fix: strip dynamic custom provider route prefixes

maintainer edit: preserve provider-prefix CLI routing for named custom providers by stripping only the matched dynamic route prefix before sending the model id to OpenAI-compatible endpoints. This keeps ordinary namespaced model ids intact when the provider is selected explicitly.

nanobot/providers/openai_compat_provider.py

@@ -18,6 +18,7 @@ from typing import TYPE_CHECKING, Any
 from urllib.parse import urlparse
 
 from loguru import logger
+from pydantic.alias_generators import to_snake
 
 from nanobot.providers.base import (
     LLMProvider,
@@ -93,6 +94,10 @@ def _model_slug(model_name: str) -> str:
     return model_name.lower().rsplit("/", 1)[-1]
 
 
+def _provider_prefix_key(name: str) -> str:
+    return to_snake(name.replace("-", "_")).lower()
+
+
 def _requires_max_completion_tokens(model_name: str) -> bool:
     """Return True for models that reject ``max_tokens`` (GPT-5 family, o-series)."""
     slug = _model_slug(model_name)
@@ -592,6 +597,22 @@ class OpenAICompatProvider(LLMProvider):
     # Build kwargs
     # ------------------------------------------------------------------
 
+    def _request_model_name(self, model_name: str) -> str:
+        spec = self._spec
+        if not spec or "/" not in model_name:
+            return model_name
+        if spec.strip_model_prefix:
+            return model_name.split("/")[-1]
+
+        route_prefixes = getattr(spec, "strip_model_prefixes", ())
+        if not isinstance(route_prefixes, tuple) or not route_prefixes:
+            return model_name
+        model_prefix, routed_model = model_name.split("/", 1)
+        model_prefix_key = _provider_prefix_key(model_prefix)
+        if any(_provider_prefix_key(prefix) == model_prefix_key for prefix in route_prefixes):
+            return routed_model
+        return model_name
+
     @staticmethod
     def _supports_temperature(
         model_name: str,
@@ -625,8 +646,7 @@ class OpenAICompatProvider(LLMProvider):
             if any(model_name.lower().startswith(k) for k in ("anthropic/", "claude")):
                 messages, tools = self._apply_cache_control(messages, tools)
 
-        if spec and spec.strip_model_prefix:
-            model_name = model_name.split("/")[-1]
+        model_name = self._request_model_name(model_name)
 
         kwargs: dict[str, Any] = {
             "model": model_name,
@@ -830,8 +850,7 @@ class OpenAICompatProvider(LLMProvider):
     ) -> dict[str, Any]:
         """Build a Responses API body for direct OpenAI requests."""
         model_name = model or self.default_model
-        if self._spec and self._spec.strip_model_prefix:
-            model_name = model_name.split("/")[-1]
+        model_name = self._request_model_name(model_name)
         sanitized_messages = self._sanitize_messages(self._sanitize_empty_content(messages))
         instructions, input_items = convert_messages(sanitized_messages)