Models run where the data lives. Requests route to the lowest-latency region by default; pin a region or geographic zone with the X-Region-Override and X-World-Part-Override headers.
Models run where the data lives.By default, each request routes to the closest available region. Two HTTP headers override that: X-Region-Override pins a specific region, and X-World-Part-Override keeps traffic within a broader geographic zone.
X-Region-Override
X-World-Part-Override
Scope
Exact region
Geographic zone
Example value
eu-north-1
eu
Use when
You need a specific data center
You want to stay in a geography without picking an exact region
Pin to a specific data center with X-Region-Override. Use this when you have data-residency or compliance requirements that depend on a specific location.
Keep traffic within a geographic zone with X-World-Part-Override. The best available region within that zone is selected. Use this when you need to stay within a geography but do not need a specific data center.
A world part groups several regions under one value. Requests route to the best available region within that zone, which does not guarantee a specific country.
Value
Zone
na
North America
eu
Europe
eu-non-eu
Europe, non-EU
ap
Asia-Pacific
me
Middle East
If your compliance requirement depends on a specific country, use X-Region-Override with the exact region. A world part routes to the best region within a zone and does not guarantee a specific country.
Voice agents use a separate region field (us-east, eu-central, ap-south) that determines where the agent runs. It is not interchangeable with the platform headers above: the agent region ap-south, for example, routes to the platform region ap-south-1, but you set it through a different field. See the Voice Agents region table for the full mapping and the telephony country pinning each region applies.
Regional execution is not just about latency. In regulated industries it determines where data can exist and which models can process it. These constraints are respected per request.If you need a particular model hosted in a region where it is not currently available, contact us.
