diff --git a/todo/data/database.js b/todo/data/database.js
index ce7bec3c..4bb64638 100644
--- a/todo/data/database.js
+++ b/todo/data/database.js
@@ -14,19 +14,19 @@ export class Todo {}
 export class User {}
 
 // Mock authenticated ID
-const VIEWER_ID = 'me';
+const USER_ID = 'me';
 
 // Mock user data
-const viewer = new User();
-viewer.id = VIEWER_ID;
+const user = new User();
+user.id = USER_ID;
 const usersById = {
-  [VIEWER_ID]: viewer,
+  [USER_ID]: user,
 };
 
 // Mock todo data
 const todosById = {};
 const todoIdsByUser = {
-  [VIEWER_ID]: [],
+  [USER_ID]: [],
 };
 let nextTodoId = 0;
 addTodo('Taste JavaScript', true);
@@ -38,7 +38,7 @@ export function addTodo(text, complete) {
   todo.id = `${nextTodoId++}`;
   todo.text = text;
   todosById[todo.id] = todo;
-  todoIdsByUser[VIEWER_ID].push(todo.id);
+  todoIdsByUser[USER_ID].push(todo.id);
   return todo.id;
 }
 
@@ -52,7 +52,7 @@ export function getTodo(id) {
 }
 
 export function getTodos(status = 'any') {
-  const todos = todoIdsByUser[VIEWER_ID].map(id => todosById[id]);
+  const todos = todoIdsByUser[USER_ID].map(id => todosById[id]);
   if (status === 'any') {
     return todos;
   }
@@ -63,10 +63,6 @@ export function getUser(id) {
   return usersById[id];
 }
 
-export function getViewer() {
-  return getUser(VIEWER_ID);
-}
-
 export function markAllTodos(complete) {
   const changedTodos = [];
   getTodos().forEach(todo => {
@@ -79,9 +75,9 @@ export function markAllTodos(complete) {
 }
 
 export function removeTodo(id) {
-  const todoIndex = todoIdsByUser[VIEWER_ID].indexOf(id);
+  const todoIndex = todoIdsByUser[USER_ID].indexOf(id);
   if (todoIndex !== -1) {
-    todoIdsByUser[VIEWER_ID].splice(todoIndex, 1);
+    todoIdsByUser[USER_ID].splice(todoIndex, 1);
   }
   delete todosById[id];
 }
diff --git a/todo/data/schema.graphql b/todo/data/schema.graphql
index b5553e08..c0a51bfa 100644
--- a/todo/data/schema.graphql
+++ b/todo/data/schema.graphql
@@ -5,7 +5,6 @@ input AddTodoInput {
 
 type AddTodoPayload {
   todoEdge: TodoEdge
-  viewer: User
   clientMutationId: String
 }
 
@@ -17,7 +16,6 @@ input ChangeTodoStatusInput {
 
 type ChangeTodoStatusPayload {
   todo: Todo
-  viewer: User
   clientMutationId: String
 }
 
@@ -28,7 +26,6 @@ input MarkAllTodosInput {
 
 type MarkAllTodosPayload {
   changedTodos: [Todo]
-  viewer: User
   clientMutationId: String
 }
 
@@ -63,7 +60,7 @@ type PageInfo {
 }
 
 type Query {
-  viewer: User
+  user(id: String): User
 
   # Fetches an object given its ID
   node(
@@ -78,7 +75,6 @@ input RemoveCompletedTodosInput {
 
 type RemoveCompletedTodosPayload {
   deletedTodoIds: [String]
-  viewer: User
   clientMutationId: String
 }
 
@@ -89,7 +85,6 @@ input RemoveTodoInput {
 
 type RemoveTodoPayload {
   deletedTodoId: ID
-  viewer: User
   clientMutationId: String
 }
 
diff --git a/todo/data/schema.js b/todo/data/schema.js
index 49f11e1c..21fe58cc 100644
--- a/todo/data/schema.js
+++ b/todo/data/schema.js
@@ -41,7 +41,6 @@ import {
   getTodo,
   getTodos,
   getUser,
-  getViewer,
   markAllTodos,
   removeCompletedTodos,
   removeTodo,
@@ -123,9 +122,12 @@ const GraphQLUser = new GraphQLObjectType({
 const Query = new GraphQLObjectType({
   name: 'Query',
   fields: {
-    viewer: {
+    user: {
       type: GraphQLUser,
-      resolve: () => getViewer(),
+      args: {
+        id: { type: GraphQLString }
+      },
+      resolve: (root, { id }) => getUser(id),
     },
     node: nodeField,
   },
@@ -146,11 +148,7 @@ const GraphQLAddTodoMutation = mutationWithClientMutationId({
           node: todo,
         };
       },
-    },
-    viewer: {
-      type: GraphQLUser,
-      resolve: () => getViewer(),
-    },
+    }
   },
   mutateAndGetPayload: ({text}) => {
     const localTodoId = addTodo(text);
@@ -168,11 +166,7 @@ const GraphQLChangeTodoStatusMutation = mutationWithClientMutationId({
     todo: {
       type: GraphQLTodo,
       resolve: ({localTodoId}) => getTodo(localTodoId),
-    },
-    viewer: {
-      type: GraphQLUser,
-      resolve: () => getViewer(),
-    },
+    }
   },
   mutateAndGetPayload: ({id, complete}) => {
     const localTodoId = fromGlobalId(id).id;
@@ -190,11 +184,7 @@ const GraphQLMarkAllTodosMutation = mutationWithClientMutationId({
     changedTodos: {
       type: new GraphQLList(GraphQLTodo),
       resolve: ({changedTodoLocalIds}) => changedTodoLocalIds.map(getTodo),
-    },
-    viewer: {
-      type: GraphQLUser,
-      resolve: () => getViewer(),
-    },
+    }
   },
   mutateAndGetPayload: ({complete}) => {
     const changedTodoLocalIds = markAllTodos(complete);
@@ -209,11 +199,7 @@ const GraphQLRemoveCompletedTodosMutation = mutationWithClientMutationId({
     deletedTodoIds: {
       type: new GraphQLList(GraphQLString),
       resolve: ({deletedTodoIds}) => deletedTodoIds,
-    },
-    viewer: {
-      type: GraphQLUser,
-      resolve: () => getViewer(),
-    },
+    }
   },
   mutateAndGetPayload: () => {
     const deletedTodoLocalIds = removeCompletedTodos();
@@ -231,11 +217,7 @@ const GraphQLRemoveTodoMutation = mutationWithClientMutationId({
     deletedTodoId: {
       type: GraphQLID,
       resolve: ({id}) => id,
-    },
-    viewer: {
-      type: GraphQLUser,
-      resolve: () => getViewer(),
-    },
+    }
   },
   mutateAndGetPayload: ({id}) => {
     const localTodoId = fromGlobalId(id).id;
diff --git a/todo/js/app.js b/todo/js/app.js
index 8e73f5de..5edac0a2 100644
--- a/todo/js/app.js
+++ b/todo/js/app.js
@@ -62,16 +62,18 @@ ReactDOM.render(
   <QueryRenderer
     environment={modernEnvironment}
     query={graphql`
-      query appQuery {
-        viewer {
-          ...TodoApp_viewer
+      query appQuery($userId: String) {
+        user(id: $userId) {
+          ...TodoApp_user
         }
       }
     `}
-    variables={{}}
+    variables={{
+      userId: "me"
+    }}
     render={({error, props}) => {
       if (props) {
-        return <TodoApp viewer={props.viewer} />;
+        return <TodoApp user={props.user} />;
       } else {
         return <div>Loading</div>;
       }
diff --git a/todo/js/components/Todo.js b/todo/js/components/Todo.js
index fd71087f..b89e849b 100644
--- a/todo/js/components/Todo.js
+++ b/todo/js/components/Todo.js
@@ -32,7 +32,7 @@ class Todo extends React.Component {
       this.props.relay.environment,
       complete,
       this.props.todo,
-      this.props.viewer,
+      this.props.user,
     );
   };
   _handleDestroyClick = () => {
@@ -60,7 +60,7 @@ class Todo extends React.Component {
     RemoveTodoMutation.commit(
       this.props.relay.environment,
       this.props.todo,
-      this.props.viewer,
+      this.props.user,
     );
   }
   _setEditMode = (shouldEdit) => {
@@ -114,8 +114,8 @@ export default createFragmentContainer(Todo, {
       text,
     }
   `,
-  viewer: graphql`
-    fragment Todo_viewer on User {
+  user: graphql`
+    fragment Todo_user on User {
       id,
       totalCount,
       completedCount,
diff --git a/todo/js/components/TodoApp.js b/todo/js/components/TodoApp.js
index 86ba8e3f..f9ba9e47 100644
--- a/todo/js/components/TodoApp.js
+++ b/todo/js/components/TodoApp.js
@@ -26,11 +26,11 @@ class TodoApp extends React.Component {
     AddTodoMutation.commit(
       this.props.relay.environment,
       text,
-      this.props.viewer,
+      this.props.user,
     );
   };
   render() {
-    const hasTodos = this.props.viewer.totalCount > 0;
+    const hasTodos = this.props.user.totalCount > 0;
     return (
       <div>
         <section className="todoapp">
@@ -45,11 +45,11 @@ class TodoApp extends React.Component {
               placeholder="What needs to be done?"
             />
           </header>
-          <TodoList viewer={this.props.viewer} />
+          <TodoList user={this.props.user} />
           {hasTodos &&
             <TodoListFooter
-              todos={this.props.viewer.todos}
-              viewer={this.props.viewer}
+              todos={this.props.user.todos}
+              user={this.props.user}
             />
           }
         </section>
@@ -72,12 +72,12 @@ class TodoApp extends React.Component {
 }
 
 export default createFragmentContainer(TodoApp, {
-  viewer: graphql`
-    fragment TodoApp_viewer on User {
+  user: graphql`
+    fragment TodoApp_user on User {
       id,
       totalCount,
-      ...TodoListFooter_viewer,
-      ...TodoList_viewer,
+      ...TodoListFooter_user,
+      ...TodoList_user,
     }
   `,
 });
diff --git a/todo/js/components/TodoList.js b/todo/js/components/TodoList.js
index a02376c2..9139ce84 100644
--- a/todo/js/components/TodoList.js
+++ b/todo/js/components/TodoList.js
@@ -25,22 +25,22 @@ class TodoList extends React.Component {
     MarkAllTodosMutation.commit(
       this.props.relay.environment,
       complete,
-      this.props.viewer.todos,
-      this.props.viewer,
+      this.props.user.todos,
+      this.props.user,
     );
   };
   renderTodos() {
-    return this.props.viewer.todos.edges.map(edge =>
+    return this.props.user.todos.edges.map(edge =>
       <Todo
         key={edge.node.id}
         todo={edge.node}
-        viewer={this.props.viewer}
+        user={this.props.user}
       />
     );
   }
   render() {
-    const numTodos = this.props.viewer.totalCount;
-    const numCompletedTodos = this.props.viewer.completedCount;
+    const numTodos = this.props.user.totalCount;
+    const numCompletedTodos = this.props.user.completedCount;
     return (
       <section className="main">
         <input
@@ -61,8 +61,8 @@ class TodoList extends React.Component {
 }
 
 export default createFragmentContainer(TodoList, {
-  viewer: graphql`
-    fragment TodoList_viewer on User {
+  user: graphql`
+    fragment TodoList_user on User {
       todos(
         first: 2147483647  # max GraphQLInt
       ) @connection(key: "TodoList_todos") {
@@ -77,7 +77,7 @@ export default createFragmentContainer(TodoList, {
       id,
       totalCount,
       completedCount,
-      ...Todo_viewer,
+      ...Todo_user,
     }
   `,
 });
diff --git a/todo/js/components/TodoListFooter.js b/todo/js/components/TodoListFooter.js
index a2d10343..adb8ad57 100644
--- a/todo/js/components/TodoListFooter.js
+++ b/todo/js/components/TodoListFooter.js
@@ -22,13 +22,13 @@ class TodoListFooter extends React.Component {
   _handleRemoveCompletedTodosClick = () => {
     RemoveCompletedTodosMutation.commit(
       this.props.relay.environment,
-      this.props.viewer.completedTodos,
-      this.props.viewer,
+      this.props.user.completedTodos,
+      this.props.user,
     );
   };
   render() {
-    const numCompletedTodos = this.props.viewer.completedCount;
-    const numRemainingTodos = this.props.viewer.totalCount - numCompletedTodos;
+    const numCompletedTodos = this.props.user.completedCount;
+    const numRemainingTodos = this.props.user.totalCount - numCompletedTodos;
     return (
       <footer className="footer">
         <span className="todo-count">
@@ -49,7 +49,7 @@ class TodoListFooter extends React.Component {
 export default createFragmentContainer(
   TodoListFooter,
   graphql`
-    fragment TodoListFooter_viewer on User {
+    fragment TodoListFooter_user on User {
       id,
       completedCount,
       completedTodos: todos(
diff --git a/todo/js/mutations/AddTodoMutation.js b/todo/js/mutations/AddTodoMutation.js
index 464f9ef9..4f0d5b17 100644
--- a/todo/js/mutations/AddTodoMutation.js
+++ b/todo/js/mutations/AddTodoMutation.js
@@ -28,10 +28,6 @@ const mutation = graphql`
           text
         }
       }
-      viewer {
-        id
-        totalCount
-      }
     }
   }
 `;
diff --git a/todo/js/mutations/ChangeTodoStatusMutation.js b/todo/js/mutations/ChangeTodoStatusMutation.js
index 46ee92f7..4318092d 100644
--- a/todo/js/mutations/ChangeTodoStatusMutation.js
+++ b/todo/js/mutations/ChangeTodoStatusMutation.js
@@ -22,18 +22,14 @@ const mutation = graphql`
         id
         complete
       }
-      viewer {
-        id
-        completedCount
-      }
     }
   }
 `;
 
 function getOptimisticResponse(complete, todo, user) {
-  const viewerPayload = {id: user.id};
+  const userPayload = {id: user.id};
   if (user.completedCount != null) {
-    viewerPayload.completedCount = complete ?
+    userPayload.completedCount = complete ?
       user.completedCount + 1 :
       user.completedCount - 1;
   }
@@ -43,7 +39,7 @@ function getOptimisticResponse(complete, todo, user) {
         complete: complete,
         id: todo.id,
       },
-      viewer: viewerPayload,
+      user: userPayload,
     },
   };
 }
diff --git a/todo/js/mutations/MarkAllTodosMutation.js b/todo/js/mutations/MarkAllTodosMutation.js
index e979a1d3..cb7693b1 100644
--- a/todo/js/mutations/MarkAllTodosMutation.js
+++ b/todo/js/mutations/MarkAllTodosMutation.js
@@ -22,16 +22,12 @@ const mutation = graphql`
         id
         complete
       }
-      viewer {
-        id
-        completedCount
-      }
     }
   }
 `;
 
 function getOptimisticResponse(complete, todos, user) {
-  const payload = {viewer: {id: user.id}};
+  const payload = {user: {id: user.id}};
   if (todos && todos.edges) {
     payload.changedTodos = todos.edges
       .filter(edge => edge.node.complete !== complete)
@@ -41,7 +37,7 @@ function getOptimisticResponse(complete, todos, user) {
       }));
   }
   if (user.totalCount != null) {
-    payload.viewer.completedCount = complete ?
+    payload.user.completedCount = complete ?
       user.totalCount :
       0;
   }
diff --git a/todo/js/mutations/RemoveCompletedTodosMutation.js b/todo/js/mutations/RemoveCompletedTodosMutation.js
index 7aaed200..06648f8a 100644
--- a/todo/js/mutations/RemoveCompletedTodosMutation.js
+++ b/todo/js/mutations/RemoveCompletedTodosMutation.js
@@ -19,11 +19,7 @@ import {ConnectionHandler} from 'relay-runtime';
 const mutation = graphql`
   mutation RemoveCompletedTodosMutation($input: RemoveCompletedTodosInput!) {
     removeCompletedTodos(input: $input) {
-      deletedTodoIds,
-      viewer {
-        completedCount,
-        totalCount,
-      },
+      deletedTodoIds
     }
   }
 `;
diff --git a/todo/js/mutations/RemoveTodoMutation.js b/todo/js/mutations/RemoveTodoMutation.js
index 7d239e9b..d26e0258 100644
--- a/todo/js/mutations/RemoveTodoMutation.js
+++ b/todo/js/mutations/RemoveTodoMutation.js
@@ -19,11 +19,7 @@ import {ConnectionHandler} from 'relay-runtime';
 const mutation = graphql`
   mutation RemoveTodoMutation($input: RemoveTodoInput!) {
     removeTodo(input: $input) {
-      deletedTodoId,
-      viewer {
-        completedCount,
-        totalCount,
-      },
+      deletedTodoId
     }
   }
 `;