Fix default chat model, default to config.qa.model

CHANGELOG.md

@@ -5,6 +5,7 @@
 
 - **Compatibility with haiku.skills 0.5.1**: Replaced removed `SkillToolset.system_prompt` with `build_system_prompt(toolset.skill_catalog)` across chat TUI, backend app, and examples
 - **Minimum dependency**: Bumped `haiku.skills` requirement to `>=0.5.1`
+- **Chat model default**: Chat TUI and backend app now use the configured QA model instead of hardcoded `openai:gpt-4o`
 
 ## [0.32.1] - 2026-02-26
 

app/backend/main.py

@@ -17,6 +17,7 @@ from haiku.rag.client import HaikuRAG
 from haiku.rag.config import load_yaml_config
 from haiku.rag.config.models import AppConfig
 from haiku.rag.skills.rag import AGENT_PREAMBLE, create_skill
+from haiku.rag.utils import get_model
 from haiku.skills import SkillDeps, SkillToolset
 from haiku.skills.prompts import build_system_prompt
 
@@ -68,7 +69,7 @@ skill = create_skill(db_path=db_path, config=Config)
 toolset = SkillToolset(skills=[skill])
 
 agent = Agent(
-    os.getenv("HAIKU_CHAT_MODEL", "openai:gpt-4o"),
+    get_model(Config.qa.model, Config),
     instructions=build_system_prompt(toolset.skill_catalog, preamble=AGENT_PREAMBLE),
     toolsets=[toolset],
     deps_type=SkillDeps,

haiku_rag_slim/haiku/rag/chat/__init__.py

@@ -25,6 +25,7 @@ def run_chat(
 
     from haiku.rag.config import get_config
     from haiku.rag.skills.rag import create_skill
+    from haiku.rag.utils import get_model
 
     config = get_config()
     if db_path is None:
@@ -37,6 +38,6 @@ def run_chat(
         skill=skill,
         read_only=read_only,
         before=before,
-        model=model,
+        model=model or get_model(config.qa.model, config),
     )
     app.run()

haiku_rag_slim/haiku/rag/chat/app.py

@@ -102,7 +102,7 @@ class ChatApp(App):
         self._skill = skill
         self.read_only = read_only
         self.before = before
-        self._model = model or "openai:gpt-4o"
+        self._model = model
         self.client: HaikuRAG | None = None
         self.config = get_config()
         self._toolset: SkillToolset | None = None