feat(v1): stateless tool continuation + sampling-param passthrough

- Stateless tool continuation. OpenAI-compatible clients (opencode, etc.)
  resend the full messages array — system, user, assistant(tool_calls),
  tool(results) — but no conversation_id, so the prior
  "conversation_id required for tool continuation" 400 broke every tool call.
  When no conversation_id is present, rebuild the agent + pending tool calls +
  tool results directly from the resent messages
  (StreamProcessor.build_continuation_from_messages) instead of loading
  server-side pending_tool_state, and call gen_continuation.

- Forward OpenAI sampling params (temperature, max_tokens,
  max_completion_tokens, top_p, frequency_penalty, presence_penalty, stop,
  seed) from the request to the LLM gen call; the agent otherwise uses its
  configured defaults.

application/agents/base.py

@@ -35,6 +35,7 @@ class BaseAgent(ABC):
         json_schema: Optional[Dict] = None,
         json_schema_strict: bool = True,
         json_object: bool = False,
+        llm_params: Optional[Dict] = None,
         limited_token_mode: Optional[bool] = False,
         token_limit: Optional[int] = settings.DEFAULT_AGENT_LIMITS["token_limit"],
         limited_request_mode: Optional[bool] = False,
@@ -115,6 +116,9 @@ class BaseAgent(ABC):
         # ``json_object`` mirrors response_format {"type":"json_object"}.
         self.json_schema_strict = json_schema_strict
         self.json_object = json_object
+        # OpenAI sampling params forwarded from the request (temperature,
+        # max_tokens, top_p, ...). Empty when the caller sent none.
+        self.llm_params = llm_params or {}
         self.limited_token_mode = limited_token_mode
         self.token_limit = token_limit
         self.limited_request_mode = limited_request_mode
@@ -602,6 +606,10 @@ class BaseAgent(ABC):
             previous_response_id = self._previous_response_id()
             if previous_response_id:
                 gen_kwargs["previous_response_id"] = previous_response_id
+
+        # Forward OpenAI sampling params (temperature, max_tokens, top_p, ...).
+        if self.llm_params:
+            gen_kwargs.update(self.llm_params)
         resp = self.llm.gen_stream(**gen_kwargs)
 
         if log_context:

application/api/answer/services/stream_processor.py

@@ -172,6 +172,63 @@ class StreamProcessor:
             tools_data=tools_data,
         )
 
+    def build_continuation_from_messages(self, messages, tool_actions):
+        """Rebuild a tool continuation from the request messages (STATELESS).
+
+        OpenAI-compatible clients (opencode, etc.) resend the full conversation
+        -- system, user, assistant(tool_calls), tool(results) -- but carry no
+        conversation_id, so there is no server-side ``pending_tool_state`` to
+        load. Reconstruct the agent + continuation context directly from the
+        resent messages and return the same tuple as ``resume_from_tool_actions``:
+        (agent, messages, tools_dict, pending_tool_calls, tool_actions,
+        reasoning_content).
+        """
+        # Locate the last assistant message that issued tool calls.
+        pending_idx = None
+        for i in range(len(messages) - 1, -1, -1):
+            m = messages[i]
+            if m.get("role") == "assistant" and m.get("tool_calls"):
+                pending_idx = i
+                break
+        if pending_idx is None:
+            raise ValueError(
+                "No assistant message with tool_calls found for continuation"
+            )
+
+        pending_tool_calls = []
+        for tc in messages[pending_idx].get("tool_calls") or []:
+            fn = tc.get("function") or {}
+            raw_args = fn.get("arguments")
+            try:
+                args = (
+                    json.loads(raw_args)
+                    if isinstance(raw_args, str)
+                    else (raw_args or {})
+                )
+            except (json.JSONDecodeError, TypeError):
+                args = {}
+            name = fn.get("name", "")
+            pending_tool_calls.append(
+                {
+                    "call_id": tc.get("id", ""),
+                    "name": name,
+                    "tool_name": name,
+                    "action_name": name,
+                    "llm_name": name,
+                    "arguments": args,
+                }
+            )
+
+        # The conversation up to (but not including) the assistant tool_calls;
+        # gen_continuation re-appends the assistant message + tool results.
+        prior_messages = [dict(m) for m in messages[:pending_idx]]
+
+        # Build a normal agent (config / LLM / client tools), no new question.
+        agent = self.build_agent("")
+        tools_dict = agent.tool_executor.get_tools()
+
+        return agent, prior_messages, tools_dict, pending_tool_calls, tool_actions, ""
+
     def _load_conversation_history(self):
         """Load conversation history either from DB or request"""
         if self.conversation_id and self.initial_user_id:
@@ -1268,6 +1325,7 @@ class StreamProcessor:
             "json_schema": self.agent_config.get("json_schema"),
             "json_schema_strict": self.agent_config.get("json_schema_strict", True),
             "json_object": self.agent_config.get("json_object", False),
+            "llm_params": self.data.get("llm_params") or {},
             "compressed_summary": self.compressed_summary,
             "llm": llm,
             "llm_handler": llm_handler,

application/api/v1/routes.py

@@ -106,21 +106,32 @@ def chat_completions():
         if internal_data.get("tool_actions"):
             # Continuation mode
             conversation_id = internal_data.get("conversation_id")
-            if not conversation_id:
-                return make_response(
-                    jsonify({"error": {"message": "conversation_id required for tool continuation", "type": "invalid_request"}}),
-                    400,
+            if conversation_id:
+                (
+                    agent,
+                    messages,
+                    tools_dict,
+                    pending_tool_calls,
+                    tool_actions,
+                    reasoning_content,
+                ) = processor.resume_from_tool_actions(
+                    internal_data["tool_actions"], conversation_id
+                )
+            else:
+                # Stateless continuation: OpenAI-compatible clients (opencode,
+                # etc.) resend the full messages array but no conversation_id,
+                # so rebuild the agent + pending calls from the request itself.
+                (
+                    agent,
+                    messages,
+                    tools_dict,
+                    pending_tool_calls,
+                    tool_actions,
+                    reasoning_content,
+                ) = processor.build_continuation_from_messages(
+                    internal_data.get("messages", []),
+                    internal_data["tool_actions"],
                 )
-            (
-                agent,
-                messages,
-                tools_dict,
-                pending_tool_calls,
-                tool_actions,
-                reasoning_content,
-            ) = processor.resume_from_tool_actions(
-                internal_data["tool_actions"], conversation_id
-            )
             continuation = {
                 "messages": messages,
                 "tools_dict": tools_dict,

application/api/v1/translator.py

@@ -212,6 +212,16 @@ def translate_request(
     json_schema_strict = bool((_rf.get("json_schema") or {}).get("strict", True))
     json_object_mode = _rf.get("type") == "json_object"
 
+    # OpenAI sampling params, forwarded to the LLM gen call (the agent otherwise
+    # uses its configured defaults).
+    sampling_params = {}
+    for _k in (
+        "temperature", "max_tokens", "max_completion_tokens",
+        "top_p", "frequency_penalty", "presence_penalty", "stop", "seed",
+    ):
+        if data.get(_k) is not None:
+            sampling_params[_k] = data[_k]
+
     # Check for continuation (tool results after assistant tool_calls)
     if is_continuation(messages):
         tool_actions = extract_tool_results(messages)
@@ -222,6 +232,10 @@ def translate_request(
             "conversation_id": conversation_id,
             "tool_actions": tool_actions,
             "api_key": api_key,
+            # Full messages array for STATELESS continuation: OpenAI clients
+            # (opencode, etc.) don't carry a conversation_id, so the agent is
+            # rebuilt from the resent messages instead of server-side state.
+            "messages": messages,
         }
         # A continuation only exists if turn 1 was saved, so default to True —
         # otherwise the final turn and its WAL row are never persisted. An
@@ -276,6 +290,8 @@ def translate_request(
         result["json_schema_strict"] = json_schema_strict
     if json_object_mode:
         result["json_object"] = True
+    if sampling_params:
+        result["llm_params"] = sampling_params
 
     return result