feat: add ChatCompletionsTransport + wire all default paths

agent/transports/__init__.py

@@ -41,3 +41,7 @@ def _discover_transports() -> None:
         import agent.transports.codex  # noqa: F401
     except ImportError:
         pass
+    try:
+        import agent.transports.chat_completions  # noqa: F401
+    except ImportError:
+        pass

agent/transports/chat_completions.py

@@ -0,0 +1,387 @@
+"""OpenAI Chat Completions transport.
+
+Handles the default api_mode ('chat_completions') used by ~16 OpenAI-compatible
+providers (OpenRouter, Nous, NVIDIA, Qwen, Ollama, DeepSeek, xAI, Kimi, etc.).
+
+Messages and tools are already in OpenAI format — convert_messages and
+convert_tools are near-identity.  The complexity lives in build_kwargs
+which has provider-specific conditionals for max_tokens defaults,
+reasoning configuration, temperature handling, and extra_body assembly.
+"""
+
+import copy
+from typing import Any, Dict, List, Optional
+
+from agent.prompt_builder import DEVELOPER_ROLE_MODELS
+from agent.transports.base import ProviderTransport
+from agent.transports.types import NormalizedResponse, ToolCall, Usage
+
+
+class ChatCompletionsTransport(ProviderTransport):
+    """Transport for api_mode='chat_completions'.
+
+    The default path for OpenAI-compatible providers.
+    """
+
+    @property
+    def api_mode(self) -> str:
+        return "chat_completions"
+
+    def convert_messages(self, messages: List[Dict[str, Any]], **kwargs) -> List[Dict[str, Any]]:
+        """Messages are already in OpenAI format — sanitize Codex leaks only.
+
+        Strips Codex Responses API fields (``codex_reasoning_items`` on the
+        message, ``call_id``/``response_item_id`` on tool_calls) that strict
+        chat-completions providers reject with 400/422.
+        """
+        needs_sanitize = False
+        for msg in messages:
+            if not isinstance(msg, dict):
+                continue
+            if "codex_reasoning_items" in msg:
+                needs_sanitize = True
+                break
+            tool_calls = msg.get("tool_calls")
+            if isinstance(tool_calls, list):
+                for tc in tool_calls:
+                    if isinstance(tc, dict) and ("call_id" in tc or "response_item_id" in tc):
+                        needs_sanitize = True
+                        break
+                if needs_sanitize:
+                    break
+
+        if not needs_sanitize:
+            return messages
+
+        sanitized = copy.deepcopy(messages)
+        for msg in sanitized:
+            if not isinstance(msg, dict):
+                continue
+            msg.pop("codex_reasoning_items", None)
+            tool_calls = msg.get("tool_calls")
+            if isinstance(tool_calls, list):
+                for tc in tool_calls:
+                    if isinstance(tc, dict):
+                        tc.pop("call_id", None)
+                        tc.pop("response_item_id", None)
+        return sanitized
+
+    def convert_tools(self, tools: List[Dict[str, Any]]) -> List[Dict[str, Any]]:
+        """Tools are already in OpenAI format — identity."""
+        return tools
+
+    def build_kwargs(
+        self,
+        model: str,
+        messages: List[Dict[str, Any]],
+        tools: Optional[List[Dict[str, Any]]] = None,
+        **params,
+    ) -> Dict[str, Any]:
+        """Build chat.completions.create() kwargs.
+
+        This is the most complex transport method — it handles ~16 providers
+        via params rather than subclasses.
+
+        params:
+            timeout: float — API call timeout
+            max_tokens: int | None — user-configured max tokens
+            ephemeral_max_output_tokens: int | None — one-shot override (error recovery)
+            max_tokens_param_fn: callable — returns {max_tokens: N} or {max_completion_tokens: N}
+            reasoning_config: dict | None
+            request_overrides: dict | None
+            session_id: str | None
+            qwen_session_metadata: dict | None — {sessionId, promptId} precomputed
+            model_lower: str — lowercase model name for pattern matching
+            # Provider detection flags (all optional, default False)
+            is_openrouter: bool
+            is_nous: bool
+            is_qwen_portal: bool
+            is_github_models: bool
+            is_nvidia_nim: bool
+            is_kimi: bool
+            is_custom_provider: bool
+            ollama_num_ctx: int | None
+            # Provider routing
+            provider_preferences: dict | None
+            # Qwen-specific
+            qwen_prepare_fn: callable | None — runs AFTER codex sanitization
+            qwen_prepare_inplace_fn: callable | None — in-place variant for deepcopied lists
+            # Temperature
+            fixed_temperature: Any — from _fixed_temperature_for_model()
+            omit_temperature: bool
+            # Reasoning
+            supports_reasoning: bool
+            github_reasoning_extra: dict | None
+            # Claude on OpenRouter/Nous max output
+            anthropic_max_output: int | None
+            # Extra
+            extra_body_additions: dict | None — pre-built extra_body entries
+        """
+        # Codex sanitization: drop reasoning_items / call_id / response_item_id
+        sanitized = self.convert_messages(messages)
+
+        # Qwen portal prep AFTER codex sanitization.  If sanitize already
+        # deepcopied, reuse that copy via the in-place variant to avoid a
+        # second deepcopy.
+        is_qwen = params.get("is_qwen_portal", False)
+        if is_qwen:
+            qwen_prep = params.get("qwen_prepare_fn")
+            qwen_prep_inplace = params.get("qwen_prepare_inplace_fn")
+            if sanitized is messages:
+                if qwen_prep is not None:
+                    sanitized = qwen_prep(sanitized)
+            else:
+                # Already deepcopied — transform in place
+                if qwen_prep_inplace is not None:
+                    qwen_prep_inplace(sanitized)
+                elif qwen_prep is not None:
+                    sanitized = qwen_prep(sanitized)
+
+        # Developer role swap for GPT-5/Codex models
+        model_lower = params.get("model_lower", (model or "").lower())
+        if (
+            sanitized
+            and isinstance(sanitized[0], dict)
+            and sanitized[0].get("role") == "system"
+            and any(p in model_lower for p in DEVELOPER_ROLE_MODELS)
+        ):
+            sanitized = list(sanitized)
+            sanitized[0] = {**sanitized[0], "role": "developer"}
+
+        api_kwargs: Dict[str, Any] = {
+            "model": model,
+            "messages": sanitized,
+        }
+
+        timeout = params.get("timeout")
+        if timeout is not None:
+            api_kwargs["timeout"] = timeout
+
+        # Temperature
+        fixed_temp = params.get("fixed_temperature")
+        omit_temp = params.get("omit_temperature", False)
+        if omit_temp:
+            api_kwargs.pop("temperature", None)
+        elif fixed_temp is not None:
+            api_kwargs["temperature"] = fixed_temp
+
+        # Qwen metadata (caller precomputes {sessionId, promptId})
+        qwen_meta = params.get("qwen_session_metadata")
+        if qwen_meta and is_qwen:
+            api_kwargs["metadata"] = qwen_meta
+
+        # Tools
+        if tools:
+            api_kwargs["tools"] = tools
+
+        # max_tokens resolution — priority: ephemeral > user > provider default
+        max_tokens_fn = params.get("max_tokens_param_fn")
+        ephemeral = params.get("ephemeral_max_output_tokens")
+        max_tokens = params.get("max_tokens")
+        anthropic_max_out = params.get("anthropic_max_output")
+        is_nvidia_nim = params.get("is_nvidia_nim", False)
+        is_kimi = params.get("is_kimi", False)
+        reasoning_config = params.get("reasoning_config")
+
+        if ephemeral is not None and max_tokens_fn:
+            api_kwargs.update(max_tokens_fn(ephemeral))
+        elif max_tokens is not None and max_tokens_fn:
+            api_kwargs.update(max_tokens_fn(max_tokens))
+        elif is_nvidia_nim and max_tokens_fn:
+            api_kwargs.update(max_tokens_fn(16384))
+        elif is_qwen and max_tokens_fn:
+            api_kwargs.update(max_tokens_fn(65536))
+        elif is_kimi and max_tokens_fn:
+            # Kimi/Moonshot: 32000 matches Kimi CLI's default
+            api_kwargs.update(max_tokens_fn(32000))
+        elif anthropic_max_out is not None:
+            api_kwargs["max_tokens"] = anthropic_max_out
+
+        # Kimi: top-level reasoning_effort (unless thinking disabled)
+        if is_kimi:
+            _kimi_thinking_off = bool(
+                reasoning_config
+                and isinstance(reasoning_config, dict)
+                and reasoning_config.get("enabled") is False
+            )
+            if not _kimi_thinking_off:
+                _kimi_effort = "medium"
+                if reasoning_config and isinstance(reasoning_config, dict):
+                    _e = (reasoning_config.get("effort") or "").strip().lower()
+                    if _e in ("low", "medium", "high"):
+                        _kimi_effort = _e
+                api_kwargs["reasoning_effort"] = _kimi_effort
+
+        # extra_body assembly
+        extra_body: Dict[str, Any] = {}
+
+        is_openrouter = params.get("is_openrouter", False)
+        is_nous = params.get("is_nous", False)
+        is_github_models = params.get("is_github_models", False)
+
+        provider_prefs = params.get("provider_preferences")
+        if provider_prefs and is_openrouter:
+            extra_body["provider"] = provider_prefs
+
+        # Kimi extra_body.thinking
+        if is_kimi:
+            _kimi_thinking_enabled = True
+            if reasoning_config and isinstance(reasoning_config, dict):
+                if reasoning_config.get("enabled") is False:
+                    _kimi_thinking_enabled = False
+            extra_body["thinking"] = {
+                "type": "enabled" if _kimi_thinking_enabled else "disabled",
+            }
+
+        # Reasoning
+        if params.get("supports_reasoning", False):
+            if is_github_models:
+                gh_reasoning = params.get("github_reasoning_extra")
+                if gh_reasoning is not None:
+                    extra_body["reasoning"] = gh_reasoning
+            else:
+                if reasoning_config is not None:
+                    rc = dict(reasoning_config)
+                    if is_nous and rc.get("enabled") is False:
+                        pass  # omit for Nous when disabled
+                    else:
+                        extra_body["reasoning"] = rc
+                else:
+                    extra_body["reasoning"] = {"enabled": True, "effort": "medium"}
+
+        if is_nous:
+            extra_body["tags"] = ["product=hermes-agent"]
+
+        # Ollama num_ctx
+        ollama_ctx = params.get("ollama_num_ctx")
+        if ollama_ctx:
+            options = extra_body.get("options", {})
+            options["num_ctx"] = ollama_ctx
+            extra_body["options"] = options
+
+        # Ollama/custom think=false
+        if params.get("is_custom_provider", False):
+            if reasoning_config and isinstance(reasoning_config, dict):
+                _effort = (reasoning_config.get("effort") or "").strip().lower()
+                _enabled = reasoning_config.get("enabled", True)
+                if _effort == "none" or _enabled is False:
+                    extra_body["think"] = False
+
+        if is_qwen:
+            extra_body["vl_high_resolution_images"] = True
+
+        # Merge any pre-built extra_body additions
+        additions = params.get("extra_body_additions")
+        if additions:
+            extra_body.update(additions)
+
+        if extra_body:
+            api_kwargs["extra_body"] = extra_body
+
+        # Request overrides last (service_tier etc.)
+        overrides = params.get("request_overrides")
+        if overrides:
+            api_kwargs.update(overrides)
+
+        return api_kwargs
+
+    def normalize_response(self, response: Any, **kwargs) -> NormalizedResponse:
+        """Normalize OpenAI ChatCompletion to NormalizedResponse.
+
+        For chat_completions, this is near-identity — the response is already
+        in OpenAI format.  extra_content on tool_calls (Gemini thought_signature)
+        is preserved via ToolCall.provider_data.  reasoning_details (OpenRouter
+        unified format) and reasoning_content (DeepSeek/Moonshot) are also
+        preserved for downstream replay.
+        """
+        choice = response.choices[0]
+        msg = choice.message
+        finish_reason = choice.finish_reason or "stop"
+
+        tool_calls = None
+        if msg.tool_calls:
+            tool_calls = []
+            for tc in msg.tool_calls:
+                # Preserve provider-specific extras on the tool call.
+                # Gemini 3 thinking models attach extra_content with
+                # thought_signature — without replay on the next turn the API
+                # rejects the request with 400.
+                tc_provider_data: Dict[str, Any] = {}
+                extra = getattr(tc, "extra_content", None)
+                if extra is None and hasattr(tc, "model_extra"):
+                    extra = (tc.model_extra or {}).get("extra_content")
+                if extra is not None:
+                    if hasattr(extra, "model_dump"):
+                        try:
+                            extra = extra.model_dump()
+                        except Exception:
+                            pass
+                    tc_provider_data["extra_content"] = extra
+                tool_calls.append(ToolCall(
+                    id=tc.id,
+                    name=tc.function.name,
+                    arguments=tc.function.arguments,
+                    provider_data=tc_provider_data or None,
+                ))
+
+        usage = None
+        if hasattr(response, "usage") and response.usage:
+            u = response.usage
+            usage = Usage(
+                prompt_tokens=getattr(u, "prompt_tokens", 0) or 0,
+                completion_tokens=getattr(u, "completion_tokens", 0) or 0,
+                total_tokens=getattr(u, "total_tokens", 0) or 0,
+            )
+
+        # Preserve reasoning fields separately.  DeepSeek/Moonshot use
+        # ``reasoning_content``; others use ``reasoning``.  Downstream code
+        # (_extract_reasoning, thinking-prefill retry) reads both distinctly,
+        # so keep them apart in provider_data rather than merging.
+        reasoning = getattr(msg, "reasoning", None)
+        reasoning_content = getattr(msg, "reasoning_content", None)
+
+        provider_data: Dict[str, Any] = {}
+        if reasoning_content:
+            provider_data["reasoning_content"] = reasoning_content
+        rd = getattr(msg, "reasoning_details", None)
+        if rd:
+            provider_data["reasoning_details"] = rd
+
+        return NormalizedResponse(
+            content=msg.content,
+            tool_calls=tool_calls,
+            finish_reason=finish_reason,
+            reasoning=reasoning,
+            usage=usage,
+            provider_data=provider_data or None,
+        )
+
+    def validate_response(self, response: Any) -> bool:
+        """Check that response has valid choices."""
+        if response is None:
+            return False
+        if not hasattr(response, "choices") or response.choices is None:
+            return False
+        if not response.choices:
+            return False
+        return True
+
+    def extract_cache_stats(self, response: Any) -> Optional[Dict[str, int]]:
+        """Extract OpenRouter/OpenAI cache stats from prompt_tokens_details."""
+        usage = getattr(response, "usage", None)
+        if usage is None:
+            return None
+        details = getattr(usage, "prompt_tokens_details", None)
+        if details is None:
+            return None
+        cached = getattr(details, "cached_tokens", 0) or 0
+        written = getattr(details, "cache_write_tokens", 0) or 0
+        if cached or written:
+            return {"cached_tokens": cached, "creation_tokens": written}
+        return None
+
+
+# Auto-register on import
+from agent.transports import register_transport  # noqa: E402
+
+register_transport("chat_completions", ChatCompletionsTransport)