In IBM API Connect, rate limits are configured at two primary levels to govern API consumption. First, they are defined within a Plan, which is part of a Product. This allows for creating different service tiers (e.g., Basic, Premium) with distinct rate limits that application developers can subscribe to. Second, a default rate limit can be set at the Catalog level. This Catalog-level limit is automatically applied to any Plan within that Catalog that does not have its own specific rate limit defined, ensuring a baseline level of governance and protection for all published APIs.

1. IBM API Connect v10.0.x Documentation

"Editing a Product draft": This document details the configuration of Plans within a Product. In the "Plans" section

it states

"In the Rate limits section

you can add new rate limits for the plan... Each rate limit has a name

is specified as a value per time interval...". This confirms that rate limits are defined at the Plan level.

2. IBM API Connect v10.0.x Documentation

"Creating and configuring Catalogs": This source describes the settings available for a Catalog. Under the "Catalog settings" tab details

it specifies the "Default plan rate limit" option and explains

"Apply a default rate limit to all plans in this Catalog. The default rate limit is not enforced for a plan if that plan has its own rate limit." This confirms that a default rate limit can be defined at the Catalog level.