API for data transfer Salesforce/OSC

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We have an upcoming project with a requirement to transfer incidents from OSC to another system (Salesforce) through SOA service when an update happens to an incident in OSC.   Is it possible to call an external API to send the data to a different system?  Can you point me to any documentation?  We've read the REST/SOAP API documentation and see that we can update data in OSC from external systems but do not see that it can be done in reverse.