rest api variable substitution

[soibam_ana_sing]

We are facing some challenges in complex variable substitution in outbound rest API web service.   

Endpoint:  https://<ip_address>/rest/server-hardware?filter=${filter}

Method: GET

Variable substitution:  "name EQ 'SGH817YECA, bay 12' "

yours helps/inputs are greatly appreciated. 

Regards

Soibam 

[soibam_ana_sing]

Tested it with 4 variable substitution but fails with message "invalid query"