feat: stream provider responses

docs/CHATGPT_HANDOFF.md

@@ -106,6 +106,9 @@ Rootserver:
   Behandlungs- und medizinische Notfallfragen sind zwingend lokal `never`.
 - `/privacy` trennt Inhaltsklassifikation, tatsächlichen Provider, Unterdrückung
   durch Modus `local` und technischen Provider-Fallback.
+- Ollama, Gemini, Hybridrouter, Chatservice und CLI streamen sichtbare Antwortteile.
+  Verdeckte Gedanken werden nicht angefordert oder ausgegeben; Terminal-Markdown
+  wird lesbar bereinigt. Strg+C verwirft Teilantworten atomar und kehrt zum Chat zurück.
 
 ## Aktuelle Architektur
 
@@ -114,6 +117,8 @@ Rootserver:
 - Modell-Provider als kleine austauschbare Schnittstelle
 - Ollama-Provider akzeptiert nur lokale HTTP-Loopback-Adressen
 - SQLite-Sitzungsspeicher mit atomaren Benutzer-/Assistentenpaaren
+- Streaming wird erst nach vollständigem Abschluss atomar gespeichert; bei Abbruch
+  bleibt weder die Benutzerfrage noch eine unvollständige Antwort im Verlauf.
 - Laufzeitdaten außerhalb von Git über `JAVIS_DATA_DIR` oder sicheren Plattformstandard
 - Hybridprovider bevorzugt Gemini für cloudgeeignete Inhalte und verwendet
   Ollama bei Datenschutz, Ablehnung, Offline-, Quota- und Providerfehlern
@@ -164,6 +169,10 @@ Rootserver:
 - Lesender Ollama-Status prüft nur Loopback-Erreichbarkeit und Modellliste.
 - Sicheres PowerShell-Startskript und kompakte Startdokumentation ergänzt; keine
   PATH-, Registry-, Autostart-, Dienst- oder Richtlinienänderung.
+- Medizinische Inhalte vor Cloudclient-Erstellung strikt auf `never` gesetzt.
+- Echtes Ollama-/Gemini-Streaming, providerübergreifendes Fallback vor der ersten
+  Ausgabe und sicheren Streaming-Abbruch nach Teilausgabe implementiert.
+- CLI-Streaming mit lesbarer Markdown-Bereinigung und sicherem Strg+C ergänzt.
 
 ## Aktuelle Tests
 
@@ -178,7 +187,8 @@ Letzter bestätigter Projektstand:
 - uv-Lock und `uv sync --dev`: bestanden
 - Python in `.venv`: 3.12.13
 - Ruff in `.venv`: 0.16.0
-- Unit-Tests: 69 bestanden; medizinisches `never` und Cloudclient-Sperre abgedeckt
+- Unit-Tests: 82 bestanden; medizinisches `never`, Streaming, Gedankenfilter,
+  Cloudclient-Sperre, Fallback und atomarer Strg+C-Abbruch abgedeckt
 - PowerShell-Syntax des Startskripts: erfolgreich geparst
 - Ruff Lint: bestanden
 - Ruff Formatprüfung: bestanden
@@ -220,7 +230,9 @@ Abnahmestatus:
 
 ## Git-Stand
 
-- aktueller und stabiler Branch: `main`
+- aktueller Arbeitsbranch: `feat/chat-comfort`
+- stabiler Ausgangsstand: `main` bei `77b510b`
+- medizinischer Datenschutz-Fix: `9148193`
 - Feature-Branch ist als `7a14fe8` zu
   `origin/feat/gemini-privacy-router` gepusht
 - konfliktfreier Merge nach `main`: `564a3fd`
@@ -249,23 +261,11 @@ Abnahmestatus:
 - `origin` verwendet HTTPS
 - kein Force-Push und keine umgeschriebene Historie
 
-## Kompakter Changelog
-
-- `49a1dd3`: erster Gitea-Verbindungstest
-- `6d04171`: sicheres Javis-Grundgerüst
-- `0e82748`: Werkzeug-, Token- und Handoff-Regeln
-- `e6eb995`: einmalige Archivierung und Verdichtung des Handoffs
-- aktuell: isolierte Python-Toolchain und reproduzierbare Entwicklungsumgebung
-- aktuell: portable Ollama-Laufzeit und `qwen3:8b` außerhalb von Git verifiziert
-- aktuell: lokaler CLI-Chat und persistente SQLite-Sitzungen vollständig abgenommen
-- aktuell: Gemini-Free-Hybridrouting, Datenschutz und Nullkostenmodus
-  automatisiert und durch Pascal manuell vollständig abgenommen
-
 ## Offene Entscheidungen und Fehler
 
 - endgültiger Produkt-/Repositoryname bleibt offen
 - Startskript startet Ollama bei Bedarf pro Prozess; kein Autostart oder Dienst
-- Antworten werden noch nicht gestreamt; Sitzungen besitzen noch keine Titel oder Suche
+- Antworten werden gestreamt; Sitzungen besitzen noch keine Titel oder Suche
 - genauer späterer Obsidian-Schreibbereich ist nicht freigegeben
 - normaler Secret-Provider ist festgelegt: Betriebssystem-Keyring; eine
   Klartext-XML wird nicht für API-Schlüssel verwendet
@@ -289,7 +289,8 @@ Abnahmestatus:
 
 ## Nächster sinnvoller Auftrag
 
-Auf `feat/chat-comfort` als nächstes Streaming mit sicherem Abbruch umsetzen.
+Auf `feat/chat-comfort` als Nächstes SQLite-Titelmigration, lokale automatische
+Titel sowie `/rename`, `/sessions`, `/load` und `/search` umsetzen.
 Medizinische Antwortqualität bleibt ein späteres Sicherheits-/Systemprompt-Thema.
 Noch keine Obsidian-Integration oder Tools beginnen.
 

src/javis/core/chat_service.py

@@ -2,10 +2,15 @@
 
 from __future__ import annotations
 
+from collections.abc import Iterator
 from dataclasses import dataclass
 
 from javis.memory.sqlite_store import ChatSession, SQLiteSessionStore
-from javis.providers.base import ChatMessage, LocalModelProvider
+from javis.providers.base import (
+    ChatMessage,
+    InvalidProviderResponseError,
+    LocalModelProvider,
+)
 
 
 class SessionProviderMismatchError(RuntimeError):
@@ -59,5 +64,43 @@ class ChatService:
         self.store.append_exchange(session_id, normalized, response)
         return response
 
+    def stream_send(self, session_id: str, text: str) -> Iterator[str]:
+        normalized = text.strip()
+        if not normalized:
+            raise ValueError("Eine leere Nachricht wird nicht gesendet.")
+        loaded = self.load_session(session_id)
+        messages = [*loaded.messages, ChatMessage("user", normalized)]
+        stream_method = getattr(self.provider, "stream_chat", None)
+        stream = (
+            stream_method(messages)
+            if callable(stream_method)
+            else iter((self.provider.chat(messages),))
+        )
+        chunks: list[str] = []
+        completed = False
+        try:
+            for chunk in stream:
+                if not isinstance(chunk, str):
+                    raise InvalidProviderResponseError(
+                        "Der Provider lieferte einen ungültigen Streaming-Abschnitt."
+                    )
+                if not chunk:
+                    continue
+                chunks.append(chunk)
+                yield chunk
+            completed = True
+        finally:
+            if not completed:
+                close_stream = getattr(stream, "close", None)
+                if callable(close_stream):
+                    close_stream()
+
+        response = "".join(chunks).strip()
+        if not response:
+            raise InvalidProviderResponseError(
+                "Der Provider lieferte keine verwendbare Streaming-Antwort."
+            )
+        self.store.append_exchange(session_id, normalized, response)
+
     def clear_session(self, session_id: str) -> None:
         self.store.clear_messages(session_id)

src/javis/core/provider_router.py

@@ -2,17 +2,19 @@
 
 from __future__ import annotations
 
-from collections.abc import Callable
+from collections.abc import Callable, Iterator
 from dataclasses import dataclass
 
 from javis.memory.usage_store import ProviderEvent, SQLiteUsageStore, UsageStoreError
 from javis.providers.base import (
     ChatMessage,
     InvalidApiKeyError,
+    InvalidProviderResponseError,
     LocalModelProvider,
     MissingApiKeyError,
     ProviderError,
     ProviderUsage,
+    ResponseAbortedError,
 )
 from javis.security.privacy import CloudPolicy, PrivacyDecision, PrivacyRouter
 
@@ -165,6 +167,245 @@ class HybridProvider:
         )
         return response
 
+    def stream_chat(self, messages: list[ChatMessage]) -> Iterator[str]:
+        current_text = messages[-1].content if messages else ""
+        decision = self._privacy_router.classify(
+            current_text,
+            cloud_requested=self.mode == "gemini",
+        )
+
+        if self.mode == "local":
+            yield from self._stream_local(
+                messages,
+                decision,
+                "lokaler Modus",
+                fallback=False,
+                cloud_suppressed_by_local_mode=True,
+            )
+            return
+        if decision.policy is CloudPolicy.NEVER:
+            yield from self._stream_local(
+                messages,
+                decision,
+                decision.reason,
+                fallback=True,
+            )
+            return
+
+        approved = decision.policy is CloudPolicy.ALLOWED
+        if decision.policy is CloudPolicy.ASK:
+            approved = self._approval_callback(decision)
+            if not approved:
+                yield from self._stream_local(
+                    messages,
+                    decision,
+                    "Cloudfreigabe abgelehnt",
+                    fallback=True,
+                )
+                return
+
+        unavailable_reason = self._cloud_unavailable_reason()
+        if unavailable_reason:
+            yield from self._stream_local(
+                messages,
+                decision,
+                unavailable_reason,
+                fallback=True,
+            )
+            return
+        if len(current_text) > self._max_cloud_input_chars:
+            yield from self._stream_local(
+                messages,
+                decision,
+                "Nachricht überschreitet das lokale Cloud-Größenlimit",
+                fallback=True,
+            )
+            return
+
+        cloud_messages = self._privacy_router.minimal_context(
+            messages,
+            current_policy=decision.policy,
+            approved=approved,
+            max_chars=self._max_cloud_input_chars,
+            max_messages=self._max_cloud_context_messages,
+        )
+        if not cloud_messages:
+            yield from self._stream_local(
+                messages,
+                decision,
+                "kein freigegebener Cloudkontext",
+                fallback=True,
+            )
+            return
+
+        emitted = False
+        try:
+            cloud_provider = self._cloud_provider_factory()
+            for chunk in self._provider_chunks(cloud_provider, cloud_messages):
+                emitted = True
+                yield chunk
+        except InvalidApiKeyError as exc:
+            self._cloud_session_disabled = True
+            if emitted:
+                self._raise_interrupted_cloud(decision, exc)
+            yield from self._stream_cloud_failure(
+                messages,
+                decision,
+                exc,
+                disable_notice=True,
+            )
+            return
+        except (MissingApiKeyError, ProviderError) as exc:
+            if emitted:
+                self._raise_interrupted_cloud(decision, exc)
+            yield from self._stream_cloud_failure(messages, decision, exc)
+            return
+
+        if not emitted:
+            error = InvalidProviderResponseError(
+                "Gemini hat keine verwendbare Streaming-Antwort geliefert."
+            )
+            yield from self._stream_cloud_failure(messages, decision, error)
+            return
+
+        usage = getattr(cloud_provider, "last_usage", ProviderUsage())
+        self._record(
+            ProviderEvent(
+                provider=cloud_provider.name,
+                model=cloud_provider.model,
+                success=True,
+                error_category=None,
+                fallback=False,
+                privacy_policy=decision.policy.value,
+                input_tokens=usage.input_tokens,
+                output_tokens=usage.output_tokens,
+            )
+        )
+        self.last_route = RouteStatus(
+            provider=cloud_provider.name,
+            privacy_policy=decision.policy,
+            fallback=False,
+            cloud_suppressed_by_local_mode=False,
+            technical_fallback=False,
+            reason="Cloudstream erfolgreich",
+        )
+
+    @staticmethod
+    def _provider_chunks(
+        provider: LocalModelProvider,
+        messages: list[ChatMessage],
+    ) -> Iterator[str]:
+        stream_method = getattr(provider, "stream_chat", None)
+        chunks = (
+            stream_method(messages) if callable(stream_method) else iter((provider.chat(messages),))
+        )
+        completed = False
+        try:
+            for chunk in chunks:
+                if not isinstance(chunk, str):
+                    raise InvalidProviderResponseError(
+                        "Der Provider lieferte einen ungültigen Streaming-Abschnitt."
+                    )
+                if chunk:
+                    yield chunk
+            completed = True
+        finally:
+            if not completed:
+                close = getattr(chunks, "close", None)
+                if callable(close):
+                    close()
+
+    def _stream_cloud_failure(
+        self,
+        messages: list[ChatMessage],
+        decision: PrivacyDecision,
+        error: ProviderError,
+        *,
+        disable_notice: bool = False,
+    ) -> Iterator[str]:
+        self._record_cloud_error(decision, error)
+        reason = "Gemini nicht verfügbar"
+        if disable_notice:
+            reason = "Gemini-Schlüssel abgelehnt; Cloud für diese Sitzung deaktiviert"
+        yield from self._stream_local(
+            messages,
+            decision,
+            reason,
+            fallback=True,
+            technical_fallback=True,
+        )
+
+    def _raise_interrupted_cloud(
+        self,
+        decision: PrivacyDecision,
+        error: ProviderError,
+    ) -> None:
+        self._record_cloud_error(decision, error)
+        self.last_route = RouteStatus(
+            provider="gemini",
+            privacy_policy=decision.policy,
+            fallback=False,
+            cloud_suppressed_by_local_mode=False,
+            technical_fallback=True,
+            reason="Cloudstream nach Teilausgabe abgebrochen",
+        )
+        raise ResponseAbortedError(
+            "Der Gemini-Stream wurde nach einer Teilausgabe abgebrochen; "
+            "es wurde kein lokaler Ersatz angehängt."
+        ) from error
+
+    def _stream_local(
+        self,
+        messages: list[ChatMessage],
+        decision: PrivacyDecision,
+        reason: str,
+        *,
+        fallback: bool,
+        cloud_suppressed_by_local_mode: bool = False,
+        technical_fallback: bool = False,
+    ) -> Iterator[str]:
+        if fallback:
+            self._notice_callback(f"{reason} – lokale Antwort mit Ollama.")
+        emitted = False
+        try:
+            for chunk in self._provider_chunks(self.local_provider, messages):
+                emitted = True
+                yield chunk
+        except ProviderError as exc:
+            self._record(
+                ProviderEvent(
+                    provider=self.local_provider.name,
+                    model=self.local_provider.model,
+                    success=False,
+                    error_category=type(exc).__name__,
+                    fallback=fallback,
+                    privacy_policy=decision.policy.value,
+                )
+            )
+            raise
+        if not emitted:
+            raise InvalidProviderResponseError(
+                "Ollama hat keine verwendbare Streaming-Antwort geliefert."
+            )
+        self._record(
+            ProviderEvent(
+                provider=self.local_provider.name,
+                model=self.local_provider.model,
+                success=True,
+                error_category=None,
+                fallback=fallback,
+                privacy_policy=decision.policy.value,
+            )
+        )
+        self.last_route = RouteStatus(
+            provider=self.local_provider.name,
+            privacy_policy=decision.policy,
+            fallback=fallback,
+            cloud_suppressed_by_local_mode=cloud_suppressed_by_local_mode,
+            technical_fallback=technical_fallback,
+            reason=reason,
+        )
+
     def _cloud_unavailable_reason(self) -> str | None:
         if not self._cloud_enabled:
             return "Gemini ist lokal nicht aktiviert"
@@ -188,17 +429,7 @@ class HybridProvider:
         *,
         disable_notice: bool = False,
     ) -> str:
-        error_category = type(error).__name__
+        self._record_cloud_error(decision, error)
-        self._record(
-            ProviderEvent(
-                provider="gemini",
-                model=self._cloud_model,
-                success=False,
-                error_category=error_category,
-                fallback=False,
-                privacy_policy=decision.policy.value,
-            )
-        )
         reason = "Gemini nicht verfügbar"
         if disable_notice:
             reason = "Gemini-Schlüssel abgelehnt; Cloud für diese Sitzung deaktiviert"
@@ -210,6 +441,22 @@ class HybridProvider:
             technical_fallback=True,
         )
 
+    def _record_cloud_error(
+        self,
+        decision: PrivacyDecision,
+        error: ProviderError,
+    ) -> None:
+        self._record(
+            ProviderEvent(
+                provider="gemini",
+                model=self._cloud_model,
+                success=False,
+                error_category=type(error).__name__,
+                fallback=False,
+                privacy_policy=decision.policy.value,
+            )
+        )
+
     def _local(
         self,
         messages: list[ChatMessage],

src/javis/interface/cli.py

@@ -4,6 +4,7 @@ from __future__ import annotations
 
 import argparse
 import getpass
+import re
 import sys
 from collections.abc import Callable, Sequence
 from pathlib import Path
@@ -27,6 +28,7 @@ from javis.security.secrets import SecretProvider, SecretStoreError
 
 InputFunction = Callable[[str], str]
 OutputFunction = Callable[[str], None]
+StreamOutputFunction = Callable[[str], None]
 StatusFunction = Callable[[], list[str]]
 
 HELP_TEXT = """Befehle:
@@ -144,12 +146,48 @@ def _show_sessions(sessions: list[ChatSession], output: OutputFunction) -> None:
         )
 
 
+class TerminalMarkdownRenderer:
+    """Turn common Markdown markers into readable incremental terminal text."""
+
+    _tail_size = 3
+
+    def __init__(self) -> None:
+        self._pending = ""
+
+    @staticmethod
+    def _clean(text: str) -> str:
+        text = re.sub(r"(?m)^[ \t]{0,3}#{1,6}[ \t]+", "", text)
+        for marker in ("```", "**", "__", "~~", "`"):
+            text = text.replace(marker, "")
+        return text
+
+    def feed(self, chunk: str) -> str:
+        combined = self._pending + chunk
+        if len(combined) <= self._tail_size:
+            self._pending = combined
+            return ""
+        visible = combined[: -self._tail_size]
+        self._pending = combined[-self._tail_size :]
+        return self._clean(visible)
+
+    def finish(self) -> str:
+        visible = self._clean(self._pending)
+        self._pending = ""
+        return visible
+
+
+def _terminal_write(text: str) -> None:
+    sys.stdout.write(text)
+    sys.stdout.flush()
+
+
 def run_chat(
     service: ChatService,
     *,
     session_id: str | None = None,
     input_fn: InputFunction = input,
     output: OutputFunction = print,
+    stream_output: StreamOutputFunction | None = None,
     status_fn: StatusFunction | None = None,
 ) -> int:
     try:
@@ -262,12 +300,41 @@ def run_chat(
             output("Unbekannter Befehl. /help zeigt die verfügbaren Befehle.")
             continue
 
+        stream = service.stream_send(active_id, entered)
+        writer = stream_output or (_terminal_write if output is print else output)
+        renderer = TerminalMarkdownRenderer()
+        started = False
         try:
-            response = service.send(active_id, entered)
+            for chunk in stream:
-            output(f"Javis: {response}")
+                visible = renderer.feed(chunk)
+                if not visible:
+                    continue
+                if not started:
+                    writer("Javis: ")
+                    started = True
+                writer(visible)
+            remaining = renderer.finish()
+            if remaining:
+                if not started:
+                    writer("Javis: ")
+                    started = True
+                writer(remaining)
+            if started:
+                writer("\n")
+        except KeyboardInterrupt:
+            close = getattr(stream, "close", None)
+            if callable(close):
+                close()
+            if started:
+                writer("\n")
+            output("Generierung abgebrochen. Die unvollständige Antwort wurde nicht gespeichert.")
         except (ProviderError, SessionStoreError, SessionProviderMismatchError) as exc:
+            if started:
+                writer("\n")
             output(f"Fehler: {exc}")
         except ValueError as exc:
+            if started:
+                writer("\n")
             output(f"Fehler: {exc}")
 
 

src/javis/providers/base.py

@@ -2,6 +2,7 @@
 
 from __future__ import annotations
 
+from collections.abc import Iterator
 from dataclasses import dataclass
 from typing import Protocol, runtime_checkable
 
@@ -70,3 +71,13 @@ class LocalModelProvider(Protocol):
     def chat(self, messages: list[ChatMessage]) -> str:
         """Return one complete assistant response."""
         ...
+
+
+@runtime_checkable
+class StreamingModelProvider(Protocol):
+    name: str
+    model: str
+
+    def stream_chat(self, messages: list[ChatMessage]) -> Iterator[str]:
+        """Yield only visible assistant text chunks."""
+        ...

src/javis/providers/gemini.py

@@ -2,7 +2,7 @@
 
 from __future__ import annotations
 
-from collections.abc import Callable
+from collections.abc import Callable, Iterator
 from typing import Any
 
 import httpx
@@ -49,6 +49,7 @@ class GeminiProvider:
         self._config = types.GenerateContentConfig(
             candidate_count=1,
             max_output_tokens=max_output_tokens,
+            thinking_config=types.ThinkingConfig(include_thoughts=False),
         )
         self._client = client_factory(
             api_key=api_key,
@@ -104,6 +105,73 @@ class GeminiProvider:
         )
         return text.strip()
 
+    def stream_chat(self, messages: list[ChatMessage]) -> Iterator[str]:
+        contents = [
+            types.Content(
+                role="model" if message.role == "assistant" else "user",
+                parts=[types.Part.from_text(text=message.content)],
+            )
+            for message in messages
+        ]
+        self.last_usage = ProviderUsage()
+        visible_text_received = False
+        try:
+            responses = self._client.models.generate_content_stream(
+                model=self.model,
+                contents=contents,
+                config=self._config,
+            )
+            for response in responses:
+                usage = getattr(response, "usage_metadata", None)
+                if usage is not None:
+                    self.last_usage = ProviderUsage(
+                        input_tokens=self._token_count(usage, "prompt_token_count"),
+                        output_tokens=self._token_count(
+                            usage,
+                            "candidates_token_count",
+                        ),
+                    )
+                for text in self._visible_text_parts(response):
+                    visible_text_received = True
+                    yield text
+        except errors.APIError as exc:
+            self._raise_api_error(exc)
+        except httpx.TimeoutException as exc:
+            raise ProviderTimeoutError("Gemini hat nicht rechtzeitig geantwortet.") from exc
+        except httpx.NetworkError as exc:
+            raise CloudNetworkError(
+                "Gemini ist wegen eines Netzwerkfehlers nicht erreichbar."
+            ) from exc
+        except (OSError, ConnectionError) as exc:
+            raise CloudNetworkError(
+                "Gemini ist wegen eines Netzwerkfehlers nicht erreichbar."
+            ) from exc
+
+        if not visible_text_received:
+            raise InvalidProviderResponseError(
+                "Gemini hat keine verwendbare Streaming-Antwort geliefert."
+            )
+
+    @staticmethod
+    def _visible_text_parts(response: object) -> Iterator[str]:
+        candidates = getattr(response, "candidates", None)
+        if isinstance(candidates, list) and candidates:
+            for candidate in candidates:
+                content = getattr(candidate, "content", None)
+                parts = getattr(content, "parts", None)
+                if not isinstance(parts, list):
+                    continue
+                for part in parts:
+                    if getattr(part, "thought", False):
+                        continue
+                    text = getattr(part, "text", None)
+                    if isinstance(text, str) and text:
+                        yield text
+            return
+        text = getattr(response, "text", None)
+        if isinstance(text, str) and text:
+            yield text
+
     @staticmethod
     def _token_count(usage: object, name: str) -> int | None:
         value = getattr(usage, name, None)

src/javis/providers/ollama.py

@@ -4,6 +4,7 @@ from __future__ import annotations
 
 import json
 import socket
+from collections.abc import Iterator
 from dataclasses import dataclass
 from urllib.error import HTTPError, URLError
 from urllib.request import Request, urlopen
@@ -107,3 +108,76 @@ class OllamaProvider:
                 "Ollama hat keine verwendbare Textantwort geliefert."
             )
         return content.strip()
+
+    def stream_chat(self, messages: list[ChatMessage]) -> Iterator[str]:
+        payload = {
+            "model": self.model,
+            "messages": [
+                {"role": message.role, "content": message.content} for message in messages
+            ],
+            "stream": True,
+            "think": False,
+        }
+        request = Request(
+            self._endpoint,
+            data=json.dumps(payload).encode("utf-8"),
+            headers={"Content-Type": "application/json"},
+            method="POST",
+        )
+        completed = False
+        visible_text_received = False
+        try:
+            with urlopen(request, timeout=self._timeout_seconds) as response:
+                for raw_line in response:
+                    if not raw_line.strip():
+                        continue
+                    try:
+                        result = json.loads(raw_line)
+                    except (json.JSONDecodeError, UnicodeDecodeError) as exc:
+                        raise InvalidProviderResponseError(
+                            "Ollama hat einen ungültigen Streaming-Abschnitt geliefert."
+                        ) from exc
+                    error = result.get("error")
+                    if isinstance(error, str) and error:
+                        if "not found" in error.lower():
+                            raise ModelNotInstalledError(
+                                f"Das lokale Modell '{self.model}' ist nicht installiert."
+                            )
+                        raise ProviderUnavailableError("Ollama hat den Stream abgelehnt.")
+                    content = result.get("message", {}).get("content")
+                    if content is not None and not isinstance(content, str):
+                        raise InvalidProviderResponseError(
+                            "Ollama hat ungültigen sichtbaren Text geliefert."
+                        )
+                    if content:
+                        visible_text_received = True
+                        yield content
+                    if result.get("done") is True:
+                        completed = True
+                        break
+        except HTTPError as exc:
+            details = exc.read().decode("utf-8", errors="replace")
+            if exc.code == 404 or "not found" in details.lower():
+                raise ModelNotInstalledError(
+                    f"Das lokale Modell '{self.model}' ist nicht installiert."
+                ) from exc
+            raise ProviderUnavailableError(f"Ollama meldet HTTP-Fehler {exc.code}.") from exc
+        except TimeoutError as exc:
+            raise ProviderTimeoutError(
+                "Die Modellantwort hat das Zeitlimit überschritten."
+            ) from exc
+        except URLError as exc:
+            if isinstance(exc.reason, (TimeoutError, socket.timeout)):
+                raise ProviderTimeoutError(
+                    "Die Modellantwort hat das Zeitlimit überschritten."
+                ) from exc
+            raise ProviderUnavailableError(
+                "Ollama ist unter der konfigurierten lokalen Adresse nicht erreichbar."
+            ) from exc
+
+        if not completed:
+            raise ResponseAbortedError("Der Ollama-Stream wurde vorzeitig beendet.")
+        if not visible_text_received:
+            raise InvalidProviderResponseError(
+                "Ollama hat keine verwendbare Streaming-Antwort geliefert."
+            )

tests/unit/test_chat_service.py

@@ -4,7 +4,7 @@ from pathlib import Path
 
 from javis.core.chat_service import ChatService
 from javis.memory.sqlite_store import SQLiteSessionStore
-from javis.providers.base import ChatMessage, LocalModelProvider
+from javis.providers.base import ChatMessage, LocalModelProvider, ProviderUnavailableError
 
 
 class RecordingProvider:
@@ -19,6 +19,19 @@ class RecordingProvider:
         return f"Antwort {len(self.calls)}"
 
 
+class StreamingProvider(RecordingProvider):
+    def __init__(self, *, fail_after_first: bool = False) -> None:
+        super().__init__()
+        self.fail_after_first = fail_after_first
+
+    def stream_chat(self, messages: list[ChatMessage]):
+        self.calls.append(messages)
+        yield "Teil "
+        if self.fail_after_first:
+            raise ProviderUnavailableError("Streamfehler")
+        yield "Antwort"
+
+
 class ChatServiceTests(unittest.TestCase):
     def setUp(self) -> None:
         self.temporary_directory = tempfile.TemporaryDirectory()
@@ -52,6 +65,41 @@ class ChatServiceTests(unittest.TestCase):
             ],
         )
 
+    def test_streaming_response_is_persisted_exactly_once_after_completion(self) -> None:
+        provider = StreamingProvider()
+        service = ChatService(self.service.store, provider)
+        session = service.new_session()
+
+        chunks = list(service.stream_send(session.id, "Hallo"))
+
+        self.assertEqual(chunks, ["Teil ", "Antwort"])
+        self.assertEqual(
+            [message.content for message in service.load_session(session.id).messages],
+            ["Hallo", "Teil Antwort"],
+        )
+        self.assertEqual(service.load_session(session.id).session.message_count, 2)
+
+    def test_closed_stream_does_not_persist_partial_response(self) -> None:
+        provider = StreamingProvider()
+        service = ChatService(self.service.store, provider)
+        session = service.new_session()
+        stream = service.stream_send(session.id, "Hallo")
+
+        self.assertEqual(next(stream), "Teil ")
+        stream.close()
+
+        self.assertEqual(service.load_session(session.id).messages, [])
+
+    def test_provider_error_during_stream_does_not_persist_partial_response(self) -> None:
+        provider = StreamingProvider(fail_after_first=True)
+        service = ChatService(self.service.store, provider)
+        session = service.new_session()
+
+        with self.assertRaises(ProviderUnavailableError):
+            list(service.stream_send(session.id, "Hallo"))
+
+        self.assertEqual(service.load_session(session.id).messages, [])
+
 
 if __name__ == "__main__":
     unittest.main()

tests/unit/test_cli.py

@@ -19,6 +19,22 @@ class _FakeProvider:
     def chat(self, messages: list[ChatMessage]) -> str:
         return f"Echo: {messages[-1].content}"
 
+    def stream_chat(self, messages: list[ChatMessage]):
+        yield "Echo: "
+        yield messages[-1].content
+
+
+class _MarkdownProvider(_FakeProvider):
+    def stream_chat(self, messages: list[ChatMessage]):
+        yield "## **Ant"
+        yield "wort**\n`SQLite`"
+
+
+class _InterruptingProvider(_FakeProvider):
+    def stream_chat(self, messages: list[ChatMessage]):
+        yield "angefangene Antwort"
+        raise KeyboardInterrupt
+
 
 class _FakeHybridProvider(_FakeProvider):
     name = "hybrid"
@@ -59,10 +75,53 @@ class CliTests(unittest.TestCase):
             )
 
         self.assertEqual(result, 0)
-        self.assertTrue(any(line == "Javis: Echo: Hallo" for line in output))
+        self.assertIn("Javis: Echo: Hallo\n", "".join(output))
         self.assertTrue(any("Nachrichten" in line for line in output))
         self.assertEqual(output[-1], "Chat beendet.")
 
+    def test_streaming_cleans_terminal_markdown_but_persists_raw_answer(self) -> None:
+        with tempfile.TemporaryDirectory() as directory:
+            store = SQLiteSessionStore(Path(directory) / "sessions.sqlite3")
+            service = ChatService(store, _MarkdownProvider())
+            inputs = iter(["Frage", "/exit"])
+            output: list[str] = []
+            streamed: list[str] = []
+
+            result = run_chat(
+                service,
+                input_fn=lambda _prompt: next(inputs),
+                output=output.append,
+                stream_output=streamed.append,
+            )
+            session = service.list_sessions()[0]
+            messages = service.load_session(session.id).messages
+
+        self.assertEqual(result, 0)
+        self.assertEqual("".join(streamed), "Javis: Antwort\nSQLite\n")
+        self.assertEqual(messages[-1].content, "## **Antwort**\n`SQLite`")
+
+    def test_keyboard_interrupt_drops_partial_answer_and_returns_to_prompt(self) -> None:
+        with tempfile.TemporaryDirectory() as directory:
+            store = SQLiteSessionStore(Path(directory) / "sessions.sqlite3")
+            service = ChatService(store, _InterruptingProvider())
+            inputs = iter(["Frage", "/exit"])
+            output: list[str] = []
+            streamed: list[str] = []
+
+            result = run_chat(
+                service,
+                input_fn=lambda _prompt: next(inputs),
+                output=output.append,
+                stream_output=streamed.append,
+            )
+            session = service.list_sessions()[0]
+            messages = service.load_session(session.id).messages
+
+        self.assertEqual(result, 0)
+        self.assertEqual(messages, [])
+        self.assertTrue(any("nicht gespeichert" in line for line in output))
+        self.assertEqual(output[-1], "Chat beendet.")
+
     def test_provider_privacy_and_status_commands_are_sanitized(self) -> None:
         with tempfile.TemporaryDirectory() as directory:
             store = SQLiteSessionStore(Path(directory) / "sessions.sqlite3")

tests/unit/test_gemini_provider.py

@@ -23,6 +23,7 @@ class _FakeModels:
     def __init__(self, result: object) -> None:
         self.result = result
         self.call: dict[str, Any] | None = None
+        self.stream_call: dict[str, Any] | None = None
 
     def generate_content(self, **kwargs: object) -> object:
         self.call = kwargs
@@ -30,6 +31,14 @@ class _FakeModels:
             raise self.result
         return self.result
 
+    def generate_content_stream(self, **kwargs: object):
+        self.stream_call = kwargs
+        if isinstance(self.result, BaseException):
+            raise self.result
+        if isinstance(self.result, list):
+            return iter(self.result)
+        return iter((self.result,))
+
 
 class _FakeClient:
     def __init__(self, result: object) -> None:
@@ -56,6 +65,23 @@ def _response(text: str = "Cloud-Antwort") -> SimpleNamespace:
     )
 
 
+def _stream_response(
+    visible_text: str,
+    *,
+    thought_text: str | None = None,
+    with_usage: bool = False,
+) -> SimpleNamespace:
+    parts = []
+    if thought_text:
+        parts.append(SimpleNamespace(text=thought_text, thought=True))
+    parts.append(SimpleNamespace(text=visible_text, thought=False))
+    usage = SimpleNamespace(prompt_token_count=12, candidates_token_count=7) if with_usage else None
+    return SimpleNamespace(
+        candidates=[SimpleNamespace(content=SimpleNamespace(parts=parts))],
+        usage_metadata=usage,
+    )
+
+
 class GeminiProviderTests(unittest.TestCase):
     def _provider(
         self, result: object, **overrides: object
@@ -99,6 +125,39 @@ class GeminiProviderTests(unittest.TestCase):
         self.assertEqual([content.role for content in call["contents"]], ["user", "model", "user"])
         self.assertEqual(call["config"].max_output_tokens, 1024)
         self.assertIsNone(call["config"].tools)
+        self.assertFalse(call["config"].thinking_config.include_thoughts)
+
+    def test_streaming_yields_only_visible_text_and_tracks_usage(self) -> None:
+        provider, factory = self._provider(
+            [
+                _stream_response("Cloud ", thought_text="verstecktes Denken"),
+                _stream_response("Antwort", with_usage=True),
+            ]
+        )
+
+        chunks = list(provider.stream_chat([ChatMessage("user", "Was ist SQLite?")]))
+
+        self.assertEqual(chunks, ["Cloud ", "Antwort"])
+        self.assertNotIn("verstecktes Denken", "".join(chunks))
+        self.assertEqual(provider.last_usage.input_tokens, 12)
+        self.assertEqual(provider.last_usage.output_tokens, 7)
+        self.assertEqual(
+            factory.client.models.stream_call["model"],
+            "gemini-3.6-flash",
+        )
+
+    def test_streaming_error_is_sanitized(self) -> None:
+        provider, _ = self._provider(
+            errors.ClientError(
+                429,
+                {"message": "quota test-key-not-a-real-secret"},
+            )
+        )
+
+        with self.assertRaises(ProviderRateLimitError) as raised:
+            list(provider.stream_chat([ChatMessage("user", "Was ist Python?")]))
+
+        self.assertNotIn("test-key-not-a-real-secret", str(raised.exception))
 
     def test_missing_key_stops_before_client_creation(self) -> None:
         factory = _ClientFactory(_response())

tests/unit/test_ollama_provider.py

@@ -4,22 +4,39 @@ import unittest
 from http.server import BaseHTTPRequestHandler, ThreadingHTTPServer
 from typing import ClassVar
 
-from javis.providers.base import ChatMessage
+from javis.providers.base import ChatMessage, ResponseAbortedError
 from javis.providers.ollama import OllamaProvider
 
 
 class _OllamaHandler(BaseHTTPRequestHandler):
     request_payload: ClassVar[dict[str, object]] = {}
+    abort_stream: ClassVar[bool] = False
 
     def do_POST(self) -> None:
         length = int(self.headers["Content-Length"])
         type(self).request_payload = json.loads(self.rfile.read(length))
-        body = json.dumps(
+        if type(self).request_payload["stream"]:
-            {
+            chunks = [
-                "message": {"role": "assistant", "content": "Lokale Antwort"},
+                {
-                "done": True,
+                    "message": {"role": "assistant", "content": "Lokale "},
-            }
+                    "done": False,
-        ).encode()
+                }
+            ]
+            if not type(self).abort_stream:
+                chunks.append(
+                    {
+                        "message": {"role": "assistant", "content": "Antwort"},
+                        "done": True,
+                    }
+                )
+            body = b"".join(json.dumps(chunk).encode() + b"\n" for chunk in chunks)
+        else:
+            body = json.dumps(
+                {
+                    "message": {"role": "assistant", "content": "Lokale Antwort"},
+                    "done": True,
+                }
+            ).encode()
         self.send_response(200)
         self.send_header("Content-Type", "application/json")
         self.send_header("Content-Length", str(len(body)))
@@ -39,6 +56,9 @@ class _OllamaHandler(BaseHTTPRequestHandler):
 
 
 class OllamaProviderTests(unittest.TestCase):
+    def setUp(self) -> None:
+        _OllamaHandler.abort_stream = False
+
     def test_provider_uses_local_chat_endpoint(self) -> None:
         server = ThreadingHTTPServer(("127.0.0.1", 0), _OllamaHandler)
         thread = threading.Thread(target=server.serve_forever, daemon=True)
@@ -62,6 +82,44 @@ class OllamaProviderTests(unittest.TestCase):
         self.assertTrue(status.reachable)
         self.assertTrue(status.model_available)
 
+    def test_provider_streams_visible_text_without_thinking(self) -> None:
+        server = ThreadingHTTPServer(("127.0.0.1", 0), _OllamaHandler)
+        thread = threading.Thread(target=server.serve_forever, daemon=True)
+        thread.start()
+        try:
+            provider = OllamaProvider(
+                "test-model",
+                f"http://127.0.0.1:{server.server_port}",
+                2,
+            )
+            chunks = list(provider.stream_chat([ChatMessage("user", "Hallo")]))
+        finally:
+            server.shutdown()
+            server.server_close()
+            thread.join()
+
+        self.assertEqual(chunks, ["Lokale ", "Antwort"])
+        self.assertTrue(_OllamaHandler.request_payload["stream"])
+        self.assertFalse(_OllamaHandler.request_payload["think"])
+
+    def test_provider_rejects_incomplete_stream(self) -> None:
+        _OllamaHandler.abort_stream = True
+        server = ThreadingHTTPServer(("127.0.0.1", 0), _OllamaHandler)
+        thread = threading.Thread(target=server.serve_forever, daemon=True)
+        thread.start()
+        try:
+            provider = OllamaProvider(
+                "test-model",
+                f"http://127.0.0.1:{server.server_port}",
+                2,
+            )
+            with self.assertRaises(ResponseAbortedError):
+                list(provider.stream_chat([ChatMessage("user", "Hallo")]))
+        finally:
+            server.shutdown()
+            server.server_close()
+            thread.join()
+
 
 if __name__ == "__main__":
     unittest.main()

tests/unit/test_provider_router.py

@@ -16,6 +16,7 @@ from javis.providers.base import (
     ProviderRateLimitError,
     ProviderTimeoutError,
     ProviderUsage,
+    ResponseAbortedError,
 )
 from javis.security.privacy import CloudPolicy, PrivacyRouter
 
@@ -28,11 +29,15 @@ class _RecordingProvider:
         *,
         answer: str = "Antwort",
         error: Exception | None = None,
+        stream_chunks: tuple[str, ...] | None = None,
+        stream_error: Exception | None = None,
     ) -> None:
         self.name = name
         self.model = model
         self.answer = answer
         self.error = error
+        self.stream_chunks = stream_chunks
+        self.stream_error = stream_error
         self.calls: list[list[ChatMessage]] = []
         self.last_usage = ProviderUsage(11, 5)
 
@@ -42,6 +47,17 @@ class _RecordingProvider:
             raise self.error
         return self.answer
 
+    def stream_chat(self, messages: list[ChatMessage]):
+        self.calls.append(messages)
+        if self.stream_chunks is None:
+            if self.error:
+                raise self.error
+            yield self.answer
+        else:
+            yield from self.stream_chunks
+        if self.stream_error:
+            raise self.stream_error
+
 
 class HybridProviderTests(unittest.TestCase):
     def setUp(self) -> None:
@@ -283,6 +299,64 @@ class HybridProviderTests(unittest.TestCase):
         self.assertFalse(router.last_route.cloud_suppressed_by_local_mode)
         self.assertTrue(router.last_route.technical_fallback)
 
+    def test_allowed_cloud_response_streams_visible_chunks(self) -> None:
+        self.cloud.stream_chunks = ("Cloud ", "Stream")
+        router = self._router()
+
+        chunks = list(router.stream_chat([ChatMessage("user", "Wie funktioniert SQLite?")]))
+
+        self.assertEqual(chunks, ["Cloud ", "Stream"])
+        self.assertEqual(router.last_route.provider, "gemini")
+        self.assertFalse(router.last_route.fallback)
+
+    def test_cloud_stream_error_before_output_falls_back_locally(self) -> None:
+        self.cloud.stream_chunks = ()
+        self.cloud.stream_error = CloudNetworkError("offline")
+        self.local.stream_chunks = ("Lokaler ", "Ersatz")
+        router = self._router()
+
+        chunks = list(router.stream_chat([ChatMessage("user", "Wie funktioniert Python?")]))
+
+        self.assertEqual(chunks, ["Lokaler ", "Ersatz"])
+        self.assertTrue(router.last_route.fallback)
+        self.assertTrue(router.last_route.technical_fallback)
+        self.assertIn("lokale Antwort", self.notices[-1])
+
+    def test_cloud_stream_error_after_output_never_appends_local_answer(self) -> None:
+        self.cloud.stream_chunks = ("Teilantwort",)
+        self.cloud.stream_error = CloudNetworkError("offline")
+        self.local.stream_chunks = ("Lokaler Ersatz",)
+        router = self._router()
+        stream = router.stream_chat([ChatMessage("user", "Wie funktioniert Python?")])
+
+        self.assertEqual(next(stream), "Teilantwort")
+        with self.assertRaises(ResponseAbortedError):
+            next(stream)
+
+        self.assertFalse(self.local.calls)
+        self.assertFalse(router.last_route.fallback)
+        self.assertTrue(router.last_route.technical_fallback)
+
+    def test_medical_never_streams_locally_before_cloud_construction(self) -> None:
+        constructed = False
+        self.local.stream_chunks = ("Lokal",)
+
+        def cloud_factory() -> _RecordingProvider:
+            nonlocal constructed
+            constructed = True
+            return self.cloud
+
+        router = self._router(cloud_provider_factory=cloud_factory, mode="gemini")
+
+        chunks = list(
+            router.stream_chat([ChatMessage("user", "Welche Diagnose passt zu meinen Schmerzen?")])
+        )
+
+        self.assertEqual(chunks, ["Lokal"])
+        self.assertFalse(constructed)
+        self.assertFalse(self.approvals)
+        self.assertEqual(router.last_route.privacy_policy, CloudPolicy.NEVER)
+
 
 if __name__ == "__main__":
     unittest.main()