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ant_ai.llm.exceptions

ContextWindowExceededError

Bases: Exception

The conversation no longer fits the model's context window.

Backends raise this in place of their provider's own error (LiteLLM's ContextWindowExceededError, OpenAI's BadRequestError with code context_length_exceeded, ...) so the condition can be recognised without importing the provider. The provider's exception is chained as __cause__ for logs.

The message is written here, not copied from the provider, so it carries no prompt content or endpoint detail and is safe to forward to whoever called the agent — which A2AExecutor does.

Parameters:

Name Type Description Default
model str | None

The model that refused the request, kept for logs.

 None
Source code in src/ant_ai/llm/exceptions.py 
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class ContextWindowExceededError(Exception):
    """The conversation no longer fits the model's context window.

    Backends raise this in place of their provider's own error (LiteLLM's
    `ContextWindowExceededError`, OpenAI's `BadRequestError` with code
    `context_length_exceeded`, ...) so the condition can be recognised without
    importing the provider. The provider's exception is chained as `__cause__`
    for logs.

    The message is written here, not copied from the provider, so it carries no
    prompt content or endpoint detail and is safe to forward to whoever called
    the agent — which `A2AExecutor` does.

    Args:
        model: The model that refused the request, kept for logs.
    """

    def __init__(self, model: str | None = None) -> None:
        self.model = model
        super().__init__(
            "The conversation exceeds the model's context window. "
            "Start a new conversation or reduce the material attached to this one."
        )