The API Gateway has a default mediation flow that is executed in each API invocation. You can do additional custom mediation for the messages in the API Gateway by extending its mediation flow. An extension is provided as a synapse mediation sequence.
You can design all sequences using a tool like WSO2 Developer Studio, and store the sequence.xml file in the governance registry. The registry collection where sequences are stored is customsequences, which is available by default in apimgt governance registry location. The registry path is /_system/governance/apimgt/customsequences. Store the InSequence files in apimgt/customsequences/in folder and the OutSequence files in apimgt/customsequences/out folder. For example, if you have an in sequence file as testInSequence, you must save it in /_system/governance/apimgt/customsequences/in/testInSequence.xml and if you have an out sequence file as testOutSequence, save it in /_system/governance/apimgt/customsequences/out/testOutSequence.xml.
There are two ways to apply mediation extensions to messages. They are as follows:
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To populate these drop-down lists, you can write custom sequences using a tool like WSO2 Developer Studio and store the sequence.xml file in the API Manager governance registry. For more information, see must add mediation sequences as explained in the beginning.
Invoking the extension sequences
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