home-assistant/core · error · HomeAssistantError

unexpected_chat_log_content

Error message

unexpected_chat_log_content

What it means

A HomeAssistantError with translation key 'unexpected_chat_log_content' raised by _convert_content in the Anthropic entity when it encounters a chat log content item whose Python type it does not handle. The placeholder 'type' carries the offending class name. Only UserContent, AssistantContent, and ToolContent branches are handled; everything else (e.g. SystemContent reaching this path) is rejected.

Source

Thrown at homeassistant/components/anthropic/entity.py:485

                        for tool_call in content.tool_calls
                    ]
                )

            if not messages[-1]["content"]:
                # Drop assistant messages that ended up without any content
                # (e.g. whitespace-only text): the API rejects empty messages
                messages.pop()
            elif (
                isinstance(messages[-1]["content"], list)
                and len(messages[-1]["content"]) == 1
                and messages[-1]["content"][0]["type"] == "text"
            ):
                # If there is only one text block, simplify the content to a string
                messages[-1]["content"] = messages[-1]["content"][0]["text"]
        else:
            # Note: We don't pass SystemContent here as it's
            # passed to the API as the prompt
            raise HomeAssistantError(
                translation_domain=DOMAIN,
                translation_key="unexpected_chat_log_content",
                translation_placeholders={"type": type(content).__name__},
            )

    return messages, container_id


class AnthropicDeltaStream:
    """Transform the response stream into HA format.

    A typical stream of responses might look something like the following:
    - RawMessageStartEvent with no content
    - RawContentBlockStartEvent with an empty ThinkingBlock
      (if extended thinking is enabled)
    - RawContentBlockDeltaEvent with a ThinkingDelta
    - RawContentBlockDeltaEvent with a ThinkingDelta
    - RawContentBlockDeltaEvent with a ThinkingDelta

View on GitHub (pinned to 58a3fdb3ea)

Solutions

1. Read the 'type' placeholder in the error to identify the unsupported content class
2. Align versions: update Home Assistant core and the anthropic integration together so content types are handled
3. Start a new conversation (new conversation_id) to drop the malformed chat log history

from homeassistant.components import conversation

HANDLED = (conversation.UserContent, conversation.AssistantContent, conversation.ToolContent)

def chat_log_convertible(content: list) -> bool:
    return all(isinstance(item, HANDLED) for item in content)

try:
    messages, container_id = _convert_content(chat_log.content[1:])
except HomeAssistantError as err:
    if err.translation_key == "unexpected_chat_log_content":
        # start a new conversation with clean history
        ...

When it happens

Trigger: chat_log.content[1:] containing an item that is not one of the handled content classes — for example a SystemContent injected mid-conversation, or a new content type introduced by a newer homeassistant conversation API that the Anthropic integration has not mapped.

Common situations: Version skew: running a custom/modified anthropic integration against a newer Home Assistant core that adds content block types; or another integration appending non-standard items to the shared conversation chat log.

Related errors

• response_not_found
• system_message_not_found
• user_message_not_found
• json_parse_error
• api_authentication_error

AI-assisted analysis of home-assistant/core@58a3fdb3ea (2026-08-14). Data as JSON: /api/errors/57756cfe4c40ee4f. Report an issue: GitHub.