diff --git a/engine/app/backend_client.py b/engine/app/backend_client.py
index 1e716dc..4d8aa8c 100644
--- a/engine/app/backend_client.py
+++ b/engine/app/backend_client.py
@@ -1,4 +1,4 @@
-"""Backend API client for assistant config."""
+"""Backend API client for assistant config and history persistence."""
 
 from __future__ import annotations
 
@@ -42,3 +42,107 @@ async def fetch_assistant_config(assistant_id: str) -> Optional[Dict[str, Any]]:
         logger.warning(f"Failed to fetch assistant config ({assistant_id}): {exc}")
         return None
 
+
+def _backend_base_url() -> Optional[str]:
+    if not settings.backend_url:
+        return None
+    return settings.backend_url.rstrip("/")
+
+
+def _timeout() -> aiohttp.ClientTimeout:
+    return aiohttp.ClientTimeout(total=settings.backend_timeout_sec)
+
+
+async def create_history_call_record(
+    *,
+    user_id: int,
+    assistant_id: Optional[str],
+    source: str = "debug",
+) -> Optional[str]:
+    """Create a call record via backend history API and return call_id."""
+    base_url = _backend_base_url()
+    if not base_url:
+        return None
+
+    url = f"{base_url}/api/history"
+    payload: Dict[str, Any] = {
+        "user_id": user_id,
+        "assistant_id": assistant_id,
+        "source": source,
+        "status": "connected",
+    }
+
+    try:
+        async with aiohttp.ClientSession(timeout=_timeout()) as session:
+            async with session.post(url, json=payload) as resp:
+                resp.raise_for_status()
+                data = await resp.json()
+                call_id = str((data or {}).get("id") or "")
+                return call_id or None
+    except Exception as exc:
+        logger.warning(f"Failed to create history call record: {exc}")
+        return None
+
+
+async def add_history_transcript(
+    *,
+    call_id: str,
+    turn_index: int,
+    speaker: str,
+    content: str,
+    start_ms: int,
+    end_ms: int,
+    confidence: Optional[float] = None,
+    duration_ms: Optional[int] = None,
+) -> bool:
+    """Append a transcript segment to backend history."""
+    base_url = _backend_base_url()
+    if not base_url or not call_id:
+        return False
+
+    url = f"{base_url}/api/history/{call_id}/transcripts"
+    payload: Dict[str, Any] = {
+        "turn_index": turn_index,
+        "speaker": speaker,
+        "content": content,
+        "confidence": confidence,
+        "start_ms": start_ms,
+        "end_ms": end_ms,
+        "duration_ms": duration_ms,
+    }
+
+    try:
+        async with aiohttp.ClientSession(timeout=_timeout()) as session:
+            async with session.post(url, json=payload) as resp:
+                resp.raise_for_status()
+                return True
+    except Exception as exc:
+        logger.warning(f"Failed to append history transcript (call_id={call_id}, turn={turn_index}): {exc}")
+        return False
+
+
+async def finalize_history_call_record(
+    *,
+    call_id: str,
+    status: str,
+    duration_seconds: int,
+) -> bool:
+    """Finalize a call record with status and duration."""
+    base_url = _backend_base_url()
+    if not base_url or not call_id:
+        return False
+
+    url = f"{base_url}/api/history/{call_id}"
+    payload: Dict[str, Any] = {
+        "status": status,
+        "duration_seconds": duration_seconds,
+    }
+
+    try:
+        async with aiohttp.ClientSession(timeout=_timeout()) as session:
+            async with session.put(url, json=payload) as resp:
+                resp.raise_for_status()
+                return True
+    except Exception as exc:
+        logger.warning(f"Failed to finalize history call record ({call_id}): {exc}")
+        return False
diff --git a/engine/app/config.py b/engine/app/config.py
index 0c10fc1..95b92e1 100644
--- a/engine/app/config.py
+++ b/engine/app/config.py
@@ -91,6 +91,11 @@ class Settings(BaseSettings):
     ws_api_key: Optional[str] = Field(default=None, description="Optional API key required for WS hello auth")
     ws_require_auth: bool = Field(default=False, description="Require auth in hello message even when ws_api_key is not set")
 
+    # Backend bridge configuration (for call/transcript persistence)
+    backend_url: Optional[str] = Field(default=None, description="Backend API base URL (e.g. http://localhost:8787)")
+    backend_timeout_sec: int = Field(default=10, description="Backend API request timeout in seconds")
+    history_default_user_id: int = Field(default=1, description="Fallback user_id for history records")
+
     @property
     def chunk_size_bytes(self) -> int:
         """Calculate chunk size in bytes based on sample rate and duration."""
diff --git a/engine/core/session.py b/engine/core/session.py
index 7ff368e..460cd6d 100644
--- a/engine/core/session.py
+++ b/engine/core/session.py
@@ -2,12 +2,19 @@
 
 import uuid
 import json
+import time
 from enum import Enum
 from typing import Optional, Dict, Any
 from loguru import logger
 
+from app.backend_client import (
+    create_history_call_record,
+    add_history_transcript,
+    finalize_history_call_record,
+)
 from core.transports import BaseTransport
 from core.duplex_pipeline import DuplexPipeline
+from core.conversation import ConversationTurn
 from app.config import settings
 from models.ws_v1 import (
     parse_client_message,
@@ -67,6 +74,12 @@ class Session:
 
         # Track IDs
         self.current_track_id: Optional[str] = str(uuid.uuid4())
+        self._history_call_id: Optional[str] = None
+        self._history_turn_index: int = 0
+        self._history_call_started_mono: Optional[float] = None
+        self._history_finalized: bool = False
+
+        self.pipeline.conversation.on_turn_complete(self._on_turn_complete)
 
         logger.info(f"Session {self.id} created (duplex={self.use_duplex})")
 
@@ -206,8 +219,13 @@ class Session:
             await self._send_error("client", "Duplicate session.start", "protocol.order")
             return
 
+        metadata = message.metadata or {}
+
+        # Create history call record early so later turn callbacks can append transcripts.
+        await self._start_history_bridge(metadata)
+
         # Apply runtime service/prompt overrides from backend if provided
-        self.pipeline.apply_runtime_overrides(message.metadata)
+        self.pipeline.apply_runtime_overrides(metadata)
 
         # Start duplex pipeline
         if not self._pipeline_started:
@@ -241,6 +259,7 @@ class Session:
                 reason=stop_reason,
             )
         )
+        await self._finalize_history(status="connected")
         await self.transport.close()
 
     async def _send_error(self, sender: str, error_message: str, code: str) -> None:
@@ -270,5 +289,83 @@ class Session:
     async def cleanup(self) -> None:
         """Cleanup session resources."""
         logger.info(f"Session {self.id} cleaning up")
+        await self._finalize_history(status="connected")
         await self.pipeline.cleanup()
         await self.transport.close()
+
+    async def _start_history_bridge(self, metadata: Dict[str, Any]) -> None:
+        """Initialize backend history call record for this session."""
+        if self._history_call_id:
+            return
+
+        history_meta: Dict[str, Any] = {}
+        if isinstance(metadata.get("history"), dict):
+            history_meta = metadata["history"]
+
+        raw_user_id = history_meta.get("userId", metadata.get("userId", settings.history_default_user_id))
+        try:
+            user_id = int(raw_user_id)
+        except (TypeError, ValueError):
+            user_id = settings.history_default_user_id
+
+        assistant_id = history_meta.get("assistantId", metadata.get("assistantId"))
+        source = str(history_meta.get("source", metadata.get("source", "debug")))
+
+        call_id = await create_history_call_record(
+            user_id=user_id,
+            assistant_id=str(assistant_id) if assistant_id else None,
+            source=source,
+        )
+        if not call_id:
+            return
+
+        self._history_call_id = call_id
+        self._history_call_started_mono = time.monotonic()
+        self._history_turn_index = 0
+        self._history_finalized = False
+        logger.info(f"Session {self.id} history bridge enabled (call_id={call_id}, source={source})")
+
+    async def _on_turn_complete(self, turn: ConversationTurn) -> None:
+        """Persist completed turns to backend call transcripts."""
+        if not self._history_call_id:
+            return
+        if not turn.text or not turn.text.strip():
+            return
+
+        role = (turn.role or "").lower()
+        speaker = "human" if role == "user" else "ai"
+
+        end_ms = 0
+        if self._history_call_started_mono is not None:
+            end_ms = max(0, int((time.monotonic() - self._history_call_started_mono) * 1000))
+        estimated_duration_ms = max(300, min(12000, len(turn.text.strip()) * 80))
+        start_ms = max(0, end_ms - estimated_duration_ms)
+
+        turn_index = self._history_turn_index
+        await add_history_transcript(
+            call_id=self._history_call_id,
+            turn_index=turn_index,
+            speaker=speaker,
+            content=turn.text.strip(),
+            start_ms=start_ms,
+            end_ms=end_ms,
+            duration_ms=max(1, end_ms - start_ms),
+        )
+        self._history_turn_index += 1
+
+    async def _finalize_history(self, status: str) -> None:
+        """Finalize history call record once."""
+        if not self._history_call_id or self._history_finalized:
+            return
+
+        duration_seconds = 0
+        if self._history_call_started_mono is not None:
+            duration_seconds = max(0, int(time.monotonic() - self._history_call_started_mono))
+
+        ok = await finalize_history_call_record(
+            call_id=self._history_call_id,
+            status=status,
+            duration_seconds=duration_seconds,
+        )
+        if ok:
+            self._history_finalized = True
diff --git a/web/pages/Assistants.tsx b/web/pages/Assistants.tsx
index f273c1b..f15703b 100644
--- a/web/pages/Assistants.tsx
+++ b/web/pages/Assistants.tsx
@@ -1420,6 +1420,11 @@ export const DebugDrawer: React.FC<{
         systemPrompt: assistant.prompt || '',
         greeting: assistant.opener || '',
         services,
+        history: {
+          assistantId: assistant.id,
+          userId: 1,
+          source: 'debug',
+        },
       },
     };