RAML: REST API Modeling Language. RAML is used to design and manage the whole REST API lifecycle.

MULE API Kit: Helps to build the APIs from Anypoint Studio using a RAML file.

I will be explaining the generating flows from the RAML file and executing it.

Prerequisite: Basic knowledge of RAML and basic knowledge of mule flows.

Step 1:

Create a new project in MULE.

Step 2:

Create a RAML file using the RAML API editor in Anypoint Studio (I am using version 6.0.0).

#%RAML 0.8
    title: RAMLwithMULE
    version: 1.0
    baseUri: http://localhost:8080/api

    /get:
        get:
            description: sample
            responses:
                200:
                    body:
                        text/plain:
                            example: This is get call, MULE flow from RAML
    /show:
        get:
            description: sample
            responses:
                200:
                    body:
                        text/plain:
                            example: This is get call and name show, MULE flow from RAML

Step 3:

Generate flows from RAML.  Right click on RAML file ->MULE->Generate Flows from RAML.

Step 4:

A MULE XML file will be generated based on the RAML file.

Flow xml image-

Flow XML -

<?xml version="1.0" encoding="UTF-8"?>
<mule xmlns:doc="http://www.mulesoft.org/schema/mule/documentation" xmlns="http://www.mulesoft.org/schema/mule/core" xmlns:apikit="http://www.mulesoft.org/schema/mule/apikit" xmlns:http="http://www.mulesoft.org/schema/mule/http" xmlns:spring="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.mulesoft.org/schema/mule/core http://www.mulesoft.org/schema/mule/core/current/mule.xsd
http://www.mulesoft.org/schema/mule/http http://www.mulesoft.org/schema/mule/http/current/mule-http.xsd
http://www.mulesoft.org/schema/mule/apikit http://www.mulesoft.org/schema/mule/apikit/current/mule-apikit.xsd
http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.1.xsd">
    <http:listener-config name="test2-httpListenerConfig" host="0.0.0.0" port="8081" doc:name="HTTP Listener Configuration"/>
    <apikit:config name="test2-config" raml="test2.raml" consoleEnabled="true" consolePath="console" doc:name="Router"/>
    <flow name="test2-main">
        <http:listener config-ref="test2-httpListenerConfig" path="/api/*" doc:name="HTTP"/>
        <apikit:router config-ref="test2-config" doc:name="APIkit Router"/>
        <exception-strategy ref="test2-apiKitGlobalExceptionMapping" doc:name="Reference Exception Strategy"/>
    </flow>
    <flow name="get:/get:test2-config">
        <set-payload value="This is get call, generated MULE flow from RAML" doc:name="Set Payload"/>
    </flow>
    <flow name="get:/show:test2-config">
        <set-payload value="This is get call and name show, generated MULE flow from RAML" doc:name="Set Payload"/>
    </flow>
    <apikit:mapping-exception-strategy name="test2-apiKitGlobalExceptionMapping">
        <apikit:mapping statusCode="404">
            <apikit:exception value="org.mule.module.apikit.exception.NotFoundException" />
            <set-property propertyName="Content-Type" value="application/json" doc:name="Property"/>
            <set-payload value="{ &quot;message&quot;: &quot;Resource not found&quot; }" doc:name="Set Payload"/>
        </apikit:mapping>
        <apikit:mapping statusCode="405">
            <apikit:exception value="org.mule.module.apikit.exception.MethodNotAllowedException" />
            <set-property propertyName="Content-Type" value="application/json" doc:name="Property"/>
            <set-payload value="{ &quot;message&quot;: &quot;Method not allowed&quot; }" doc:name="Set Payload"/>
        </apikit:mapping>
        <apikit:mapping statusCode="415">
            <apikit:exception value="org.mule.module.apikit.exception.UnsupportedMediaTypeException" />
            <set-property propertyName="Content-Type" value="application/json" doc:name="Property"/>
            <set-payload value="{ &quot;message&quot;: &quot;Unsupported media type&quot; }" doc:name="Set Payload"/>
        </apikit:mapping>
        <apikit:mapping statusCode="406">
            <apikit:exception value="org.mule.module.apikit.exception.NotAcceptableException" />
            <set-property propertyName="Content-Type" value="application/json" doc:name="Property"/>
            <set-payload value="{ &quot;message&quot;: &quot;Not acceptable&quot; }" doc:name="Set Payload"/>
        </apikit:mapping>
        <apikit:mapping statusCode="400">
            <apikit:exception value="org.mule.module.apikit.exception.BadRequestException" />
            <set-property propertyName="Content-Type" value="application/json" doc:name="Property"/>
            <set-payload value="{ &quot;message&quot;: &quot;Bad request&quot; }" doc:name="Set Payload"/>
        </apikit:mapping>
    </apikit:mapping-exception-strategy>
</mule>

Run the project as a MULE application and access the API.

Two methods defined in the RAML file:

•  http://localhost:8080/api/get -output in browser -

This is a get call, generated MULE flow from RAML.

• http://localhost:8080/api/show -output in browser -

This is get call and method name show, generated MULE flow from RAML.