This thing is not trivial and I couldn’t find a simple explanation. Here is the exact sequence to add a Get By ID -style path parameter like /users/{userid} in API Gateway and wire it to Lambda. Goal Turn an existing resource like /users into: /users /users/{userid} (new resource) Step-by-step Select an existing resource (e.g. users ). Click Actions and select Create Resource . In Resource Name , put the parameter name in curly braces (e.g. {userid} ). In Resource Path , you should see read-only text like /users/ and a textbox for the parameter. Enter {userid} in the textbox and click Create Resource . You should now see a new branch in your API tree: /{userid} . Select it. Click Actions → Create Method and add ANY (or the specific method you need). ...