitizer.sanitize_message(
+            "#service, /POST/&lt;script&gt;alert(1)&lt;/script&gt;foo"
+        )
+        assert result == "#service, /POST/foo"
+
+    def test_html_entities_unescaped_prefix_intact(self) -> None:
+        """html.unescape() runs inside strip_html_tags(); confirm it does not alter #, comma, or /."""
+        result = InputSanitizer.sanitize_message("#service, /POST/foo&amp;bar")
+        assert result == "#service, /POST/foo&bar"
+
+    def test_hash_not_treated_as_html_tag(self) -> None:
+        """# is never matched by <[^>]+>; verify it is never stripped."""
+        result = InputSanitizer.sanitize_message("#service, /GET/list")
+        assert result.startswith("#service")
+
+    def test_forward_slash_not_stripped(self) -> None:
+        """/ characters must survive all three passes of strip_html_tags()."""
+        result = InputSanitizer.sanitize_message("#service, /POST/a/b/c")
+        assert "/POST/a/b/c" in result
+
+    def test_comma_not_stripped(self) -> None:
+        """Comma separator between prefix and path must survive sanitization."""
+        result = InputSanitizer.sanitize_message("#service, /GET/list")
+        assert ", " in result
+
+
+class TestSanitizeMessageWhitespace:
+    """Documents whitespace normalisation rules that apply even to #service payloads.
+
+    Callers constructing #service payloads must use exactly one space after
+    the comma; this class documents what happens if they don't.
+    """
+
+    def test_single_space_after_comma_preserved(self) -> None:
+        """A single space between the comma and the slash is NOT collapsed or removed."""
+        msg = "#service, /POST/services/active/foo"
+        assert InputSanitizer.sanitize_message(msg) == msg
+
+    def test_double_space_after_comma_collapsed_to_single(self) -> None:
+        """Two consecutive spaces are collapsed to one; callers must send exactly one space."""
+        result = InputSanitizer.sanitize_message("#service,  /POST/services/active/foo")
+        assert result == "#service, /POST/services/active/foo"
+
+    def test_leading_whitespace_stripped(self) -> None:
+        result = InputSanitizer.sanitize_message(
+            "  #service, /POST/services/active/foo"
+        )
+        assert result == "#service, /POST/services/active/foo"
+
+    def test_trailing_whitespace_stripped(self) -> None:
+        result = InputSanitizer.sanitize_message(
+            "#service, /POST/services/active/foo  "
+        )
+        assert result == "#service, /POST/services/active/foo"
+
+    def test_tab_in_prefix_converted_to_space_then_collapsed(self) -> None:
+        """Tabs within the prefix are normalised along with spaces; a tab after the comma becomes a single space."""
+        result = InputSanitizer.sanitize_message("#service,\t/POST/services/active/foo")
+        assert result == "#service, /POST/services/active/foo"