gistfile1.m

 RKObjectManager* objectManager = [RKObjectManager objectManagerWithBaseURL:@"http://10.0.1.4:3000"];

    
    RKObjectMapping* busesMapping = [RKObjectMapping mappingForClass:[Autobus class]];
    [busesMapping mapKeyPath:@"model" toAttribute:@"model"];
    [busesMapping mapKeyPath:@"tour_id" toAttribute:@"tourId"];
    [busesMapping mapKeyPath:@"seat" toAttribute:@"seats"];
    [busesMapping mapKeyPath:@"bus_number" toAttribute:@"busNumber"];
    [busesMapping mapKeyPath:@"created_at" toAttribute:@"createdAt"];
    [busesMapping mapKeyPath:@"updated_at" toAttribute:@"updatedAt"];
    [busesMapping mapKeyPath:@"registar_number" toAttribute:@"registarNumber"];
    [busesMapping mapKeyPath:@"id" toAttribute:@"busId"];
    [busesMapping mapKeyPath:@"longitude" toAttribute:@"long"];
    [busesMapping mapKeyPath:@"latitude" toAttribute:@"lat"];
    
    [objectManager.mappingProvider setMapping:busesMapping forKeyPath:@"buses"];
    
    params = [NSDictionary dictionaryWithObjectsAndKeys: @"2011-08-16", @"datum", @"TRUE", @"fromSerbia", nil];
    [objectManager.client URLForResourcePath:@"/service/getLocations.json" queryParams:params];
   
    [objectManager loadObjectsAtResourcePath:@"/service/getLocations.json" delegate:self];

NSURL *someURL = [objectManager.client URLForResourcePath:@"/service/getLocations.json" queryParams:params];
[objectManager loadObjectsAtResourcePath:[someURL absoluteString] delegate:self];