diff --git a/changelogs/unreleased/32364-updating-slack-notification-not-working-by-api.yml b/changelogs/unreleased/32364-updating-slack-notification-not-working-by-api.yml
new file mode 100644
index 00000000000..e3fae55c6f0
--- /dev/null
+++ b/changelogs/unreleased/32364-updating-slack-notification-not-working-by-api.yml
@@ -0,0 +1,5 @@
+---
+title: Support new chat notifications parameters in Services API
+merge_request: 11435
+author:
+type: added
diff --git a/doc/api/services.md b/doc/api/services.md
index 08df26db3ec..7e2afc71f9a 100644
--- a/doc/api/services.md
+++ b/doc/api/services.md
@@ -1,5 +1,7 @@
 # Services API
 
+>**Note:** This API requires an access token with Master or Owner permissions
+
 ## Asana
 
 Asana - Teamwork without email
@@ -16,8 +18,10 @@ PUT /projects/:id/services/asana
 
 Parameters:
 
-- `api_key` (**required**) - User API token. User must have access to task, all comments will be attributed to this user.
-- `restrict_to_branch` (optional) - Comma-separated list of branches which will be automatically inspected. Leave blank to include all branches.
+| Parameter | Type | Required | Description |
+| --------- | ---- | -------- | ----------- |
+| `api_key` | string | true | User API token. User must have access to task, all comments will be attributed to this user. |
+| `restrict_to_branch` | string | false | Comma-separated list of branches which will be automatically inspected. Leave blank to include all branches. |
 
 ### Delete Asana service
 
@@ -49,8 +53,10 @@ PUT /projects/:id/services/assembla
 
 Parameters:
 
-- `token` (**required**)
-- `subdomain` (optional)
+| Parameter | Type | Required | Description |
+| --------- | ---- | -------- | ----------- |
+| `token` | string | true | The authentication token
+| `subdomain` | string | false | The subdomain setting |
 
 ### Delete Assembla service
 
@@ -84,10 +90,12 @@ PUT /projects/:id/services/bamboo
 
 Parameters:
 
-- `bamboo_url` (**required**) - Bamboo root URL like https://bamboo.example.com
-- `build_key` (**required**) - Bamboo build plan key like KEY
-- `username` (**required**) - A user with API access, if applicable
-- `password` (**required**)
+| Parameter | Type | Required | Description |
+| --------- | ---- | -------- | ----------- |
+| `bamboo_url` | string | true | Bamboo root URL like https://bamboo.example.com |
+| `build_key` | string | true | Bamboo build plan key like KEY |
+| `username` | string | true | A user with API access, if applicable |
+| `password` | string | true | Password of the user |
 
 ### Delete Atlassian Bamboo CI service
 
@@ -105,6 +113,44 @@ Get Atlassian Bamboo CI service settings for a project.
 GET /projects/:id/services/bamboo
 ```
 
+## Bugzilla
+
+Bugzilla Issue Tracker
+
+### Create/Edit Buildkite service
+
+Set Bugzilla service for a project.
+
+```
+PUT /projects/:id/services/bugzilla
+```
+
+Parameters:
+
+| Parameter | Type | Required | Description |
+| --------- | ---- | -------- | ----------- |
+| `new_issue_url` | string | true |  New Issue url |
+| `issues_url` | string | true | Issue url |
+| `project_url` | string | true | Project url |
+| `description` | string | false | Description |
+| `title` | string | false | Title |
+
+### Delete Bugzilla Service
+
+Delete Bugzilla service for a project.
+
+```
+DELETE /projects/:id/services/bugzilla
+```
+
+### Get Bugzilla Service Settings
+
+Get Bugzilla service settings for a project.
+
+```
+GET /projects/:id/services/bugzilla
+```
+
 ## Buildkite
 
 Continuous integration and deployments
@@ -119,9 +165,11 @@ PUT /projects/:id/services/buildkite
 
 Parameters:
 
-- `token` (**required**) - Buildkite project GitLab token
-- `project_url` (**required**) - https://buildkite.com/example/project
-- `enable_ssl_verification` (optional) - Enable SSL verification
+| Parameter | Type | Required | Description |
+| --------- | ---- | -------- | ----------- |
+| `token` | string | true | Buildkite project GitLab token |
+| `project_url` | string | true | https://buildkite.com/example/project |
+| `enable_ssl_verification` | boolean | false | Enable SSL verification |
 
 ### Delete Buildkite service
 
@@ -153,9 +201,11 @@ PUT /projects/:id/services/campfire
 
 Parameters:
 
-- `token` (**required**)
-- `subdomain` (optional)
-- `room` (optional)
+| Parameter | Type | Required | Description |
+| --------- | ---- | -------- | ----------- |
+| `token` | string | true | Campfire token |
+| `subdomain` | string | false | Campfire subdomain |
+| `room`  | string | false | Campfire room |
 
 ### Delete Campfire service
 
@@ -187,11 +237,13 @@ PUT /projects/:id/services/custom-issue-tracker
 
 Parameters:
 
-- `new_issue_url` (**required**) - New Issue url
-- `issues_url` (**required**) - Issue url
-- `project_url` (**required**) - Project url
-- `description` (optional) - Custom issue tracker
-- `title` (optional) - Custom Issue Tracker
+| Parameter | Type | Required | Description |
+| --------- | ---- | -------- | ----------- |
+| `new_issue_url` | string | true |  New Issue url
+| `issues_url` | string | true | Issue url
+| `project_url` | string | true | Project url
+| `description` | string | false | Description
+| `title` | string | false | Title
 
 ### Delete Custom Issue Tracker service
 
@@ -223,9 +275,11 @@ PUT /projects/:id/services/drone-ci
 
 Parameters:
 
-- `token` (**required**) - Drone CI project specific token
-- `drone_url` (**required**) - http://drone.example.com
-- `enable_ssl_verification` (optional) - Enable SSL verification
+| Parameter | Type | Required | Description |
+| --------- | ---- | -------- | ----------- |
+| `token` | string | true | Drone CI project specific token |
+| `drone_url` | string | true | http://drone.example.com |
+| `enable_ssl_verification` | boolean | false | Enable SSL verification |
 
 ### Delete Drone CI service
 
@@ -257,9 +311,11 @@ PUT /projects/:id/services/emails-on-push
 
 Parameters:
 
-- `recipients` (**required**) - Emails separated by whitespace
-- `disable_diffs` (optional) - Disable code diffs
-- `send_from_committer_email` (optional) - Send from committer
+| Parameter | Type | Required | Description |
+| --------- | ---- | -------- | ----------- |
+| `recipients` | string | true | Emails separated by whitespace |
+| `disable_diffs` | boolean | false | Disable code diffs |
+| `send_from_committer_email` | boolean | false | Send from committer |
 
 ### Delete Emails on push service
 
@@ -291,7 +347,9 @@ PUT /projects/:id/services/external-wiki
 
 Parameters:
 
-- `external_wiki_url` (**required**) - The URL of the external Wiki
+| Parameter | Type | Required | Description |
+| --------- | ---- | -------- | ----------- |
+| `external_wiki_url` | string | true | The URL of the external Wiki |
 
 ### Delete External Wiki service
 
@@ -323,7 +381,9 @@ PUT /projects/:id/services/flowdock
 
 Parameters:
 
-- `token` (**required**) - Flowdock Git source token
+| Parameter | Type | Required | Description |
+| --------- | ---- | -------- | ----------- |
+| `token` | string | true | Flowdock Git source token |
 
 ### Delete Flowdock service
 
@@ -355,8 +415,10 @@ PUT /projects/:id/services/gemnasium
 
 Parameters:
 
-- `api_key` (**required**) - Your personal API KEY on gemnasium.com
-- `token` (**required**) - The project's slug on gemnasium.com
+| Parameter | Type | Required | Description |
+| --------- | ---- | -------- | ----------- |
+| `api_key` | string | true | Your personal API KEY on gemnasium.com |
+| `token`  | string | true | The project's slug on gemnasium.com |
 
 ### Delete Gemnasium service
 
@@ -388,12 +450,14 @@ PUT /projects/:id/services/hipchat
 
 Parameters:
 
-- `token` (**required**) - Room token
-- `color` (optional)
-- `notify` (optional)
-- `room` (optional) - Room name or ID
-- `api_version` (optional) - Leave blank for default (v2)
-- `server` (optional) - Leave blank for default. https://hipchat.example.com
+| Parameter | Type | Required | Description |
+| --------- | ---- | -------- | ----------- |
+| `token` | string | true | Room token |
+| `color` | string | false | The room color |
+| `notify` | boolean | false | Enable notifications |
+| `room` | string | false |Room name or ID |
+| `api_version` | string | false | Leave blank for default (v2) |
+| `server` | string | false | Leave blank for default. https://hipchat.example.com |
 
 ### Delete HipChat service
 
@@ -427,11 +491,13 @@ PUT /projects/:id/services/irker
 
 Parameters:
 
-- `recipients` (**required**) - Recipients/channels separated by whitespaces
-- `default_irc_uri` (optional) - irc://irc.network.net:6697/
-- `server_port` (optional) - 6659
-- `server_host` (optional) - localhost
-- `colorize_messages` (optional)
+| Parameter | Type | Required | Description |
+| --------- | ---- | -------- | ----------- |
+| `recipients` | string | true | Recipients/channels separated by whitespaces |
+| `default_irc_uri` | string | false | irc://irc.network.net:6697/ |
+| `server_host` | string | false | localhost |
+| `server_port` | integer | false | 6659 |
+| `colorize_messages` | boolean | false | Colorize messages |
 
 ### Delete Irker (IRC gateway) service
 
@@ -474,7 +540,9 @@ Set JIRA service for a project.
 PUT /projects/:id/services/jira
 ```
 
-| Attribute | Type | Required | Description |
+Parameters:
+
+| Parameter | Type | Required | Description |
 | --------- | ---- | -------- | ----------- |
 | `url`           | string | yes | The URL to the JIRA project which is being linked to this GitLab project, e.g., `https://jira.example.com`. |
 | `project_key`   | string | yes | The short identifier for your JIRA project, all uppercase, e.g., `PROJ`. |
@@ -569,7 +637,7 @@ PUT /projects/:id/services/slack-slash-commands
 
 Parameters:
 
-| Attribute | Type | Required | Description |
+| Parameter | Type | Required | Description |
 | --------- | ---- | -------- | ----------- |
 | `token` | string | yes | The Slack token |
 
@@ -604,7 +672,7 @@ PUT /projects/:id/services/mattermost-slash-commands
 
 Parameters:
 
-| Attribute | Type | Required | Description |
+| Parameter | Type | Required | Description |
 | --------- | ---- | -------- | ----------- |
 | `token` | string | yes | The Mattermost token |
 | `username` | string | no | The username to use to post the message |
@@ -665,7 +733,7 @@ PUT /projects/:id/services/pipelines-email
 
 Parameters:
 
-| Attribute | Type | Required | Description |
+| Parameter | Type | Required | Description |
 | --------- | ---- | -------- | ----------- |
 | `recipients` | string | yes | Comma-separated list of recipient email addresses |
 | `add_pusher` | boolean | no | Add pusher to recipients list |
@@ -701,8 +769,10 @@ PUT /projects/:id/services/pivotaltracker
 
 Parameters:
 
-- `token` (**required**)
-- `restrict_to_branch` (optional) - Comma-separated list of branches which will be automatically inspected. Leave blank to include all branches.
+| Parameter | Type | Required | Description |
+| --------- | ---- | -------- | ----------- |
+| `token` | string | true | The PivotalTracker token |
+| `restrict_to_branch` | boolean | false | Comma-separated list of branches which will be automatically inspected. Leave blank to include all branches. |
 
 ### Delete PivotalTracker service
 
@@ -720,6 +790,40 @@ Get PivotalTracker service settings for a project.
 GET /projects/:id/services/pivotaltracker
 ```
 
+## Prometheus
+
+Prometheus is a powerful time-series monitoring service.
+
+### Create/Edit Prometheus service
+
+Set Prometheus service for a project.
+
+```
+PUT /projects/:id/services/prometheus
+```
+
+Parameters:
+
+| Parameter | Type | Required | Description |
+| --------- | ---- | -------- | ----------- |
+| `api_url` | string | true | Prometheus API Base URL, like http://prometheus.example.com/ |
+
+### Delete Prometheus service
+
+Delete Prometheus service for a project.
+
+```
+DELETE /projects/:id/services/prometheus
+```
+
+### Get Prometheus service settings
+
+Get Prometheus service settings for a project.
+
+```
+GET /projects/:id/services/prometheus
+```
+
 ## Pushover
 
 Pushover makes it easy to get real-time notifications on your Android device, iPhone, iPad, and Desktop.
@@ -734,11 +838,13 @@ PUT /projects/:id/services/pushover
 
 Parameters:
 
-- `api_key` (**required**) - Your application key
-- `user_key` (**required**) - Your user key
-- `priority` (**required**)
-- `device` (optional) - Leave blank for all active devices
-- `sound` (optional)
+| Parameter | Type | Required | Description |
+| --------- | ---- | -------- | ----------- |
+| `api_key` | string | true | Your application key |
+| `user_key` | string | true | Your user key |
+| `priority` | string | true | The priority |
+| `device` | string | false | Leave blank for all active devices |
+| `sound` | string | false | The sound of the notification |
 
 ### Delete Pushover service
 
@@ -770,10 +876,12 @@ PUT /projects/:id/services/redmine
 
 Parameters:
 
-- `new_issue_url` (**required**) - New Issue url
-- `project_url` (**required**) - Project url
-- `issues_url` (**required**) - Issue url
-- `description` (optional) - Redmine issue tracker
+| Parameter | Type | Required | Description |
+| --------- | ---- | -------- | ----------- |
+| `new_issue_url` | string | true | New Issue url |
+| `project_url` | string | true | Project url |
+| `issues_url` | string | true | Issue url |
+| `description` | string | false | Description |
 
 ### Delete Redmine service
 
@@ -803,11 +911,33 @@ Set Slack service for a project.
 PUT /projects/:id/services/slack
 ```
 
+>**Note:** Specific event parameters (e.g. `push_events` flag and `push_channel`) were [introduced in v10.4][11435]
+
 Parameters:
 
-- `webhook` (**required**) - https://hooks.slack.com/services/...
-- `username` (optional) - username
-- `channel` (optional) - #channel
+| Parameter | Type | Required | Description |
+| --------- | ---- | -------- | ----------- |
+| `webhook` | string | true | https://hooks.slack.com/services/... |
+| `username` | string | false | username |
+| `channel` | string | false | Default channel to use if others are not configured |
+| `notify_only_broken_pipelines` | boolean | false | Send notifications for broken pipelines |
+| `notify_only_default_branch` | boolean | false | Send notifications only for the default branch |
+| `push_events` | boolean | false | Enable notifications for push events |
+| `issues_events` | boolean | false | Enable notifications for issue events |
+| `confidential_issues_events` | boolean | false | Enable notifications for confidential issue events |
+| `merge_requests_events` | boolean | false | Enable notifications for merge request events |
+| `tag_push_events` | boolean | false | Enable notifications for tag push events |
+| `note_events` | boolean | false | Enable notifications for note events |
+| `pipeline_events` | boolean | false | Enable notifications for pipeline events |
+| `wiki_page_events` | boolean | false | Enable notifications for wiki page events |
+| `push_channel` | string | false | The name of the channel to receive push events notifications |
+| `issue_channel` | string | false | The name of the channel to receive issues events notifications |
+| `confidential_issue_channel` | string | false | The name of the channel to receive confidential issues events notifications |
+| `merge_request_channel` | string | false | The name of the channel to receive merge request events notifications |
+| `note_channel` | string | false | The name of the channel to receive note events notifications |
+| `tag_push_channel` | string | false | The name of the channel to receive tag push events notifications |
+| `pipeline_channel` | string | false | The name of the channel to receive pipeline events notifications |
+| `wiki_page_channel` | string | false | The name of the channel to receive wiki page events notifications |
 
 ### Delete Slack service
 
@@ -825,6 +955,40 @@ Get Slack service settings for a project.
 GET /projects/:id/services/slack
 ```
 
+## Microsoft Teams
+
+Group Chat Software
+
+### Create/Edit Microsoft Teams service
+
+Set Microsoft Teams service for a project.
+
+```
+PUT /projects/:id/services/microsoft_teams
+```
+
+Parameters:
+
+| Parameter | Type | Required | Description |
+| --------- | ---- | -------- | ----------- |
+| `webhook` | string | true | The Microsoft Teams webhook. e.g. https://outlook.office.com/webhook/... |
+
+### Delete Microsoft Teams service
+
+Delete Microsoft Teams service for a project.
+
+```
+DELETE /projects/:id/services/microsoft_teams
+```
+
+### Get Microsoft Teams service settings
+
+Get Microsoft Teams service settings for a project.
+
+```
+GET /projects/:id/services/microsoft_teams
+```
+
 ## Mattermost notifications
 
 Receive event notifications in Mattermost
@@ -837,11 +1001,33 @@ Set Mattermost service for a project.
 PUT /projects/:id/services/mattermost
 ```
 
+>**Note:** Specific event parameters (e.g. `push_events` flag and `push_channel`) were [introduced in v10.4][11435]
+
 Parameters:
 
-- `webhook` (**required**) - https://mattermost.example/hooks/1298aff...
-- `username` (optional) - username
-- `channel` (optional) - #channel
+| Parameter | Type | Required | Description |
+| --------- | ---- | -------- | ----------- |
+| `webhook` | string | true | The Mattermost webhook. e.g. http://mattermost_host/hooks/... |
+| `username` | string | false | username |
+| `channel` | string | false | Default channel to use if others are not configured |
+| `notify_only_broken_pipelines` | boolean | false | Send notifications for broken pipelines |
+| `notify_only_default_branch` | boolean | false | Send notifications only for the default branch |
+| `push_events` | boolean | false | Enable notifications for push events |
+| `issues_events` | boolean | false | Enable notifications for issue events |
+| `confidential_issues_events` | boolean | false | Enable notifications for confidential issue events |
+| `merge_requests_events` | boolean | false | Enable notifications for merge request events |
+| `tag_push_events` | boolean | false | Enable notifications for tag push events |
+| `note_events` | boolean | false | Enable notifications for note events |
+| `pipeline_events` | boolean | false | Enable notifications for pipeline events |
+| `wiki_page_events` | boolean | false | Enable notifications for wiki page events |
+| `push_channel` | string | false | The name of the channel to receive push events notifications |
+| `issue_channel` | string | false | The name of the channel to receive issues events notifications |
+| `confidential_issue_channel` | string | false | The name of the channel to receive confidential issues events notifications |
+| `merge_request_channel` | string | false | The name of the channel to receive merge request events notifications |
+| `note_channel` | string | false | The name of the channel to receive note events notifications |
+| `tag_push_channel` | string | false | The name of the channel to receive tag push events notifications |
+| `pipeline_channel` | string | false | The name of the channel to receive pipeline events notifications |
+| `wiki_page_channel` | string | false | The name of the channel to receive wiki page events notifications |
 
 ### Delete Mattermost notifications service
 
@@ -875,10 +1061,12 @@ PUT /projects/:id/services/teamcity
 
 Parameters:
 
-- `teamcity_url` (**required**) - TeamCity root URL like https://teamcity.example.com
-- `build_type` (**required**) - Build configuration ID
-- `username` (**required**) - A user with permissions to trigger a manual build
-- `password` (**required**)
+| Parameter | Type | Required | Description |
+| --------- | ---- | -------- | ----------- |
+| `teamcity_url` | string | true | TeamCity root URL like https://teamcity.example.com |
+| `build_type` | string | true | Build configuration ID |
+| `username` | string | true | A user with permissions to trigger a manual build |
+| `password` | string | true | The password of the user |
 
 ### Delete JetBrains TeamCity CI service
 
@@ -916,7 +1104,9 @@ PUT /projects/:id/services/mock-ci
 
 Parameters:
 
-- `mock_service_url` (**required**) - http://localhost:4004
+| Parameter | Type | Required | Description |
+| --------- | ---- | -------- | ----------- |
+| `mock_service_url` | string | true | http://localhost:4004 |
 
 ### Delete MockCI service
 
@@ -933,3 +1123,5 @@ Get MockCI service settings for a project.
 ```
 GET /projects/:id/services/mock-ci
 ```
+
+[11435]: https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/11435
diff --git a/lib/api/entities.rb b/lib/api/entities.rb
index 928706dfda7..4ad4a1f7867 100644
--- a/lib/api/entities.rb
+++ b/lib/api/entities.rb
@@ -708,8 +708,9 @@ module API
 
     class ProjectService < Grape::Entity
       expose :id, :title, :created_at, :updated_at, :active
-      expose :push_events, :issues_events, :merge_requests_events
-      expose :tag_push_events, :note_events, :pipeline_events
+      expose :push_events, :issues_events, :confidential_issues_events
+      expose :merge_requests_events, :tag_push_events, :note_events
+      expose :pipeline_events, :wiki_page_events
       expose :job_events
       # Expose serialized properties
       expose :properties do |service, options|
diff --git a/lib/api/services.rb b/lib/api/services.rb
index bbcc851d07a..a7f44e2869c 100644
--- a/lib/api/services.rb
+++ b/lib/api/services.rb
@@ -1,5 +1,143 @@
 module API
   class Services < Grape::API
+    chat_notification_settings = [
+      {
+        required: true,
+        name: :webhook,
+        type: String,
+        desc: 'The chat webhook'
+      },
+      {
+        required: false,
+        name: :username,
+        type: String,
+        desc: 'The chat username'
+      },
+      {
+        required: false,
+        name: :channel,
+        type: String,
+        desc: 'The default chat channel'
+      }
+    ]
+
+    chat_notification_flags = [
+      {
+        required: false,
+        name: :notify_only_broken_pipelines,
+        type: Boolean,
+        desc: 'Send notifications for broken pipelines'
+      },
+      {
+        required: false,
+        name: :notify_only_default_branch,
+        type: Boolean,
+        desc: 'Send notifications only for the default branch'
+      }
+    ]
+
+    chat_notification_channels = [
+      {
+        required: false,
+        name: :push_channel,
+        type: String,
+        desc: 'The name of the channel to receive push_events notifications'
+      },
+      {
+        required: false,
+        name: :issue_channel,
+        type: String,
+        desc: 'The name of the channel to receive issues_events notifications'
+      },
+      {
+        required: false,
+        name: :confidential_issue_channel,
+        type: String,
+        desc: 'The name of the channel to receive confidential_issues_events notifications'
+      },
+      {
+        required: false,
+        name: :merge_request_channel,
+        type: String,
+        desc: 'The name of the channel to receive merge_requests_events notifications'
+      },
+      {
+        required: false,
+        name: :note_channel,
+        type: String,
+        desc: 'The name of the channel to receive note_events notifications'
+      },
+      {
+        required: false,
+        name: :tag_push_channel,
+        type: String,
+        desc: 'The name of the channel to receive tag_push_events notifications'
+      },
+      {
+        required: false,
+        name: :pipeline_channel,
+        type: String,
+        desc: 'The name of the channel to receive pipeline_events notifications'
+      },
+      {
+        required: false,
+        name: :wiki_page_channel,
+        type: String,
+        desc: 'The name of the channel to receive wiki_page_events notifications'
+      }
+    ]
+
+    chat_notification_events = [
+      {
+        required: false,
+        name: :push_events,
+        type: Boolean,
+        desc: 'Enable notifications for push_events'
+      },
+      {
+        required: false,
+        name: :issues_events,
+        type: Boolean,
+        desc: 'Enable notifications for issues_events'
+      },
+      {
+        required: false,
+        name: :confidential_issues_events,
+        type: Boolean,
+        desc: 'Enable notifications for confidential_issues_events'
+      },
+      {
+        required: false,
+        name: :merge_requests_events,
+        type: Boolean,
+        desc: 'Enable notifications for merge_requests_events'
+      },
+      {
+        required: false,
+        name: :note_events,
+        type: Boolean,
+        desc: 'Enable notifications for note_events'
+      },
+      {
+        required: false,
+        name: :tag_push_events,
+        type: Boolean,
+        desc: 'Enable notifications for tag_push_events'
+      },
+      {
+        required: false,
+        name: :pipeline_events,
+        type: Boolean,
+        desc: 'Enable notifications for pipeline_events'
+      },
+      {
+        required: false,
+        name: :wiki_page_events,
+        type: Boolean,
+        desc: 'Enable notifications for wiki_page_events'
+      }
+    ]
+
     services = {
       'asana' => [
         {
@@ -489,25 +627,11 @@ module API
         }
       ],
       'slack' => [
-        {
-          required: true,
-          name: :webhook,
-          type: String,
-          desc: 'The Slack webhook. e.g. https://hooks.slack.com/services/...'
-        },
-        {
-          required: false,
-          name: :new_issue_url,
-          type: String,
-          desc: 'The user name'
-        },
-        {
-          required: false,
-          name: :channel,
-          type: String,
-          desc: 'The channel name'
-        }
-      ],
+        chat_notification_settings,
+        chat_notification_flags,
+        chat_notification_channels,
+        chat_notification_events
+      ].flatten,
       'microsoft-teams' => [
         {
           required: true,
@@ -517,19 +641,11 @@ module API
         }
       ],
       'mattermost' => [
-        {
-          required: true,
-          name: :webhook,
-          type: String,
-          desc: 'The Mattermost webhook. e.g. http://mattermost_host/hooks/...'
-        },
-        {
-          required: false,
-          name: :username,
-          type: String,
-          desc: 'The username to use to post the message'
-        }
-      ],
+        chat_notification_settings,
+        chat_notification_flags,
+        chat_notification_channels,
+        chat_notification_events
+      ].flatten,
       'teamcity' => [
         {
           required: true,