From ee25a238c857caff95f733c522ecc6b2e892de8e Mon Sep 17 00:00:00 2001
From: Aran30 <aaron30@live.be>
Date: Sat, 27 Jun 2026 14:27:57 +0200
Subject: [PATCH 1/9] added llm based GUI personalization function

---
 .../backend/routers/generation_router.py      | 112 ++++++++++++++++++
 1 file changed, 112 insertions(+)

diff --git a/besser/utilities/web_modeling_editor/backend/routers/generation_router.py b/besser/utilities/web_modeling_editor/backend/routers/generation_router.py
index b93b8e074..039558685 100644
--- a/besser/utilities/web_modeling_editor/backend/routers/generation_router.py
+++ b/besser/utilities/web_modeling_editor/backend/routers/generation_router.py
@@ -228,6 +228,118 @@ async def recommend_agent_config_llm(
         raise GenerationError("Failed to generate LLM recommendation") from exc
 
 
+@router.post("/personalize-gui-page")
+@handle_endpoint_errors("personalize_gui_page")
+async def personalize_gui_page(payload: Dict[str, Any] = Body(...)):
+    """Personalize a GUI page (GrapesJS) for a user profile using an LLM.
+
+    Open endpoint (no GitHub session required). The OpenAI API key is resolved
+    from the payload or the server's ``OPENAI_API_KEY`` environment variable.
+
+    Request body:
+        guiPage: {"components": [...], "css": [...]}  -- a GrapesJS page snapshot
+        userProfileModel: <UserDiagram UML model JSON>
+        pageName: str (optional)
+        model: str (optional OpenAI model id)
+
+    Returns the same ``{components, css}`` shape adapted in style and content,
+    ready to be imported back into the editor as a page variant.
+    """
+    gui_page = payload.get("guiPage")
+    if not isinstance(gui_page, dict):
+        raise ValidationError(
+            "guiPage is required and must be a JSON object with 'components' and 'css'"
+        )
+
+    user_profile_model = payload.get("userProfileModel")
+    if not isinstance(user_profile_model, dict):
+        raise ValidationError("userProfileModel is required and must be a JSON object")
+
+    components = gui_page.get("components")
+    if not isinstance(components, list):
+        raise ValidationError("guiPage.components must be a list")
+    css = gui_page.get("css")
+    if not isinstance(css, list):
+        css = []
+
+    page_name = payload.get("pageName") if isinstance(payload.get("pageName"), str) else "page"
+    requested_model = payload.get("model")
+    llm_model = (
+        requested_model
+        if isinstance(requested_model, str) and requested_model.strip()
+        else "gpt-5"
+    )
+
+    # Transform the user profile (UserDiagram) into its JSON object representation.
+    profile_document = _generate_user_profile_document(user_profile_model)
+
+    system_prompt = (
+        "You are a UI personalization assistant for a GrapesJS-based no-code GUI editor. "
+        "You receive a single GUI page as GrapesJS data: a 'components' array (the component "
+        "tree, each node carrying fields such as type, tagName, attributes, classes, components, "
+        "and text content) and a 'css' array (GrapesJS style-rule objects with 'selectors', "
+        "'style', and 'pageId'). You also receive a user profile. "
+        "Adapt the page to this specific user in terms of CONTENT (wording, tone, labels, "
+        "headings, copy) and STYLE (colors, spacing, font sizes, emphasis via the 'style' maps). "
+        "STRICT RULES: "
+        "1) Return ONLY a single JSON object with EXACTLY this shape: "
+        '{"components": [...], "css": [...]}. No markdown, no comments, no prose. '
+        "2) Preserve the overall structure: keep each component's 'type', 'tagName', and "
+        "'attributes.id' unchanged, and do not add, remove, or reorder components. "
+        "3) You MAY change visible text content, attribute label values (placeholder, title, "
+        "alt, link text), class lists, and the 'style' objects in both components and css rules. "
+        "4) Keep every css rule's 'selectors' and 'pageId' values exactly as given. "
+        "5) The result must be valid JSON, parseable as-is, and remain a working GrapesJS page."
+    )
+    user_prompt = (
+        f'Personalize the GUI page named "{page_name}" for the following user.\n\n'
+        f"User profile document:\n{json.dumps(profile_document, ensure_ascii=False, indent=2)}\n\n"
+        "GUI page to adapt (GrapesJS):\n"
+        f"{json.dumps({'components': components, 'css': css}, ensure_ascii=False)}\n\n"
+        'Return only the personalized JSON object {"components": [...], "css": [...]}.'
+    )
+
+    try:
+        response_text = await asyncio.to_thread(
+            call_openai_chat,
+            system_prompt,
+            user_prompt,
+            model=llm_model,
+            openai_api_key=extract_openai_api_key(payload if isinstance(payload, dict) else {}),
+            config=payload,
+        )
+        parsed = extract_json_object(response_text)
+        personalized_components = parsed.get("components")
+        personalized_css = parsed.get("css", [])
+        if not isinstance(personalized_components, list):
+            raise GenerationError("LLM response did not include a valid 'components' list")
+        if not isinstance(personalized_css, list):
+            personalized_css = []
+
+        return {
+            "guiPage": {
+                "components": personalized_components,
+                "css": personalized_css,
+            },
+            "source": "openai",
+            "model": llm_model,
+            "generatedAt": _utc_now_iso(),
+        }
+    except RuntimeError as runtime_error:
+        # Raised by call_openai_chat when no OpenAI API key is configured.
+        raise ValidationError(str(runtime_error)) from runtime_error
+    except ValueError as parse_error:
+        logger.exception("Failed to parse LLM personalization response")
+        raise GenerationError("Failed to parse LLM personalization response") from parse_error
+    except (ValidationError, GenerationError):
+        raise
+    except HTTPException:
+        raise
+    except Exception as exc:
+        logger.exception("Failed to personalize GUI page")
+        raise GenerationError("Failed to personalize GUI page") from exc
+
+
 @router.get("/agent-config-manual-mapping")
 @handle_endpoint_errors("get_agent_config_manual_mapping")
 async def get_agent_config_manual_mapping(

From d43fded5e776c8d2171b86e93447a9b137f20a81 Mon Sep 17 00:00:00 2001
From: aran30 <aaron30@live.be>
Date: Tue, 30 Jun 2026 16:36:01 +0200
Subject: [PATCH 2/9] improved the prompt for the automatic personalization of
 guis

---
 .../backend/routers/generation_router.py      | 48 +++++++++++++++----
 1 file changed, 40 insertions(+), 8 deletions(-)

diff --git a/besser/utilities/web_modeling_editor/backend/routers/generation_router.py b/besser/utilities/web_modeling_editor/backend/routers/generation_router.py
index 039558685..f3a82461e 100644
--- a/besser/utilities/web_modeling_editor/backend/routers/generation_router.py
+++ b/besser/utilities/web_modeling_editor/backend/routers/generation_router.py
@@ -278,25 +278,57 @@ async def personalize_gui_page(payload: Dict[str, Any] = Body(...)):
         "You receive a single GUI page as GrapesJS data: a 'components' array (the component "
         "tree, each node carrying fields such as type, tagName, attributes, classes, components, "
         "and text content) and a 'css' array (GrapesJS style-rule objects with 'selectors', "
-        "'style', and 'pageId'). You also receive a user profile. "
-        "Adapt the page to this specific user in terms of CONTENT (wording, tone, labels, "
-        "headings, copy) and STYLE (colors, spacing, font sizes, emphasis via the 'style' maps). "
-        "STRICT RULES: "
+        "'style', and 'pageId'). You also receive a user profile.\n\n"
+        "Your job is NOT to redesign the page. It is to make the SMALLEST set of changes that a "
+        "SPECIFIC, CONCRETE attribute in the user profile actually requires — and nothing else. "
+        "The default outcome is to return the page UNCHANGED. Only deviate from the original when "
+        "an attribute in the profile creates a real, demonstrable accessibility or comprehension "
+        "need for THIS user.\n\n"
+        "DECISION PROCESS (apply silently, then output only the JSON):\n"
+        "1) For each attribute in the user profile, ask: 'Does this attribute imply a concrete UI "
+        "barrier on THIS page?' Most attributes do not. An attribute justifies a change only if "
+        "there is a direct, well-established causal link between it and a UI adaptation.\n"
+        "2) If an attribute has no such link, IGNORE it. Do not invent a need. Demographic, "
+        "cultural, religious, gender, name, or location attributes almost never justify visual or "
+        "textual changes on their own — leave the page as-is for them.\n"
+        "3) Only when a link exists, apply the minimal adaptation that resolves that specific need, "
+        "and touch only the components/styles relevant to it. Leave everything else identical.\n\n"
+        "EXAMPLES OF JUSTIFIED CHANGES (only act when the profile clearly states the trait):\n"
+        "- Low vision / visual impairment -> increase font-size, contrast, and spacing.\n"
+        "- Stated reading level below the page's wording (e.g. B1 English on advanced copy) -> "
+        "simplify the wording while keeping meaning; do NOT translate unless a different language "
+        "is explicitly the user's language.\n"
+        "- Color blindness -> avoid color as the sole signal / adjust conflicting color pairs.\n"
+        "- Motor impairment -> enlarge click targets (padding) on interactive elements.\n"
+        "- A stated preferred language different from the page's language -> translate the visible "
+        "text into that language.\n\n"
+        "EXAMPLES OF NON-JUSTIFIED (return unchanged for these): a user who reads English fluently "
+        "on an English page; religion, ethnicity, gender, age alone, job title, hobbies, or any "
+        "attribute with no direct UI consequence. NEVER map an irrelevant attribute to a styling "
+        "change (e.g. do not change font size because of someone's religion or nationality).\n\n"
+        "STRICT OUTPUT RULES: "
         "1) Return ONLY a single JSON object with EXACTLY this shape: "
         '{"components": [...], "css": [...]}. No markdown, no comments, no prose. '
         "2) Preserve the overall structure: keep each component's 'type', 'tagName', and "
         "'attributes.id' unchanged, and do not add, remove, or reorder components. "
         "3) You MAY change visible text content, attribute label values (placeholder, title, "
-        "alt, link text), class lists, and the 'style' objects in both components and css rules. "
+        "alt, link text), class lists, and the 'style' objects in both components and css rules — "
+        "but ONLY for the specific needs you justified above. Every other value must be byte-for-byte "
+        "identical to the input. "
         "4) Keep every css rule's 'selectors' and 'pageId' values exactly as given. "
-        "5) The result must be valid JSON, parseable as-is, and remain a working GrapesJS page."
+        "5) If no profile attribute justifies any change, return the input page verbatim. "
+        "6) The result must be valid JSON, parseable as-is, and remain a working GrapesJS page."
     )
     user_prompt = (
-        f'Personalize the GUI page named "{page_name}" for the following user.\n\n'
+        f'Personalize the GUI page named "{page_name}" for the following user — but only if the '
+        "profile actually warrants it.\n\n"
         f"User profile document:\n{json.dumps(profile_document, ensure_ascii=False, indent=2)}\n\n"
         "GUI page to adapt (GrapesJS):\n"
         f"{json.dumps({'components': components, 'css': css}, ensure_ascii=False)}\n\n"
-        'Return only the personalized JSON object {"components": [...], "css": [...]}.'
+        "First, silently identify which (if any) profile attributes create a concrete UI need for "
+        "this user. Change ONLY what those needs require and leave every other part of the page "
+        "exactly as given. If nothing in the profile warrants a change, return the page unchanged. "
+        'Return only the resulting JSON object {"components": [...], "css": [...]}.'
     )
 
     try:

From a8cc8b7304548881337ddc40ee0c83c975e238ba Mon Sep 17 00:00:00 2001
From: Aran30 <aaron30@live.be>
Date: Wed, 1 Jul 2026 16:49:41 +0200
Subject: [PATCH 3/9] added the code generation of variants of the gui

---
 .../backend/routers/generation_router.py      | 116 ++++++++++++------
 1 file changed, 76 insertions(+), 40 deletions(-)

diff --git a/besser/utilities/web_modeling_editor/backend/routers/generation_router.py b/besser/utilities/web_modeling_editor/backend/routers/generation_router.py
index f3a82461e..bd3531a00 100644
--- a/besser/utilities/web_modeling_editor/backend/routers/generation_router.py
+++ b/besser/utilities/web_modeling_editor/backend/routers/generation_router.py
@@ -714,45 +714,67 @@ async def _handle_web_app_project_generation(input_data: ProjectInput, generator
             detail="ClassDiagram is required for Web App generator"
         )
 
+    # Personalization versions (optional). When present, the frontend has
+    # pre-assembled one COMPLETE GUI model per version (base + each user
+    # profile), each already resolved page-by-page. When absent, we generate a
+    # single app from the GUI diagram's own model (unchanged behavior).
+    web_app_versions = config.get("webAppVersions") if isinstance(config, dict) else None
+    if web_app_versions:
+        version_specs = [
+            (str(v.get("slug") or f"version-{i + 1}"), v.get("guiModel"))
+            for i, v in enumerate(web_app_versions)
+        ]
+    else:
+        version_specs = [(None, gui_diagram.model)]
+
+    multi = len(version_specs) > 1
+    generator_class = generator_info.generator_class
+
     with tempfile.TemporaryDirectory(prefix=TEMP_DIR_PREFIX) as temp_dir:
-        # Process class diagram to BUML
-        buml_model = process_class_diagram(class_diagram.model_dump())
-
-        gui_model = process_gui_diagram(gui_diagram.model, class_diagram.model, buml_model)
-
-        # Collect every AgentDiagram in the project if the GUI uses agent components.
-        # The frontend dropdown enumerates all agents, so the generator must
-        # satisfy any binding — we don't filter to the active reference here.
-        agent_models = []
-        agent_configs = {}
-        agent_config_yamls: dict = {}
-        has_agent_components = _check_for_agent_components(gui_model)
-
-        if has_agent_components:
-            project_agent_config = config.get('agentConfig') if isinstance(config, dict) else None
-            default_cfg = project_agent_config or config
-            agent_models, agent_configs, agent_config_yamls = collect_agents_from_diagrams(
-                input_data.diagrams.get("AgentDiagram", []),
-                default_config=default_cfg,
-            )
-            for name, cfg in agent_configs.items():
-                logger.debug("[WebApp agent] resolved config for %s: %s",
-                             name,
-                             json.dumps(sanitize_config(cfg), indent=2, default=str) if cfg else 'None')
-            if not agent_models:
-                logger.warning(
-                    "GUI contains agent components but no AgentDiagram was found. "
-                    "Agent components will not be functional."
+        for slug, gui_json in version_specs:
+            # Re-derive the class BUML per version so the generator can't leak
+            # mutations from one version into the next.
+            buml_model = process_class_diagram(class_diagram.model_dump())
+            gui_model = process_gui_diagram(gui_json, class_diagram.model, buml_model)
+
+            # Collect every AgentDiagram in the project if this version's GUI uses
+            # agent components. The frontend dropdown enumerates all agents, so the
+            # generator must satisfy any binding — we don't filter to the active
+            # reference here.
+            agent_models = []
+            agent_configs = {}
+            agent_config_yamls: dict = {}
+            if _check_for_agent_components(gui_model):
+                project_agent_config = config.get('agentConfig') if isinstance(config, dict) else None
+                default_cfg = project_agent_config or config
+                agent_models, agent_configs, agent_config_yamls = collect_agents_from_diagrams(
+                    input_data.diagrams.get("AgentDiagram", []),
+                    default_config=default_cfg,
                 )
+                for name, cfg in agent_configs.items():
+                    logger.debug("[WebApp agent] resolved config for %s: %s",
+                                 name,
+                                 json.dumps(sanitize_config(cfg), indent=2, default=str) if cfg else 'None')
+                if not agent_models:
+                    logger.warning(
+                        "GUI contains agent components but no AgentDiagram was found. "
+                        "Agent components will not be functional."
+                    )
+
+            # Single version → generate at the zip root (current layout).
+            # Multiple versions → one profile-named subfolder each.
+            out_dir = temp_dir
+            if multi:
+                out_dir = _safe_path(temp_dir, os.path.basename(slug))
+                os.makedirs(out_dir, exist_ok=True)
+
+            await _run_web_app_generator(
+                buml_model, gui_model, generator_class, out_dir,
+                agent_models=agent_models, agent_configs=agent_configs,
+                agent_config_yamls=agent_config_yamls,
+            )
 
-        # Generate Web App TypeScript project
-        generator_class = generator_info.generator_class
-
-        return await _generate_web_app(
-            buml_model, gui_model, generator_class, config, temp_dir,
-            agent_models=agent_models, agent_configs=agent_configs,
-            agent_config_yamls=agent_config_yamls,
-        )
+        return _create_zip_response(temp_dir, "web_app")
 
 
 def _streaming_zip(zip_buffer: io.BytesIO, file_name: str) -> StreamingResponse:
@@ -1215,19 +1237,33 @@ def _check_container_for_agent_components(container):
                 return True
     return False
 
+async def _run_web_app_generator(buml_model, gui_model, generator_class, out_dir: str,
+                                 agent_models=None, agent_configs=None, agent_config_yamls=None):
+    """Run the web app generator into ``out_dir`` WITHOUT zipping.
+
+    Split out from ``_generate_web_app`` so multiple personalization versions can
+    each be generated into their own subdirectory before a single zip is built.
+    """
+    generator_instance = generator_class(
+        buml_model, gui_model, output_dir=out_dir,
+        agent_models=agent_models, agent_configs=agent_configs,
+        agent_config_yamls=agent_config_yamls,
+    )
+    await asyncio.to_thread(generator_instance.generate)
+
+
 async def _generate_web_app(buml_model, gui_model, generator_class, config: dict, temp_dir: str,
                             agent_models=None, agent_configs=None, agent_config_yamls=None):
-    """Generate web application files.
+    """Generate web application files (single version) and return a ZIP response.
 
     Supports multi-agent projects: ``agent_models`` is a list and each is emitted
     under ``agents/<slug>/`` in the generated output.
     """
-    generator_instance = generator_class(
-        buml_model, gui_model, output_dir=temp_dir,
+    await _run_web_app_generator(
+        buml_model, gui_model, generator_class, temp_dir,
         agent_models=agent_models, agent_configs=agent_configs,
         agent_config_yamls=agent_config_yamls,
     )
-    await asyncio.to_thread(generator_instance.generate)
     return _create_zip_response(temp_dir, "web_app")
 
 @handle_endpoint_errors("_generate_standard")

From 5bd294ffbd997285856240512cf80971ca2cd6be Mon Sep 17 00:00:00 2001
From: aran30 <aaron30@live.be>
Date: Wed, 8 Jul 2026 14:56:37 +0200
Subject: [PATCH 4/9] changed gpt version for faster generation

---
 .../agents/agent_personalization.py           | 42 ++++++++++---------
 .../backend/routers/generation_router.py      |  2 +-
 2 files changed, 23 insertions(+), 21 deletions(-)

diff --git a/besser/generators/agents/agent_personalization.py b/besser/generators/agents/agent_personalization.py
index e86bed2a9..2c670b277 100644
--- a/besser/generators/agents/agent_personalization.py
+++ b/besser/generators/agents/agent_personalization.py
@@ -80,7 +80,7 @@ def flatten_agent_config_structure(raw_config):
     return flattened
 
 
-def call_openai_chat(system_prompt, user_prompt, model="gpt-5", openai_api_key=None, config=None):
+def call_openai_chat(system_prompt, user_prompt, model="gpt-5.4-mini", openai_api_key=None, config=None):
     """
     Calls OpenAI ChatCompletion with a system prompt and user prompt (openai>=1.0.0).
     Returns the response text only.
@@ -97,6 +97,7 @@ def call_openai_chat(system_prompt, user_prompt, model="gpt-5", openai_api_key=N
         raise ImportError(
             "OpenAI personalization requires the 'agents' extra: pip install besser[agents]"
         ) from exc
+    print("calling now")
     client = OpenAI(api_key=resolved_api_key)
     response = client.chat.completions.create(
         model=model,
@@ -111,9 +112,9 @@ def call_openai_chat(system_prompt, user_prompt, model="gpt-5", openai_api_key=N
 
 
 
-def translate_text_batch(texts, target_language, model="gpt-5", openai_api_key=None, config=None):
+def translate_text_batch(texts, target_language, model="gpt-5.4-mini", openai_api_key=None, config=None):
     """
-    Translates each text in `texts` to the target language using OpenAI GPT-5.
+    Translates each text in `texts` to the target language using OpenAI gpt-5.4-mini.
     Returns a list of translated texts in the same order as input.
     """
     if not isinstance(texts, (list, tuple)):
@@ -170,7 +171,7 @@ def translate_text_api(text, target_language):
 
 
 
-def style_text_batch(texts, style, model="gpt-5", openai_api_key=None, config=None):
+def style_text_batch(texts, style, model="gpt-5.4-mini", openai_api_key=None, config=None):
     """
     Rewrites each text in `texts` to the requested `style` while preserving meaning and content.
     `style` should be one of 'formal', 'informal', 'friendly', or 'technical'.
@@ -338,6 +339,19 @@ def replace_reply_batch(messages: list[str], config: dict, openai_api_key: str =
         target_language = config['agentLanguage']
         for i, msg in enumerate(personalized_messages):
             personalized_messages[i] = translate_text_api(msg, target_language)
+    if 'agentLanguage' in config and config['agentLanguage'] != 'none' and config['agentLanguage'] != 'original':
+        if not openai_api_key:
+            raise RuntimeError(
+                f"OpenAI API key is required for agent personalization. Set '{OPENAI_API_KEY_ENV_VAR}' "
+                "or include 'openaiApiKey'/'openai_api_key' in generator config."
+            )
+        target_language = config['agentLanguage']
+        personalized_messages = translate_text_batch(
+            personalized_messages,
+            target_language,
+            openai_api_key=openai_api_key,
+            config=config,
+        )
     if 'agentStyle' in config and config['agentStyle'] != 'original':
         if not openai_api_key:
             raise RuntimeError(
@@ -388,19 +402,7 @@ def replace_reply_batch(messages: list[str], config: dict, openai_api_key: str =
             config,
             openai_api_key=openai_api_key,
         )
-    if 'agentLanguage' in config and config['agentLanguage'] != 'none' and config['agentLanguage'] != 'original':
-        if not openai_api_key:
-            raise RuntimeError(
-                f"OpenAI API key is required for agent personalization. Set '{OPENAI_API_KEY_ENV_VAR}' "
-                "or include 'openaiApiKey'/'openai_api_key' in generator config."
-            )
-        target_language = config['agentLanguage']
-        personalized_messages = translate_text_batch(
-            personalized_messages,
-            target_language,
-            openai_api_key=openai_api_key,
-            config=config,
-        )
+
 
     return personalized_messages
 
@@ -421,7 +423,7 @@ def replace_content_profile_batch(messages: list[str], config: dict, openai_api_
 
     model_name = flattened_config.get('llm')
     if not isinstance(model_name, str) or not model_name.strip():
-        model_name = 'gpt-5'
+        model_name = 'gpt-5.4-mini'
     else:
         model_name = model_name.strip()
 
@@ -495,7 +497,7 @@ def append_speech(match):
     text = match.group(1)
     return f"session.reply('{text}')\n    platform.reply_speech(session, '{text}')"
 
-def complexity_text_batch(texts, complexity, model="gpt-5", openai_api_key=None, config=None):
+def complexity_text_batch(texts, complexity, model="gpt-5.4-mini", openai_api_key=None, config=None):
     """
     Adjusts the complexity of each text in `texts` based on the specified `complexity` level.
     Complexity can be "simple", "medium", or "complex".
@@ -551,7 +553,7 @@ def complexity_text_batch(texts, complexity, model="gpt-5", openai_api_key=None,
     return results
 
 
-def sentence_length_batch(texts, preference, model="gpt-5", openai_api_key=None, config=None):
+def sentence_length_batch(texts, preference, model="gpt-5.4-mini", openai_api_key=None, config=None):
     """
     Adjusts each text in `texts` to be more concise or verbose.
     `preference` accepts "concise" or "verbose" (case-insensitive).
diff --git a/besser/utilities/web_modeling_editor/backend/routers/generation_router.py b/besser/utilities/web_modeling_editor/backend/routers/generation_router.py
index bd3531a00..181efce76 100644
--- a/besser/utilities/web_modeling_editor/backend/routers/generation_router.py
+++ b/besser/utilities/web_modeling_editor/backend/routers/generation_router.py
@@ -267,7 +267,7 @@ async def personalize_gui_page(payload: Dict[str, Any] = Body(...)):
     llm_model = (
         requested_model
         if isinstance(requested_model, str) and requested_model.strip()
-        else "gpt-5"
+        else "gpt-5.4-mini"
     )
 
     # Transform the user profile (UserDiagram) into its JSON object representation.

From 679271de5b54401faa33a3ff7d516cea65df8a0b Mon Sep 17 00:00:00 2001
From: aran30 <aaron30@live.be>
Date: Fri, 10 Jul 2026 11:19:55 +0200
Subject: [PATCH 5/9] updated prompt for GUI generation

---
 .../backend/routers/generation_router.py      | 58 +++++++------------
 1 file changed, 21 insertions(+), 37 deletions(-)

diff --git a/besser/utilities/web_modeling_editor/backend/routers/generation_router.py b/besser/utilities/web_modeling_editor/backend/routers/generation_router.py
index 181efce76..46e7ec923 100644
--- a/besser/utilities/web_modeling_editor/backend/routers/generation_router.py
+++ b/besser/utilities/web_modeling_editor/backend/routers/generation_router.py
@@ -279,55 +279,39 @@ async def personalize_gui_page(payload: Dict[str, Any] = Body(...)):
         "tree, each node carrying fields such as type, tagName, attributes, classes, components, "
         "and text content) and a 'css' array (GrapesJS style-rule objects with 'selectors', "
         "'style', and 'pageId'). You also receive a user profile.\n\n"
-        "Your job is NOT to redesign the page. It is to make the SMALLEST set of changes that a "
-        "SPECIFIC, CONCRETE attribute in the user profile actually requires — and nothing else. "
-        "The default outcome is to return the page UNCHANGED. Only deviate from the original when "
-        "an attribute in the profile creates a real, demonstrable accessibility or comprehension "
-        "need for THIS user.\n\n"
-        "DECISION PROCESS (apply silently, then output only the JSON):\n"
-        "1) For each attribute in the user profile, ask: 'Does this attribute imply a concrete UI "
-        "barrier on THIS page?' Most attributes do not. An attribute justifies a change only if "
-        "there is a direct, well-established causal link between it and a UI adaptation.\n"
-        "2) If an attribute has no such link, IGNORE it. Do not invent a need. Demographic, "
-        "cultural, religious, gender, name, or location attributes almost never justify visual or "
-        "textual changes on their own — leave the page as-is for them.\n"
-        "3) Only when a link exists, apply the minimal adaptation that resolves that specific need, "
-        "and touch only the components/styles relevant to it. Leave everything else identical.\n\n"
-        "EXAMPLES OF JUSTIFIED CHANGES (only act when the profile clearly states the trait):\n"
-        "- Low vision / visual impairment -> increase font-size, contrast, and spacing.\n"
-        "- Stated reading level below the page's wording (e.g. B1 English on advanced copy) -> "
-        "simplify the wording while keeping meaning; do NOT translate unless a different language "
-        "is explicitly the user's language.\n"
-        "- Color blindness -> avoid color as the sole signal / adjust conflicting color pairs.\n"
-        "- Motor impairment -> enlarge click targets (padding) on interactive elements.\n"
-        "- A stated preferred language different from the page's language -> translate the visible "
-        "text into that language.\n\n"
-        "EXAMPLES OF NON-JUSTIFIED (return unchanged for these): a user who reads English fluently "
-        "on an English page; religion, ethnicity, gender, age alone, job title, hobbies, or any "
-        "attribute with no direct UI consequence. NEVER map an irrelevant attribute to a styling "
-        "change (e.g. do not change font size because of someone's religion or nationality).\n\n"
+        "You also receive a user profile model. Your job is to adapt the frontend to this user, "
+        "making decisions based on the information in the profile. Do NOT change the semantics of "
+        "the page (its meaning, message, and purpose stay the same) — change only its style and "
+        "presentation.\n\n"
         "STRICT OUTPUT RULES: "
         "1) Return ONLY a single JSON object with EXACTLY this shape: "
         '{"components": [...], "css": [...]}. No markdown, no comments, no prose. '
         "2) Preserve the overall structure: keep each component's 'type', 'tagName', and "
         "'attributes.id' unchanged, and do not add, remove, or reorder components. "
-        "3) You MAY change visible text content, attribute label values (placeholder, title, "
-        "alt, link text), class lists, and the 'style' objects in both components and css rules — "
-        "but ONLY for the specific needs you justified above. Every other value must be byte-for-byte "
+        "3) You MAY change class lists and the 'style' objects in both components and css rules to "
+        "adapt style and presentation to the user profile. Every other value must be byte-for-byte "
         "identical to the input. "
+        "3a) Do NOT change the semantics: preserve the visible text content, attribute label "
+        "values (placeholder, title, alt, link text), and the page's message and purpose. A visual "
+        "adaptation such as enlarging the font is made ENTIRELY through 'style'/class changes; "
+        "never rewrite text into a description of the adaptation (e.g. do NOT turn a heading into "
+        "'bigger text for readability'). "
         "4) Keep every css rule's 'selectors' and 'pageId' values exactly as given. "
-        "5) If no profile attribute justifies any change, return the input page verbatim. "
+        "5) Return the input page verbatim if the profile gives no basis to adapt the presentation. "
         "6) The result must be valid JSON, parseable as-is, and remain a working GrapesJS page."
     )
     user_prompt = (
-        f'Personalize the GUI page named "{page_name}" for the following user — but only if the '
-        "profile actually warrants it.\n\n"
-        f"User profile document:\n{json.dumps(profile_document, ensure_ascii=False, indent=2)}\n\n"
+        f'Personalize the GUI page named "{page_name}" for the following user profile model.\n\n'
+        f"User profile model:\n{json.dumps(profile_document, ensure_ascii=False, indent=2)}\n\n"
         "GUI page to adapt (GrapesJS):\n"
         f"{json.dumps({'components': components, 'css': css}, ensure_ascii=False)}\n\n"
-        "First, silently identify which (if any) profile attributes create a concrete UI need for "
-        "this user. Change ONLY what those needs require and leave every other part of the page "
-        "exactly as given. If nothing in the profile warrants a change, return the page unchanged. "
+        "Make decisions based on the information in the profile. "
+        "Only change something if you feel that the user profile gives a clear reason to adapt the page's style and presentation. " 
+        "You can assume that the profile contains the most important information about the user and anything that is missing can be assumed that the user does not have that characteristic." 
+        ". Adapt the page's style and "
+        "presentation to this user; do not change its core semantics. Presentation refers also to textual changes, " 
+        "like making text more concise or verbose," 
+        "or changing the tone of voice, language, etc. "
         'Return only the resulting JSON object {"components": [...], "css": [...]}.'
     )
 

From fd35855bc44eb37528909819005349f94e7db658 Mon Sep 17 00:00:00 2001
From: aran30 <aaron30@live.be>
Date: Wed, 15 Jul 2026 09:28:06 +0200
Subject: [PATCH 6/9] improved prompt for personalization

---
 .../backend/routers/generation_router.py      | 63 ++++++++++++-------
 1 file changed, 42 insertions(+), 21 deletions(-)

diff --git a/besser/utilities/web_modeling_editor/backend/routers/generation_router.py b/besser/utilities/web_modeling_editor/backend/routers/generation_router.py
index 46e7ec923..a1039fc77 100644
--- a/besser/utilities/web_modeling_editor/backend/routers/generation_router.py
+++ b/besser/utilities/web_modeling_editor/backend/routers/generation_router.py
@@ -267,7 +267,7 @@ async def personalize_gui_page(payload: Dict[str, Any] = Body(...)):
     llm_model = (
         requested_model
         if isinstance(requested_model, str) and requested_model.strip()
-        else "gpt-5.4-mini"
+        else "gpt-5.6-luna"
     )
 
     # Transform the user profile (UserDiagram) into its JSON object representation.
@@ -277,26 +277,44 @@ async def personalize_gui_page(payload: Dict[str, Any] = Body(...)):
         "You are a UI personalization assistant for a GrapesJS-based no-code GUI editor. "
         "You receive a single GUI page as GrapesJS data: a 'components' array (the component "
         "tree, each node carrying fields such as type, tagName, attributes, classes, components, "
-        "and text content) and a 'css' array (GrapesJS style-rule objects with 'selectors', "
-        "'style', and 'pageId'). You also receive a user profile.\n\n"
-        "You also receive a user profile model. Your job is to adapt the frontend to this user, "
-        "making decisions based on the information in the profile. Do NOT change the semantics of "
-        "the page (its meaning, message, and purpose stay the same) — change only its style and "
-        "presentation.\n\n"
+        "style, and text content) and a 'css' array (GrapesJS style-rule objects with 'selectors', "
+        "'selectorsAdd', 'style', and 'pageId'). You also receive a user profile model.\n\n"
+        "Your job is to adapt the page's PRESENTATION to this user, making decisions based on the "
+        "information in the profile. Do NOT change the semantics of the page (its meaning, message, "
+        "and purpose stay the same) — change only its style and presentation.\n\n"
+        "HOW TO APPLY STYLE — TWO TIERS:\n"
+        "Tier 1 (PREFER THIS): express broad, consistent adaptations as high-level CSS rules keyed "
+        "by semantic category, appended to the 'css' array. Target a category with the "
+        "'selectorsAdd' field (a raw CSS selector string), NOT the 'selectors' array. Useful "
+        "categories: 'body' (base font-size and line-height — most text inherits from here), "
+        "headings ('h1, h2, h3, h4, h5, h6'), buttons ('button, .btn, a.button'), form fields "
+        "('input, textarea, select'), 'label', links ('a'). Many components in this editor ship "
+        "with baked-in inline/id-level styles that would otherwise win the cascade, so EVERY "
+        "declaration in a Tier-1 rule MUST end with '!important' (e.g. {\"font-size\": \"20px "
+        "!important\"}). A single 'body' rule with a larger font-size and line-height is the "
+        "correct way to enlarge text everywhere — do NOT resize each text node individually.\n"
+        "Tier 2 (USE SPARINGLY): for an adaptation a category rule cannot express (e.g. emphasizing "
+        "one specific call-to-action), you MAY edit the 'style' object of individual components in "
+        "the 'components' tree. Keep this to a small, deliberate set of nodes, and append "
+        "'!important' when overriding an existing baked-in value.\n\n"
         "STRICT OUTPUT RULES: "
         "1) Return ONLY a single JSON object with EXACTLY this shape: "
         '{"components": [...], "css": [...]}. No markdown, no comments, no prose. '
         "2) Preserve the overall structure: keep each component's 'type', 'tagName', and "
         "'attributes.id' unchanged, and do not add, remove, or reorder components. "
-        "3) You MAY change class lists and the 'style' objects in both components and css rules to "
-        "adapt style and presentation to the user profile. Every other value must be byte-for-byte "
-        "identical to the input. "
+        "3) You MAY (a) append new high-level rules to the 'css' array, (b) change the 'style' "
+        "objects of existing css rules, and (c) change class lists and 'style' objects of "
+        "individual components (Tier 2). Every OTHER value must be byte-for-byte identical to the "
+        "input. "
         "3a) Do NOT change the semantics: preserve the visible text content, attribute label "
         "values (placeholder, title, alt, link text), and the page's message and purpose. A visual "
-        "adaptation such as enlarging the font is made ENTIRELY through 'style'/class changes; "
-        "never rewrite text into a description of the adaptation (e.g. do NOT turn a heading into "
-        "'bigger text for readability'). "
-        "4) Keep every css rule's 'selectors' and 'pageId' values exactly as given. "
+        "adaptation such as enlarging the font is made ENTIRELY through 'style'/class/CSS-rule "
+        "changes; never rewrite text into a description of the adaptation (e.g. do NOT turn a "
+        "heading into 'bigger text for readability'). "
+        "4) Keep every EXISTING css rule's 'selectors', 'selectorsAdd', and 'pageId' values exactly "
+        "as given (you may still edit its 'style'). For each NEW Tier-1 rule you add, set "
+        "'selectors' to an empty array and put the category selector in 'selectorsAdd'; you may "
+        "omit 'pageId'. "
         "5) Return the input page verbatim if the profile gives no basis to adapt the presentation. "
         "6) The result must be valid JSON, parseable as-is, and remain a working GrapesJS page."
     )
@@ -305,13 +323,16 @@ async def personalize_gui_page(payload: Dict[str, Any] = Body(...)):
         f"User profile model:\n{json.dumps(profile_document, ensure_ascii=False, indent=2)}\n\n"
         "GUI page to adapt (GrapesJS):\n"
         f"{json.dumps({'components': components, 'css': css}, ensure_ascii=False)}\n\n"
-        "Make decisions based on the information in the profile. "
-        "Only change something if you feel that the user profile gives a clear reason to adapt the page's style and presentation. " 
-        "You can assume that the profile contains the most important information about the user and anything that is missing can be assumed that the user does not have that characteristic." 
-        ". Adapt the page's style and "
-        "presentation to this user; do not change its core semantics. Presentation refers also to textual changes, " 
-        "like making text more concise or verbose," 
-        "or changing the tone of voice, language, etc. "
+        "Make decisions based on the information in the profile. Only adapt something when the "
+        "profile gives a clear reason to. You can assume the profile contains the most important "
+        "information about the user, and anything missing can be assumed absent.\n\n"
+        "Prefer Tier-1 category CSS rules (every declaration ending with '!important') for anything "
+        "that should apply broadly and consistently — e.g. if the user needs larger text, add a "
+        "'body' rule with a larger font-size and line-height rather than resizing individual "
+        "nodes. Use Tier-2 per-component edits only for targeted exceptions. Presentation includes "
+        "textual presentation too (tone, verbosity, language) as long as the core meaning is "
+        "preserved, as well as colors, contrast, font sizing, spacing, and forms. Your goal is the "
+        "best possible experience for this user with all their needs met.\n\n"
         'Return only the resulting JSON object {"components": [...], "css": [...]}.'
     )
 

From bc1c5562571de61dd630674a691eef0b6e289019 Mon Sep 17 00:00:00 2001
From: aran30 <aaron30@live.be>
Date: Wed, 15 Jul 2026 09:38:43 +0200
Subject: [PATCH 7/9] further improved prompt

---
 .../backend/routers/generation_router.py      | 28 ++++++++++++-------
 1 file changed, 18 insertions(+), 10 deletions(-)

diff --git a/besser/utilities/web_modeling_editor/backend/routers/generation_router.py b/besser/utilities/web_modeling_editor/backend/routers/generation_router.py
index a1039fc77..c0fb2b5af 100644
--- a/besser/utilities/web_modeling_editor/backend/routers/generation_router.py
+++ b/besser/utilities/web_modeling_editor/backend/routers/generation_router.py
@@ -280,8 +280,12 @@ async def personalize_gui_page(payload: Dict[str, Any] = Body(...)):
         "style, and text content) and a 'css' array (GrapesJS style-rule objects with 'selectors', "
         "'selectorsAdd', 'style', and 'pageId'). You also receive a user profile model.\n\n"
         "Your job is to adapt the page's PRESENTATION to this user, making decisions based on the "
-        "information in the profile. Do NOT change the semantics of the page (its meaning, message, "
-        "and purpose stay the same) — change only its style and presentation.\n\n"
+        "information in the profile. Presentation covers both visual styling AND the wording of the "
+        "page — its language, tone, and verbosity. Preserve the page's MEANING (its message, "
+        "purpose, and the information each element conveys), but you MAY re-express that meaning in "
+        "different words when the profile calls for it. When the profile clearly implies a "
+        "preference — for example a single language the user reads, a reading level, or a tone — "
+        "act on it decisively across the WHOLE page rather than leaving the wording unchanged.\n\n"
         "HOW TO APPLY STYLE — TWO TIERS:\n"
         "Tier 1 (PREFER THIS): express broad, consistent adaptations as high-level CSS rules keyed "
         "by semantic category, appended to the 'css' array. Target a category with the "
@@ -303,14 +307,18 @@ async def personalize_gui_page(payload: Dict[str, Any] = Body(...)):
         "2) Preserve the overall structure: keep each component's 'type', 'tagName', and "
         "'attributes.id' unchanged, and do not add, remove, or reorder components. "
         "3) You MAY (a) append new high-level rules to the 'css' array, (b) change the 'style' "
-        "objects of existing css rules, and (c) change class lists and 'style' objects of "
-        "individual components (Tier 2). Every OTHER value must be byte-for-byte identical to the "
-        "input. "
-        "3a) Do NOT change the semantics: preserve the visible text content, attribute label "
-        "values (placeholder, title, alt, link text), and the page's message and purpose. A visual "
-        "adaptation such as enlarging the font is made ENTIRELY through 'style'/class/CSS-rule "
-        "changes; never rewrite text into a description of the adaptation (e.g. do NOT turn a "
-        "heading into 'bigger text for readability'). "
+        "objects of existing css rules, (c) change class lists and 'style' objects of individual "
+        "components (Tier 2), and (d) rewrite the user-visible wording of the page — text-node "
+        "content and text-bearing attributes/properties (placeholder, title, alt, aria-label, link "
+        "text, button and field labels) — to translate it or adjust its tone/verbosity. Every "
+        "OTHER value must be byte-for-byte identical to the input. "
+        "3a) Preserve MEANING, not exact words: when you rewrite wording (per 3d) the message, "
+        "purpose, and information of every element must stay identical — translation and "
+        "tone/verbosity changes are allowed, but do NOT add, drop, or alter what the page tells the "
+        "user. A VISUAL adaptation such as enlarging the font is made ENTIRELY through "
+        "'style'/class/CSS-rule changes and must not touch wording; never rewrite text into a "
+        "description of the adaptation (e.g. do NOT turn a heading into 'bigger text for "
+        "readability'). "
         "4) Keep every EXISTING css rule's 'selectors', 'selectorsAdd', and 'pageId' values exactly "
         "as given (you may still edit its 'style'). For each NEW Tier-1 rule you add, set "
         "'selectors' to an empty array and put the category selector in 'selectorsAdd'; you may "

From ce6d5c3c1ce331232c8f66a796f8bc0cfdd1db49 Mon Sep 17 00:00:00 2001
From: aran30 <aaron30@live.be>
Date: Wed, 15 Jul 2026 14:53:14 +0200
Subject: [PATCH 8/9] fix empty attribute problem when using agent for user
 profile modeling

---
 .../json_to_buml/object_diagram_processor.py  |  9 +++-
 .../converters/test_converter_roundtrip.py    | 43 +++++++++++++++++++
 2 files changed, 50 insertions(+), 2 deletions(-)

diff --git a/besser/utilities/web_modeling_editor/backend/services/converters/json_to_buml/object_diagram_processor.py b/besser/utilities/web_modeling_editor/backend/services/converters/json_to_buml/object_diagram_processor.py
index 344321845..1cd887037 100644
--- a/besser/utilities/web_modeling_editor/backend/services/converters/json_to_buml/object_diagram_processor.py
+++ b/besser/utilities/web_modeling_editor/backend/services/converters/json_to_buml/object_diagram_processor.py
@@ -198,8 +198,13 @@ def process_object_diagram(json_data, domain_model):
                         continue
                 elif attr_type == "UserModelAttribute":
                     operator = attr_element.get("attributeOperator", "==")
-                    if operator and operator in attr_string:
-                        attr_part, value_part = attr_string.split(operator, 1)
+                    # The editor renders equality as a single '=' (e.g.
+                    # "age = 18") while storing the operator as '=='. Match on
+                    # the *displayed* symbol so equality criteria are parsed
+                    # instead of dropped (which left every '==' attribute empty).
+                    display_operator = "=" if operator == "==" else operator
+                    if display_operator and display_operator in attr_string:
+                        attr_part, value_part = attr_string.split(display_operator, 1)
                         attr_name = attr_part.strip()
                         value = value_part.strip()
                     else:
diff --git a/tests/utilities/web_modeling_editor/backend/services/converters/test_converter_roundtrip.py b/tests/utilities/web_modeling_editor/backend/services/converters/test_converter_roundtrip.py
index 693421761..cac215deb 100644
--- a/tests/utilities/web_modeling_editor/backend/services/converters/test_converter_roundtrip.py
+++ b/tests/utilities/web_modeling_editor/backend/services/converters/test_converter_roundtrip.py
@@ -1322,6 +1322,49 @@ def test_object_attribute_values(self, object_diagram_with_attrs_json, minimal_c
                 }
                 assert slot_values.get("name") == "Fitzgerald"
 
+    def test_user_model_equality_attribute_value(self, minimal_class_diagram_json):
+        """UserModelAttribute equality criteria ('==') are parsed, not dropped.
+
+        Regression test: the editor renders equality as a single '=' (e.g.
+        "title = TheGreatGatsby") while storing attributeOperator as '=='. The
+        parser must split on the displayed symbol; otherwise every '=='
+        criterion falls through with an empty value ("attributes are empty").
+        """
+        domain_model = process_class_diagram(minimal_class_diagram_json)
+        user_diagram_json = {
+            "title": "UserProfile",
+            "model": {
+                "type": "UserDiagram",
+                "elements": {
+                    "u-book1": {
+                        "id": "u-book1",
+                        "name": "book1",
+                        "type": "UserModelName",
+                        "owner": None,
+                        "bounds": {"x": 0, "y": 0, "width": 200, "height": 100},
+                        "attributes": ["u-title"],
+                        "methods": [],
+                        "className": "Book",
+                    },
+                    "u-title": {
+                        "id": "u-title",
+                        "name": "title = TheGreatGatsby",
+                        "type": "UserModelAttribute",
+                        "owner": "u-book1",
+                        "attributeOperator": "==",
+                        "bounds": {"x": 0, "y": 30, "width": 199, "height": 30},
+                    },
+                },
+                "relationships": {},
+            },
+        }
+
+        obj_model = process_object_diagram(user_diagram_json, domain_model)
+
+        book = next(obj for obj in obj_model.objects if obj.name == "book1")
+        slot_values = {slot.attribute.name: slot.value.value for slot in book.slots}
+        assert slot_values.get("title") == "TheGreatGatsby"
+
 
 # ===========================================================================
 # NN Diagram Roundtrip: JSON -> NN -> JSON

From 12adb80d8abb9aa4aef63252022a3c71ffa08e57 Mon Sep 17 00:00:00 2001
From: ArmSL <scorp-arm@hotmail.com>
Date: Tue, 21 Jul 2026 12:10:27 +0200
Subject: [PATCH 9/9] refactor(gui-personalization): extract endpoint to a
 service module + cleanup

Addresses review feedback on #577 (organization + correctness):

- Extract the ~150-line /personalize-gui-page endpoint body into a new
  services/utils/gui_personalization_utils.py, mirroring the
  agent_personalization pattern: the ~40-line LLM system prompt is now a
  module constant, and personalize_gui_page() owns validation, prompt
  building, the OpenAI call and response parsing. The router endpoint is
  now a thin validate -> delegate -> shape-response handler.
- Consolidate the OpenAI model default into one DEFAULT_OPENAI_MODEL =
  'gpt-5' constant. Removes the inconsistent/invalid defaults the PR
  introduced (gpt-5.4-mini x7, gpt-5.6-luna) that would 404 at runtime.
- Remove a leftover print('calling now') debug statement.
- Remove two dead '... and False' branches in replace_reply_batch.
- Add test_gui_personalization.py (10 tests, LLM mocked) covering
  validation, model selection, response parsing and error mapping.

Left as-is: the translate-before-style reorder in replace_reply_batch
(appears intentional); pre-existing gpt-5.5 default at generation_router
line 172 (out of scope).
---
 .../agents/agent_personalization.py           |  25 +--
 .../backend/routers/generation_router.py      | 160 +++------------
 .../utils/gui_personalization_utils.py        | 182 ++++++++++++++++++
 .../utils/test_gui_personalization.py         | 101 ++++++++++
 4 files changed, 316 insertions(+), 152 deletions(-)
 create mode 100644 besser/utilities/web_modeling_editor/backend/services/utils/gui_personalization_utils.py
 create mode 100644 tests/utilities/web_modeling_editor/backend/services/utils/test_gui_personalization.py

diff --git a/besser/generators/agents/agent_personalization.py b/besser/generators/agents/agent_personalization.py
index 2c670b277..ce3b6aa82 100644
--- a/besser/generators/agents/agent_personalization.py
+++ b/besser/generators/agents/agent_personalization.py
@@ -9,6 +9,9 @@
 
 OPENAI_API_KEY_ENV_VAR = "OPENAI_API_KEY"
 
+# Single default model for all OpenAI-backed personalization helpers.
+DEFAULT_OPENAI_MODEL = "gpt-5"
+
 
 def _resolve_openai_api_key(config: dict = None, openai_api_key: str = None) -> str | None:
     if isinstance(openai_api_key, str) and openai_api_key.strip():
@@ -80,7 +83,7 @@ def flatten_agent_config_structure(raw_config):
     return flattened
 
 
-def call_openai_chat(system_prompt, user_prompt, model="gpt-5.4-mini", openai_api_key=None, config=None):
+def call_openai_chat(system_prompt, user_prompt, model=DEFAULT_OPENAI_MODEL, openai_api_key=None, config=None):
     """
     Calls OpenAI ChatCompletion with a system prompt and user prompt (openai>=1.0.0).
     Returns the response text only.
@@ -97,7 +100,6 @@ def call_openai_chat(system_prompt, user_prompt, model="gpt-5.4-mini", openai_ap
         raise ImportError(
             "OpenAI personalization requires the 'agents' extra: pip install besser[agents]"
         ) from exc
-    print("calling now")
     client = OpenAI(api_key=resolved_api_key)
     response = client.chat.completions.create(
         model=model,
@@ -112,9 +114,9 @@ def call_openai_chat(system_prompt, user_prompt, model="gpt-5.4-mini", openai_ap
 
 
 
-def translate_text_batch(texts, target_language, model="gpt-5.4-mini", openai_api_key=None, config=None):
+def translate_text_batch(texts, target_language, model=DEFAULT_OPENAI_MODEL, openai_api_key=None, config=None):
     """
-    Translates each text in `texts` to the target language using OpenAI gpt-5.4-mini.
+    Translates each text in `texts` to the target language using OpenAI.
     Returns a list of translated texts in the same order as input.
     """
     if not isinstance(texts, (list, tuple)):
@@ -171,7 +173,7 @@ def translate_text_api(text, target_language):
 
 
 
-def style_text_batch(texts, style, model="gpt-5.4-mini", openai_api_key=None, config=None):
+def style_text_batch(texts, style, model=DEFAULT_OPENAI_MODEL, openai_api_key=None, config=None):
     """
     Rewrites each text in `texts` to the requested `style` while preserving meaning and content.
     `style` should be one of 'formal', 'informal', 'friendly', or 'technical'.
@@ -332,13 +334,6 @@ def replace_reply_batch(messages: list[str], config: dict, openai_api_key: str =
     config = flatten_agent_config_structure(config or {})
     personalized_messages = messages
 
-    if 'agentLanguage' in config and config['agentLanguage'] != 'none' and False:
-        target_language = config['agentLanguage']
-        # personalized_message = translate_text(personalized_message, target_language)
-    elif 'agentLanguage' in config and config['agentLanguage'] != 'none' and config['agentLanguage'] != 'original' and False:
-        target_language = config['agentLanguage']
-        for i, msg in enumerate(personalized_messages):
-            personalized_messages[i] = translate_text_api(msg, target_language)
     if 'agentLanguage' in config and config['agentLanguage'] != 'none' and config['agentLanguage'] != 'original':
         if not openai_api_key:
             raise RuntimeError(
@@ -423,7 +418,7 @@ def replace_content_profile_batch(messages: list[str], config: dict, openai_api_
 
     model_name = flattened_config.get('llm')
     if not isinstance(model_name, str) or not model_name.strip():
-        model_name = 'gpt-5.4-mini'
+        model_name = DEFAULT_OPENAI_MODEL
     else:
         model_name = model_name.strip()
 
@@ -497,7 +492,7 @@ def append_speech(match):
     text = match.group(1)
     return f"session.reply('{text}')\n    platform.reply_speech(session, '{text}')"
 
-def complexity_text_batch(texts, complexity, model="gpt-5.4-mini", openai_api_key=None, config=None):
+def complexity_text_batch(texts, complexity, model=DEFAULT_OPENAI_MODEL, openai_api_key=None, config=None):
     """
     Adjusts the complexity of each text in `texts` based on the specified `complexity` level.
     Complexity can be "simple", "medium", or "complex".
@@ -553,7 +548,7 @@ def complexity_text_batch(texts, complexity, model="gpt-5.4-mini", openai_api_ke
     return results
 
 
-def sentence_length_batch(texts, preference, model="gpt-5.4-mini", openai_api_key=None, config=None):
+def sentence_length_batch(texts, preference, model=DEFAULT_OPENAI_MODEL, openai_api_key=None, config=None):
     """
     Adjusts each text in `texts` to be more concise or verbose.
     `preference` accepts "concise" or "verbose" (case-insensitive).
diff --git a/besser/utilities/web_modeling_editor/backend/routers/generation_router.py b/besser/utilities/web_modeling_editor/backend/routers/generation_router.py
index c0fb2b5af..a16c3d9b5 100644
--- a/besser/utilities/web_modeling_editor/backend/routers/generation_router.py
+++ b/besser/utilities/web_modeling_editor/backend/routers/generation_router.py
@@ -75,6 +75,9 @@
     normalize_user_model_output as _normalize_user_model_output,
     safe_path as _safe_path,
 )
+from besser.utilities.web_modeling_editor.backend.services.utils.gui_personalization_utils import (
+    personalize_gui_page as run_gui_personalization,
+)
 
 # Backend configuration
 from besser.utilities.web_modeling_editor.backend.config import (
@@ -245,144 +248,27 @@ async def personalize_gui_page(payload: Dict[str, Any] = Body(...)):
     Returns the same ``{components, css}`` shape adapted in style and content,
     ready to be imported back into the editor as a page variant.
     """
-    gui_page = payload.get("guiPage")
-    if not isinstance(gui_page, dict):
-        raise ValidationError(
-            "guiPage is required and must be a JSON object with 'components' and 'css'"
-        )
-
-    user_profile_model = payload.get("userProfileModel")
-    if not isinstance(user_profile_model, dict):
-        raise ValidationError("userProfileModel is required and must be a JSON object")
-
-    components = gui_page.get("components")
-    if not isinstance(components, list):
-        raise ValidationError("guiPage.components must be a list")
-    css = gui_page.get("css")
-    if not isinstance(css, list):
-        css = []
-
-    page_name = payload.get("pageName") if isinstance(payload.get("pageName"), str) else "page"
-    requested_model = payload.get("model")
-    llm_model = (
-        requested_model
-        if isinstance(requested_model, str) and requested_model.strip()
-        else "gpt-5.6-luna"
-    )
-
-    # Transform the user profile (UserDiagram) into its JSON object representation.
-    profile_document = _generate_user_profile_document(user_profile_model)
-
-    system_prompt = (
-        "You are a UI personalization assistant for a GrapesJS-based no-code GUI editor. "
-        "You receive a single GUI page as GrapesJS data: a 'components' array (the component "
-        "tree, each node carrying fields such as type, tagName, attributes, classes, components, "
-        "style, and text content) and a 'css' array (GrapesJS style-rule objects with 'selectors', "
-        "'selectorsAdd', 'style', and 'pageId'). You also receive a user profile model.\n\n"
-        "Your job is to adapt the page's PRESENTATION to this user, making decisions based on the "
-        "information in the profile. Presentation covers both visual styling AND the wording of the "
-        "page — its language, tone, and verbosity. Preserve the page's MEANING (its message, "
-        "purpose, and the information each element conveys), but you MAY re-express that meaning in "
-        "different words when the profile calls for it. When the profile clearly implies a "
-        "preference — for example a single language the user reads, a reading level, or a tone — "
-        "act on it decisively across the WHOLE page rather than leaving the wording unchanged.\n\n"
-        "HOW TO APPLY STYLE — TWO TIERS:\n"
-        "Tier 1 (PREFER THIS): express broad, consistent adaptations as high-level CSS rules keyed "
-        "by semantic category, appended to the 'css' array. Target a category with the "
-        "'selectorsAdd' field (a raw CSS selector string), NOT the 'selectors' array. Useful "
-        "categories: 'body' (base font-size and line-height — most text inherits from here), "
-        "headings ('h1, h2, h3, h4, h5, h6'), buttons ('button, .btn, a.button'), form fields "
-        "('input, textarea, select'), 'label', links ('a'). Many components in this editor ship "
-        "with baked-in inline/id-level styles that would otherwise win the cascade, so EVERY "
-        "declaration in a Tier-1 rule MUST end with '!important' (e.g. {\"font-size\": \"20px "
-        "!important\"}). A single 'body' rule with a larger font-size and line-height is the "
-        "correct way to enlarge text everywhere — do NOT resize each text node individually.\n"
-        "Tier 2 (USE SPARINGLY): for an adaptation a category rule cannot express (e.g. emphasizing "
-        "one specific call-to-action), you MAY edit the 'style' object of individual components in "
-        "the 'components' tree. Keep this to a small, deliberate set of nodes, and append "
-        "'!important' when overriding an existing baked-in value.\n\n"
-        "STRICT OUTPUT RULES: "
-        "1) Return ONLY a single JSON object with EXACTLY this shape: "
-        '{"components": [...], "css": [...]}. No markdown, no comments, no prose. '
-        "2) Preserve the overall structure: keep each component's 'type', 'tagName', and "
-        "'attributes.id' unchanged, and do not add, remove, or reorder components. "
-        "3) You MAY (a) append new high-level rules to the 'css' array, (b) change the 'style' "
-        "objects of existing css rules, (c) change class lists and 'style' objects of individual "
-        "components (Tier 2), and (d) rewrite the user-visible wording of the page — text-node "
-        "content and text-bearing attributes/properties (placeholder, title, alt, aria-label, link "
-        "text, button and field labels) — to translate it or adjust its tone/verbosity. Every "
-        "OTHER value must be byte-for-byte identical to the input. "
-        "3a) Preserve MEANING, not exact words: when you rewrite wording (per 3d) the message, "
-        "purpose, and information of every element must stay identical — translation and "
-        "tone/verbosity changes are allowed, but do NOT add, drop, or alter what the page tells the "
-        "user. A VISUAL adaptation such as enlarging the font is made ENTIRELY through "
-        "'style'/class/CSS-rule changes and must not touch wording; never rewrite text into a "
-        "description of the adaptation (e.g. do NOT turn a heading into 'bigger text for "
-        "readability'). "
-        "4) Keep every EXISTING css rule's 'selectors', 'selectorsAdd', and 'pageId' values exactly "
-        "as given (you may still edit its 'style'). For each NEW Tier-1 rule you add, set "
-        "'selectors' to an empty array and put the category selector in 'selectorsAdd'; you may "
-        "omit 'pageId'. "
-        "5) Return the input page verbatim if the profile gives no basis to adapt the presentation. "
-        "6) The result must be valid JSON, parseable as-is, and remain a working GrapesJS page."
+    if not isinstance(payload, dict):
+        raise ValidationError("Request body must be a JSON object")
+
+    # All validation, prompt building, the LLM call and response parsing live in
+    # gui_personalization_utils (mirroring agent_personalization). The router
+    # only resolves the API key, delegates off the event loop, and shapes the
+    # HTTP response; @handle_endpoint_errors maps ValidationError/GenerationError.
+    result = await asyncio.to_thread(
+        run_gui_personalization,
+        payload.get("guiPage"),
+        payload.get("userProfileModel"),
+        page_name=payload.get("pageName"),
+        model=payload.get("model"),
+        openai_api_key=extract_openai_api_key(payload),
     )
-    user_prompt = (
-        f'Personalize the GUI page named "{page_name}" for the following user profile model.\n\n'
-        f"User profile model:\n{json.dumps(profile_document, ensure_ascii=False, indent=2)}\n\n"
-        "GUI page to adapt (GrapesJS):\n"
-        f"{json.dumps({'components': components, 'css': css}, ensure_ascii=False)}\n\n"
-        "Make decisions based on the information in the profile. Only adapt something when the "
-        "profile gives a clear reason to. You can assume the profile contains the most important "
-        "information about the user, and anything missing can be assumed absent.\n\n"
-        "Prefer Tier-1 category CSS rules (every declaration ending with '!important') for anything "
-        "that should apply broadly and consistently — e.g. if the user needs larger text, add a "
-        "'body' rule with a larger font-size and line-height rather than resizing individual "
-        "nodes. Use Tier-2 per-component edits only for targeted exceptions. Presentation includes "
-        "textual presentation too (tone, verbosity, language) as long as the core meaning is "
-        "preserved, as well as colors, contrast, font sizing, spacing, and forms. Your goal is the "
-        "best possible experience for this user with all their needs met.\n\n"
-        'Return only the resulting JSON object {"components": [...], "css": [...]}.'
-    )
-
-    try:
-        response_text = await asyncio.to_thread(
-            call_openai_chat,
-            system_prompt,
-            user_prompt,
-            model=llm_model,
-            openai_api_key=extract_openai_api_key(payload if isinstance(payload, dict) else {}),
-            config=payload,
-        )
-        parsed = extract_json_object(response_text)
-        personalized_components = parsed.get("components")
-        personalized_css = parsed.get("css", [])
-        if not isinstance(personalized_components, list):
-            raise GenerationError("LLM response did not include a valid 'components' list")
-        if not isinstance(personalized_css, list):
-            personalized_css = []
-
-        return {
-            "guiPage": {
-                "components": personalized_components,
-                "css": personalized_css,
-            },
-            "source": "openai",
-            "model": llm_model,
-            "generatedAt": _utc_now_iso(),
-        }
-    except RuntimeError as runtime_error:
-        # Raised by call_openai_chat when no OpenAI API key is configured.
-        raise ValidationError(str(runtime_error)) from runtime_error
-    except ValueError as parse_error:
-        logger.exception("Failed to parse LLM personalization response")
-        raise GenerationError("Failed to parse LLM personalization response") from parse_error
-    except (ValidationError, GenerationError):
-        raise
-    except HTTPException:
-        raise
-    except Exception as exc:
-        logger.exception("Failed to personalize GUI page")
-        raise GenerationError("Failed to personalize GUI page") from exc
+    return {
+        "guiPage": {"components": result["components"], "css": result["css"]},
+        "source": "openai",
+        "model": result["model"],
+        "generatedAt": _utc_now_iso(),
+    }
 
 
 @router.get("/agent-config-manual-mapping")
diff --git a/besser/utilities/web_modeling_editor/backend/services/utils/gui_personalization_utils.py b/besser/utilities/web_modeling_editor/backend/services/utils/gui_personalization_utils.py
new file mode 100644
index 000000000..c950cb47d
--- /dev/null
+++ b/besser/utilities/web_modeling_editor/backend/services/utils/gui_personalization_utils.py
@@ -0,0 +1,182 @@
+"""GUI page personalization via an LLM.
+
+Mirrors the ``agent_personalization`` module pattern: all prompt construction,
+the OpenAI call and response parsing live here so the router stays a thin HTTP
+layer. The router imports :func:`personalize_gui_page` and delegates to it.
+"""
+import json
+import logging
+
+from besser.generators.agents.agent_personalization import (
+    DEFAULT_OPENAI_MODEL,
+    call_openai_chat,
+)
+from besser.utilities.web_modeling_editor.backend.services.exceptions import (
+    GenerationError,
+    ValidationError,
+)
+from besser.utilities.web_modeling_editor.backend.services.utils.agent_config_recommendation_utils import (
+    extract_json_object,
+)
+from besser.utilities.web_modeling_editor.backend.services.utils.user_profile_utils import (
+    generate_user_profile_document,
+)
+
+logger = logging.getLogger(__name__)
+
+
+# LLM instruction for adapting a single GrapesJS page to a user profile.
+# Kept as a module constant so it can be versioned, reviewed and tested in
+# isolation rather than being buried inside a request handler.
+GUI_PERSONALIZATION_SYSTEM_PROMPT = (
+    "You are a UI personalization assistant for a GrapesJS-based no-code GUI editor. "
+    "You receive a single GUI page as GrapesJS data: a 'components' array (the component "
+    "tree, each node carrying fields such as type, tagName, attributes, classes, components, "
+    "style, and text content) and a 'css' array (GrapesJS style-rule objects with 'selectors', "
+    "'selectorsAdd', 'style', and 'pageId'). You also receive a user profile model.\n\n"
+    "Your job is to adapt the page's PRESENTATION to this user, making decisions based on the "
+    "information in the profile. Presentation covers both visual styling AND the wording of the "
+    "page — its language, tone, and verbosity. Preserve the page's MEANING (its message, "
+    "purpose, and the information each element conveys), but you MAY re-express that meaning in "
+    "different words when the profile calls for it. When the profile clearly implies a "
+    "preference — for example a single language the user reads, a reading level, or a tone — "
+    "act on it decisively across the WHOLE page rather than leaving the wording unchanged.\n\n"
+    "HOW TO APPLY STYLE — TWO TIERS:\n"
+    "Tier 1 (PREFER THIS): express broad, consistent adaptations as high-level CSS rules keyed "
+    "by semantic category, appended to the 'css' array. Target a category with the "
+    "'selectorsAdd' field (a raw CSS selector string), NOT the 'selectors' array. Useful "
+    "categories: 'body' (base font-size and line-height — most text inherits from here), "
+    "headings ('h1, h2, h3, h4, h5, h6'), buttons ('button, .btn, a.button'), form fields "
+    "('input, textarea, select'), 'label', links ('a'). Many components in this editor ship "
+    "with baked-in inline/id-level styles that would otherwise win the cascade, so EVERY "
+    "declaration in a Tier-1 rule MUST end with '!important' (e.g. {\"font-size\": \"20px "
+    "!important\"}). A single 'body' rule with a larger font-size and line-height is the "
+    "correct way to enlarge text everywhere — do NOT resize each text node individually.\n"
+    "Tier 2 (USE SPARINGLY): for an adaptation a category rule cannot express (e.g. emphasizing "
+    "one specific call-to-action), you MAY edit the 'style' object of individual components in "
+    "the 'components' tree. Keep this to a small, deliberate set of nodes, and append "
+    "'!important' when overriding an existing baked-in value.\n\n"
+    "STRICT OUTPUT RULES: "
+    "1) Return ONLY a single JSON object with EXACTLY this shape: "
+    '{"components": [...], "css": [...]}. No markdown, no comments, no prose. '
+    "2) Preserve the overall structure: keep each component's 'type', 'tagName', and "
+    "'attributes.id' unchanged, and do not add, remove, or reorder components. "
+    "3) You MAY (a) append new high-level rules to the 'css' array, (b) change the 'style' "
+    "objects of existing css rules, (c) change class lists and 'style' objects of individual "
+    "components (Tier 2), and (d) rewrite the user-visible wording of the page — text-node "
+    "content and text-bearing attributes/properties (placeholder, title, alt, aria-label, link "
+    "text, button and field labels) — to translate it or adjust its tone/verbosity. Every "
+    "OTHER value must be byte-for-byte identical to the input. "
+    "3a) Preserve MEANING, not exact words: when you rewrite wording (per 3d) the message, "
+    "purpose, and information of every element must stay identical — translation and "
+    "tone/verbosity changes are allowed, but do NOT add, drop, or alter what the page tells the "
+    "user. A VISUAL adaptation such as enlarging the font is made ENTIRELY through "
+    "'style'/class/CSS-rule changes and must not touch wording; never rewrite text into a "
+    "description of the adaptation (e.g. do NOT turn a heading into 'bigger text for "
+    "readability'). "
+    "4) Keep every EXISTING css rule's 'selectors', 'selectorsAdd', and 'pageId' values exactly "
+    "as given (you may still edit its 'style'). For each NEW Tier-1 rule you add, set "
+    "'selectors' to an empty array and put the category selector in 'selectorsAdd'; you may "
+    "omit 'pageId'. "
+    "5) Return the input page verbatim if the profile gives no basis to adapt the presentation. "
+    "6) The result must be valid JSON, parseable as-is, and remain a working GrapesJS page."
+)
+
+
+def build_user_prompt(page_name: str, profile_document, components, css) -> str:
+    """Build the per-request user prompt for GUI page personalization."""
+    return (
+        f'Personalize the GUI page named "{page_name}" for the following user profile model.\n\n'
+        f"User profile model:\n{json.dumps(profile_document, ensure_ascii=False, indent=2)}\n\n"
+        "GUI page to adapt (GrapesJS):\n"
+        f"{json.dumps({'components': components, 'css': css}, ensure_ascii=False)}\n\n"
+        "Make decisions based on the information in the profile. Only adapt something when the "
+        "profile gives a clear reason to. You can assume the profile contains the most important "
+        "information about the user, and anything missing can be assumed absent.\n\n"
+        "Prefer Tier-1 category CSS rules (every declaration ending with '!important') for anything "
+        "that should apply broadly and consistently — e.g. if the user needs larger text, add a "
+        "'body' rule with a larger font-size and line-height rather than resizing individual "
+        "nodes. Use Tier-2 per-component edits only for targeted exceptions. Presentation includes "
+        "textual presentation too (tone, verbosity, language) as long as the core meaning is "
+        "preserved, as well as colors, contrast, font sizing, spacing, and forms. Your goal is the "
+        "best possible experience for this user with all their needs met.\n\n"
+        'Return only the resulting JSON object {"components": [...], "css": [...]}.'
+    )
+
+
+def personalize_gui_page(
+    gui_page,
+    user_profile_model,
+    *,
+    page_name: str = "page",
+    model=None,
+    openai_api_key=None,
+) -> dict:
+    """Personalize a single GrapesJS page for a user profile using an LLM.
+
+    Args:
+        gui_page: a GrapesJS page snapshot ``{"components": [...], "css": [...]}``.
+        user_profile_model: a UserDiagram UML model JSON.
+        page_name: the page name (used in the prompt only).
+        model: optional OpenAI model id; falls back to ``DEFAULT_OPENAI_MODEL``.
+        openai_api_key: resolved OpenAI API key (the caller resolves it).
+
+    Returns:
+        ``{"components": [...], "css": [...], "model": <id>}`` — the adapted page
+        plus the model actually used.
+
+    Raises:
+        ValidationError: on malformed input or a missing OpenAI API key.
+        GenerationError: when the LLM response cannot be parsed or is malformed.
+    """
+    if not isinstance(gui_page, dict):
+        raise ValidationError(
+            "guiPage is required and must be a JSON object with 'components' and 'css'"
+        )
+    if not isinstance(user_profile_model, dict):
+        raise ValidationError("userProfileModel is required and must be a JSON object")
+
+    components = gui_page.get("components")
+    if not isinstance(components, list):
+        raise ValidationError("guiPage.components must be a list")
+    css = gui_page.get("css")
+    if not isinstance(css, list):
+        css = []
+
+    if not isinstance(page_name, str) or not page_name.strip():
+        page_name = "page"
+    llm_model = model if isinstance(model, str) and model.strip() else DEFAULT_OPENAI_MODEL
+
+    # Transform the user profile (UserDiagram) into its JSON object representation.
+    profile_document = generate_user_profile_document(user_profile_model)
+    user_prompt = build_user_prompt(page_name, profile_document, components, css)
+
+    try:
+        response_text = call_openai_chat(
+            GUI_PERSONALIZATION_SYSTEM_PROMPT,
+            user_prompt,
+            model=llm_model,
+            openai_api_key=openai_api_key,
+        )
+    except RuntimeError as runtime_error:
+        # Raised by call_openai_chat when no OpenAI API key is configured.
+        raise ValidationError(str(runtime_error)) from runtime_error
+
+    try:
+        parsed = extract_json_object(response_text)
+    except ValueError as parse_error:
+        logger.exception("Failed to parse LLM personalization response")
+        raise GenerationError("Failed to parse LLM personalization response") from parse_error
+
+    personalized_components = parsed.get("components")
+    if not isinstance(personalized_components, list):
+        raise GenerationError("LLM response did not include a valid 'components' list")
+    personalized_css = parsed.get("css", [])
+    if not isinstance(personalized_css, list):
+        personalized_css = []
+
+    return {
+        "components": personalized_components,
+        "css": personalized_css,
+        "model": llm_model,
+    }
diff --git a/tests/utilities/web_modeling_editor/backend/services/utils/test_gui_personalization.py b/tests/utilities/web_modeling_editor/backend/services/utils/test_gui_personalization.py
new file mode 100644
index 000000000..99c04eed7
--- /dev/null
+++ b/tests/utilities/web_modeling_editor/backend/services/utils/test_gui_personalization.py
@@ -0,0 +1,101 @@
+"""Tests for gui_personalization_utils.personalize_gui_page.
+
+The OpenAI call is mocked, so these run offline and exercise the validation,
+model-selection, response-parsing and error-mapping logic in isolation.
+"""
+from unittest.mock import patch
+
+import pytest
+
+from besser.utilities.web_modeling_editor.backend.services.utils.gui_personalization_utils import (
+    personalize_gui_page,
+    DEFAULT_OPENAI_MODEL,
+)
+from besser.utilities.web_modeling_editor.backend.services.exceptions import (
+    ValidationError,
+    GenerationError,
+)
+
+MODULE = "besser.utilities.web_modeling_editor.backend.services.utils.gui_personalization_utils"
+
+_PAGE = {"components": [{"type": "text", "content": "Hello"}], "css": []}
+_PROFILE = {"type": "UserDiagram", "elements": {}, "relationships": {}}
+
+
+def _mock_llm(return_value=None, side_effect=None):
+    """Patch both the LLM call and the profile-document builder."""
+    return (
+        patch(f"{MODULE}.call_openai_chat", return_value=return_value, side_effect=side_effect),
+        patch(f"{MODULE}.generate_user_profile_document", return_value={}),
+    )
+
+
+class TestPersonalizeGuiPageValidation:
+    def test_gui_page_must_be_dict(self):
+        with pytest.raises(ValidationError):
+            personalize_gui_page("not-a-dict", _PROFILE)
+
+    def test_user_profile_must_be_dict(self):
+        with pytest.raises(ValidationError):
+            personalize_gui_page(_PAGE, "not-a-dict")
+
+    def test_components_must_be_a_list(self):
+        with pytest.raises(ValidationError):
+            personalize_gui_page({"components": "nope"}, _PROFILE)
+
+    def test_validation_happens_before_any_llm_call(self):
+        # A bad payload must never reach call_openai_chat.
+        with patch(f"{MODULE}.call_openai_chat") as chat:
+            with pytest.raises(ValidationError):
+                personalize_gui_page("bad", _PROFILE)
+        chat.assert_not_called()
+
+
+class TestPersonalizeGuiPageBehavior:
+    def test_happy_path_parses_llm_response(self):
+        llm_out = (
+            '{"components": [{"type": "text", "content": "Bonjour"}], '
+            '"css": [{"selectorsAdd": "body", "style": {"font-size": "20px !important"}}]}'
+        )
+        chat, profile = _mock_llm(return_value=llm_out)
+        with chat as chat_mock, profile:
+            result = personalize_gui_page(_PAGE, _PROFILE, openai_api_key="sk-test")
+        assert result["components"][0]["content"] == "Bonjour"
+        assert result["css"][0]["selectorsAdd"] == "body"
+        assert result["model"] == DEFAULT_OPENAI_MODEL
+        # the shared default model is what was actually sent to OpenAI
+        assert chat_mock.call_args.kwargs["model"] == DEFAULT_OPENAI_MODEL
+
+    def test_explicit_model_overrides_default(self):
+        chat, profile = _mock_llm(return_value='{"components": [], "css": []}')
+        with chat as chat_mock, profile:
+            result = personalize_gui_page(_PAGE, _PROFILE, model="gpt-5-mini", openai_api_key="sk-test")
+        assert result["model"] == "gpt-5-mini"
+        assert chat_mock.call_args.kwargs["model"] == "gpt-5-mini"
+
+    def test_missing_css_defaults_to_empty_list(self):
+        chat, profile = _mock_llm(return_value='{"components": []}')
+        with chat, profile:
+            result = personalize_gui_page(_PAGE, _PROFILE, openai_api_key="sk-test")
+        assert result["css"] == []
+
+
+class TestPersonalizeGuiPageErrors:
+    def test_missing_api_key_becomes_validation_error(self):
+        # call_openai_chat raises RuntimeError when no key is configured.
+        chat, profile = _mock_llm(side_effect=RuntimeError("OpenAI API key not found"))
+        with chat, profile:
+            with pytest.raises(ValidationError):
+                personalize_gui_page(_PAGE, _PROFILE)
+
+    def test_unparseable_llm_response_becomes_generation_error(self):
+        chat, profile = _mock_llm(return_value="this is not json")
+        with chat, profile:
+            with pytest.raises(GenerationError):
+                personalize_gui_page(_PAGE, _PROFILE, openai_api_key="sk-test")
+
+    def test_llm_response_without_components_list_raises(self):
+        chat, profile = _mock_llm(return_value='{"css": []}')
+        with chat, profile:
+            with pytest.raises(GenerationError):
+                personalize_gui_page(_PAGE, _PROFILE, openai_api_key="sk-test")