_get_request_payload() — langchain Function Reference

Architecture documentation for the _get_request_payload() function in chat_models.py from the langchain codebase.

Function python LangChainCore LanguageModelBase

Entity Profile

LangChainCore→ LanguageModelBase→ _get_request_payload() — langchain Function Reference

Dependency Diagram

graph TD
  c47b3765_db6e_5e49_7f83_88810118f15c["_get_request_payload()"]
  f3181e26_0568_4993_612c_5b8d73ad3c37["ChatDeepSeek"]
  c47b3765_db6e_5e49_7f83_88810118f15c -->|defined in| f3181e26_0568_4993_612c_5b8d73ad3c37
  style c47b3765_db6e_5e49_7f83_88810118f15c fill:#6366f1,stroke:#818cf8,color:#fff

Relationship Graph

Source Code

libs/partners/deepseek/langchain_deepseek/chat_models.py lines 257–279

    def _get_request_payload(
        self,
        input_: LanguageModelInput,
        *,
        stop: list[str] | None = None,
        **kwargs: Any,
    ) -> dict:
        payload = super()._get_request_payload(input_, stop=stop, **kwargs)
        for message in payload["messages"]:
            if message["role"] == "tool" and isinstance(message["content"], list):
                message["content"] = json.dumps(message["content"])
            elif message["role"] == "assistant" and isinstance(
                message["content"], list
            ):
                # DeepSeek API expects assistant content to be a string, not a list.
                # Extract text blocks and join them, or use empty string if none exist.
                text_parts = [
                    block.get("text", "")
                    for block in message["content"]
                    if isinstance(block, dict) and block.get("type") == "text"
                ]
                message["content"] = "".join(text_parts) if text_parts else ""
        return payload