mattermost/mattermost-test-data

Mattermost Test Data & MCP Usage

Populate a Mattermost server with realistic test data and interact with it using the connected Mattermost MCP tools.

Available MCP Tools

Write Operations

| Tool | Purpose | |------|---------| | create_user | Create user accounts (username, email, password, names, nickname, optional profile_image) | | create_team | Create teams (name, display_name, type O=open/I=invite, description, optional team_icon) | | create_channel | Create channels (name, display_name, type O=public/P=private, team_id, purpose, header) | | create_post | Post as the authenticated bot/admin user (channel_id, message, optional root_id for replies, optional attachments) | | create_post_as_user | Post as a specific user via username/password login - critical for realistic multi-user conversations | | add_user_to_team | Add a user to a team by user_id and team_id | | add_user_to_channel | Add a user to a channel by user_id and channel_id | | dm_self | Send a DM to yourself (the authenticated user) |

Read Operations

| Tool | Purpose | |------|---------| | get_channel_info | Look up channel by ID, display_name, or name. Optional team_id scope | | get_channel_members | List members of a channel with pagination | | get_team_info | Look up team by ID, display_name, or name | | get_team_members | List members of a team with pagination | | read_channel | Read recent posts from a channel (limit, since timestamp) | | read_post | Read a specific post and its thread | | search_posts | Search posts by query, optional team_id/channel_id scope | | search_users | Search users by username, email, or name |

Test Data Creation Workflow

Follow this order to avoid missing dependencies:

Step 1: Gather Requirements from User

Ask the user what kind of environment they want. If they don't specify, offer a default scenario. Key questions:

• Theme: What kind of team? (engineering, sales, support, devops, etc.)
• Scale: How many users, channels, and messages?
• Conversation topics: Any specific scenarios to demonstrate?
• Realism level: Casual startup vs formal enterprise tone?

Merge user instructions with the defaults below. User instructions always take priority.

Step 2: Create the Team

create_team:
  name: url-friendly-name (lowercase, hyphens)
  display_name: Human Readable Name
  type: O (open) or I (invite-only)
  description: Brief team description

Save the returned team_id for subsequent calls.

Step 3: Create Users

Create users with realistic, diverse profiles. For each user, define a persona that guides their communication style throughout all conversations.

Guidelines:

• Use first.last format for usernames
• Use realistic email addresses (e.g., [email protected])
• Use password Testpassword1! for all test users (simple, meets complexity requirements)
• Give each user a distinct role and communication style
• Vary seniority levels (lead, senior, mid, junior, etc.)

Save each returned user_id.

Persona template (track internally, do not post):

Name: [Full Name]
Username: [first.last]
Role: [Job title]
Style: [Communication traits - e.g., concise and technical, friendly and verbose, asks lots of questions]
Expertise: [Domain strengths]

Step 4: Add Users to Team

Call add_user_to_team for each user with the team_id from Step 2.

Step 5: Create Channels

Create channels appropriate for the team theme. Always include:

• A general channel for announcements and broad discussion
• A random channel for casual/off-topic conversation
• 2-4 topic-specific channels matching the team's domain

For each channel, provide a meaningful purpose and header.

Save each returned channel_id.

Step 6: Add Users to Channels

Call add_user_to_channel for each user+channel combination. Not every user needs to be in every channel - match membership to roles.

Step 7: Create Conversations

This is the most important step. Use create_post_as_user to post as each user with their username and password.

Conversation Quality Guidelines

Message variety:

• Mix short responses ("Sounds good!", "On it.") with detailed technical messages
• Include markdown formatting where natural (code blocks, bullet lists, bold)
• Some messages should reference external links or tools
• Vary message length by persona (seniors write concisely, juniors explain more)

Thread usage:

• Use root_id to create threaded replies for detailed discussions
• Not every message needs a thread - quick acknowledgments stay in main channel
• Threads should have 2-5 replies typically, occasionally more for complex topics

Persona consistency:

• The team lead coordinates, makes decisions, celebrates wins
• Senior engineers give concise technical guidance
• Junior engineers ask questions, share what they learned
• Each person has a distinct voice

Natural flow:

• Conversations should reference each other implicitly ("as we discussed in #incidents")
• Include realistic work artifacts (deployment commands, config snippets, monitoring queries)
• Show collaboration: someone asks a question, others help, problem gets resolved

Conversation Templates

For each channel, create 2-4 distinct conversation threads. Example patterns:

Problem-solving thread:

1. Someone reports an issue
2. Others investigate and discuss
3. Solution is found and confirmed
4. Brief wrap-up or action items

Coordination thread:

1. Someone proposes a plan or schedule
2. Others confirm availability or raise concerns
3. Plan is finalized

Knowledge-sharing thread:

1. Someone shares an article, tool, or technique
2. Brief discussion about applicability
3. Maybe a follow-up action

Casual thread (for #random):

1. Light topic (weekend, conference, food)
2. A few friendly replies
3. Naturally fizzles out

Tips for Realistic Data

• Don't over-emoji. Real engineers use them sparingly. One or two per conversation, not every message.
• Include imperfections. Occasional typos, self-corrections ("wait, I meant..."), or "nvm, found it" messages.
• Reference real tools. Mention Grafana, Terraform, Kubernetes, Jenkins, GitHub, etc. by name.
• Show team dynamics. The lead praises good work. The junior asks for help. The senior mentors casually.
• Keep it proportional. 3-5 messages per simple thread, 6-10 for complex discussions. Don't create 50-message threads.

Reading and Searching Data

Find existing data

search_users: term="john"            # Find users by name/email
get_team_info: team_display_name="Engineering"  # Find team by name
get_channel_info: channel_display_name="General" # Find channel by name

Read conversations

read_channel: channel_id="...", limit=50        # Recent messages
read_channel: channel_id="...", since="2024-01-01T00:00:00Z"  # Since timestamp
read_post: post_id="...", include_thread=true   # Full thread
search_posts: query="deployment", team_id="..." # Search by keyword

Inspect membership

get_team_members: team_id="...", limit=50, page=0
get_channel_members: channel_id="...", limit=50, page=0

Common Pitfalls

• Channel name vs display_name: name must be URL-friendly (lowercase, hyphens, no spaces). display_name is what users see.
• Team type: Use O for open, I for invite-only. Most test scenarios want O.
• Channel type: Use O for public, P for private.
• Post ordering: Posts appear in creation order. Create them in the order you want them to appear.
• Thread replies: Set root_id to the parent post's ID. The channel_id must match the parent post's channel.
• User passwords: When using create_post_as_user, you need the password you set during user creation. Keep it consistent.
• IDs are 26 characters: All Mattermost IDs (team, channel, user, post) are exactly 26 alphanumeric characters.

Example: Minimal Quick Setup

For a fast demo with minimal data:

1. Create team "demo-team"
2. Create 3 users (lead, senior, junior)
3. Add users to team
4. Create 2 channels (general, project)
5. Add users to channels
6. Create 5-8 messages per channel with 1-2 threaded discussions

This produces a believable workspace in ~30 tool calls.