Class HistoryMessage

src/mcp_cli/chat/models.py:123–199

A message in the conversation history (dict-based tool_calls for SessionManager compat). This is the LOCAL message model used by ChatContext/SessionManager. For chuk_llm's canonical Message with typed ToolCall objects, use mcp_cli.chat.response_models.Message instead.

class HistoryMessage(BaseModel):
    """A message in the conversation history (dict-based tool_calls for SessionManager compat).

    This is the LOCAL message model used by ChatContext/SessionManager.
    For chuk_llm's canonical Message with typed ToolCall objects,
    use mcp_cli.chat.response_models.Message instead.
    """

    role: MessageRole = Field(
        description="Message role (user, assistant, system, tool)"
    )
    content: str | list[dict[str, Any]] | None = Field(
        default=None,
        description="Message content (string, or list of content blocks for multimodal)",
    )
    name: str | None = Field(default=None, description="Name (for tool messages)")
    tool_calls: list[dict[str, Any]] | None = Field(
        default=None, description="Tool calls (for assistant messages with tools)"
    )
    tool_call_id: str | None = Field(
        default=None, description="Tool call ID (for tool response messages)"
    )
    reasoning_content: str | None = Field(
        default=None,
        description="Reasoning content (for models like DeepSeek reasoner)",
    )

    model_config = {"frozen": False}

    def to_dict(self) -> dict[str, Any]:
        """Convert to dict for LLM API calls.

        Handles provider-specific requirements:
        - OpenAI: Requires 'content' field in assistant messages with tool_calls
        - DeepSeek Reasoner: Requires 'reasoning_content' field when model provided it
        """
        result = self.model_dump(exclude_none=True, mode="json")

        # CRITICAL FIX: OpenAI (especially newer models like gpt-5-mini) requires
        # the 'content' field to be present in assistant messages with tool_calls,
        # even if it's null. Without this, some models may hang or reject the request.
        if self.role == MessageRole.ASSISTANT and MessageField.TOOL_CALLS in result:
            if MessageField.CONTENT not in result:
                result[MessageField.CONTENT] = None

        # NOTE: reasoning_content is automatically included if set (not None)
        # because we're not explicitly excluding it. The exclude_none=True will
        # only exclude it if it's None. This is correct behavior per DeepSeek docs:
        # https://api-docs.deepseek.com/guides/thinking_mode#tool-calls
        # "the user needs to send the reasoning content back to the API"

        return result  # type: ignore[no-any-return]

    @classmethod
    def from_dict(cls, data: dict[str, Any]) -> "HistoryMessage":
        """Create from dict."""
        return cls.model_validate(data)  # type: ignore[no-any-return]