Bridge + Third-Party API: Anyone successfully configured IP allow listing for outbound calls?

Dylan T

We're building an integration between Bridge and an external HCM/payroll API. The third-party system requires strict IP-based allow listing for any external connections and cannot accept DNS records or hostnames as a substitute.

The challenge: Smartsheet's documentation only references webhooks.smartsheet.com for inbound traffic, but we need to know what IP addresses Bridge uses as the source when making outbound HTTP calls via the Call API utility.

A few specific questions:

1. Has anyone successfully gotten Bridge's outbound IP addresses or CIDR ranges from Smartsheet support?
2. Are these IPs static, or does Bridge use dynamic IPs for outbound calls?
3. If dynamic, has anyone found a reliable workaround short of setting up a dedicated middleware proxy?

We've already submitted a support ticket but figured this community may have run into the same wall. I saw one thread referencing a similar issue with ServiceNow ACLs but couldn't find a resolution.

Any firsthand experience appreciated.

rampawankumar

We've faced this before. As far as I know, Bridge does not publicly provide static outbound IPs for Call API traffic, and I wouldn't assume the egress IPs are fixed unless Smartsheet Support confirms it.

If your third-party system requires strict IP allowlisting, the most reliable solution is usually a middleware/proxy with a static public IP (AWS NAT Gateway, Azure NAT Gateway, etc.) and have Bridge call that instead.

I'd be interested to hear what Support tells you, as this seems to be a common limitation when integrating with payroll/HCM systems.