diff --git a/lib/restapi.js b/lib/restapi.js
index fb424ae..0165521 100644
--- a/lib/restapi.js
+++ b/lib/restapi.js
@@ -267,4 +267,58 @@ RestApi.prototype.query = function(options, callback) {
     return deferred.promise.nodeify(callback);
 };
 
+function collectionPost(options, operation, callback) {
+    var deferred = Q.defer();
+    this.request.post(_.merge({
+            url: refUtils.getRelative(options.ref) + '/' + options.collection + '/' + operation,
+            json: {CollectionItems: options.data}
+        }, options.requestOptions,
+        optionsToRequestOptions(options)), function(error, result) {
+        if (error) {
+            deferred.reject(error);
+        } else {
+            deferred.resolve(result);
+        }
+    });
+    return deferred.promise.nodeify(callback);
+}
+
+/**
+ Adds items to a collection
+ @param {object} options - The add options (required)
+ - @member {string} ref - The ref of the collection to update, e.g. /user/12345 (required)
+ - @member {string} collection - The name of the collection to update, e.g. 'TeamMemberships (required)
+ - @member {object} data - [{_ref: objectRef}, {Name:"Joe"}], things to be added to the collection (required)
+ - @member {string/string[]} fetch - the fields to include on the returned records
+ - @member {object} scope - the default scoping to use.  if not specified server default will be used.
+ - @member {ref} scope.workspace - the workspace
+ - @member {object} requestOptions - Additional options to be applied to the request: https://github.com/mikeal/request (optional)
+ @param {function} callback - A callback to be called when the operation completes
+ - @param {string[]} errors - Any errors which occurred
+ - @param {object} result - the operation result
+ @return {promise}
+ */
+RestApi.prototype.add = function(options, callback) {
+    return collectionPost.call(this, options, 'add', callback);
+};
+
+/**
+ Remove items from a collection
+ @param {object} options - The remove options (required)
+ - @member {string} ref - The ref of the collection to update, e.g. /user/12345 (required)
+ - @member {string} collection - The name of the collection to update, e.g. 'TeamMemberships (required)
+ - @member {object} data - [{_ref: objectRef}], where the objectRefs are to be removed from the collection (required)
+ - @member {string/string[]} fetch - the fields to include on the returned records
+ - @member {object} scope - the default scoping to use.  if not specified server default will be used.
+ - @member {ref} scope.workspace - the workspace
+ - @member {object} requestOptions - Additional options to be applied to the request: https://github.com/mikeal/request (optional)
+ @param {function} callback - A callback to be called when the operation completes
+ - @param {string[]} errors - Any errors which occurred
+ - @param {object} result - the operation result
+ @return {promise}
+ */
+RestApi.prototype.remove = function(options, callback) {
+    return collectionPost.call(this, options, 'remove', callback);
+};
+
 module.exports = RestApi;
diff --git a/spec/restapi.spec.js b/spec/restapi.spec.js
index 58b9e00..ba5283f 100644
--- a/spec/restapi.spec.js
+++ b/spec/restapi.spec.js
@@ -573,5 +573,205 @@ describe('RestApi', function() {
                     }).done();
             });
         });
+
+        describe('add', function() {
+            it('translates request options', function() {
+                var restApi = new RestApi();
+                restApi.add({
+                    ref: '/defect/1234',
+                    data: [{_ref: '/defect/2345'}],
+                    collection: 'Duplicates',
+                    scope: {workspace: '/workspace/1234'},
+                    fetch: ['FormattedID'],
+                    requestOptions: {
+                        qs: {foo: 'bar'}
+                    }
+                });
+
+                this.post.callCount.should.eql(1);
+                var args = this.post.firstCall.args[0];
+                args.qs.workspace.should.eql('/workspace/1234');
+                args.qs.fetch.should.eql('FormattedID');
+                args.qs.foo.should.eql('bar');
+            });
+
+            it('generates correct post request', function() {
+                var restApi = new RestApi();
+                var callback = sinon.stub();
+                restApi.add({
+                    ref: '/defect/1234',
+                    data: [{_ref: '/defect/2345'}],
+                    collection: 'Duplicates'
+                }, callback);
+
+                this.post.callCount.should.eql(1);
+                var args = this.post.firstCall.args;
+                args[0].url.should.eql('/defect/1234/Duplicates/add');
+                args[0].json.should.eql({CollectionItems: [{_ref: '/defect/2345'}]});
+            });
+
+            it('calls back with result', function(done) {
+                this.post.yieldsAsync(null, {Errors: [], Warnings: [], Results: [{_ref: '/defect/2345'}]});
+                var restApi = new RestApi();
+                restApi.add({
+                    ref: '/defect/1234',
+                    data: [{_ref: '/defect/2345'}],
+                    collection: 'Duplicates'
+                }, function(error, result) {
+                    should.not.exist(error);
+                    result.Errors.should.eql([]);
+                    result.Warnings.should.eql([]);
+                    result.Results.should.eql([{_ref: '/defect/2345'}]);
+                    done();
+                });
+            });
+
+            it('resolves promise with result', function(done) {
+                this.post.yieldsAsync(null, {Errors: [], Warnings: [], Results: [{_ref: '/defect/2345'}]});
+                var restApi = new RestApi();
+                var onError = sinon.stub();
+                restApi.add({
+                    ref: '/defect/1234',
+                    data: [{_ref: '/defect/2345'}],
+                    collection: 'Duplicates'
+                }).then(function(result) {
+                    onError.callCount.should.eql(0);
+                    result.Errors.should.eql([]);
+                    result.Warnings.should.eql([]);
+                    result.Results.should.eql([{_ref: '/defect/2345'}]);
+                    done();
+                }, onError).done();
+            });
+
+            it('calls back with error', function(done) {
+                var error = 'Error!';
+                this.post.yieldsAsync([error], null);
+                var restApi = new RestApi();
+                restApi.add({
+                    ref: '/defect/1234',
+                    data: [{_ref: '/defect/2345'}],
+                    collection: 'Duplicates'
+                }, function(err, result) {
+                    err.should.eql([error]);
+                    should.not.exist(result);
+                    done();
+                });
+            });
+
+            it('rejects promise with error', function(done) {
+                var error = 'Error!';
+                this.post.yieldsAsync([error], null);
+                var restApi = new RestApi();
+                var onSuccess = sinon.stub();
+                restApi.add({
+                    ref: '/defect/1234',
+                    data: [{_ref: '/defect/2345'}],
+                    collection: 'Duplicates'
+                }).then(onSuccess, function(err) {
+                    onSuccess.callCount.should.eql(0);
+                    err.should.eql([error]);
+                    done();
+                }).done();
+            });
+        });
+
+        describe('remove', function() {
+            it('translates request options', function() {
+                var restApi = new RestApi();
+                restApi.remove({
+                    ref: '/defect/1234',
+                    data: [{_ref: '/defect/2345'}],
+                    collection: 'Duplicates',
+                    scope: {workspace: '/workspace/1234'},
+                    fetch: ['FormattedID'],
+                    requestOptions: {
+                        qs: {foo: 'bar'}
+                    }
+                });
+
+                this.post.callCount.should.eql(1);
+                var args = this.post.firstCall.args[0];
+                args.qs.workspace.should.eql('/workspace/1234');
+                args.qs.fetch.should.eql('FormattedID');
+                args.qs.foo.should.eql('bar');
+            });
+
+            it('generates correct post request', function() {
+                var restApi = new RestApi();
+                var callback = sinon.stub();
+                restApi.remove({
+                    ref: '/defect/1234',
+                    data: [{_ref: '/defect/2345'}],
+                    collection: 'Duplicates'
+                }, callback);
+
+                this.post.callCount.should.eql(1);
+                var args = this.post.firstCall.args;
+                args[0].url.should.eql('/defect/1234/Duplicates/remove');
+                args[0].json.should.eql({CollectionItems: [{_ref: '/defect/2345'}]});
+            });
+
+            it('calls back with result', function(done) {
+                this.post.yieldsAsync(null, {Errors: [], Warnings: []});
+                var restApi = new RestApi();
+                restApi.remove({
+                    ref: '/defect/1234',
+                    data: [{_ref: '/defect/2345'}],
+                    collection: 'Duplicates'
+                }, function(error, result) {
+                    should.not.exist(error);
+                    result.Errors.should.eql([]);
+                    result.Warnings.should.eql([]);
+                    done();
+                });
+            });
+
+            it('resolves promise with result', function(done) {
+                this.post.yieldsAsync(null, {Errors: [], Warnings: []});
+                var restApi = new RestApi();
+                var onError = sinon.stub();
+                restApi.remove({
+                    ref: '/defect/1234',
+                    data: [{_ref: '/defect/2345'}],
+                    collection: 'Duplicates'
+                }).then(function(result) {
+                    onError.callCount.should.eql(0);
+                    result.Errors.should.eql([]);
+                    result.Warnings.should.eql([]);
+                    done();
+                }, onError).done();
+            });
+
+            it('calls back with error', function(done) {
+                var error = 'Error!';
+                this.post.yieldsAsync([error], null);
+                var restApi = new RestApi();
+                restApi.remove({
+                    ref: '/defect/1234',
+                    data: [{_ref: '/defect/2345'}],
+                    collection: 'Duplicates'
+                }, function(err, result) {
+                    err.should.eql([error]);
+                    should.not.exist(result);
+                    done();
+                });
+            });
+
+            it('rejects promise with error', function(done) {
+                var error = 'Error!';
+                this.post.yieldsAsync([error], null);
+                var restApi = new RestApi();
+                var onSuccess = sinon.stub();
+                restApi.remove({
+                    ref: '/defect/1234',
+                    data: [{_ref: '/defect/2345'}],
+                    collection: 'Duplicates'
+                }).then(onSuccess, function(err) {
+                    onSuccess.callCount.should.eql(0);
+                    err.should.eql([error]);
+                    done();
+                }).done();
+            });
+        });
     });
 });