The Mattermost Emoji Picker and Emoji autocomplete use generic skin tones. To access alternate skin tones, you can use the native emoji pickers provided on your platform or device. Use the keyboard shortcut: Windows Key +. (period) to open the native emoji picker for Windows 10. Select an alternate skin tone and then select an. Mattermost 3.5 improves mobile and web performance, adds Minio support, Russian language; Open source Slack-alternative integrates 700 apps with Markdown support (Mattermost 3.4) Mattermost 3.2: German, Custom Emoji, Exchange & XMPP integrations, Windows & Mac Apps and more.
Note
This is the admin documentation for incoming webhooks. If you’re a developer looking to build an integration, see our developer documentation.
Mattermost supports webhooks to easily integrate external applications into the server.
Use incoming webhooks to post messages to Mattermost public channels, private channels and direct messages. Messages are sent via an HTTP POST request to a Mattermost URL generated for each application and contain a specifically formatted JSON payload in the request body.
An example of a GitHub integration that posts updates to a Developers channel
Use curl, a simple command line tool for sending HTTP requests in the examples that follow.
Note
To prevent malicious users from trying to perform phishing attacks, a BOT indicator appears next to posts coming from webhooks regardless of what username is specified.
Simple Incoming Webhook¶
Paragraphs
Let’s learn how to create a simple incoming webhook that posts the following message to Mattermost.

First, go to Main Menu > Integrations > Incoming Webhook.
If you don’t have the Integrations option in your Main Menu, incoming webhooks may not be enabled on your Mattermost server or may be disabled for non-admins. They can be enabled by a System Admin from System Console > Integrations > Integration Management. Then continue with the steps below.
Select Add Incoming Webhook and add name and description for the webhook. The description can be up to 500 characters.
Select the channel to receive webhook payloads, then click Add to create the webhook.
Use a curl command from your terminal or commandline to send the following JSON payload in a HTTP POST request:
Matter Most Markdown Time
If you’re running cURL on Windows, ensure inner double quotes are escaped with a backslash. Here’s an example payload on Windows:
See developer documentation for details on what parameters are supported by incoming webhooks. For instance, you can override the username and profile picture the messages post as, or specify a custom post type when sending a webhook message for use by plugins. The following payload gives an example webhook that uses additional parameters and formatting options:
This content will be displayed in the Town Square channel.
Messages with advanced formatting can be created by including an attachment array and interactive message buttons in the JSON payload.
Note
Enable integrations to override usernames must be set to true
in config.json
to override usernames. Enable them from System Console > Integrations > Integration Management, or ask your System Admin to do so. If not enabled, the username is set to webhook
.
Mattermost Markdown Reference | Markdown Guide
Similarly, Enable integrations to override profile picture icons must be set to true
in config.json
to override profile picture icons. Enable them from System Console > Integrations > Integration Management, or ask your System Admin to do so. If not enabled, the icon of the creator of the webhook URL is used to post messages.
Tips and Best Practices¶
Webhooks are designed to easily allow you to post messages. For other actions such as channel creation, you must also use the Mattermost APIs.
If the text is longer than the allowable character limit per post, the message is split into multiple consecutive posts, each within the character limit. Servers running Mattermost Server v5.0 or later can support posts up to 16383 characters.
You can restrict who can create incoming webhooks in System Console > Integrations > Integration Management.
Mattermost incoming webhooks are Slack-compatible. You can copy-and-paste code used for a Slack incoming webhook to create Mattermost integrations. Mattermost automatically translates the Slack’s proprietary JSON payload format.
The external application may be written in any programming language as long as it supports sending an HTTP POST request in the required JSON format to a specified Mattermost URL.
For the HTTP request body, if
Content-Type
is specified asapplication/json
in the header of the HTTP request, then the body can be direct JSON. For example,
When using the
icon_emoji
parameter, the user profile image is replaced by the emoji provided. This will also override theicon_url
parameter if both are provided.
Share Your Integration¶
If you’ve built an integration for Mattermost, please consider sharing your work in our app directory.
The app directory lists open source integrations developed by the Mattermost community and are available for download, customization and deployment to your private cloud or self-managed infrastructure.
Slack Compatibility¶
Mattermost makes it easy to migrate integrations written for Slack to Mattermost. Using the Slack icon_emoji
parameter overrides the profile icon and the icon_url
parameter and is supported from version 5.14.
Translate Slack’s data format to Mattermost¶
Mattermost automatically translates the data coming from Slack:
JSON payloads written for Slack, that contain the following, are translated to Mattermost markdown and rendered equivalently to Slack:
<>
to denote a URL link, such as{'text':'<https://mattermost.com/>'}
|
within a<>
to define linked text, such as{'text':'Click<https://mattermost.com/|here>foralink.'}
<userid>
to trigger a mention to a user, such as{'text':'<5fb5f7iw8tfrfcwssd1xmx3j7y>thisisanotification.'}
<!channel>
,<!here>
or<!all>
to trigger a mention to a channel, such as{'text':'<!channel>thisisanotification.'}
You can override the channel name with a @username, such as
`payload={'text':'Hi',channel:'@jim'}
to send a direct message like in Slack.You can prepend a channel name with # and the message will still be sent to the correct channel like in Slack.
Mattermost webhooks in GitLab using Slack UI¶
GitLab is the leading open-source alternative to GitHub and offers built-in integrations with Slack. You can use the Slack interface in GitLab to add Mattermost webhooks directly without changing code:
In GitLab, go to Settings > Services and select Slack.
Paste the incoming webhook URL provided by Mattermost from Main Menu > Integrations > Incoming Webhooks.
Optionally set the Username you’d like displayed when the notification is made. Leave the Channel field blank.
Select Save, then test the settings to confirm messages are sent successfully to Mattermost.
Known Slack compatibility issues¶
Referencing channels using
<#CHANNEL_ID>
does not link to the channel.<!everyone>
and<!group>
are not supported.Parameters “mrkdwn”, “parse”, and “link_names” are not supported. Mattermost converts Markdown by default and automatically links @mentions.
Bold formatting as
*bold*
is not supported (must be done as**bold**
).Webhooks cannot direct message the user who created the webhook.
Troubleshooting¶

To debug incoming webhooks in System Console > Logs, set System Console > Logging > Enable Webhook Debugging to true, and set System Console > Logging > Console Log Level to DEBUG.
Some common error messages include:
Couldn'tfindthechannel
: Indicates that the channel doesn’t exist or is invalid. Please modify thechannel
parameter before sending another request.Couldn'tfindtheuser
: Indicates that the user doesn’t exist or is invalid. Please modify thechannel
parameter before sending another request.Unabletoparseincomingdata
: Indicates that the request received is malformed. Try reviewing that the JSON payload is in a correct format and doesn’t have typos such as extra “.curl:(3)[globbing]unmatchedclosebrace/bracketincolumnN
: Typically an error when using cURL on Windows, when:
You have space around JSON separator colons,
payload={'Hello':'test'}
orYou are using single quotes to wrap the
-d
data,-d'payload={'Hello':'test'}'
If your integration prints the JSON payload data instead of rendering the generated message, make sure your integration is returning the application/json
content-type.

For further assistance, review the Troubleshooting forum for previously reported errors, or join the Mattermost user community for troubleshooting help.
Frequently Asked Questions¶
How do I send a webhook post to a Direct Message channel?¶
To send a message to a Direct Message channel, add an “@” symbol followed by the username to the channel parameter. You can add your own username to send the webhook posts to a Direct Message channel with yourself.
This will send a message from the account that has set up the incoming webhook to the username after the “@” symbol. For example, if you create a webhook with the user alice
and send a Direct Message to bob
using a webhook, it will show up as a direct message from alice
to bob
regardless of other settings such as username.
To send a message to a different Direct Mssage channel between two other users, you can specify the channel with the user IDs for the users separated with two underscore (_) symbols. To find the user ID you can use the ``mattermost` command - see details here.
