HKUDS/Vibe-Trading · error · RuntimeError

Anthropic provider requires langchain-anthropic. Install the

Error message

Anthropic provider requires langchain-anthropic. Install the optional extra: pip install "vibe-trading-ai[anthropic]" (or pip install langchain-anthropic).

What it means

build_llm was configured to use the Anthropic provider, but the langchain_anthropic package cannot be imported. The library wraps the ImportError with an install hint pointing at the optional extra vibe-trading-ai[anthropic].

Source

Thrown at agent/src/providers/llm.py:1075

    temperature: float,
    callbacks: Any = None,
    effort: str = "",
) -> Any:
    """Build the native Anthropic Messages API adapter.

    Uses a temperature-safe subclass so models that deprecate the `temperature`
    field (e.g. claude-opus-5 / claude-sonnet-5) work transparently while models
    that still accept it keep the configured deterministic value.

    `effort` is the configured LANGCHAIN_REASONING_EFFORT, forwarded only to
    models that accept it (see `_anthropic_supports_effort`); an empty string
    means unset.
    """
    try:
        module = import_module("langchain_anthropic")
        chat_anthropic = getattr(module, "ChatAnthropic")
    except Exception as exc:  # noqa: BLE001 - dependency error with install hint
        raise RuntimeError(
            "Anthropic provider requires langchain-anthropic. Install the optional "
            'extra: pip install "vibe-trading-ai[anthropic]" (or pip install langchain-anthropic).'
        ) from exc

    safe_anthropic = _make_temperature_safe_anthropic(chat_anthropic)
    use_effort = (
        bool(effort)
        and _anthropic_supports_effort(model)
        and _adapter_accepts_effort(chat_anthropic)
    )
    # Effort makes langchain-anthropic enable adaptive thinking, and the API
    # then rejects any temperature other than 1:
    #   `temperature` may only be set to 1 when thinking is enabled or in
    #   adaptive mode
    # The platform's default is 0.0, so temperature is omitted entirely
    # whenever effort is in play. The temperature-safe wrapper above does not
    # cover this: it handles models that reject `temperature` outright, not
    # this thinking-conditional variant.

View on GitHub (pinned to 80ffdda44c)

Solutions

Install the extra: pip install "vibe-trading-ai[anthropic]"
Or install directly: pip install langchain-anthropic
Verify import works: python -c "import langchain_anthropic"; if it fails, fix the underlying ImportError shown in the chain

Example fix

# before
pip install vibe-trading-ai

# after
pip install "vibe-trading-ai[anthropic]"

Defensive patterns

Strategy: validation

Validate before calling

try:
    import langchain_anthropic  # noqa: F401
except ImportError:
    raise SystemExit('Install first: pip install "vibe-trading-ai[anthropic]"')

Try / catch

try:
    llm = build_llm()
except RuntimeError as e:
    if 'langchain-anthropic' in str(e):
        subprocess.check_call([sys.executable, '-m', 'pip', 'install', 'langchain-anthropic'])
        llm = build_llm()

Prevention

Declare extras in requirements/lockfile per provider you enable
Add a startup dependency check that imports each provider package

When it happens

Trigger: Setting LANGCHAIN_PROVIDER=anthropic (or an Anthropic model name) without having installed langchain-anthropic; a broken/partial install where the package exists but raises on import (missing transitive deps).

Common situations: Fresh environments where only core dependencies were installed; upgrading broke a transitive dependency; running in a slim Docker image or CI cache that skipped extras.

Understand the failure class

Background: "X is not installed. Please install it with pip install Y": missing optional dependency errors — ImportError/ValueError raised when a library's optional extra was never installed — this error's family across 22 libraries.

Related errors

AI-assisted analysis of HKUDS/Vibe-Trading@80ffdda44c (2026-08-28). Data as JSON: /api/errors/429ece1fbe18afe0. Report an issue: GitHub.