Merge remote-tracking branch 'origin/main'

# Conflicts:
#	README.md
#	nanobot/agent/context.py
#	nanobot/agent/loop.py
#	nanobot/channels/telegram.py

nanobot/providers/__init__.py

@@ -1,8 +1,30 @@
 """LLM provider abstraction module."""
 
+from __future__ import annotations
+
+from importlib import import_module
+from typing import TYPE_CHECKING
+
 from nanobot.providers.base import LLMProvider, LLMResponse
-from nanobot.providers.litellm_provider import LiteLLMProvider
-from nanobot.providers.openai_codex_provider import OpenAICodexProvider
-from nanobot.providers.azure_openai_provider import AzureOpenAIProvider
 
 __all__ = ["LLMProvider", "LLMResponse", "LiteLLMProvider", "OpenAICodexProvider", "AzureOpenAIProvider"]
+
+_LAZY_IMPORTS = {
+    "LiteLLMProvider": ".litellm_provider",
+    "OpenAICodexProvider": ".openai_codex_provider",
+    "AzureOpenAIProvider": ".azure_openai_provider",
+}
+
+if TYPE_CHECKING:
+    from nanobot.providers.azure_openai_provider import AzureOpenAIProvider
+    from nanobot.providers.litellm_provider import LiteLLMProvider
+    from nanobot.providers.openai_codex_provider import OpenAICodexProvider
+
+
+def __getattr__(name: str):
+    """Lazily expose provider implementations without importing all backends up front."""
+    module_name = _LAZY_IMPORTS.get(name)
+    if module_name is None:
+        raise AttributeError(f"module {__name__!r} has no attribute {name!r}")
+    module = import_module(module_name, __name__)
+    return getattr(module, name)

nanobot/providers/base.py

@@ -89,14 +89,6 @@ class LLMProvider(ABC):
         "server error",
         "temporarily unavailable",
     )
-    _IMAGE_UNSUPPORTED_MARKERS = (
-        "image_url is only supported",
-        "does not support image",
-        "images are not supported",
-        "image input is not supported",
-        "image_url is not supported",
-        "unsupported image input",
-    )
 
     _SENTINEL = object()
 
@@ -107,11 +99,7 @@ class LLMProvider(ABC):
 
     @staticmethod
     def _sanitize_empty_content(messages: list[dict[str, Any]]) -> list[dict[str, Any]]:
-        """Replace empty text content that causes provider 400 errors.
-
-        Empty content can appear when MCP tools return nothing. Most providers
-        reject empty-string content or empty text blocks in list content.
-        """
+        """Sanitize message content: fix empty blocks, strip internal _meta fields."""
         result: list[dict[str, Any]] = []
         for msg in messages:
             content = msg.get("content")
@@ -123,18 +111,25 @@ class LLMProvider(ABC):
                 continue
 
             if isinstance(content, list):
-                filtered = [
-                    item for item in content
-                    if not (
+                new_items: list[Any] = []
+                changed = False
+                for item in content:
+                    if (
                         isinstance(item, dict)
                         and item.get("type") in ("text", "input_text", "output_text")
                         and not item.get("text")
-                    )
-                ]
-                if len(filtered) != len(content):
+                    ):
+                        changed = True
+                        continue
+                    if isinstance(item, dict) and "_meta" in item:
+                        new_items.append({k: v for k, v in item.items() if k != "_meta"})
+                        changed = True
+                    else:
+                        new_items.append(item)
+                if changed:
                     clean = dict(msg)
-                    if filtered:
-                        clean["content"] = filtered
+                    if new_items:
+                        clean["content"] = new_items
                     elif msg.get("role") == "assistant" and msg.get("tool_calls"):
                         clean["content"] = None
                     else:
@@ -197,11 +192,6 @@ class LLMProvider(ABC):
         err = (content or "").lower()
         return any(marker in err for marker in cls._TRANSIENT_ERROR_MARKERS)
 
-    @classmethod
-    def _is_image_unsupported_error(cls, content: str | None) -> bool:
-        err = (content or "").lower()
-        return any(marker in err for marker in cls._IMAGE_UNSUPPORTED_MARKERS)
-
     @staticmethod
     def _strip_image_content(messages: list[dict[str, Any]]) -> list[dict[str, Any]] | None:
         """Replace image_url blocks with text placeholder. Returns None if no images found."""
@@ -213,7 +203,9 @@ class LLMProvider(ABC):
                 new_content = []
                 for b in content:
                     if isinstance(b, dict) and b.get("type") == "image_url":
-                        new_content.append({"type": "text", "text": "[image omitted]"})
+                        path = (b.get("_meta") or {}).get("path", "")
+                        placeholder = f"[image: {path}]" if path else "[image omitted]"
+                        new_content.append({"type": "text", "text": placeholder})
                         found = True
                     else:
                         new_content.append(b)
@@ -267,11 +259,10 @@ class LLMProvider(ABC):
                 return response
 
             if not self._is_transient_error(response.content):
-                if self._is_image_unsupported_error(response.content):
-                    stripped = self._strip_image_content(messages)
-                    if stripped is not None:
-                        logger.warning("Model does not support image input, retrying without images")
-                        return await self._safe_chat(**{**kw, "messages": stripped})
+                stripped = self._strip_image_content(messages)
+                if stripped is not None:
+                    logger.warning("Non-transient LLM error with image content, retrying without images")
+                    return await self._safe_chat(**{**kw, "messages": stripped})
                 return response
 
             logger.warning(