Chat: use cached endpoint model ids before probing

routes/chat_helpers.py

@@ -3,6 +3,7 @@
 import asyncio
 import json
 import logging
+import os
 import re
 from dataclasses import dataclass, field
 from typing import Any, Optional
@@ -11,6 +12,7 @@ from core.models import ChatMessage
 from core.database import SessionLocal
 from core.database import Session as DBSession, ModelEndpoint
 from src.llm_core import normalize_model_id
+from src.endpoint_resolver import normalize_base
 from src.context_compactor import maybe_compact, trim_for_context
 from src.auth_helpers import get_current_user
 from src.prompt_security import untrusted_context_message
@@ -337,6 +339,63 @@ def resolve_session_auth(sess, session_id: str):
         logger.warning(f"Failed to resolve session headers: {e}")
 
 
+def _match_cached_model_id(requested: str, models) -> Optional[str]:
+    if not requested or not models:
+        return None
+    model_ids = [str(m) for m in models if m]
+    if requested in model_ids:
+        return requested
+
+    req_base = os.path.basename(requested.rstrip("/"))
+    for model_id in model_ids:
+        if os.path.basename(model_id.rstrip("/")) == req_base:
+            return model_id
+    return None
+
+
+def _normalize_model_id_from_cache(sess) -> Optional[str]:
+    """Use stored endpoint model IDs before falling back to a live /models probe."""
+    endpoint_url = getattr(sess, "endpoint_url", "") or ""
+    requested = getattr(sess, "model", "") or ""
+    if not endpoint_url or not requested:
+        return None
+
+    try:
+        session_base = normalize_base(endpoint_url)
+    except Exception:
+        session_base = endpoint_url.rstrip("/")
+    if not session_base:
+        return None
+
+    db = SessionLocal()
+    try:
+        endpoints = db.query(ModelEndpoint).filter(ModelEndpoint.is_enabled == True).all()
+        for ep in endpoints:
+            try:
+                if normalize_base(getattr(ep, "base_url", "") or "") != session_base:
+                    continue
+            except Exception:
+                continue
+
+            raw_models = getattr(ep, "cached_models", None)
+            if not raw_models:
+                continue
+            try:
+                models = json.loads(raw_models) if isinstance(raw_models, str) else raw_models
+            except Exception:
+                continue
+
+            matched = _match_cached_model_id(requested, models)
+            if matched:
+                return matched
+    except Exception as e:
+        logger.debug("Cached model normalization skipped: %s", e)
+    finally:
+        db.close()
+
+    return None
+
+
 async def build_chat_context(
     sess,
     request,
@@ -437,8 +496,9 @@ async def build_chat_context(
     for transcript in preprocessed.youtube_transcripts:
         preface.append(untrusted_context_message("youtube transcript", transcript))
 
-    # Normalize model ID
-    norm = normalize_model_id(sess.endpoint_url, sess.model)
+    # Normalize model ID. Prefer cached endpoint models so group chat does not
+    # re-hit slow local /models endpoints on every participant turn.
+    norm = _normalize_model_id_from_cache(sess) or normalize_model_id(sess.endpoint_url, sess.model)
     if norm:
         sess.model = norm
 

tests/test_chat_cached_model_normalization.py

@@ -0,0 +1,20 @@
+from pathlib import Path
+
+
+ROOT = Path(__file__).resolve().parents[1]
+
+
+def test_chat_context_uses_cached_models_before_live_model_probe():
+    source = (ROOT / "routes" / "chat_helpers.py").read_text()
+
+    assert "def _normalize_model_id_from_cache" in source
+    assert "cached_models" in source
+    assert "norm = _normalize_model_id_from_cache(sess) or normalize_model_id" in source
+
+
+def test_cached_model_match_keeps_basename_normalization():
+    source = (ROOT / "routes" / "chat_helpers.py").read_text()
+
+    assert "def _match_cached_model_id" in source
+    assert "os.path.basename(requested.rstrip(\"/\"))" in source
+    assert "os.path.basename(model_id.rstrip(\"/\")) == req_base" in source