diff --git a/server/src/errors/index.js b/server/src/errors/index.js
new file mode 100644
index 000000000..eb000c4ee
--- /dev/null
+++ b/server/src/errors/index.js
@@ -0,0 +1,4 @@
+export class AuthentificationError extends Error {
+  code = 401
+  message = 'You have to be authentificated to ' + ( this.message || "perform this action")
+}
diff --git a/server/src/index.js b/server/src/index.js
index 8b63b3f94..a37022464 100644
--- a/server/src/index.js
+++ b/server/src/index.js
@@ -6,7 +6,7 @@ import graphqlHTTP from 'express-graphql'
 import expressPlayground from 'graphql-playground-middleware-express'
 
 import schema from './schema'
-const Sentry = require('@sentry/node')
+import * as Sentry from '@sentry/node'
 
 // Initialise express
 const app = express()
diff --git a/server/src/schema/mutations/AddPrize.js b/server/src/schema/mutations/AddPrize.js
index 0e31a3ba1..620442ab6 100644
--- a/server/src/schema/mutations/AddPrize.js
+++ b/server/src/schema/mutations/AddPrize.js
@@ -3,6 +3,7 @@ import {
   GraphQLID,
   GraphQLInt
 } from 'graphql'
+import { AuthentificationError } from '../../errors'
 import { EventType } from '../types'
 import { Event } from '../../models'
 
@@ -13,8 +14,12 @@ const args = {
 }
 
 const resolve = (parent, { eventDesignator, rank, amount }, context) => {
+  const hostId = context.userId
+  if (!hostId) {
+    throw new AuthentificationError()
+  }
   return new Promise((resolve, reject) => {
-    Event.findOne({ designator: eventDesignator, hostId: context.userId }).exec((err, event) => {
+    Event.findOne({ designator: eventDesignator, hostId }).exec((err, event) => {
       if (err || !event) {
         reject(err)
       } else {
diff --git a/server/src/schema/mutations/AddRule.js b/server/src/schema/mutations/AddRule.js
index 606729114..b3183fb6c 100644
--- a/server/src/schema/mutations/AddRule.js
+++ b/server/src/schema/mutations/AddRule.js
@@ -3,6 +3,7 @@ import {
   GraphQLID,
   GraphQLString
 } from 'graphql'
+import { AuthentificationError } from '../../errors'
 import { EventType } from '../types'
 import { Event } from '../../models'
 
@@ -13,8 +14,12 @@ const args = {
 }
 
 const resolve = (parent, { eventDesignator, title, description }, context) => {
+  const hostId = context.userId
+  if (!hostId) {
+    throw new AuthentificationError()
+  }
   return new Promise((resolve, reject) => {
-    Event.findOne({ designator: eventDesignator, hostId: context.userId }).exec((err, event) => {
+    Event.findOne({ designator: eventDesignator, hostId }).exec((err, event) => {
       if (err || !event) {
         reject(err)
       } else {
diff --git a/server/src/schema/mutations/CreateAndSetFormula.js b/server/src/schema/mutations/CreateAndSetFormula.js
index 1da7c5e5b..f8e145a22 100644
--- a/server/src/schema/mutations/CreateAndSetFormula.js
+++ b/server/src/schema/mutations/CreateAndSetFormula.js
@@ -2,6 +2,7 @@ import {
   GraphQLNonNull,
   GraphQLString
 } from 'graphql'
+import { AuthentificationError } from '../../errors'
 import { EventType } from '../types'
 import { Event, Formula } from '../../models'
 
@@ -12,6 +13,9 @@ const args = {
 
 const resolve = (parent, { name, eventDesignator }, context) => {
   const ownerId = context.userId
+  if (!ownerId) {
+    throw new AuthentificationError()
+  }
   let newFormula = new Formula({ name, ownerId })
   return new Promise((resolve, reject) => {
     Event.findOne({ designator: eventDesignator, hostId: ownerId }).exec((err, event) => {
diff --git a/server/src/schema/mutations/CreateAndSetPlotter.js b/server/src/schema/mutations/CreateAndSetPlotter.js
index c8e850d05..75d518614 100644
--- a/server/src/schema/mutations/CreateAndSetPlotter.js
+++ b/server/src/schema/mutations/CreateAndSetPlotter.js
@@ -2,6 +2,7 @@ import {
   GraphQLNonNull,
   GraphQLString
 } from 'graphql'
+import { AuthentificationError } from '../../errors'
 import { EventType } from '../types'
 import { Event, Plotter } from '../../models'
 
@@ -15,6 +16,9 @@ const args = {
 
 const resolve = (parent, { name, host, repo, moduleName, eventDesignator }, context) => {
   const ownerId = context.userId
+  if (!ownerId) {
+    throw new AuthentificationError()
+  }
   let newPlotter = new Plotter({ name, host, repo, moduleName, ownerId })
   return new Promise((resolve, reject) => {
     Event.findOne({ designator: eventDesignator, hostId: ownerId }).exec((err, event) => {
diff --git a/server/src/schema/mutations/CreateFormula.js b/server/src/schema/mutations/CreateFormula.js
index 89fd9b611..a8153209a 100644
--- a/server/src/schema/mutations/CreateFormula.js
+++ b/server/src/schema/mutations/CreateFormula.js
@@ -2,6 +2,7 @@ import {
   GraphQLNonNull,
   GraphQLString
 } from 'graphql'
+import { AuthentificationError } from '../../errors'
 import { FormulaType } from '../types'
 import { Formula } from '../../models'
 
@@ -11,6 +12,9 @@ const args = {
 
 const resolve = (parent, { name }, context) => {
   const ownerId = context.userId
+  if (!ownerId) {
+    throw new AuthentificationError()
+  }
   let newFormula = new Formula({ name, ownerId })
   return new Promise((resolve, reject) => {
     newFormula.save((err) => {
diff --git a/server/src/schema/mutations/CreatePlotter.js b/server/src/schema/mutations/CreatePlotter.js
index 30e290b99..669dc81ec 100644
--- a/server/src/schema/mutations/CreatePlotter.js
+++ b/server/src/schema/mutations/CreatePlotter.js
@@ -2,6 +2,7 @@ import {
   GraphQLNonNull,
   GraphQLString
 } from 'graphql'
+import { AuthentificationError } from '../../errors'
 import { PlotterType } from '../types'
 import { Plotter } from '../../models'
 
@@ -14,6 +15,9 @@ const args = {
 
 const resolve = (parent, { name, host, repo, moduleName }, context) => {
   const ownerId = context.userId
+  if (!ownerId) {
+    throw new AuthentificationError()
+  }
   let newPlotter = new Plotter({ name, host, repo, moduleName, ownerId })
   return new Promise((resolve, reject) => {
     newPlotter.save((err) => {
diff --git a/server/src/schema/mutations/EditEvent.js b/server/src/schema/mutations/EditEvent.js
index 1e093b8e5..f36fa26f9 100644
--- a/server/src/schema/mutations/EditEvent.js
+++ b/server/src/schema/mutations/EditEvent.js
@@ -4,6 +4,7 @@ import {
   GraphQLInt,
   GraphQLString
 } from 'graphql'
+import { AuthentificationError } from '../../errors'
 import { EventType } from '../types'
 import { Event } from '../../models'
 
@@ -18,8 +19,12 @@ const args = {
 }
 
 const resolve = (parent, { designator, name, description, startDatetime, finishDatetime, formulaId, plotterId }, context) => {
+  const hostId = context.userId
+  if (!hostId) {
+    throw new AuthentificationError()
+  }
   return new Promise((resolve, reject) => {
-    Event.findOne({ designator, hostId: context.userId }).exec((err, event) => {
+    Event.findOne({ designator, hostId }).exec((err, event) => {
       if (err || !event) {
         reject(err)
       } else {
diff --git a/server/src/schema/mutations/EditParticipant.js b/server/src/schema/mutations/EditParticipant.js
index 6adac2274..3b8462da5 100644
--- a/server/src/schema/mutations/EditParticipant.js
+++ b/server/src/schema/mutations/EditParticipant.js
@@ -3,6 +3,7 @@ import {
   GraphQLID,
   GraphQLString
 } from 'graphql'
+import { AuthentificationError } from '../../errors'
 import { EventType } from '../types'
 import { Event } from '../../models'
 
@@ -14,6 +15,10 @@ const args = {
 }
 
 const resolve = (parent, { eventDesignator, teamId, botId, releaseId }, context) => {
+  const hostId = context.userId
+  if (!hostId) {
+    throw new AuthentificationError()
+  }
   return new Promise((resolve, reject) => {
     Event.findOne({ designator: eventDesignator }).exec((err, event) => {
       if (err) reject(err)
diff --git a/server/src/schema/mutations/EditRule.js b/server/src/schema/mutations/EditRule.js
index 4ec533f94..1821d8aeb 100644
--- a/server/src/schema/mutations/EditRule.js
+++ b/server/src/schema/mutations/EditRule.js
@@ -3,6 +3,7 @@ import {
   GraphQLID,
   GraphQLString
 } from 'graphql'
+import { AuthentificationError } from '../../errors'
 import { EventType } from '../types'
 import { Event } from '../../models'
 
@@ -14,8 +15,12 @@ const args = {
 }
 
 const resolve = (parent, { eventDesignator, title, newtitle, description }, context) => {
+  const hostId = context.userId
+  if (!hostId) {
+    throw new AuthentificationError()
+  }
   return new Promise((resolve, reject) => {
-    Event.findOne({ designator: eventDesignator, hostId: context.userId }).exec((err, event) => {
+    Event.findOne({ designator: eventDesignator, hostId }).exec((err, event) => {
       if (err || !event) {
         reject(err)
       } else {
diff --git a/server/src/schema/mutations/HostEvent.js b/server/src/schema/mutations/HostEvent.js
index c2145736b..a562f6cb4 100644
--- a/server/src/schema/mutations/HostEvent.js
+++ b/server/src/schema/mutations/HostEvent.js
@@ -3,6 +3,7 @@ import {
   GraphQLInt,
   GraphQLString
 } from 'graphql'
+import { AuthentificationError } from '../../errors'
 import { EventType } from '../types'
 import { Event } from '../../models'
 import { slugify } from '../../utils/functions'
@@ -16,6 +17,9 @@ const args = {
 
 const resolve = (parent, { name, description, startDatetime, finishDatetime }, context) => {
   const hostId = context.userId
+  if (!hostId) {
+    throw new AuthentificationError()
+  }
   let newEvent = new Event({
     hostId,
     name,
diff --git a/server/src/schema/mutations/RegisterToEvent.js b/server/src/schema/mutations/RegisterToEvent.js
index 1c2e5f1a0..c34a29b57 100644
--- a/server/src/schema/mutations/RegisterToEvent.js
+++ b/server/src/schema/mutations/RegisterToEvent.js
@@ -3,6 +3,7 @@ import {
   GraphQLID,
   GraphQLString
 } from 'graphql'
+import { AuthentificationError } from '../../errors'
 import { EventType } from '../types'
 import { Event } from '../../models'
 
@@ -14,6 +15,10 @@ const args = {
 }
 
 const resolve = (parent, { designator, teamId, botId, releaseId }, context) => {
+  const hostId = context.userId
+  if (!hostId) {
+    throw new AuthentificationError()
+  }
   return new Promise((resolve, reject) => {
     Event.findOne({ designator }).exec((err, event) => {
       if (err) reject(err)
diff --git a/server/src/schema/mutations/ReorderRules.js b/server/src/schema/mutations/ReorderRules.js
index 7e14e114e..00846507e 100644
--- a/server/src/schema/mutations/ReorderRules.js
+++ b/server/src/schema/mutations/ReorderRules.js
@@ -3,6 +3,7 @@ import {
   GraphQLID,
   GraphQLInt
 } from 'graphql'
+import { AuthentificationError } from '../../errors'
 import { isBetween } from '../../utils/functions'
 import { EventType } from '../types'
 import { Event } from '../../models'
@@ -14,6 +15,10 @@ const args = {
 }
 
 const resolve = (parent, { eventDesignator, fromPosition, toPosition }, context) => {
+  const hostId = context.userId
+  if (!hostId) {
+    throw new AuthentificationError()
+  }
   return new Promise((resolve, reject) => {
     Event.findOne({ designator: eventDesignator, hostId: context.userId }).exec((err, event) => {
       if (err || !event) {