Bulk loading data

Available on all plans

self-hosted deployments

Large quantities of data can be imported from a JSONL file into Mattermost at the command line using the bulk loading feature. This feature is most suitable for migrating data from an existing system, or for pre-populating a new installation with data.

You can import the following data types:

• Teams

• Threaded discussions

• Channels (public and private)

• Users

• Users’ team memberships

• Users’ channel memberships

• Users’ notification preferences

• Users’ custom status

• Posts (regular, non-reply posts)

• Posts’ replies

• Posts’ reactions

• Posts’ file attachments

• Direct message and group message channels

• Direct message and group message channels’ read/unread status

• Direct messages and group messages

• Direct messages from a user to themselves

• Permissions schemes

• Custom emoji

• Bot users

Importing additional types of posts is not yet supported.

About the bulk loading command

The bulk loading command is interruptible and idempotent

If the import is interrupted for any reason, it continues from where it left off the next time you run it. You can run the command repeatedly with the same data file, and the data is imported only once. Posts with matching timestamps to incoming posts will have their attachments replaced by the incoming data. Prior to v5.20 any updates to posts with matching timestamps were appended to older posts.

You can run the bulk loading command on a live system

Although you don’t need to shut down Mattermost to run the command, changes made by users of the system between runs can be overwritten if the corresponding fields exist in the data file.

Some data fields are optional

Not all fields are mandatory. If an optional field is missing from the object that is being imported, the field’s current value in the database is not changed.

The bulk loading command is not a synchronization tool

You cannot use the bulk loading command to remove any objects or their fields from the Mattermost database. The command only creates or overwrites fields.

Important

The bulk loading command runs in the mmctl and operates in the security context of the mmctl. This means it has full permissions to access and alter everything in the Mattermost database.

Bulk load data

Before running the bulk loading command, you must first create a JSONL file that contains the data that you want to import in your Mattermost directory. The file can have any name, but in this example it’s called data.jsonl. The format of the file is described in the data-format section.

Next, zip it by running the zip -r data.zip data.jsonl command.

Using mmctl local mode

From Mattermost v9.5, the mmctl bulk import process command in local mode supports processing an import file without uploading it to the server.

Run mmctl import process --bypass-upload <file>.zip --local to start your import and enable the Mattermost server to read from the file directly.

Not using mmctl local mode

If you’re not running mmctl commands in local mode:

1. Upload the ZIP file to the database by running the mmctl import upload command. For example: mmctl import upload data.zip.

2. Confirm that the file is uploaded and ready for use by running the mmctl import list available command.

3. Import your uploaded file by running the mmctl import process command. For example: mmctl import process <importedid>_data.zip (use the name of the uploaded file from mmctl import list available command).

Data format

The input data file must be a valid JSONL file with the following objects, each on its own line in the file. The objects must occur in the file in the order listed.

Version

Mandatory. The Version object must be the first line in the file, and must occur only once. The version is the version of the bulk importer tool, which is currently 1.

Scheme

Optional. If present, Scheme objects must occur after the Version object but before any Team objects.

Emoji

Optional. If present, Emoji objects must occur after the Version objects but before any Team objects.

Team

Optional. If present, Team objects must occur after any Scheme objects and before any Channel objects.

Channel

Optional. If present, Channel objects must occur after all Team objects and before any User objects.

User

Optional. If present, User objects must occur after the Team and Channel objects in the file and before any Post objects. Each User object defines the teams and channels that the user is a member of. If the corresponding teams and channels are not in the data file, then they must exist in the Mattermost database.

Post

Optional. If present, Post objects must occur after the last User object but before any DirectChannel objects. Each Post object defines the team, the channel, and the username of the user who posted the message. If the corresponding team, channel, or user are not in the data file, then they must exist in the Mattermost database.

DirectChannel

Optional. If present, DirectChannel objects must occur after all Post objects in the file and before any DirectPost objects.

DirectPost

Optional. If present, DirectPost objects must occur after all other objects in the file. Each DirectPost object defines the usernames of the channel members and the username of the user who posted the message. If the corresponding usernames are not in the data file, then they must exist in the Mattermost database.

With the exception of the Version object, each object has a field or a combination of fields that is used as the unique identifier of that object. The bulk loader uses the unique identifier to determine if the object being imported is a new object or an update to an existing object.

The identifiers for each object are listed in the following table:

Objects and their unique identifiers

Object	Unique Identifier
Version	Not Applicable
Scheme	name
Role	name
Emoji	name
Team	name
Channel	name, team
User	username
UserNotifyProps	username
UserTeamMembership	team, username
UserChannelMembership	team, channel, username
Post	channel, message, create_at
Reply	post, message, create_at
Reaction	post, emoji_name, create_at
Attachment	path
DirectChannel	members
DirectPost	channel_members, user, message, create_at

The following fragment is from a file that imports two teams, each with two channels, many users, and many posts.

{ "type": "version", ... }
{ "type": "team", "team": { "name": "TeamA", ...} }
{ "type": "team", "team": { "name": "TeamB", ...} }
{ "type": "channel", "channel": { "team": "TeamA", "name": "channel_a1", ...} }
{ "type": "channel", "channel": { "team": "TeamA", "name": "channel_a2", ...} }
{ "type": "channel", "channel": { "team": "TeamB", "name": "channel_b1", ...} }
{ "type": "channel", "channel": { "team": "TeamB", "name": "channel_b2", ...} }
{ "type": "user", "user": { "username": "user001", ...} }
{ "type": "user", "user": { "username": "user002", ...} }
{ "type": "user", "user": { "username": "user003", ...} }
{ "type": "user", ... }
{ "type": "user", ... }
{ "type": "user", ... }
.
.
.
{ "type": "post", { "team": "TeamA", "name": "channel_a1", "user": "user001", ...} }
{ "type": "post", { "team": "TeamA", "name": "channel_a1", "user": "user001", ...} }
{ "type": "post", { "team": "TeamA", "name": "channel_a1", "user": "user001", ...} }
.
.
.

Version object

The Version object must be the first object in the data file, and can appear only once. The version represents the version of the bulk import tool and currently is 1.

Example Version object

For clarity, the object is shown using regular JSON formatting, but in the data file it cannot be spread across several lines. It must be all on one line.

{
  "type": "version",
  "version": 1
}

Fields of the Version object

Field name	Type	Description	Validated	Mandatory
type	string	Must be the string "version"	Yes	Yes
version	number	Must be the number 1.	Yes	Yes

Scheme object

Scheme objects represent Permissions Schemes in the Mattermost permissions system. If present, Scheme objects must occur after the Version object and before any Team objects.

Example Scheme object

For clarity, the object is shown using regular JSON formatting, but in the data file it cannot be spread across several lines. It must be all on one line.

{
  "type": "scheme",
  "scheme": {
    "name": "custom_scheme_name",
    "display_name": "Custom Scheme Name",
    "description": "This is a custom override scheme.",
    "scope": "team",
    "default_team_admin_role": {
      "name": "custom_scheme_team_admin_role",
      "display_name": "Custom Scheme Team Admin Role",
      "description": "This is the default team admin role for the custom scheme.",
      "permissions": ["add_user_to_team", "manage_team_roles"],
    },
    "default_team_user_role": {
      "name": "custom_scheme_team_user_role",
      "display_name": "Custom Scheme Team User Role",
      "description": "This is the default team user role for the custom scheme.",
      "permissions": ["create_public_channel", "create_private_channel"],
    },
    "default_channel_admin_role": {
      "name": "custom_scheme_channel_admin_role",
      "display_name": "Custom Scheme Channel Admin Role",
      "description": "This is the default channel admin role for the custom scheme.",
      "permissions": ["manage_private_channel_members", "manage_channel_roles"],
    },
    "default_channel_user_role": {
      "name": "custom_scheme_channel_user_role",
      "display_name": "Custom Scheme Channel User Role",
      "description": "This is the default channel user role for the custom scheme.",
      "permissions": ["manage_public_channel_members", "manage_public_channel_properties"],
    },
  }
}

Fields of the Scheme object

Field name	Type	Description	Validated	Mandatory
name	string	The scheme name. Must start with and contain only lowercase letters ([a-z0-9]) or _, and must be between 2-64 characters in length.	Yes	Yes
display_name	string	The display name for the scheme.	Yes	Yes
scope	string	The scope for the scheme. Must be either "team" or "channel".	Yes	Yes
description	string	The description of the scheme.	Yes	No
default_team_admin_role	Role object	The default role applied to team admins in teams using this scheme. This field is mandatory if the scheme scope is set to "team", otherwise must not be present.	Yes	No
default_team_user_role	Role object	The default role applied to Team Users in teams using this scheme. This field is mandatory if the scheme scope is set to "team", otherwise must not be present.	Yes	No
default_channel_admin_role	Role object	The default role applied to channel admins in channels using this scheme. This field is mandatory for both "team" and "channel" scope schemes.	Yes	Yes
default_channel_user_role	Role object	The default role applied to Channel Users in channels using this scheme. This field is mandatory for both "team" and "channel" scope schemes.	Yes	Yes

Fields of the Role object

This object is a member of the Scheme object.

Field name	Type	Description	Validated	Mandatory
name	string	The scheme name.	Yes	Yes
display_name	string	The display name for the scheme.	Yes	Yes
description	string	The description of the scheme.	Yes	No
permissions	array	The permissions the role should grant. This is an array of strings where the strings are the names of individual permissions in the Mattermost permissions system.	Yes	No

Emoji object

Emoji objects represent custom Emoji. If present, Emoji objects must occur after the Version object and before any Team objects.

Example Emoji object

For clarity, the object is shown using regular JSON formatting, but in the data file it cannot be spread across several lines. It must be all on one line.

{
"type": "emoji",
"emoji": {
  "name": "custom-emoji-troll",
  "image": "bulkdata/emoji/trollolol.png"
  }
}

Fields of the Emoji object

Field name	Type	Description	Validated	Mandatory
name	string	The emoji name.	Yes	Yes
image	string	The path (either absolute or relative to the current working directory) to the image file for this emoji.	No	Yes

Team object

If present, Team objects must occur after the Version object and before any Channel objects.

Example Team object

For clarity, the object is shown using regular JSON formatting, but in the data file it cannot be spread across several lines. It must be all on one line.

{
"type": "team",
"team": {
  "name": "team-name",
  "display_name": "Team Display Name",
  "type": "O",
  "description": "The Team Description",
  "allow_open_invite": true
  }
}

Fields of the Team object

[1] Not validated, but an error occurs if no such scheme exists when running in apply mode.
Field name	Type	Description	Validated	Mandatory
name	string	The team name.	Yes	Yes
display_name	string	The display name for the team.	Yes	Yes
type	string	The type of team. Can have one the following values: O for an open team I for an invite-only team.	Yes	Yes
description	string	The team description.	Yes	No
allow_open_invite	bool	Whether to allow open invitations. Must have one of the following values: true false	Yes	No
scheme	string	The name of the Scheme that should be applied to this team.	No [1]	No

Channel object

If present, Channel objects must occur after all Team objects and before any User objects.

Example Channel object

For clarity, the object is shown using regular JSON formatting, but in the data file it cannot be spread across several lines. It must be all on one line.

{
  "type": "channel",
  "channel": {
    "team": "team-name",
    "name": "channel-name",
    "display_name": "Channel Name",
    "type": "O",
    "header": "The Channel Header",
    "purpose": "The Channel Purpose",
  }
}

Fields of the Channel object

[1] Not validated, but an error occurs if no such team/scheme exists when running in apply mode.
Field name	Type	Description	Validated	Mandatory
team	string	The name of the team this channel belongs to.	No [1]	Yes
name	string	The name of the channel. Must start with and contain only lowercase letters ([a-z0-9]) or - or _.	Yes	Yes
display_name	string	The display name for the channel.	Yes	yes
type	string	The type of channel. Can have one the following values: O for a public channel. P for a private channel.	Yes	Yes
header	string	The channel header.	Yes	No
purpose	string	The channel purpose.	Yes	No
scheme	string	The name of the Scheme that should be applied to this team.	No [1]	No

User object

If present, User objects must occur after the Team and Channel objects in the file and before any Post objects.

Example User object

For clarity, the object is shown using regular JSON formatting, but in the data file it cannot be spread across several lines. It must be all on one line.

{
  "type": "user",
  "user": {
    "profile_image": "profile-picture.png",
    "username": "username",
    "email": "email@example.com",
    "auth_service": "",
    "password": "passw0rd",
    "nickname": "bobuser",
    "first_name": "Bob",
    "last_name": "User",
    "position": "Senior Developer",
    "roles": "system_user",
    "locale": "pt_BR",
    "teams": [
      {
        "name": "team-name",
        "theme": "{
            \"awayIndicator\":\"#DBBD4E\",
            \"buttonBg\":\"#23A1FF\",
            \"buttonColor\":\"#FFFFFF\",
            \"centerChannelBg\":\"#ffffff\",
            \"centerChannelColor\":\"#333333\",
            \"codeTheme\":\"github\",
            \"linkColor\":\"#2389d7\",
            \"mentionBg\":\"#2389d7\",
            \"mentionColor\":\"#ffffff\",
            \"mentionHighlightBg\":\"#fff2bb\",
            \"mentionHighlightLink\":\"#2f81b7\",
            \"newMessageSeparator\":\"#FF8800\",
            \"onlineIndicator\":\"#7DBE00\",
            \"sidebarBg\":\"#fafafa\",
            \"sidebarHeaderBg\":\"#3481B9\",
            \"sidebarHeaderTextColor\":\"#ffffff\",
            \"sidebarText\":\"#333333\",
            \"sidebarTextActiveBorder\":\"#378FD2\",
            \"sidebarTextActiveColor\":\"#111111\",
            \"sidebarTextHoverBg\":\"#e6f2fa\",
            \"sidebarUnreadText\":\"#333333\",
            }",
        "roles": "team_user team_admin",
        "channels": [
          {
            "name": "channel-name",
            "roles": "channel_user",
            "notify_props": {
              "desktop": "default",
              "mark_unread": "all"
            }
          }
        ]
      }
    ]
  }
}

Fields of the User object

Field name	Type	Description	Validated	Mandatory
profile_image	string	The user’s profile image. This must be an existing file path.	Yes	No
username	string	The user’s username. This is the unique identifier for the user.	Yes	Yes
email	string	The user’s email address.	Yes	Yes
auth_service	string	The authentication service to use for this user account. If not provided, it defaults to password-based authentication. Must be one of the following values: "" or not provided - password authentication. "gitlab" - GitLab authentication. "ldap" - LDAP authentication (Enterprise and Professional) "saml" - Generic SAML based authentication (Enterprise) "google" - Google OAuth authentication (Enterprise) "entra id" - Microsoft Entra ID OAuth Authentication (Enterprise)	No	No
auth_data	string	The authentication data if auth_service is used. The value depends on the auth_service that is specified. The data comes from the following fields for the respective auth_services: "" or not provided - must be omitted. "gitlab" - The value of the Id attribute provided in the GitLab auth data. "ldap" - The value of the LDAP attribute specified as the "ID Attribute" in the Mattermost LDAP configuration. "saml" - The value of the SAML Email address attribute. "google" - The value of the OAuth Id attribute. "office365" - The value of the OAuth Id attribute.	No	No
password	string	A password for the user. Can be present only when password-based authentication is used. When password-based authentication is used and the password is not present, the bulk loader generates a password.	Yes	No
nickname	string	The user’s nickname.	Yes	No
first_name	string	The user’s first name.	Yes	No
last_name	string	The user’s last name.	Yes	No
position	string	The user’s position.	Yes	No
roles	string	The user’s roles. Must be one of the following values: "system_user" "system_admin system_user"	Yes	No
locale	string	The user’s locale. This must be a valid locale for which Mattermost has been localised.	No	No
delete_at	int64	Timestamp for when the user was deactivated.	No	No
teams	array	The teams which the user will be made a member of. Must be an array of UserTeamMembership objects.	Yes	No
theme	string	The user’s theme. Formatted as a Mattermost theme string.	No	No
military_time	string	How times should be displayed to this user. Must be one of the following values: "true" - Use 24 hour clock. "false" - Use 12 hour clock.	No	No
collapse_previews	string	Whether to collapse or expand link previews by default. Must be one of the following values: "true" - Collapsed by default. "false" - Expanded by default.	No	No
message_display	string	Which style to use for displayed messages. Must be one of the following values: "clean" - Use the standard style. "compact" - Use the compact style.	No	No
channel_display_mode	string	How to display channel messages. Must be one of the following values: "full" - Use the full width of the screen. "centered" - Use a fixed width, centered block.	No	No
tutorial_step	string	Where to start the user tutorial. Must be one of the following values: "1", "2" or "3" - Start from the specified tutorial step. "999" - Skip the user tutorial.	No	No
use_markdown_preview	bool	Enable preview of message markdown formatting. Can have one the following values: "True" "False"	Yes	Yes
use_formatting	bool	Enable post formatting for links, emoji, text styles and line breaks. Can have one the following values: "True" "False"	Yes	Yes
show_unread_section	bool	Enable showing unread messages at top of channel sidebar. Can have one the following values: "True" "False"	Yes	Yes
email_interval	string	Specify an email batching interval during bulk import. Can have one of the following values: "immediate" - Emails are sent immediately. "fifteen" - Emails are batched and sent every 15 minutes. "hour" - Emails are batched and sent every hour.	Yes	Yes
notify_props	UserNotifyProps object	The user’s notify preferences, as defined by the UserNotifyProps object.	Yes	No

Fields of the UserNotifyProps object

This object is a member of the User object.

[1] Not validated, but an error occurs if no such team exists when running in apply mode.
Field name	Type	Description	Validated	Mandatory
desktop	string	Preference for sending desktop notifications. Must be one of the following values: "all" - For all activity. "mention" - Only for mentions. "none" - Never.	Yes	No
desktop_sound	string	Preference for whether desktop notification sound is played. Must be one of the following values: "true" - Sound is played. "false" - Sound is not played.	Yes	No
email	string	Preference for email notifications. Must be one of the following values: "true" - Email notifications are sent based on the email_interval setting "false" - Email notifications are not sent.	No	No
mobile	string	Preference for sending mobile push notifications. Must be one of the following values: "all" - For all activity. "mention" - Only for mentions. "none" - Never.	Yes	No
mobile_push_status	string	Preference for when push notifications are triggered. Must be one of the following values: "online" - When online, away or offline. "away" - When away or offline. "offline" - When offline.	Yes	No
channel	string	Whether @all, @channel and @here trigger mentions. Must be one of the following values: "true" - Mentions are triggered. "false" - Mentions are not triggered.	Yes	No
comments	string	Preference for reply mention notifications. Must be one of the following values: "any" - Trigger notifications on messages in reply threads that the user starts or participates in. "root" - Trigger notifications on messages in threads that the user starts. "never" - Do not trigger notifications on messages in reply threads unless the user is mentioned.	Yes	No
mention_keys	string	Preference for custom non-case sensitive words that trigger mentions. Words must be separated by commas.	No	No

Fields of the UserTeamMembership object

This object is a member of the User object.

[1] Not validated, but an error occurs if no such team exists when running in apply mode.
Field name	Type	Description	Validated	Mandatory
name	string	The name of the team this user should be a member of.	No [1]	Yes
theme	string	The user’s theme for the specified team. Formatted as a Mattermost theme string.	Yes	No
roles	string	The roles the user should have within this team. Must be one of the following values: "team_user" "team_admin team_user"	Yes	No
channels	array	The channels within this team that the user should be made a member of. Must be an array of UserChannelMembership objects.	Yes	No

Fields of the UserChannelMembership object

This object is a member of the TeamMembership object.

[1] Not validated, but an error occurs if the parent channel does not exist when running in apply mode.
Field name	Type	Description	Validated	Mandatory
name	string	The name of the channel in the parent team that this user should be a member of.	No [1]	Yes
roles	string	The roles the user should have within this channel. Must be one of the following values: "channel_user" "channel_user channel_admin"	Yes	No
notify_props	object	The notify preferences for this user in this channel. Must be a ChannelNotifyProps object	Yes	No
favorite	boolean	Whether to favorite the channel. Must be one of the following values: "true" - Yes. "false" - No.	No	No

Fields of the ChannelNotifyProps object

This object is a member of the ChannelMembership object.

Field name	Type	Description	Validated	Mandatory
desktop	string	Preference for sending desktop notifications. Must be one of the following values: "default" - Global default. "all" - For all activity. "mention" - Only for mentions. "none" - Never.	Yes	No
mobile	string	Preference for sending mobile notifications. Must be one of the following values: "default" - Global default. "all" - For all activity. "mention" - Only for mentions. "none" - Never.	Yes	No
mark_unread	string	Preference for marking channel as unread. Must be one of the following values: "all" - For all unread messages. "mention" - Only for mentions.	Yes	No

Post object

If present, Post objects must occur after the last User object in the file, but before any DirectChannel objects.

Example Post object

For clarity, the object is shown using regular JSON formatting, but in the data file it cannot be spread across several lines. It must be all on one line.

{
  "type": "post",
  "post": {
    "team": "team-name",
    "channel": "channel-name",
    "user": "username",
    "message": "The post message",
    "props": {
      "attachments": [{
        "pretext": "This is the attachment pretext.",
        "text": "This is the attachment text."
      }]
    },
    "create_at": 140012340013,
    "flagged_by": [
      "username1",
      "username2",
      "username3"
    ],
    "replies": [{
      "user": "username4",
      "message": "The reply message",
      "create_at": 140012352049,
      "attachments": [{
          "path": "/some/valid/file/path/1"
      }],
    }, {
      "user": "username5",
      "message": "Other reply message",
      "create_at": 140012353057,
    }],
    "reactions": [{
      "user": "username6",
      "emoji_name": "+1",
      "create_at": 140012356032,
    }, {
      "user": "username7",
      "emoji_name": "heart",
      "create_at": 140012359034,
    }],
    "attachments": [{
      "path": "/some/valid/file/path/1"
    }, {
      "path": "/some/valid/file/path/2"
    }]
  }
}

Fields of the Post object

[1] Not validated, but an error occurs if the team does not exist when running in apply mode. [2] Not validated, but an error occurs if the channel does not exist in the corresponding team when running in apply mode. [3] Not validated, but an error occurs if the user does not exist when running in apply mode.
Field name	Type	Description	Validated	Mandatory
team	string	The name of the team that this post is in.	No [1]	Yes
channel	string	The name of the channel that this post is in.	No [2]	Yes
user	string	The username of the user for this post.	No [3]	Yes
message	string	The message that the post contains.	Yes	Yes
props	object	The props for a post. Contains additional formatting information used by integrations and bot posts. For a more detailed explanation see the message attachments documentation.	Yes	Yes
create_at	int	The timestamp for the post, in milliseconds since the Unix epoch.	Yes	Yes
flagged_by	array	Must contain a list of members who have flagged the post.	No	No
replies	array	The posts in reply to this post. Must be an array of Reply objects.	Yes	No
reactions	array	The emoji reactions to this post. Must be an array of Reaction objects.	Yes	No
attachments	array	File attachments associated with this post. Must be an array of Attachment objects.	Yes	No

Fields of the Reply object

This object is a member of the Post/DirectPost object.

Field name	Type	Description	Validated	Mandatory
user	string	The username of the user for this reply.	No [3]	Yes
message	string	The message that the reply contains.	Yes	Yes
create_at	int	The timestamp for the reply, in milliseconds since the Unix epoch.	Yes	Yes
flagged_by	array	Must contain a list of members who have flagged the post.	No	No
reactions	array	The emoji reactions to this post. Must be an array of Reaction objects.	Yes	No
attachments	array	The file attachments to this post. Must be an array of Attachment objects.	Yes	No

Fields of the Reaction object

This object is a member of the Post/DirectPost object.

Field name	Type	Description	Validated	Mandatory
user	string	The username of the user for this reply.	No [3]	Yes
emoji_name	string	The emoji of the reaction.	Yes	Yes
create_at	int	The timestamp for the reply, in milliseconds since the Unix epoch.	Yes	Yes

Fields of the Attachment object

This object is a member of the Post/DirectPost object.

[1] Not validated, but an error occurs if the file path is not found or accessible when running in apply mode.
Field name	Type	Description	Validated	Mandatory
path	string	The path to the file to be attached to the post.	No [1]	Yes

DirectChannel object

A direct channel can have from two to eight users as members of the channel. If there are only two members, Mattermost treats it as a Direct Message channel. If there are three or more members, Mattermost treats it as a Group Message channel.

Example DirectChannel object

For clarity, the object is shown using regular JSON formatting, but in the data file it cannot be spread across several lines. It must be all on one line.

{
  "type": "direct_channel",
  "direct_channel": {
    "members": [
      "username1",
      "username2",
      "username3"
    ],
    "header": "The Channel Header",
    "favorited_by": [
      "username1",
      "username2",
      "username3"
    ]
  }
}

Fields of the DirectChannel object

[1] Not validated, but an error occurs if one or more of the users don't exist when running in apply mode.
Field name	Type	Description	Validated	Mandatory
members	array	Must contain a list of members, with a minimum of two usernames and a maximum of eight usernames.	No [1]	Yes
header	string	The channel header.	Yes	No
favorited_by	array	Must contain a list of members who have favorited the channel.	No	No

DirectPost object

DirectPost objects must occur after all other objects in the file.

Example DirectPost object

For clarity, the object is shown using regular JSON formatting, but in the data file it cannot be spread across several lines. It must be all on one line.

{
  "type": "direct_post",
  "direct_post": {
    "channel_members": [
      "username1",
      "username2",
      "username3",
    ],
    "user": "username2",
    "message": "Hello Group Channel",
    "create_at": 140012340013,
    "flagged_by": [
      "username1",
      "username2",
      "username3"
    ],
    "replies": [{
      "user": "username4",
      "message": "The reply message",
      "create_at": 140012352049,
    }, {
      "user": "username5",
      "message": "Other reply message",
      "create_at": 140012353057,
    }],
    "reactions": [{
      "user": "username6",
      "emoji_name": "+1",
      "create_at": 140012356032,
    }, {
      "user": "username7",
      "emoji_name": "heart",
      "create_at": 140012359034,
    }]
  }
}

Fields of the DirectPost object

[1] Not validated, but an error occurs if no channels contain an identical list when running in apply mode. [2] Not validated, but an error occurs if the user does not exist when running in apply mode.
Field name	Type	Description	Validated	Mandatory
channel_members	array	Must contain a list of members, with a minimum of two usernames and a maximum of eight usernames.	No [1]	Yes
user	string	The username of the user for this post.	No [2]	Yes
message	string	The message that the post contains.	Yes	Yes
create_at	int	The timestamp for the post, in milliseconds since the Unix epoch.	Yes	Yes
flagged_by	array	Must contain a list of members who have flagged the post.	No	No
replies	array	The posts in reply to this direct post. Must be an array of Reply objects.	Yes	No
reactions	array	The emoji reactions to this direct post. Must be an array of Reaction objects.	Yes	No
attachments	array	The attachments to this direct post. Must be an array of Attachment objects.	Yes	No

Common issues

Run the bulk import command as the mattermost user. Running it as root or any other user will cause issues with file permissions on imported attachments.

Ensure that file attachments are enabled, that you have enough free space in your file storage system to support the incoming attachments, and that your maximum file size is appropriate.

Make sure you have enough free space for logs on the Mattermost server as well as free space on the database server for both the database itself and transaction logs.

Disable anti-virus or any other plugins that might interfere with attachment uploading. They could potentially block uploading of attachments and cause the import to fail if configured incorrectly. If you need anti-virus scanning, scan the attachment folder before the import.

Troubleshooting

Running bulk loading tool hangs and doesn’t complete

If you have Bleve search indexing enabled, temporarily disable it in System Console > Experimental > Bleve and run the command again.

Bleve does not support multiple processes opening and manipulating the same index. Therefore, if the Mattermost server is running, an attempt to run the bulk loading tool will lock when trying to open the indeces.

If you are not using the Bleve search indexing, feel free to post in our Troubleshooting forum for help.