BerriAI/litellm · error · ValueError

Missing SLACK_WEBHOOK_URL from environment

Error message

Missing SLACK_WEBHOOK_URL from environment

What it means

For alert types configured with digest mode, litellm resolves a webhook URL (per-alert mapping, then default_webhook_url, then SLACK_WEBHOOK_URL env) before enqueueing a digest entry; if all three are None it raises ValueError (litellm/integrations/SlackAlerting/slack_alerting.py:1345).

Source

Thrown at litellm/integrations/SlackAlerting/slack_alerting.py:1345

            return
        if alert_type not in self.alert_types:
            return

        from datetime import datetime

        # Check if digest mode is enabled for this alert type
        alert_type_name_str: Final = getattr(alert_type, "value", str(alert_type))
        _atc: Final = self.alert_type_config.get(alert_type_name_str)
        if _atc is not None and _atc.digest:
            # Resolve webhook URL for this alert type (needed for digest entry)
            if self.alert_to_webhook_url is not None and alert_type in self.alert_to_webhook_url:
                _digest_webhook: str | list[str] | None = self.alert_to_webhook_url[alert_type]
            elif self.default_webhook_url is not None:
                _digest_webhook = self.default_webhook_url
            else:
                _digest_webhook = os.getenv("SLACK_WEBHOOK_URL", None)
            if _digest_webhook is None:
                raise ValueError("Missing SLACK_WEBHOOK_URL from environment")

            digest_key: Final = f"{alert_type_name_str}:{request_model or ''}:{api_base or ''}"

            async with self.digest_lock:
                now: Final = datetime.now()
                if digest_key in self.digest_buckets:
                    self.digest_buckets[digest_key]["count"] += 1
                    self.digest_buckets[digest_key]["last_time"] = now
                else:
                    self.digest_buckets[digest_key] = DigestEntry(
                        alert_type=alert_type_name_str,
                        request_model=request_model or "",
                        api_base=api_base or "",
                        first_message=message,
                        level=level,
                        count=1,
                        start_time=now,
                        last_time=now,

View on GitHub (pinned to 6c2dcb801b)

Solutions

1. Set SLACK_WEBHOOK_URL in the proxy environment
2. Or configure a webhook URL in general_settings (default webhook) or per-alert in alert_to_webhook_url
3. Disable digest mode for that alert type if no webhook is intended
4. Verify env propagation into docker/k8s deployment

Example fix

# before
litellm_settings:
  alerting: ["spend_tracked"]  # no webhook anywhere

# after
# env: SLACK_WEBHOOK_URL=https://hooks.slack.com/services/T000/B000/XXXX
litellm_settings:
  alerting: ["spend_tracked"]

import os

def digest_webhook_available(alerting) -> bool:
    return bool(
        getattr(alerting, "default_webhook_url", None)
        or getattr(alerting, "alert_to_webhook_url", None)
        or os.getenv("SLACK_WEBHOOK_URL")
    )

try:
    await alerting._send_alert(...)
except ValueError as e:
    if "Missing SLACK_WEBHOOK_URL" in str(e):
        log.warning("alert skipped: no webhook configured")
    else:
        raise

When it happens

Trigger: Enabling a digest alert type in alert_types (e.g. 'spend_tracked') without configuring any webhook: no alert_to_webhook_url entry, no default SLACK_WEBHOOK_URL in env/config, and SLACK_WEBHOOK_URL unset.

Common situations: Enabling new alert types in litellm.yaml while the webhook is only configured for other types; deploying to a new environment missing the SLACK_WEBHOOK_URL secret.

Related errors

• Missing webhook_url from environment
• PAGERDUTY_API_KEY is not set
• Trying to Customize Email Alerting {CommonProxyErrors.not_p
• AZURE_SENTINEL_DCR_IMMUTABLE_ID is required. Set it as an en
• AZURE_SENTINEL_ENDPOINT is required. Set it as an environmen

AI-assisted analysis of BerriAI/litellm@6c2dcb801b (2026-08-15). Data as JSON: /api/errors/aecc297b688051bd. Report an issue: GitHub.