xai-org/x-algorithm · error · RuntimeError

BDSM_CHALLENGE_SALT env var is required for challenge routin

Error message

BDSM_CHALLENGE_SALT env var is required for challenge routing

What it means

Challenge routing in the focal score sink hashes labels with a salt from the BDSM_CHALLENGE_SALT environment variable. _challenge_salt raises RuntimeError when the var is unset or empty, because unsalted routing would be predictable and gameable.

Source

Thrown at bdsm/runtime/score_results_sink_focal.py:59

        def is_active(self, uid):
            return False

        def is_active_many(self, uids):
            return set()

        def mark_active(self, uid):
            pass

        def get_metrics(self):
            return {"enabled": False}

    _trace = _NoopTrace()


def _challenge_salt() -> bytes:
    salt = os.environ.get("BDSM_CHALLENGE_SALT", "")
    if not salt:
        raise RuntimeError("BDSM_CHALLENGE_SALT env var is required for challenge routing")
    return salt.encode()


DEFAULT_BOOTSTRAP = "localhost:9092"

HEAD_NAMES = {
    0: "FollowBot",
    1: "LikeBot",
    2: "EngagementAmplifier",
    3: "ReplySpamBot",
    4: "TweetSpamBot",
    5: "RTBot",
    6: "MultiActionBot",
    7: "LegitimateUser",
}


def _resolve_head_names(_model_version):

View on GitHub (pinned to 24c60942c5)

Solutions

1. Set BDSM_CHALLENGE_SALT to the deployment's salt value (from the secret store) before starting the sink
2. Add it to the container spec/k8s secret so it is always mounted
3. Add a startup preflight assertion for required env vars to fail before any work begins
4. Document required env vars in the service runbook

Example fix

# before
python -m bdsm.runtime.score_results_sink_focal ...
# after
export BDSM_CHALLENGE_SALT="$SALT_FROM_SECRET_STORE"
python -m bdsm.runtime.score_results_sink_focal ...

import os
assert os.environ.get('BDSM_CHALLENGE_SALT'), 'BDSM_CHALLENGE_SALT must be set'

try:
    salt = _challenge_salt()
except RuntimeError:
    salt = load_salt_from_secret_store().encode()

When it happens

Trigger: Running score_results_sink_focal (or any path reaching pick_challenge_label/_cusp_lane/_paused_head_lane/_spam_bounce_lane) in a process where BDSM_CHALLENGE_SALT is unset or empty; a dotenv file that omits it; the var lost in a container image rebuild.

Common situations: New deployment environment (k8s secret not mounted); local run without copying the env template; secret renamed; CI run lacking prod secrets.

Understand the failure class

Background: "environment variable is not set" and "Missing keys in environment" errors: what missing required env var messages mean and how to fix them — this error's family across 28 libraries.

Related errors

• XAI_USER environment variable is required
• XAI_JOB_NAME environment variable is required
• XAI_CLUSTER environment variable is required
• batch size must be a positive integer
• cannot pass empty collection to Foldl1()

AI-assisted analysis of xai-org/x-algorithm@24c60942c5 (2026-08-28). Data as JSON: /api/errors/a767c12ae59f9a48. Report an issue: GitHub.