diff --git a/agent/auxiliary_client.py b/agent/auxiliary_client.py
index fc3df8209..6b7bf1966 100644
--- a/agent/auxiliary_client.py
+++ b/agent/auxiliary_client.py
@@ -23,17 +23,13 @@ Resolution order for vision/multimodal tasks (auto mode):
   6. Custom endpoint (for local vision models: Qwen-VL, LLaVA, Pixtral, etc.)
   7. None
 
-Per-task provider overrides (e.g. AUXILIARY_VISION_PROVIDER,
-CONTEXT_COMPRESSION_PROVIDER) can force a specific provider for each task.
+Per-task overrides are configured in config.yaml under the ``auxiliary:`` section
+(e.g. ``auxiliary.vision.provider``, ``auxiliary.compression.model``).
 Default "auto" follows the chains above.
 
-Per-task model overrides (e.g. AUXILIARY_VISION_MODEL,
-AUXILIARY_WEB_EXTRACT_MODEL) let callers use a different model slug
-than the provider's default.
-
-Per-task direct endpoint overrides (e.g. AUXILIARY_VISION_BASE_URL,
-AUXILIARY_VISION_API_KEY) let callers route a specific auxiliary task to a
-custom OpenAI-compatible endpoint without touching the main model settings.
+Legacy env var overrides (AUXILIARY_{TASK}_PROVIDER, AUXILIARY_{TASK}_MODEL,
+AUXILIARY_{TASK}_BASE_URL, etc.) are still read as a backward-compat fallback
+but config.yaml takes priority.  New configuration should always use config.yaml.
 
 Payment / credit exhaustion fallback:
   When a resolved provider returns HTTP 402 or a credit-related error,
@@ -1968,8 +1964,8 @@ def _resolve_task_provider_model(
 
     Priority:
       1. Explicit provider/model/base_url/api_key args (always win)
-      2. Env var overrides (AUXILIARY_{TASK}_*, CONTEXT_{TASK}_*)
-      3. Config file (auxiliary.{task}.* or compression.*)
+      2. Config file (auxiliary.{task}.* or compression.*)
+      3. Env var overrides (backward-compat: AUXILIARY_{TASK}_*, CONTEXT_{TASK}_*)
       4. "auto" (full auto-detection chain)
 
     Returns (provider, model, base_url, api_key, api_mode) where model may
@@ -2012,10 +2008,11 @@ def _resolve_task_provider_model(
                 _sbu = comp.get("summary_base_url") or ""
                 cfg_base_url = cfg_base_url or _sbu.strip() or None
 
+    # Env vars are backward-compat fallback only — config.yaml is primary.
     env_model = _get_auxiliary_env_override(task, "MODEL") if task else None
     env_api_mode = _get_auxiliary_env_override(task, "API_MODE") if task else None
-    resolved_model = model or env_model or cfg_model
-    resolved_api_mode = env_api_mode or cfg_api_mode
+    resolved_model = model or cfg_model or env_model
+    resolved_api_mode = cfg_api_mode or env_api_mode
 
     if base_url:
         return "custom", resolved_model, base_url, api_key, resolved_api_mode
@@ -2023,19 +2020,23 @@ def _resolve_task_provider_model(
         return provider, resolved_model, base_url, api_key, resolved_api_mode
 
     if task:
+        # Config.yaml is the primary source for per-task overrides.
+        if cfg_base_url:
+            return "custom", resolved_model, cfg_base_url, cfg_api_key, resolved_api_mode
+        if cfg_provider and cfg_provider != "auto":
+            return cfg_provider, resolved_model, None, None, resolved_api_mode
+
+        # Env vars are backward-compat fallback for users who haven't
+        # migrated to config.yaml yet.
         env_base_url = _get_auxiliary_env_override(task, "BASE_URL")
         env_api_key = _get_auxiliary_env_override(task, "API_KEY")
         if env_base_url:
-            return "custom", resolved_model, env_base_url, env_api_key or cfg_api_key, resolved_api_mode
+            return "custom", resolved_model, env_base_url, env_api_key, resolved_api_mode
 
         env_provider = _get_auxiliary_provider(task)
         if env_provider != "auto":
             return env_provider, resolved_model, None, None, resolved_api_mode
 
-        if cfg_base_url:
-            return "custom", resolved_model, cfg_base_url, cfg_api_key, resolved_api_mode
-        if cfg_provider and cfg_provider != "auto":
-            return cfg_provider, resolved_model, None, None, resolved_api_mode
         return "auto", resolved_model, None, None, resolved_api_mode
 
     return "auto", resolved_model, None, None, resolved_api_mode
diff --git a/hermes_cli/config.py b/hermes_cli/config.py
index 1738a8f88..4661455d1 100644
--- a/hermes_cli/config.py
+++ b/hermes_cli/config.py
@@ -32,7 +32,6 @@ _ENV_VAR_NAME_RE = re.compile(r"^[A-Za-z_][A-Za-z0-9_]*$")
 _EXTRA_ENV_KEYS = frozenset({
     "OPENAI_API_KEY", "OPENAI_BASE_URL",
     "ANTHROPIC_API_KEY", "ANTHROPIC_TOKEN",
-    "AUXILIARY_VISION_MODEL",
     "DISCORD_HOME_CHANNEL", "TELEGRAM_HOME_CHANNEL",
     "SIGNAL_ACCOUNT", "SIGNAL_HTTP_URL",
     "SIGNAL_ALLOWED_USERS", "SIGNAL_GROUP_ALLOWED_USERS",