Oracle Integration Cloud (OIC) provides various services and capabilities for integrating applications, data, and services across cloud and on-premises environments. The maximum message size that OIC can handle depends on the specific service or component you’re using within the platform.

For example:

1. Integration Flows: OIC allows you to create integration flows that connect various applications and services. The maximum message size for an integration flow can vary depending on the specific connectors and adapters you’re using. For many connectors, the maximum payload size could be around 50 MB.

2. File Transfers: OIC includes capabilities for transferring files between systems. The maximum file size for these transfers can vary based on the configuration and the type of integration.

3. REST and SOAP Services: If you’re exposing REST or SOAP services through OIC, the payload size could again depend on the configuration and service implementation.