Fix podcasts generating in English + failing with invalid JSON

Two root causes, both fixed in the bind-mounted podcast prompt templates
(prompts/podcast/*.jinja):

1. Language: the episode profile's `language` field IS passed to both
   podcast_creator templates as {{ language }}, but the stock templates never
   reference it — so podcasts came out English (driven only by the English
   stock briefings/speakers), then read aloud by the German-locked Chatterbox
   TTS = "English with a German accent". Added a CRITICAL LANGUAGE REQUIREMENT
   block keyed on {{ language }} to both templates; now `language: "de"`
   actually forces German. Verified end-to-end: a full run produced a 44-line
   all-German transcript + audio.

2. Invalid json output failures: qwen3.5:27b is a thinking model; on long
   segments the <think> block ate the response-token budget and truncated the
   JSON. Prepended /no_think to both templates (~3x faster, valid JSON).

Templates are bind-mounted read-only via docker-compose (directory mount, so
edits survive a container restart without inode-staleness). Bundled briefings
and speaker backstories were also translated to German to reduce drift.

Known limitation documented: feeding an entire book (~70k tokens) as podcast
content makes each of the 6 LLM calls take ~3.5 min and is unreliable; use a
shorter source or summary. Confirmed working with concise content.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

BEDIENUNGSANLEITUNG.md

@@ -379,21 +379,36 @@ Das Episode- oder Sprecherprofil verweist auf ein Modell ohne konfiguriertes Cre
 `PUT /api/speaker-profiles/{id}` (`voice_model`) auf registrierte lokale/OpenRouter-Modelle
 umstellen — siehe `scripts/setup_models.sh` für die IDs der Standardmodelle.
 
-### Podcast wird auf Englisch statt Deutsch erzeugt
+### Podcast wird auf Englisch statt Deutsch erzeugt (oder auf Englisch mit deutschem Akzent vorgelesen)
 
-Das verwendete Episode-Profil hat kein `language`-Feld gesetzt — ohne Angabe generiert das
+Das ist behoben: Die Podcast-Prompt-Vorlagen (`prompts/podcast/outline.jinja` und
-Sprachmodell standardmäßig auf Englisch, unabhängig von der Sprache der Quelle. Prüfen und
+`transcript.jinja` in diesem Projekt) wurden um eine explizite Sprachanweisung ergänzt, die das
-korrigieren:
+`language`-Feld des Episode-Profils auswertet — sie werden per Bind-Mount aus `docker-compose.yml`
+in den Container eingehängt. Setzt du am Episode-Profil `language: "de"`, kommt der Podcast auf
+Deutsch. (Vorher hatte das `language`-Feld keine Wirkung, weil die mitgelieferten Vorlagen es
+ignorierten — daher englischer Text, der von der deutsch-fixierten TTS mit Akzent vorgelesen wurde.)
+
+Falls doch wieder Englisch erscheint, prüfe das `language`-Feld:
 
 ```bash
 curl -s http://127.0.0.1:5055/api/episode-profiles | python3 -c \
   "import json,sys; [print(p['name'], p['language']) for p in json.load(sys.stdin)]"
 ```
 
-Fehlt `de`, per `PUT /api/episode-profiles/{id}` (vollständiger Body nötig, siehe oben)
+Fehlt `de`/`de-DE`, per `PUT /api/episode-profiles/{id}` (vollständiger Body) ergänzen. Zusätzlich
-`"language": "de"` ergänzen. Die drei mitgelieferten Profile (`business_analysis`,
+sind Briefing und Sprecherbeschreibungen der mitgelieferten Profile auf Deutsch übersetzt (hilft
-`solo_expert`, `tech_discussion`) sind bereits korrigiert; bei neu angelegten eigenen Profilen
+gegen Sprach-Drift, wenn der Quellinhalt englisch ist). **Wichtig:** Änderst du die
-selbst daran denken.
+Vorlagen-Dateien selbst, ist danach ein Container-Neustart nötig (`docker compose up -d
+--force-recreate open_notebook`), damit der Bind-Mount die neue Version übernimmt.
+
+### Podcast-Erzeugung schlägt mit „Invalid json output" fehl
+
+Das Textmodell hat ungültiges JSON geliefert — passierte bei `qwen3.5:27b` (einem „denkenden"
+Modell), wenn der gesamte Notebook-Inhalt (bei einem ganzen Buch ~70.000 Tokens) in jeden
+Transkript-Abschnitt gepackt wird: Der Denk-Block frisst dann das Antwort-Budget auf und das JSON
+wird abgeschnitten. Behoben durch `/no_think` als erste Zeile beider Podcast-Vorlagen (schaltet
+den Denkmodus ab, ~3× schneller, volles Budget fürs JSON). Falls es dennoch auftritt: kürzeren
+Quellinhalt verwenden (nicht das ganze Buch) oder die Generierung erneut starten.
 
 ### Weitere technische Details
 

CLAUDE.md

@@ -41,13 +41,38 @@ A separate local `llama.cpp` server exists on this machine (managed via `~/llama
 
 **Chat model context window:** the Ollama credential used for `qwen3.5:27b` (`credential:di8b31l16zikyyb6isyi`) has `num_ctx=98304` set explicitly. Without this, esperanto's `OllamaLanguageModel` silently defaults `num_ctx` to **8192** regardless of the model's real capability or `OLLAMA_CONTEXT_LENGTH` — any chat context (e.g. "full content" mode on a real document) beyond that gets truncated by Ollama, and because `qwen3.5:27b` is a thinking model, the truncated prompt frequently produces an empty final answer (the response is silently swallowed by `clean_thinking_content`) instead of a visible error — looks exactly like "chat gives no answer" from the UI. `98304` is the largest value that still keeps the whole model on GPU 1 (`ollama ps` shows `100% GPU`); `131072` spills ~91% onto CPU and makes a single response take 5-6 minutes instead of ~1-2. Even at 98304, a full-book "Volltext" chat (~70k+ tokens of context) takes ~2-3 minutes — that's inherent to processing that much context on one consumer GPU, not a bug. For large documents, the default short/RAG context mode (only relevant chunks, not the whole document) stays fast; reserve "Volltext" for shorter sources. If `qwen3.5:27b` ever gets swapped for a different Ollama chat model, re-check this credential's `num_ctx` still makes sense for its VRAM footprint.
 
-**Podcast language:** the three bundled episode profiles (`business_analysis`, `solo_expert`,
+**Podcast language + reliability — fixed via patched prompt templates (`prompts/podcast/`,
-`tech_discussion`) ship with `language: null`, which the underlying `podcast_creator` library
+bind-mounted).** Two separate problems, one fix location:
-treats as "no language specified" and defaults to English for both outline and transcript
+
-generation — regardless of what language the source content or the briefing text is in. All
+1. *Language.* The episode profile's `language` field (`"de"` → resolved to `"German"`) **is**
-three are set to `language: "de"` here. If you create a new episode profile, set `language`
+   passed into both `podcast_creator` prompt templates as a `{{ language }}` variable
-explicitly (`PUT /api/episode-profiles/{id}`, full body) — it doesn't inherit from the notebook
+   (`nodes.py`, both `generate_outline_node` and `generate_transcript_node`), but the stock
-or the source.
+   templates shipped in the image never reference it — so setting `language` had no effect and
+   podcasts came out in English (the stock briefings and speaker backstories are English, which
+   is the only language signal the model then sees). English text read aloud by the German-locked
+   Chatterbox TTS is what produced the "English with a bad German accent" symptom.
+2. *Reliability.* `qwen3.5:27b` is a thinking model. Podcast content is the **entire notebook**
+   (`Notebook.get_context()` → every source's full text + all insights; for a whole book that's
+   ~70k+ tokens), fed into *each* transcript-segment call. On long segments the `<think>` block
+   eats the 5000-token response budget and the JSON gets truncated → `Invalid json output` →
+   whole job fails. (Confirmed: `/no_think` cut a segment from 98s to 34s and left valid JSON.)
+
+Fix — both handled in the two templates under `prompts/podcast/`, bind-mounted read-only over
+the image's copies via `docker-compose.yml`:
+- Prepended `/no_think` as the first line of both templates (Qwen honors it anywhere; harmless
+  text for non-Qwen models) — disables thinking, freeing the token budget and ~3x speedup.
+- Added a `{% if language %}CRITICAL LANGUAGE REQUIREMENT … in {{ language }}{% endif %}` block
+  near the end of both templates, so the already-plumbed `language` field now actually forces the
+  output language.
+
+The bundled briefings and speaker backstory/personality were **also** translated to German (belt
+and suspenders; reduces English drift from the source content), but the template change is what
+makes `language` authoritative. **Editing these templates requires a container restart** to take
+effect — they're bind-mounted, and the mount is the directory `prompts/podcast/` (not individual
+files, which go stale on inode-replacing edits). If you switch off `qwen3.5:27b`, the `/no_think`
+line becomes inert but harmless.
+
+If you create your own episode profile, just set `language` — the template handles the rest.
 
 ### Text-to-speech / speech-to-text
 

README.md

@@ -204,6 +204,11 @@ Kurzreferenz — Details jeweils in [`CLAUDE.md`](CLAUDE.md):
   leere Chat-Antworten bei größerem Kontext, ohne sichtbaren Fehler.
 - **Neue Host-Ports brauchen eine `ufw`-Regel**, sonst kann der Container sie nicht erreichen
   (Timeout, keine Fehlermeldung in Open Notebook selbst).
-- **Podcasts werden ohne explizites `language`-Feld auf Englisch erzeugt**, unabhängig von der
+- **Podcast-Sprache** wird über das `language`-Feld des Episode-Profils gesteuert, aber nur
-  Sprache der Quelle. Die drei mitgelieferten Episode-Profile sind bereits auf `"de"` gesetzt;
+  dank der gepatchten Prompt-Vorlagen unter `prompts/podcast/` (per Bind-Mount in
-  bei selbst angelegten Profilen selbst daran denken.
+  `docker-compose.yml` eingehängt) — die Original-Vorlagen im Image ignorieren `language`, was
+  englische Podcasts (von der deutsch-fixierten TTS mit Akzent vorgelesen) verursachte. Die
+  Vorlagen enthalten zusätzlich `/no_think`, damit `qwen3.5:27b` bei langem Quellinhalt nicht
+  durch überlange Reasoning-Blöcke ungültiges JSON liefert. Änderst du die Vorlagen, danach
+  `docker compose up -d --force-recreate open_notebook`. Details:
+  [`BEDIENUNGSANLEITUNG.md`](BEDIENUNGSANLEITUNG.md#10-troubleshooting) und [`CLAUDE.md`](CLAUDE.md).

docker-compose.yml

@@ -34,3 +34,11 @@ services:
       - "host.docker.internal:host-gateway"
     volumes:
       - ./notebook_data:/app/data
+      # Podcast-Prompt-Vorlagen mit expliziter Sprachanweisung ({{ language }})
+      # und abgeschaltetem Thinking-Modus (/no_think), damit Podcasts in der
+      # eingestellten Sprache erzeugt werden (statt Englisch) und das JSON bei
+      # langen Segmenten nicht durch riesige Reasoning-Blöcke abgeschnitten wird.
+      # Verzeichnis-Mount (nicht Einzeldateien), damit Edits ohne Inode-Probleme
+      # nach einem Container-Neustart greifen. Der Ordner im Image enthält nur
+      # genau diese zwei Vorlagen.
+      - ./prompts/podcast:/app/prompts/podcast:ro

prompts/podcast/outline.jinja

@@ -0,0 +1,91 @@
+/no_think
+You are an AI assistant specialized in creating podcast outlines. Your task is to create a detailed outline for a podcast episode based on a provided briefing. The outline you create will be used to generate the podcast transcript.
+
+Here is the briefing for the podcast episode:
+<briefing>
+{{ briefing }}
+</briefing>
+
+The user has provided content to be used as the context for this podcast episode:
+<context>
+{% if context is string %}
+{{ context }}
+{% else %}
+{% for item in context %}
+<content_piece>
+{{ item }}
+</content_piece>
+{% endfor %}
+{% endif %}
+</context>
+
+The podcast will feature the following speakers:
+<speakers>
+{% for speaker in speakers %}
+- **{{ speaker.name }}**: {{ speaker.backstory }}
+  Personality: {{ speaker.personality }}
+{% endfor %}
+</speakers>
+
+Please create an outline based on this briefing. Your outline should consist of {{ num_segments }} main segments for the podcast episode, along with a description of each segment. Follow these guidelines:
+
+1. Read the briefing carefully and identify the main topics and themes.
+2. Create {{ num_segments }} distinct segments that cover the entire scope of the briefing.
+3. For each segment, provide a clear and concise name that reflects its content.
+4. Write a detailed description for each segment, explaining what will be discussed and provide suggestions of topics according to the context given. The writer will use your suggestion to design the dialogs.
+5. Consider the speaker personalities and backstories when planning segments - match content to speaker expertise.
+6. Ensure that the segments flow logically from one to the next.
+7. This is a whole podcast so no need to reintroduce speakers or topics on each segment. Segments are just markers for us to know to change the topics, nothing else.
+8. Include an introduction segment at the beginning and a conclusion or wrap-up segment at the end.
+
+Format your outline using the following structure:
+
+```json
+{
+    "segments": [
+        {
+            "name": "[Segment Name]",
+            "description": "[Description of the segment content]",
+            "size": "short"
+        },
+        {
+            "name": "[Segment Name]",
+            "description": "[Description of the segment content]",
+            "size": "medium"
+        },
+        {
+            "name": "[Segment Name]",
+            "description": "[Description of the segment content]",
+            "size": "long"
+        },
+    ...
+    ]
+}
+```
+
+Formatting instructions:
+{{ format_instructions}}
+
+Additional tips:
+- Make sure the segment names are catchy and informative.
+- In the descriptions, include key points or questions that will be addressed in each segment.
+- Consider the target audience mentioned in the briefing when crafting your outline.
+- If the briefing mentions a guest, include segments for introducing the guest and featuring their expertise.
+- The size of the segment should be short, medium or long. Think about the content of the segment and how important it is to the episode.
+
+{% if language %}
+CRITICAL LANGUAGE REQUIREMENT:
+- Write the ENTIRE outline — every segment name and every segment description — exclusively in {{ language }}.
+- Do NOT use English or any other language, not even for technical terms or proper concepts where a {{ language }} wording exists.
+- These instructions are written in English, but your output MUST be in {{ language }}.
+{% endif %}
+
+IMPORTANT OUTPUT FORMAT:
+- If you use extended thinking with <think> tags, put ALL your reasoning inside <think></think> tags
+- Put the final JSON output OUTSIDE and AFTER any <think> tags
+- Do NOT wrap the JSON in ```json code blocks - return the raw JSON object only
+- Example correct format:
+  <think>Let me analyze the briefing...</think>
+  {"segments": [...]}
+
+Please provide your outline now, following the format and guidelines provided above.

prompts/podcast/transcript.jinja

@@ -0,0 +1,142 @@
+/no_think
+You are an AI assistant specialized in creating podcast transcripts.
+Your task is to generate a transcript for a specific segment of a podcast episode based on a provided briefing and outline.
+The transcript will be used to generate podcast audio. Follow these instructions carefully:
+
+First, review the briefing for the podcast episode:
+<briefing>
+{{ briefing }}
+</briefing>
+
+The user has provided content to be used as the context for this podcast episode:
+<context>
+{% if context is string %}
+{{ context }}
+{% else %}
+{% for item in context %}
+<content_piece>
+{{ item }}
+</content_piece>
+{% endfor %}
+{% endif %}
+</context>
+
+The podcast features the following speakers:
+<speakers>
+{% for speaker in speakers %}
+- **{{ speaker.name }}**: {{ speaker.backstory }}
+  Personality: {{ speaker.personality }}
+{% endfor %}
+</speakers>
+
+Next, examine the outline produced by our director:
+<outline>
+{{ outline }}
+</outline>
+
+{% if transcript %}
+Here is the current transcript so far:
+<transcript>
+{{ transcript }}
+</transcript>
+{% endif %}
+
+{% if is_final %}
+{% if speakers|length == 1 %}
+This is the final segment of the podcast. Make sure to wrap up the presentation and provide a conclusion.
+{% else %}
+This is the final segment of the podcast. Make sure to wrap up the conversation and provide a conclusion.
+{% endif %}
+{% endif %}
+
+
+You will focus on creating the dialogue for the following segment ONLY:
+<segment>
+{{ segment }}
+</segment>
+
+{% if speakers|length == 1 %}
+IMPORTANT: This is a SOLO podcast with only ONE speaker ({{ speaker_names[0] }}). Do NOT invent or add any other speakers.
+All dialogue entries must use "{{ speaker_names[0] }}" as the speaker name.
+
+Follow these format requirements strictly:
+   - Use ONLY the speaker name "{{ speaker_names[0] }}" for all dialogue entries.
+   - Do NOT create or invent any additional speakers.
+   - Stick to the segment, do not go further than what's requested. Other agents will do the rest of the podcast.
+   - The transcript must have at least {{ turns }} dialogue segments from the speaker.
+   - The speaker should present the content in an engaging, educational manner.
+{% else %}
+Follow these format requirements strictly:
+   - Use the actual speaker names ({{ speaker_names|join(', ') }}) to denote speakers.
+   - Choose which speaker should speak based on their personality, backstory, and the content being discussed.
+   - Stick to the segment, do not go further than what's requested. Other agents will do the rest of the podcast.
+   - The transcript must have at least {{ turns }} turns of messages between the speakers.
+   - Each speaker should contribute meaningfully based on their expertise and personality.
+{% endif %}
+
+
+```json
+{
+    "transcript": [
+        {
+            "speaker": "[Actual Speaker Name]",
+            "dialogue": "[Speaker's dialogue based on their personality and expertise]"
+        },
+    ...
+    ]
+}
+```
+
+Formatting instructions:
+{{ format_instructions}}
+
+
+{% if speakers|length == 1 %}
+Guidelines for creating the transcript:
+   - Ensure the presentation flows naturally and covers all points in the outline.
+   - Ensure you return the root "transcript" key in your response.
+   - Make the content sound engaging and educational.
+   - Include relevant details from the briefing.
+   - Break up the content into digestible segments with natural transitions.
+   - Use appropriate transitions between topics.
+   - Match the speaker's dialogue to their personality and expertise.
+   - This is a whole podcast so no need to reintroduce the speaker or topics on each segment. Segments are just markers for us to know to change the topics, nothing else.
+   - CRITICAL: There is only ONE speaker. Use ONLY: {{ speaker_names[0] }}. Do NOT invent additional speakers.
+{% else %}
+Guidelines for creating the transcript:
+   - Ensure the conversation flows naturally and covers all points in the outline.
+   - Ensure you return the root "transcript" key in your response.
+   - Make the dialogue sound conversational and engaging.
+   - Include relevant details from the briefing.
+   - Avoid long monologues; keep exchanges between speakers balanced.
+   - Use appropriate transitions between topics.
+   - Match each speaker's dialogue to their personality and expertise.
+   - Choose speakers strategically based on who would naturally contribute to each topic.
+   - This is a whole podcast so no need to reintroduce speakers or topics on each segment. Segments are just markers for us to know to change the topics, nothing else.
+   - IMPORTANT: Only use the provided speaker names: {{ speaker_names|join(', ') }}
+{% endif %}
+
+{% if language %}
+CRITICAL LANGUAGE REQUIREMENT:
+- Write ALL dialogue lines exclusively in {{ language }}.
+- Do NOT use English or any other language, not even for technical terms or proper concepts where a {{ language }} wording exists.
+- These instructions are written in English, but every spoken line you produce MUST be in {{ language }}.
+{% endif %}
+
+IMPORTANT OUTPUT FORMAT:
+- If you use extended thinking with <think> tags, put ALL your reasoning inside <think></think> tags
+- Put the final JSON output OUTSIDE and AFTER any <think> tags
+- Do NOT wrap the JSON in ```json code blocks - return the raw JSON object only
+- Example correct format:
+  <think>Let me plan the dialogue...</think>
+  {"transcript": [...]}
+
+When you're ready, provide the transcript.
+{% if speakers|length == 1 %}
+Remember, you are creating a realistic solo podcast presentation based on the given information.
+Make it informative, engaging, and natural-sounding while adhering to the format requirements.
+There is only ONE speaker - do not add any other speakers.
+{% else %}
+Remember, you are creating a realistic podcast conversation based on the given information.
+Make it informative, engaging, and natural-sounding while adhering to the format requirements.
+{% endif %}