diff --git a/api/config.js b/api/config.js
index 204f993..5ce2bc4 100644
--- a/api/config.js
+++ b/api/config.js
@@ -81,6 +81,7 @@ overrides['REDIS_HOST'] = 'redis.host';
 overrides['REDIS_PORT'] = 'redis.port';
 overrides['RATELIMIT_COUNT'] = 'limit.count';
 overrides['RATELIMIT_WINDOW'] = 'limit.window';
+overrides['SLACK_SECRET'] = 'slack.secret';
 handleEnvironmentOverrides(config, overrides);
 handleAWSOverrides(config);
 
@@ -92,6 +93,7 @@ if (!config.isProduction) {
   requireds.delete(overrides['GITHUB_MOBILE_REDIRECT']);
   requireds.delete(overrides['RATELIMIT_COUNT']);
   requireds.delete(overrides['RATELIMIT_WINDOW']);
+  requireds.delete(overrides['SLACK_SECRET']);
 }
 handleEnvironmentRequireds(config, requireds);
 
diff --git a/api/v1/controllers/CheckInController.js b/api/v1/controllers/CheckInController.js
index b7d0105..91335e8 100644
--- a/api/v1/controllers/CheckInController.js
+++ b/api/v1/controllers/CheckInController.js
@@ -1,6 +1,8 @@
 const bodyParser = require('body-parser');
 const _ = require('lodash');
+const request = require('request-promise');
 
+const config = require('ctx').config();
 const services = require('../services');
 const middleware = require('../middleware');
 const requests = require('../requests');
@@ -8,6 +10,8 @@ const roles = require('../utils/roles');
 
 const router = require('express').Router();
 
+const SLACK_INVITE_URI = 'https://slack.com/api/users.admin.invite';
+
 function updateCheckInByUserId(req, res, next) {
   req.body.userId = req.params.id;
   delete req.body.credentialsRequested;
@@ -57,6 +61,18 @@ function createCheckIn(req, res, next) {
   req.body.userId = req.params.id;
   services.CheckInService
     .createCheckIn(req.body)
+    .tap((model) => services.UserService.findUserById(model.checkin.get('userId'))
+      .then((user) => request({
+        method: 'POST',
+        uri: SLACK_INVITE_URI,
+        headers: {
+          Authorization: 'Bearer ' + config.slack.secret
+        },
+        formData: {
+          email: user.get('email')
+        }
+      })
+    ))
     .then((response) => {
       response.checkin = response.checkin.toJSON();
       if (!_.isNil(response.credentials)) {
diff --git a/config/development.json.template b/config/development.json.template
index 771bdf6..e4c539d 100644
--- a/config/development.json.template
+++ b/config/development.json.template
@@ -106,5 +106,8 @@
   "limit": {
     "count": 50,
     "window": 60
+  },
+  "slack": {
+    "secret": "secret-slack-token"
   }
 }
diff --git a/config/production.json.template b/config/production.json.template
index f3dde0d..9404ed0 100644
--- a/config/production.json.template
+++ b/config/production.json.template
@@ -106,5 +106,8 @@
   "limit": {
     "count": 50,
     "window": 60
+  },
+  "slack": {
+    "secret": "secret-slack-token"
   }
 }