Mattermost is unclaimed —

Mattermost

Collaboration Platform for Mission Critical Work·mattermost.com

Mattermost is a secure, open-core collaboration platform offering channel-based messaging, workflow automation (Playbooks), audio/screen sharing (Calls), Kanban-style project tracking (Boards), and AI agent integration. It is designed for mission-critical, national security, and critical infrastructure organizations, and can be deployed self-hosted, in private/sovereign cloud, or in air-gapped environments for full data control.

What it's for

Integrated Security OperationsOut-of-Band Incident ResponseSelf-Sovereign CollaborationMission-Critical ChatOpsReal-Time DevSecOps CollaborationPurpose-Built Collaboration HubCommand + Control operations

Features 23

1:1 audio calls and screen sharing
AD/LDAP user sync
Advanced access controls
AI bot and multi-LLM integration (bring-your-own LLM)
Channel categorization and hashtags
Channel-based messaging (1:1, group, public/private channels)
Compliance exports and audit logging
Core search (up to 3 million posts)
Custom branding, themes, and emojis
Custom user groups
Data encryption at rest and in transit
File sharing with link and media previews
Group calling and screen share (up to ~50 concurrent users per server)
Guest accounts
Kanban-style project tracking via Boards
Markdown formatting support
Message priority levels and persistent notifications
Multi-window desktop support
Multifactor authentication
Open APIs, webhooks, and plugin architecture
Single sign-on (SAML, OpenID Connect, OAuth 2.0)
Threaded discussions
Workflow automation via Playbooks

At a glance

free tierfree trialopen sourceself-hostableAPI

TypeWeb app

DeploymentHybrid

PlatformsWeb, Windows, macOS, iOS, Android

LanguagesEnglish (Australian, US), Bulgarian, Chinese (Simplified and Traditional), Dutch, French, German, Hungarian, Italian, Japanese, Korean, Persian, Polish, Portuguese (Brazil), Romanian, Russian, Spanish, Swedish, Turkish, Ukrainian, Vietnamese

Forgovernments, enterprises, allied militaries, defense and national security organizations, critical infrastructure operators, financial services, energy and utilities, transportation and logistics, regulated industries

CompanyMattermost

Integrations

JiraGitHubGitLabZoomServiceNowPagerDutyTAKMicrosoft TeamsOutlookMicrosoft 365JenkinsGitAzureAWSOracleGoogleActive DirectoryLDAPPexip

Complianceself-reported

GDPRCCPA

Resources

Pricing

Professional and Enterprise plans are quote-based (Contact Sales / Get Pricing); no public numeric pricing is shown. A free, limited-use edition of Enterprise Advanced is offered for technical evaluation, and 'Mattermost Free' is referenced as a community-supported edition for organizations evaluating a future Enterprise purchase.

Mattermost FreeFree

Used by organizations to evaluate a future purchase of Mattermost Enterprise; community support via peer-to-peer forums.

Community support only

ProfessionalQuote

Channel-centric plan for team collaboration; pricing available by contacting sales. Includes business-hours Professional Support (8am-8pm US Pacific Time, next business day email/ticket response).

Maximum 250 Users

EnterpriseQuote

For secure collaborative workflows; custom pricing available on request ('Get Pricing').