Getting 401 Unauthorized immediately after a successful token refresh via authClient.refreshAccessToken(). The new access token has a valid exp claim, but the target service /api/v2/analytics/queues/summary rejects it. My server clock is 200ms ahead of NTP. Is the SDK’s iat validation too strict, or is this a known GC gateway behavior? Here’s the error payload:
{"status": 401, "code": "unauthorized", "message": "Token expired or invalid"}
Clock skew is usually the culprit here, but 200ms shouldn’t trigger a hard rejection unless your server’s system time is actually drifting significantly more than you think. The Genesys Cloud gateway validates the iat (issued at) claim against its own time, and if the difference exceeds the configured tolerance, it throws a 401.
Check your server’s NTP sync status. If you’re on Linux, run timedatectl status. If the offset is higher than a few seconds, you need to fix the underlying time source, not the SDK config.
For immediate mitigation, you can adjust the SDK’s token validation tolerance. In PureCloudPlatformClientV2, you can set the clockTolerance property. It defaults to a few seconds, but increasing it might help if your environment is unstable.
const platformClient = require('@genesyscloud/purecloud-platform-client-v2');
// Increase clock tolerance to 5000ms (5 seconds)
platformClient.PureCloudPlatformClientV2.instance.clockTolerance = 5000;
This gives the gateway more leeway before rejecting the token. Just be aware that this is a band-aid. If your clock drifts too much, you’ll run into other issues with session validity and audit logs. Fix the NTP sync first.
200ms is usually fine, but if your server clock is drifting ahead of NTP, you’re likely hitting the iat (issued at) validation on the gateway side. The Genesys Cloud API rejects tokens if the iat claim is in the future relative to their servers, even by a small margin. It’s a security measure to prevent clock-spoofing attacks.
The issue isn’t the SDK’s local validation, it’s the gateway rejecting the token because it thinks it was issued from the future. You need to sync your server time more aggressively or adjust the tolerance if you’re using a custom auth wrapper, but honestly, just fixing the NTP sync is the right move.
Here’s how to check and fix the drift on Linux:
# Check current time status and drift
timedatectl status
# If drift is > 1s, force an immediate NTP sync
sudo timedatectl set-ntp true
sudo systemctl restart systemd-timesyncd
# Verify the offset is now < 50ms
timedatectl status | grep "System clock synchronized"
If you’re running in a containerized environment (like ECS or K8s), the host time might be fine but the container clock could be off. Make sure you’re not mounting a stale /etc/localtime or overriding the timezone env vars incorrectly. Once the clock is synced, the refreshAccessToken() call should work without throwing 401s.