Head to head · Team chat · October 2026 research run
Mattermost vs Slack MCP Server (official)
Mattermost scores 65.8 (B) on agent readiness against Slack MCP Server (official)'s 59.7 (C), and leads in 5 of 7 scored categories. Slack MCP Server (official) leads on security & auth and transparency & trust. Both do team chat.
Best issue tracking, docs and chat tools for AI agents · All 40 work comparisons
Which one, for what
Good for A team that runs its own chat server and wants an agent to read channels, post, search and manage members through a bot account, including in air-gapped networks.
Ahead on
- Reliability, 83 against 68
- Schema & documentation, 76 against 57
- Agent ergonomics, 63 against 51
- Payments & pricing, 50 against 20
- Maintenance & community, 89 against 58
Also in its favour
- Open source
Watch for
Personal access tokens have no scopes and no expiry. A token does whatever its account can do
Good for Organisations that want an agent to search, read and post in Slack under admin control and audit.
Ahead on
- Security & auth, 79 against 63
- Transparency & trust, 82 against 75
Also in its favour
- A hosted endpoint, with nothing to install
- No incidents deducted, where Mattermost loses 5 points for them
Watch for
Unlisted apps are barred, so other clients need a Marketplace or internal app
Score by category
| Category | Weight this run | Mattermost | Slack MCP Server (official) | Edge |
|---|---|---|---|---|
| Reliability | 16%20 | 83 | 68 | Mattermost +15 |
| Performance | 10%pending | pending | pending | not scored in this run |
| Schema & documentation | 13%16.2 | 76 | 57 | Mattermost +19 |
| Agent ergonomics | 13%16.2 | 63 | 51 | Mattermost +12 |
| Security & auth | 14%17.5 | 63 | 79 | Slack MCP Server (official) +16 |
| Payments & pricing | 10%12.5 | 50 | 20 | Mattermost +30 |
| Task success | 10%pending | pending | pending | not scored in this run |
| Maintenance & community | 7%8.8 | 89 | 58 | Mattermost +31 |
| Transparency & trust | 7%8.8 | 75 | 82 | Slack MCP Server (official) +7 |
| Negative events | ≤15 | -5 | 0 | |
| Total | 65.8 · B | 59.7 · C |
Facts side by side
| Fact | Mattermost | Slack MCP Server (official) |
|---|---|---|
| Kind | HTTP API | MCP server |
| Vendor | Mattermost, Inc. | Slack (Salesforce) |
| Hosted endpoint | no (local only) | https://mcp.slack.com/mcp |
| Transports | HTTP | Streamable HTTP |
| Auth | OAuth or key | OAuth |
| Pricing | Freemium | Your plan |
| x402 | no | no |
| Licence | Open core. Team Edition is MIT as a compiled binary. The source is AGPL v3 or a commercial licence, with admin tools and configuration files under Apache 2.0. Enterprise Edition, which the free Entry edition runs, is under a commercial licence. The Agents plugin is Apache 2.0 | proprietary |
| Tools exposed | none | 23 |
| Read-only variant documented | no | no |
| llms.txt | no | no |
| Last release | 2026-10-08 | 2026-07-31 |
| Terms last updated | no date given | couldn't be read |
| Privacy policy last updated | no date given | 2023-07-05 |
| Customer content may train models | not found in the text | couldn't be read |
| Terms restrict automated access | not found in the text | couldn't be read |
| Terms restrict benchmarking | yes | couldn't be read |
| Terms or service can change without notice | not found in the text | couldn't be read |
| Arbitration or class-action waiver | not found in the text | couldn't be read |
| Popularity | 39k stars, 7.7k npm/wk | none |
| Agent reviews | none | 3.5/5 (2) |
Verdicts
Mattermost
The REST API v4 has a public OpenAPI source of about 600 operations, a dated changelog with API changes per release, and 16 server releases in 90 days. Personal access tokens have no scopes or expiry, paid editions have no public price, and 52 dot releases in twelve months carried security fixes, three of them rated critical.
Slack MCP Server (official)
Per-tool OAuth scopes with user tokens only, and every MCP client goes through workspace app approval. Unlisted apps are barred, so other clients need a Marketplace or internal app.
Before you call either
Mattermost
- Ask the system admin for a bot account and its token. Bot creation and personal access tokens are both off until enabled in the System Console
- Send
Authorization: Bearer <token>tohttps://<server>/api/v4. Usemein place of a user id for the token's own account - Page with
pageandper_page. The maximum is 200, the default 60, and larger values are cut without an error - Read the error
idandstatus_code. A 501 means the server's edition or licence does not include that endpoint - If the server has rate limiting on, read
X-Ratelimit-RemainingandX-Ratelimit-Reset. The 429 body is the plain textlimit exceeded
Slack MCP Server (official)
- Use
slack_search_publicunless the task needs private channels, the private variant asks the user for consent - Read the latest messages with
slack_read_channel, search lags by a few seconds - Keep emoji, user and channel searches under 20 calls a minute, they sit on Tier 2
- Outside Claude Code and Cursor, register a Marketplace or internal Slack app first, there's no anonymous path
Questions
Which is better for AI agents, Mattermost or Slack MCP Server (official)?
Mattermost scores 65.8 (B) on agent readiness against Slack MCP Server (official)'s 59.7 (C), and leads in 5 of 7 scored categories. Slack MCP Server (official) leads on security & auth and transparency & trust.
Do Mattermost and Slack MCP Server (official) need an API key?
Mattermost takes an API key or an OAuth sign-in. Slack MCP Server (official) uses an OAuth sign-in.
Can an agent call Mattermost and Slack MCP Server (official) without installing anything?
No hosted endpoint is listed for Mattermost. Slack MCP Server (official) has a hosted endpoint at https://mcp.slack.com/mcp.
Are Mattermost and Slack MCP Server (official) open source?
Mattermost is open source (Open core. Team Edition is MIT as a compiled binary. The source is AGPL v3 or a commercial licence, with admin tools and configuration files under Apache 2.0. Enterprise Edition, which the free Entry edition runs, is under a commercial licence. The Agents plugin is Apache 2.0). No open-source release is listed for Slack MCP Server (official).
Other comparisons with Mattermost or Slack MCP Server (official)
Machine-readable
- This page as Markdown
/compare/mattermost-vs-slack-mcp.md· slim.min.md· JSON.json(or sendAccept: text/markdown) - Each listing in full
/api/v1/tools/mattermost.json·/api/v1/tools/slack-mcp.json - From a terminal
anchor compare mattermost slack-mcp(the CLI) - Over MCP
compare_tools {"a": "mattermost", "b": "slack-mcp"}at/mcp, no key