Two related changes to how the master-key auth path interacts with
downstream consumers of UserAPIKeyAuth.api_key:
1. The master-key auth branch in user_api_key_auth.py now sets
`valid_token.api_key` to a stable alias
(`LITELLM_PROXY_MASTER_KEY_ALIAS = "litellm_proxy_master_key"`) instead
of the raw master key. Downstream consumers — spend logging,
Prometheus metrics, audit trails, rate limiting, cost tracking — now
receive the alias instead of the master key (which they would
previously hash and propagate). Neither the raw master key nor its
hash flows past the auth layer.
2. `_is_master_key` in spend_tracking_utils.py is reduced to a strict
raw-only constant-time comparison. The hashed form is no longer
considered equivalent.
Side effects:
- The two hash-detection blocks in `get_logging_payload` are removed.
They were re-detecting the master key per spend-log write to swap in
the alias; that detection happens once at the auth layer now.
- The `disable_adding_master_key_hash_to_db` general setting becomes a
no-op. Operators can remove it from their config; existing config is
still accepted.
- Operator dashboards that filter Prometheus metrics by the master-key
hash will need to switch to the `api_key="litellm_proxy_master_key"`
label.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
9d9f09934e