diff --git a/lib/config.js b/lib/config.js
index e9add9e..c0be31e 100644
--- a/lib/config.js
+++ b/lib/config.js
@@ -50,6 +50,14 @@ function Config(config) {
     }
   }
 
+  if (!self.npm_client_version) {
+    self.npm_client_version = "*"
+  }
+
+  if (!self.sentry_dsn) {
+    self.sentry_dsn = process.env.SENTRY_DSN;
+  }
+
   var users = {all:true, anonymous:true, 'undefined':true, owner:true, none:true}
 
   var check_user_or_uplink = function(arg) {
diff --git a/lib/index-api.js b/lib/index-api.js
index f91b624..352173e 100644
--- a/lib/index-api.js
+++ b/lib/index-api.js
@@ -4,6 +4,7 @@ var expressJson5  = require('express-json5')
 var Error         = require('http-errors')
 var Path          = require('path')
 var Middleware    = require('./middleware')
+var Semver        = require('semver');
 var Utils         = require('./utils')
 var expect_json   = Middleware.expect_json
 var match         = Middleware.match
@@ -22,6 +23,7 @@ module.exports = function(config, auth, storage) {
   app.param('tag',      validate_name)
   app.param('version',  validate_name)
   app.param('revision', validate_name)
+  app.param('token',    validate_name)
 
   // these can't be safely put into express url for some reason
   app.param('_rev',             match(/^-rev$/))
@@ -165,6 +167,11 @@ module.exports = function(config, auth, storage) {
     var token = (req.body.name && req.body.password)
               ? auth.aes_encrypt(req.body.name + ':' + req.body.password).toString('base64')
               : undefined
+
+    if (!Semver.satisfies(req.header('version'), config.npm_client_version) && config.npm_client_version !== '*') {
+      return next( Error[422]('Your npm version is not accepted. Required: "' + config.npm_client_version + '" Received: "' + req.header('version') + '"') )
+    }
+
     if (req.remote_user.name != null) {
       res.status(201)
       return next({
@@ -202,6 +209,13 @@ module.exports = function(config, auth, storage) {
     }
   })
 
+  app.delete('/-/user/token/:token', function(req, res, next) {
+    res.status(200)
+    next({
+      ok: 'Logged out',
+    })
+  })
+
   function tag_package_version(req, res, next) {
     if (typeof(req.body) !== 'string') return next('route')
 
diff --git a/lib/index.js b/lib/index.js
index 20dcfb7..1ebbac5 100644
--- a/lib/index.js
+++ b/lib/index.js
@@ -1,6 +1,7 @@
 var express       = require('express')
 var Error         = require('http-errors')
 var compression   = require('compression')
+var raven         = require('raven')
 var Auth          = require('./auth')
 var Logger        = require('./logger')
 var Config        = require('./config')
@@ -16,13 +17,20 @@ module.exports = function(config_hash) {
   var storage = Storage(config)
   var auth    = Auth(config)
   var app     = express()
+  var ravenClient = config.sentry_dsn ? new raven.Client(config.sentry_dsn) : null
 
+  if (ravenClient) {
+    ravenClient.patchGlobal()
+  }
   // run in production mode by default, just in case
   // it shouldn't make any difference anyway
   app.set('env', process.env.NODE_ENV || 'production')
 
   function error_reporting_middleware(req, res, next) {
     res.report_error = res.report_error || function(err) {
+      if (ravenClient) {
+        raven.middleware.express.errorHandler(ravenClient)(err, req, res, next)
+      }
       if (err.status && err.status >= 400 && err.status < 600) {
         if (!res.headersSent) {
           res.status(err.status)
diff --git a/package.yaml b/package.yaml
index 346232f..2b2b15e 100644
--- a/package.yaml
+++ b/package.yaml
@@ -41,6 +41,7 @@ dependencies:
   jju: '1.x'
   JSONStream: '1.x'
 
+  raven: '>=0.10.0'
   mkdirp: '>=0.3.5 <1.0.0-0'
   sinopia-htpasswd: '>= 0.4.3'
   http-errors: '>=1.2.0'
diff --git a/test/functional/index.js b/test/functional/index.js
index c424eaa..201a3d4 100644
--- a/test/functional/index.js
+++ b/test/functional/index.js
@@ -59,6 +59,7 @@ describe('Func', function() {
   require('./scoped')()
   require('./security')()
   require('./adduser')()
+  require('./logout')()
   require('./addtag')()
   require('./plugins')()
 
diff --git a/test/functional/lib/server.js b/test/functional/lib/server.js
index 3e33a9f..e2b733c 100644
--- a/test/functional/lib/server.js
+++ b/test/functional/lib/server.js
@@ -43,6 +43,13 @@ Server.prototype.auth = function(user, pass) {
   })
 }
 
+Server.prototype.logout = function(token) {
+  return this.request({
+    uri: '/-/user/token/'+encodeURIComponent(token),
+    method: 'DELETE'
+  })
+}
+
 Server.prototype.get_package = function(name) {
   return this.request({
     uri: '/'+encodeURIComponent(name),
diff --git a/test/functional/logout.js b/test/functional/logout.js
new file mode 100644
index 0000000..3729e70
--- /dev/null
+++ b/test/functional/logout.js
@@ -0,0 +1,11 @@
+module.exports = function() {
+  var server = process.server
+
+  describe('logout', function() {
+    it('should log out', function () {
+      return server.logout('some-token')
+               .status(200)
+               .body_ok(/Logged out/)
+    })
+  })
+}