Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx skills add Knuckles-Team/mattermost-mcp --skill mattermost-channel-messaginggit clone --depth 1 https://github.com/Knuckles-Team/mattermost-mcpWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/knuckles-team/mattermost-mcp/mattermost-channel-messaging)<a href="https://agentmods.dev/skills/knuckles-team/mattermost-mcp/mattermost-channel-messaging"><img src="https://agentmods.dev/badge/skills/knuckles-team/mattermost-mcp/mattermost-channel-messaging/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/knuckles-team/mattermost-mcp/mattermost-channel-messaging"><img src="https://agentmods.dev/badge/skills/knuckles-team/mattermost-mcp/mattermost-channel-messaging.svg" alt="Reviewed on agentmods" width="80" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00116 | $0.01023 |
| Opus 5 | $0.00058 | $0.00511 |
| Sonnet 5 | $0.00023 | $0.00205 |
| Haiku 4.5 | $0.00012 | $0.00102 |
Grade A, and why
mattermost-channel-messaging scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 10d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 99 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Mattermost Channel Messaging
Domain-typed access to Mattermost posts and files for reading and writing channel conversation. Prefer these tools over raw HTTP — they carry the post field conventions and return post-shaped records.
When to use
- Read the recent posts of a channel, or a full thread from a root post.
- Search for a message across a team.
- Create a post, or reply within a thread (
root_id). - Read/attach files on a post.
When NOT to use
- Create, rename, archive, or set channel privacy →
mattermost-team-administration. - Add/remove channel or team members →
mattermost-team-administration. - Push messages/channels into the knowledge graph →
mattermost-kg-ingestion.
Prerequisites & environment
Connect via the mcp-client skill against the mattermost-mcp MCP server.
| Variable | Required | Notes |
|---|---|---|
MATTERMOST_URL |
✅ | Server base URL (alias MATTERMOST_MCP_BASE_URL) |
MATTERMOST_TOKEN |
✅* | Personal-access / bot token |
MATTERMOST_MCP_USERNAME / MATTERMOST_MCP_PASSWORD |
✅* | Login fallback if no token |
MATTERMOST_MCP_SSL_VERIFY |
optional | TLS verification toggle |
*Provide either a token or username+password. MCP_TOOL_MODE
(condensed|verbose|both) selects the condensed surface used below vs. the
one-to-one verbose tools.
Tools & actions
Prefer the condensed tools; each takes action + a params_json JSON string
whose keys are passed straight to the client method.
| Condensed tool | Key actions |
|---|---|
mattermost_mcp_posts |
get_posts_for_channel, get_post, get_post_thread, create_post, search_posts, pin_post, get_file_infos_for_post |
mattermost_mcp_files |
get_file, get_file_info, upload_file |
Key parameters
channel_id— required forget_posts_for_channel.post_id— required forget_post/get_post_thread.team_id— required forsearch_posts.create_postbody:channel_id,message, optionalroot_id(thread reply), optionalfile_ids.
What ships with it
1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 10d ago First seen · 99 lines · 116 tokens per session scan A 0fdd83ea78e6
mattermost-channel-messaging is a skill published in the GitHub repository Knuckles-Team/mattermost-mcp (0 stars, last pushed 13d ago), licensed MIT. It adds 116 tokens to every session and 1,023 once invoked, about $0.0006 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.
Other skills, from other repositories
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slackdump
Collect the Slack conversation data from Slackdump Archive format.
slackdump-sqlite3
Guidance for querying a Slackdump SQLite3 database directly via the sqlite3 CLI.
slackdump-source
Explains the different Slackdump sources structure.
mattermost-workflows
Safely summarize Mattermost channels and threads, search posts, resolve Mattermost team/channel names, and draft or publish reviewed posts through the bundled local Mattermost MCP server or another compatible connected server. Use for Mattermost conversations, decisions, action items, incident context, post search…
discord
Discord ops via the message tool (channel=discord).