diff --git a/server/api/__snapshots__/auth.test.js.snap b/server/api/__snapshots__/auth.test.js.snap
new file mode 100644
index 00000000..f921db9f
--- /dev/null
+++ b/server/api/__snapshots__/auth.test.js.snap
@@ -0,0 +1,27 @@
+exports[`test should require params 1`] = `
+Object {
+  "error": "name is required",
+  "ok": false
+}
+`;
+
+exports[`test should require unique email 1`] = `
+Object {
+  "error": "User already exists with this email",
+  "ok": false
+}
+`;
+
+exports[`test should require unique username 1`] = `
+Object {
+  "error": "User already exists with this username",
+  "ok": false
+}
+`;
+
+exports[`test should require valid email 1`] = `
+Object {
+  "error": "email is invalid",
+  "ok": false
+}
+`;
diff --git a/server/api/auth.js b/server/api/auth.js
index 351331ad..6783bd7b 100644
--- a/server/api/auth.js
+++ b/server/api/auth.js
@@ -8,6 +8,36 @@ import { User, Team } from '../models';
 
 const router = new Router();
 
+router.post('auth.signup', async (ctx) => {
+  const { username, name, email, password } = ctx.request.body;
+
+  ctx.assertPresent(username, 'name is required');
+  ctx.assertPresent(name, 'name is required');
+  ctx.assertPresent(email, 'email is required');
+  ctx.assertEmail(email, 'email is invalid');
+  ctx.assertPresent(password, 'password is required');
+
+  if (await User.findOne({ where: { email } })) {
+    throw httpErrors.BadRequest('User already exists with this email');
+  }
+
+  if (await User.findOne({ where: { username } })) {
+    throw httpErrors.BadRequest('User already exists with this username');
+  }
+
+  const user = await User.create({
+    username,
+    name,
+    email,
+    password,
+  });
+
+  ctx.body = { data: {
+    user: await presentUser(ctx, user),
+    accessToken: user.getJwtToken(),
+  } };
+});
+
 router.post('auth.slack', async (ctx) => {
   const { code } = ctx.body;
   ctx.assertPresent(code, 'code is required');
diff --git a/server/api/auth.test.js b/server/api/auth.test.js
new file mode 100644
index 00000000..03fa35b1
--- /dev/null
+++ b/server/api/auth.test.js
@@ -0,0 +1,85 @@
+import TestServer from 'fetch-test-server';
+import app from '..';
+import { flushdb, sequelize, seed } from '../test/support';
+
+const server = new TestServer(app.callback());
+
+beforeEach(flushdb);
+afterAll(() => server.close());
+afterAll(() => sequelize.close());
+
+it('should signup a new user', async () => {
+  const res = await server.post('/api/auth.signup', {
+    body: {
+      username: 'testuser',
+      name: 'Test User',
+      email: 'new.user@example.com',
+      password: 'test123!',
+    },
+  });
+  const body = await res.json();
+
+  expect(res.status).toEqual(200);
+  expect(body.ok).toBe(true);
+  expect(body.data.user).toBeTruthy();
+});
+
+it('should require params', async () => {
+  const res = await server.post('/api/auth.signup', {
+    body: {
+      username: 'testuser',
+    },
+  });
+  const body = await res.json();
+
+  expect(res.status).toEqual(400);
+  expect(body).toMatchSnapshot();
+});
+
+
+it('should require valid email', async () => {
+  const res = await server.post('/api/auth.signup', {
+    body: {
+      username: 'testuser',
+      name: 'Test User',
+      email: 'example.com',
+      password: 'test123!',
+    },
+  });
+  const body = await res.json();
+
+  expect(res.status).toEqual(400);
+  expect(body).toMatchSnapshot();
+});
+
+it('should require unique email', async () => {
+  await seed();
+  const res = await server.post('/api/auth.signup', {
+    body: {
+      username: 'testuser',
+      name: 'Test User',
+      email: 'user1@example.com',
+      password: 'test123!',
+    },
+  });
+  const body = await res.json();
+
+  expect(res.status).toEqual(400);
+  expect(body).toMatchSnapshot();
+});
+
+it('should require unique username', async () => {
+  await seed();
+  const res = await server.post('/api/auth.signup', {
+    body: {
+      username: 'user1',
+      name: 'Test User',
+      email: 'userone@example.com',
+      password: 'test123!',
+    },
+  });
+  const body = await res.json();
+
+  expect(res.status).toEqual(400);
+  expect(body).toMatchSnapshot();
+});
diff --git a/server/migrations/20160911230444-user-optional-slack-id.js b/server/migrations/20160911230444-user-optional-slack-id.js
new file mode 100644
index 00000000..b1bf1f18
--- /dev/null
+++ b/server/migrations/20160911230444-user-optional-slack-id.js
@@ -0,0 +1,46 @@
+/* eslint-disable */
+'use strict';
+
+module.exports = {
+  up: function (queryInterface, Sequelize) {
+    queryInterface.changeColumn(
+      'users',
+      'slackId',
+      {
+        type: Sequelize.STRING,
+        unique: false,
+        allowNull: true,
+      }
+    );
+    queryInterface.changeColumn(
+      'teams',
+      'slackId',
+      {
+        type: Sequelize.STRING,
+        unique: false,
+        allowNull: true,
+      }
+    );
+  },
+
+  down: function (queryInterface, Sequelize) {
+    queryInterface.changeColumn(
+      'users',
+      'slackId',
+      {
+        type: Sequelize.STRING,
+        unique: true,
+        allowNull: false,
+      }
+    );
+    queryInterface.changeColumn(
+      'teams',
+      'slackId',
+      {
+        type: Sequelize.STRING,
+        unique: true,
+        allowNull: false,
+      }
+    );
+  },
+};
diff --git a/server/migrations/20160911232911-user-unique-fields.js b/server/migrations/20160911232911-user-unique-fields.js
new file mode 100644
index 00000000..d394960f
--- /dev/null
+++ b/server/migrations/20160911232911-user-unique-fields.js
@@ -0,0 +1,46 @@
+'use strict';
+
+module.exports = {
+  up: function (queryInterface, Sequelize) {
+    queryInterface.changeColumn(
+      'users',
+      'email',
+      {
+        type: Sequelize.STRING,
+        unique: true,
+        allowNull: false,
+      }
+    );
+    queryInterface.changeColumn(
+      'users',
+      'username',
+      {
+        type: Sequelize.STRING,
+        unique: true,
+        allowNull: false,
+      }
+    );
+  },
+
+  down: function (queryInterface, Sequelize) {
+    queryInterface.changeColumn(
+      'users',
+      'email',
+      {
+        type: Sequelize.STRING,
+        unique: false,
+        allowNull: true,
+      }
+    );
+
+    queryInterface.changeColumn(
+      'users',
+      'username',
+      {
+        type: Sequelize.STRING,
+        unique: false,
+        allowNull: true,
+      }
+    );
+  }
+};
diff --git a/server/models/Team.js b/server/models/Team.js
index 275fd2ef..eda54bfc 100644
--- a/server/models/Team.js
+++ b/server/models/Team.js
@@ -9,7 +9,7 @@ import User from './User';
 const Team = sequelize.define('team', {
   id: { type: DataTypes.UUID, defaultValue: DataTypes.UUIDV4, primaryKey: true },
   name: DataTypes.STRING,
-  slackId: { type: DataTypes.STRING, unique: true },
+  slackId: { type: DataTypes.STRING, allowNull: true },
   slackData: DataTypes.JSONB,
 }, {
   instanceMethods: {
diff --git a/server/models/User.js b/server/models/User.js
index 896636f8..4968e9a3 100644
--- a/server/models/User.js
+++ b/server/models/User.js
@@ -9,12 +9,12 @@ import JWT from 'jsonwebtoken';
 
 const User = sequelize.define('user', {
   id: { type: DataTypes.UUID, defaultValue: DataTypes.UUIDV4, primaryKey: true },
-  email: DataTypes.STRING,
-  username: DataTypes.STRING,
+  email: { type: DataTypes.STRING, unique: true },
+  username: { type: DataTypes.STRING, unique: true },
   name: DataTypes.STRING,
   isAdmin: DataTypes.BOOLEAN,
   slackAccessToken: encryptedFields.vault('slackAccessToken'),
-  slackId: { type: DataTypes.STRING, unique: true },
+  slackId: { type: DataTypes.STRING, allowNull: true },
   slackData: DataTypes.JSONB,
   jwtSecret: encryptedFields.vault('jwtSecret'),
 }, {
diff --git a/server/presenters/__snapshots__/user.test.js.snap b/server/presenters/__snapshots__/user.test.js.snap
index eb254de7..26af224b 100644
--- a/server/presenters/__snapshots__/user.test.js.snap
+++ b/server/presenters/__snapshots__/user.test.js.snap
@@ -6,3 +6,12 @@ Object {
   "username": "testuser"
 }
 `;
+
+exports[`test presents a user without slack data 1`] = `
+Object {
+  "avatarUrl": null,
+  "id": "123",
+  "name": "Test User",
+  "username": "testuser"
+}
+`;
diff --git a/server/presenters/user.js b/server/presenters/user.js
index 9c22daac..b8d997d9 100644
--- a/server/presenters/user.js
+++ b/server/presenters/user.js
@@ -4,9 +4,9 @@ const presentUser = (ctx, user) => {
   return new Promise(async (resolve, _reject) => {
     const data = {
       id: user.id,
-      name: user.name,
       username: user.username,
-      avatarUrl: user.slackData.image_192,
+      name: user.name,
+      avatarUrl: user.slackData ? user.slackData.image_192 : null,
     };
     resolve(data);
   });
diff --git a/server/presenters/user.test.js b/server/presenters/user.test.js
index 87967021..a26c10fd 100644
--- a/server/presenters/user.test.js
+++ b/server/presenters/user.test.js
@@ -17,3 +17,17 @@ it('presents a user', async () => {
 
   expect(user).toMatchSnapshot();
 });
+
+it('presents a user without slack data', async () => {
+  const user = await presentUser(
+    ctx,
+    {
+      id: '123',
+      name: 'Test User',
+      username: 'testuser',
+      slackData: null,
+    },
+  );
+
+  expect(user).toMatchSnapshot();
+});
diff --git a/server/test/helper.js b/server/test/helper.js
index f37bc82b..2823ad67 100644
--- a/server/test/helper.js
+++ b/server/test/helper.js
@@ -21,9 +21,9 @@ function runMigrations() {
       path: './server/migrations',
     },
   });
-  umzug.up()
+  return umzug.up()
   .then(() => {
-    sequelize.close();
+    return sequelize.close();
   });
 }