diff --git a/package.json b/package.json
index 635a15066..d2ca86843 100644
--- a/package.json
+++ b/package.json
@@ -13,7 +13,7 @@
     "compile:schema": "node ./scripts/generateSchemaTypes.js",
     "docz": "docz",
     "start": "node dist/index.js",
-    "start:development": "cross-env NODE_ENV=development ts-node --project ./src/tsconfig.json -r tsconfig-paths/register ./src/index.ts",
+    "start:development": "ts-node --project ./src/tsconfig.json -r tsconfig-paths/register ./src/index.ts",
     "start:webpackDevServer": "ts-node ./scripts/start.ts",
     "lint": "npm-run-all --parallel lint:*",
     "lint:server": "tslint --project ./src/tsconfig.json",
diff --git a/src/core/client/auth/mutations/SignInMutation.ts b/src/core/client/auth/mutations/SignInMutation.ts
new file mode 100644
index 000000000..6a88b9313
--- /dev/null
+++ b/src/core/client/auth/mutations/SignInMutation.ts
@@ -0,0 +1,23 @@
+import { Environment } from "relay-runtime";
+
+import { TalkContext } from "talk-framework/lib/bootstrap";
+import { createMutationContainer } from "talk-framework/lib/relay";
+import { signIn, SignInInput } from "talk-framework/rest";
+
+export type SignInMutation = (input: SignInInput) => Promise<void>;
+
+export async function commit(
+  environment: Environment,
+  input: SignInInput,
+  { rest, postMessage }: TalkContext
+) {
+  try {
+    const result = await signIn(rest, input);
+    postMessage.send("setAuthToken", result.token, window.opener);
+    window.close();
+  } catch (err) {
+    postMessage.send("authError", err.toString(), window.opener);
+  }
+}
+
+export const withSignInMutation = createMutationContainer("signIn", commit);
diff --git a/src/core/client/auth/mutations/SignUpMutation.ts b/src/core/client/auth/mutations/SignUpMutation.ts
new file mode 100644
index 000000000..68beaeae2
--- /dev/null
+++ b/src/core/client/auth/mutations/SignUpMutation.ts
@@ -0,0 +1,23 @@
+import { Environment } from "relay-runtime";
+
+import { TalkContext } from "talk-framework/lib/bootstrap";
+import { createMutationContainer } from "talk-framework/lib/relay";
+import { signUp, SignUpInput } from "talk-framework/rest";
+
+export type SignUpMutation = (input: SignUpInput) => Promise<void>;
+
+export async function commit(
+  environment: Environment,
+  input: SignUpInput,
+  { rest, postMessage }: TalkContext
+) {
+  try {
+    const result = await signUp(rest, input);
+    postMessage.send("setAuthToken", result.token, window.opener);
+    window.close();
+  } catch (err) {
+    postMessage.send("authError", err.toString(), window.opener);
+  }
+}
+
+export const withSignUpMutation = createMutationContainer("signUp", commit);
diff --git a/src/core/client/auth/mutations/index.ts b/src/core/client/auth/mutations/index.ts
index 50d8d059b..46e02df95 100644
--- a/src/core/client/auth/mutations/index.ts
+++ b/src/core/client/auth/mutations/index.ts
@@ -1 +1,3 @@
 export { withSetViewMutation, SetViewMutation } from "./SetViewMutation";
+export { withSignInMutation, SignInMutation } from "./SignInMutation";
+export { withSignUpMutation, SignUpMutation } from "./SignUpMutation";
diff --git a/src/core/client/framework/lib/rest.ts b/src/core/client/framework/lib/rest.ts
index b8ccdccab..6ba52b958 100644
--- a/src/core/client/framework/lib/rest.ts
+++ b/src/core/client/framework/lib/rest.ts
@@ -21,7 +21,7 @@ const handleResp = (res: Response) => {
   if (res.status > 399) {
     return res.json().then((err: any) => {
       // TODO: sync error handling with server.
-      const message = err.message || res.status;
+      const message = err.message || err.error || res.status;
       const error = new Error(message);
       throw error;
     });
@@ -43,7 +43,7 @@ export class RestClient {
     this.tokenGetter = tokenGetter;
   }
 
-  public fetch(path: string, options: PartialRequestInit): Promise<Response> {
+  public fetch<T>(path: string, options: PartialRequestInit): Promise<T> {
     let opts = options;
     if (this.tokenGetter) {
       opts = merge({}, options, {
diff --git a/src/core/client/framework/mutations/SetAuthTokenMutation.spec.ts b/src/core/client/framework/mutations/SetAuthTokenMutation.spec.ts
index 7440078ad..587ddc2d5 100644
--- a/src/core/client/framework/mutations/SetAuthTokenMutation.spec.ts
+++ b/src/core/client/framework/mutations/SetAuthTokenMutation.spec.ts
@@ -2,6 +2,7 @@ import { commitLocalUpdate, Environment, RecordSource } from "relay-runtime";
 
 import { timeout } from "talk-common/utils";
 import { LOCAL_ID } from "talk-framework/lib/relay";
+import { createInMemoryStorage } from "talk-framework/lib/storage";
 import { createRelayEnvironment } from "talk-framework/testHelpers";
 
 import { commit } from "./SetAuthTokenMutation";
@@ -16,18 +17,34 @@ beforeAll(() => {
 });
 
 it("Sets auth token", async () => {
+  const context = {
+    localStorage: createInMemoryStorage(),
+  };
   const authToken = "auth token";
-  commit(environment, { authToken });
+  commit(environment, { authToken }, context as any);
   expect(source.get(LOCAL_ID)!.authToken).toEqual(authToken);
+  expect(context.localStorage.getItem("authToken")).toEqual(authToken);
+});
+
+it("Removes auth token from localStorage", async () => {
+  const context = {
+    localStorage: createInMemoryStorage(),
+  };
+  localStorage.setItem("authToken", "tmp");
+  commit(environment, { authToken: null }, context as any);
+  expect(context.localStorage.getItem("authToken")).toBeUndefined();
 });
 
 it("Should call gc", async () => {
+  const context = {
+    localStorage: createInMemoryStorage(),
+  };
   commitLocalUpdate(environment, store => {
     store.create("should-disappear", "tmp");
   });
   const authToken = null;
   expect(source.get("should-disappear")).not.toBeUndefined();
-  commit(environment, { authToken });
+  commit(environment, { authToken }, context as any);
   await timeout();
   expect(source.get(LOCAL_ID)!.authToken).toEqual(authToken);
   expect(source.get("should-disappear")).toBeUndefined();
diff --git a/src/core/client/framework/mutations/SetAuthTokenMutation.ts b/src/core/client/framework/mutations/SetAuthTokenMutation.ts
index 38ecde460..223bc4054 100644
--- a/src/core/client/framework/mutations/SetAuthTokenMutation.ts
+++ b/src/core/client/framework/mutations/SetAuthTokenMutation.ts
@@ -1,5 +1,6 @@
 import { commitLocalUpdate, Environment } from "relay-runtime";
 
+import { TalkContext } from "talk-framework/lib/bootstrap";
 import { createMutationContainer } from "talk-framework/lib/relay";
 import { LOCAL_ID } from "talk-framework/lib/relay/withLocalStateContainer";
 
@@ -11,11 +12,17 @@ export type SetAuthTokenMutation = (input: SetAuthTokenInput) => Promise<void>;
 
 export async function commit(
   environment: Environment,
-  input: SetAuthTokenInput
+  input: SetAuthTokenInput,
+  { localStorage }: TalkContext
 ) {
   return commitLocalUpdate(environment, store => {
     const record = store.get(LOCAL_ID)!;
     record.setValue(input.authToken, "authToken");
+    if (input.authToken) {
+      localStorage.setItem("authToken", input.authToken);
+    } else {
+      localStorage.removeItem("authToken");
+    }
 
     // Force gc to trigger.
     environment
diff --git a/src/core/client/framework/rest/signIn.ts b/src/core/client/framework/rest/signIn.ts
index 4b537b01c..9f357df02 100644
--- a/src/core/client/framework/rest/signIn.ts
+++ b/src/core/client/framework/rest/signIn.ts
@@ -1,12 +1,16 @@
 import { RestClient } from "../lib/rest";
 
 export interface SignInInput {
-  username: string;
+  email: string;
   password: string;
 }
 
+export interface SignInResponse {
+  token: string;
+}
+
 export default function signIn(rest: RestClient, input: SignInInput) {
-  return rest.fetch("/tenant/auth/local", {
+  return rest.fetch<SignInResponse>("/tenant/auth/local", {
     method: "POST",
     body: input,
   });
diff --git a/src/core/client/framework/rest/signUp.ts b/src/core/client/framework/rest/signUp.ts
index eece6271b..a6aa87d76 100644
--- a/src/core/client/framework/rest/signUp.ts
+++ b/src/core/client/framework/rest/signUp.ts
@@ -6,8 +6,12 @@ export interface SignUpInput {
   email: string;
 }
 
+export interface SignUpResponse {
+  token: string;
+}
+
 export default function signUp(rest: RestClient, input: SignUpInput) {
-  return rest.fetch("/tenant/auth/local/signup", {
+  return rest.fetch<SignUpResponse>("/tenant/auth/local/signup", {
     method: "POST",
     body: input,
   });
diff --git a/src/core/client/stream/listeners/onPostMessageSetAuthToken.spec.ts b/src/core/client/stream/listeners/onPostMessageSetAuthToken.spec.ts
index 37ed034d6..c35823c8a 100644
--- a/src/core/client/stream/listeners/onPostMessageSetAuthToken.spec.ts
+++ b/src/core/client/stream/listeners/onPostMessageSetAuthToken.spec.ts
@@ -1,6 +1,7 @@
 import { Environment, RecordSource } from "relay-runtime";
 
 import { LOCAL_ID } from "talk-framework/lib/relay";
+import { createInMemoryStorage } from "talk-framework/lib/storage";
 import { createRelayEnvironment } from "talk-framework/testHelpers";
 
 import onPostMessageSetAuthToken from "./onPostMessageSetAuthToken";
@@ -24,6 +25,7 @@ it("Sets auth token", () => {
       },
     },
     relayEnvironment,
+    localStorage: createInMemoryStorage(),
   };
   onPostMessageSetAuthToken(context as any);
   expect(source.get(LOCAL_ID)!.authToken).toEqual(token);
diff --git a/src/core/client/stream/listeners/onPostMessageSetAuthToken.ts b/src/core/client/stream/listeners/onPostMessageSetAuthToken.ts
index 77be702ad..767af51f7 100644
--- a/src/core/client/stream/listeners/onPostMessageSetAuthToken.ts
+++ b/src/core/client/stream/listeners/onPostMessageSetAuthToken.ts
@@ -2,12 +2,10 @@ import { TalkContext } from "talk-framework/lib/bootstrap";
 
 import { commit as setAuthToken } from "talk-framework/mutations/SetAuthTokenMutation";
 
-export default function onPostMessageSetAuthToken({
-  relayEnvironment,
-  postMessage,
-}: TalkContext) {
+export default function onPostMessageSetAuthToken(ctx: TalkContext) {
+  const { relayEnvironment, postMessage } = ctx;
   // Auth popup will use this to handle a successful login.
   postMessage!.on("setAuthToken", (authToken: string) => {
-    setAuthToken(relayEnvironment, { authToken });
+    setAuthToken(relayEnvironment, { authToken }, ctx);
   });
 }
diff --git a/src/core/client/stream/local/initLocalState.ts b/src/core/client/stream/local/initLocalState.ts
index dd021f756..171c52294 100644
--- a/src/core/client/stream/local/initLocalState.ts
+++ b/src/core/client/stream/local/initLocalState.ts
@@ -23,6 +23,7 @@ export default async function initLocalState(
   { localStorage }: TalkContext
 ) {
   commitLocalUpdate(environment, s => {
+    // TODO: (cvle) move local, auth token and network initialization to framework.
     const root = s.getRoot();
 
     // Create the Local Record which is the Root for the client states.