Extract DEFAULT_EXECUTOR constant to eliminate hardcoded strings (#94)

The default executor value was duplicated as a string literal in 11 places
across 7 files. A single constant in executor_utils.py makes future
changes a one-line edit and also changes the default to separate_executor.

Author: catstrike

src/databao_cli/features/mcp/tools/databao_ask/agent_factory.py

@@ -7,14 +7,15 @@
 from databao.agent.core import Cache
 
 from databao_cli.features.ui.project_utils import DatabaoProjectStatus, databao_project_status, has_build_output
+from databao_cli.shared.executor_utils import DEFAULT_EXECUTOR
 from databao_cli.shared.project.layout import ProjectLayout
 
 
 def create_agent_for_tool(
     project: ProjectLayout,
     model: str | None = None,
     temperature: float = 0.0,
-    executor: str = "claude_code",
+    executor: str = DEFAULT_EXECUTOR,
     cache: Cache | None = None,
 ) -> Agent:
     """Create a Databao agent from a DCE project, configured for MCP tool use.

src/databao_cli/features/ui/app.py

@@ -24,6 +24,7 @@
     has_build_output,
 )
 from databao_cli.features.ui.services.storage import get_cache_dir
+from databao_cli.shared.executor_utils import DEFAULT_EXECUTOR
 from databao_cli.shared.project.layout import ProjectLayout, find_project
 
 logger = logging.getLogger(__name__)
@@ -60,7 +61,7 @@ def _save_settings_if_changed() -> None:
 
     changed = False
 
-    current_executor = st.session_state.get("executor_type", "claude_code")
+    current_executor = st.session_state.get("executor_type", DEFAULT_EXECUTOR)
     if settings.agent.executor_type != current_executor:
         settings.agent.executor_type = current_executor
         changed = True
@@ -105,7 +106,7 @@ def _initialize_agent(project: ProjectLayout) -> Agent | None:
         return None
 
     try:
-        executor_type = st.session_state.get("executor_type", "claude_code")
+        executor_type = st.session_state.get("executor_type", DEFAULT_EXECUTOR)
 
         cache = _get_or_create_disk_cache()
 
@@ -254,7 +255,7 @@ def mark_welcome_completed() -> None:
 
     settings = get_or_create_settings()
     settings.welcome_completed = True
-    settings.agent.executor_type = st.session_state.get("executor_type", "claude_code")
+    settings.agent.executor_type = st.session_state.get("executor_type", DEFAULT_EXECUTOR)
     llm: LLMSettings = st.session_state.get("llm_settings", LLMSettings())
     settings.agent.llm = llm
     save_settings(settings)
@@ -304,7 +305,7 @@ def init_session_state() -> None:
     if "status_message" not in st.session_state:
         st.session_state.status_message = None
     if "executor_type" not in st.session_state:
-        st.session_state.executor_type = "claude_code"
+        st.session_state.executor_type = DEFAULT_EXECUTOR
     if "llm_provider" not in st.session_state:
         st.session_state.llm_provider = LLMSettings()
 

src/databao_cli/features/ui/components/sidebar.py

@@ -7,7 +7,7 @@
 from databao_cli.features.ui.components.status import AppStatus, render_status_fragment, set_status
 from databao_cli.features.ui.project_utils import DatabaoProjectStatus, databao_project_status
 from databao_cli.features.ui.suggestions import reset_suggestions_state
-from databao_cli.shared.executor_utils import EXECUTOR_TYPES
+from databao_cli.shared.executor_utils import DEFAULT_EXECUTOR, EXECUTOR_TYPES
 from databao_cli.shared.project.layout import ProjectLayout
 
 
@@ -105,7 +105,7 @@ def render_executor_selector() -> None:
     """Render executor type selector."""
     st.markdown("### ⚙️ Executor")
 
-    current = st.session_state.get("executor_type", "claude_code")
+    current = st.session_state.get("executor_type", DEFAULT_EXECUTOR)
 
     selected = st.selectbox(
         "Executor type",

src/databao_cli/features/ui/models/settings.py

@@ -6,6 +6,8 @@
 
 import yaml
 
+from databao_cli.shared.executor_utils import DEFAULT_EXECUTOR
+
 _ENV_VAR_MAP: dict[str, str] = {
     "openai": "OPENAI_API_KEY",
     "anthropic": "ANTHROPIC_API_KEY",
@@ -53,7 +55,7 @@ def is_configured(self) -> bool:
 class AgentSettings:
     """Agent-related settings."""
 
-    executor_type: str = "claude_code"
+    executor_type: str = DEFAULT_EXECUTOR
     llm: LLMSettings = field(default_factory=LLMSettings)
 
 
@@ -105,7 +107,7 @@ def from_dict(cls, data: dict[str, Any]) -> "Settings":
 
         return cls(
             agent=AgentSettings(
-                executor_type=agent_data.get("executor_type", "claude_code"),
+                executor_type=agent_data.get("executor_type", DEFAULT_EXECUTOR),
                 llm=LLMSettings(
                     active_provider=llm_data.get("active_provider", "openai"),
                     providers=providers,

src/databao_cli/features/ui/pages/agent_settings.py

@@ -9,7 +9,7 @@
 from databao_cli.features.ui.app import _clear_all_chat_threads
 from databao_cli.features.ui.components.status import AppStatus, set_status
 from databao_cli.features.ui.models.settings import _ENV_VAR_MAP, LLMProviderConfig, LLMSettings
-from databao_cli.shared.executor_utils import EXECUTOR_TYPES, LLM_PROVIDER_MODELS, LLM_PROVIDERS
+from databao_cli.shared.executor_utils import DEFAULT_EXECUTOR, EXECUTOR_TYPES, LLM_PROVIDER_MODELS, LLM_PROVIDERS
 
 
 def render_agent_settings_page(*, auto_apply: bool = False) -> None:
@@ -27,7 +27,7 @@ def render_agent_settings_page(*, auto_apply: bool = False) -> None:
         """
     )
 
-    current = st.session_state.get("executor_type", "claude_code")
+    current = st.session_state.get("executor_type", DEFAULT_EXECUTOR)
 
     selected = st.selectbox(
         "Executor type",
@@ -66,8 +66,7 @@ def render_agent_settings_page(*, auto_apply: bool = False) -> None:
     elif selected == "claude_code":
         st.info(
             """
-            **ClaudeCodeExecutor** is the default and recommended executor.
-            It uses Claude Code as the execution backend for queries.
+            **ClaudeCodeExecutor** uses Claude Code as the execution backend for queries.
             Requires a valid Anthropic API key configured in the LLM settings.
             """,
             icon="💡",
@@ -96,7 +95,7 @@ def render_agent_settings_page(*, auto_apply: bool = False) -> None:
     provider_keys = list(LLM_PROVIDERS.keys())
     current_provider = llm.active_provider if llm.active_provider in provider_keys else "openai"
 
-    is_claude_code = st.session_state.get("executor_type", "claude_code") == "claude_code"
+    is_claude_code = st.session_state.get("executor_type", DEFAULT_EXECUTOR) == "claude_code"
 
     if is_claude_code:
         chosen_provider = "anthropic"
@@ -194,7 +193,7 @@ def _persist_current_settings() -> None:
     from databao_cli.features.ui.services.settings_persistence import get_or_create_settings, save_settings
 
     settings = get_or_create_settings()
-    settings.agent.executor_type = st.session_state.get("executor_type", "claude_code")
+    settings.agent.executor_type = st.session_state.get("executor_type", DEFAULT_EXECUTOR)
     llm: LLMSettings = st.session_state.get("llm_settings", LLMSettings())
     settings.agent.llm = llm
     save_settings(settings)

src/databao_cli/features/ui/pages/general_settings.py

@@ -8,6 +8,7 @@
 from databao_cli.features.ui.services.chat_persistence import delete_all_chats
 from databao_cli.features.ui.services.settings_persistence import delete_settings
 from databao_cli.features.ui.services.storage import get_cache_dir, get_chats_dir, get_storage_base_path
+from databao_cli.shared.executor_utils import DEFAULT_EXECUTOR
 
 logger = logging.getLogger(__name__)
 
@@ -47,7 +48,7 @@ def _confirm_reset_settings() -> None:
     with col2:
         if st.button("🔄 Reset", type="primary", use_container_width=True):
             delete_settings()
-            st.session_state.executor_type = "claude_code"
+            st.session_state.executor_type = DEFAULT_EXECUTOR
             st.session_state.databao_project = None
             st.session_state.agent = None
             _clear_all_chat_threads()

src/databao_cli/shared/executor_utils.py

@@ -2,9 +2,11 @@
 
 from databao.agent.configs.llm import LLMConfig
 
+DEFAULT_EXECUTOR = "separate_executor"
+
 EXECUTOR_TYPES = {
-    "separate_executor": "SeparateExecutor",
-    "claude_code": "ClaudeCodeExecutor (recommended)",
+    "separate_executor": "SeparateExecutor (recommended)",
+    "claude_code": "ClaudeCodeExecutor",
     "lighthouse": "LighthouseExecutor",
     "react_duckdb": "ReactDuckDBExecutor (experimental)",
     "dbt": "DbtProjectExecutor (experimental)",