BerriAI/litellm · error · ValueError

WANDB_API_KEY must be set for Weave OpenTelemetry integratio

Error message

WANDB_API_KEY must be set for Weave OpenTelemetry integration.

What it means

get_weave_otel_config builds the Weave (W&B) OpenTelemetry exporter configuration and hard-requires WANDB_API_KEY in the environment; without it there is no way to authenticate the OTLP stream, so it raises ValueError immediately. WANDB_PROJECT_ID is checked next and fails separately if the key is present but the project is not.

Source

Thrown at litellm/integrations/weave/weave_otel.py:139

    Retrieves the Weave OpenTelemetry configuration based on environment variables.

    Environment Variables:
        WANDB_API_KEY: Required. W&B API key for authentication.
        WANDB_PROJECT_ID: Required. Project ID in format <entity>/<project_name>.
        WANDB_HOST: Optional. Custom Weave host URL. Defaults to cloud endpoint.

    Returns:
        WeaveOtelConfig: A Pydantic model containing Weave OTEL configuration.

    Raises:
        ValueError: If required environment variables are missing.
    """
    api_key: Final = os.getenv("WANDB_API_KEY")
    project_id: Final = os.getenv("WANDB_PROJECT_ID")
    host = os.getenv("WANDB_HOST")

    if not api_key:
        raise ValueError("WANDB_API_KEY must be set for Weave OpenTelemetry integration.")

    if not project_id:
        raise ValueError(
            "WANDB_PROJECT_ID must be set for Weave OpenTelemetry integration. Format: <entity>/<project_name>"
        )

    if host:
        if not host.startswith("http"):
            host = "https://" + host
        # Self-managed instances use a different path
        endpoint = host.rstrip("/") + WEAVE_OTEL_ENDPOINT
        verbose_logger.debug("Using Weave OTEL endpoint from host: %s", endpoint)
    else:
        endpoint = WEAVE_BASE_URL + WEAVE_OTEL_ENDPOINT
        verbose_logger.debug("Using Weave cloud endpoint: %s", endpoint)

    # Weave uses Basic auth with format: api:<WANDB_API_KEY>
    auth_header: Final = _get_weave_authorization_header(api_key=api_key)

View on GitHub (pinned to 6c2dcb801b)

Solutions

1. Export WANDB_API_KEY (and WANDB_PROJECT_ID) before the weave callback initializes: export WANDB_API_KEY=<your-key>
2. In Docker/K8s, mount the W&B API key as an env secret on the litellm container
3. If you only wanted W&B experiment tracking, not OTEL tracing, use the wandb callback instead and unset the weave one

Example fix

# before
litellm.callbacks = ["weave"]  # ValueError: WANDB_API_KEY must be set

# after
import os
os.environ["WANDB_API_KEY"] = "wandb-api-key"
os.environ["WANDB_PROJECT_ID"] = "my-entity/my-project"
litellm.callbacks = ["weave"]

import os

for var in ("WANDB_API_KEY", "WANDB_PROJECT_ID"):
    if not os.getenv(var):
        raise RuntimeError(f"{var} is required for the weave OTEL integration")

litellm.callbacks += ["weave"]

try:
    from litellm.integrations.weave.weave_otel import get_weave_otel_config
    weave_cfg = get_weave_otel_config()
except ValueError as e:
    if "WANDB_API_KEY" in str(e):
        logger.warning("weave tracing disabled: WANDB_API_KEY not set")
        weave_cfg = None
    else:
        raise

When it happens

Trigger: Enabling the weave integration (litellm.callbacks += ["weave"] or the weave_otel config path) in a process without WANDB_API_KEY exported; keys stored only in a notebook-level wandb login that does not touch os.environ; CI runners without W&B secrets.

Common situations: Local runs where wandb was authenticated via `wandb login` (stored in ~/.netrc, not env); Docker deployments missing the secret; rotating W&B keys and forgetting the proxy's env.

Related errors

• LANGFUSE_PUBLIC_KEY and LANGFUSE_SECRET_KEY must be set for
• WANDB_PROJECT_ID must be set for Weave OpenTelemetry integra
• Qdrant url must be provided
• Missing required Redis configuration: {missing_var}. Provide
• Missing required Valkey configuration. Provide host and port

AI-assisted analysis of BerriAI/litellm@6c2dcb801b (2026-08-15). Data as JSON: /api/errors/4ea2e9f3e6772bc5. Report an issue: GitHub.