Open Knowledge
ojowwalker77/BonsAI
Authoritative agent-runtime contract for working inside an OpenKnowledge project — a markdown-CRDT knowledge base exposed over MCP.
A skill your agent uses when writing, drafting, scheduling, or improving a Slack message, announcement, or reply sent via the Slack MCP tools (slacksendmessage, slacksendmessagedraft…
Install Slack Messaging
$ npx skills add slackapi/slack-skills-plugin --skill slack-messaging -a claude-codeProject install by default; add -g for ~/.claude/skills/.
$ gh skill install slackapi/slack-skills-plugin slack-messaging --agent claude-codeProject scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).
$ git clone --depth 1 https://github.com/slackapi/slack-skills-plugin.git skills-src && mkdir -p .claude/skills && cp -r skills-src/skills/slack-messaging .claude/skills/slack-messaging && rm -rf skills-srcUse ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.
Claude Code skills documentation · loads skills from .claude/skills/
Install the "slack-messaging" agent skill from https://github.com/slackapi/slack-skills-plugin/tree/main/skills/slack-messaging into .claude/skills/slack-messaging/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "slack-messaging", then confirm the skill loads.Claude Code copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$skill-installer install https://github.com/slackapi/slack-skills-plugin/tree/main/skills/slack-messagingType this inside Codex. $skill-installer <name> installs a curated skill from openai/skills. The installer writes to $CODEX_HOME/skills (default ~/.codex/skills). Restart Codex if the skill does not show up.
$ npx skills add slackapi/slack-skills-plugin --skill slack-messaging -a codexProject install goes to .agents/skills/; add -g for ~/.codex/skills/.
$ gh skill install slackapi/slack-skills-plugin slack-messaging --agent codexProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/slackapi/slack-skills-plugin.git skills-src && mkdir -p .agents/skills && cp -r skills-src/skills/slack-messaging .agents/skills/slack-messaging && rm -rf skills-srcUse ~/.agents/skills/ instead of .agents/skills for a personal install.
Codex skills documentation · loads skills from .agents/skills/
Install the "slack-messaging" agent skill from https://github.com/slackapi/slack-skills-plugin/tree/main/skills/slack-messaging into .agents/skills/slack-messaging/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "slack-messaging", then confirm the skill loads.Codex copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add slackapi/slack-skills-plugin --skill slack-messaging -a cursorProject install goes to .agents/skills/; add -g for ~/.cursor/skills/.
$ gh skill install slackapi/slack-skills-plugin slack-messaging --agent cursorProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/slackapi/slack-skills-plugin.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/skills/slack-messaging .cursor/skills/slack-messaging && rm -rf skills-srcUse ~/.cursor/skills/ instead of .cursor/skills for a personal install.
Cursor skills documentation · loads skills from .cursor/skills/, .agents/skills/, .claude/skills/, .codex/skills/
Install the "slack-messaging" agent skill from https://github.com/slackapi/slack-skills-plugin/tree/main/skills/slack-messaging into .cursor/skills/slack-messaging/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "slack-messaging", then confirm the skill loads.Cursor copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gemini skills install https://github.com/slackapi/slack-skills-plugin.git --path skills/slack-messaging--scope user (default) or --scope workspace; --path is the subfolder of the repo that holds the skill; --consent skips the security confirmation prompt.
$ npx skills add slackapi/slack-skills-plugin --skill slack-messaging -a gemini-cliProject install goes to .agents/skills/; add -g for ~/.gemini/skills/.
$ gh skill install slackapi/slack-skills-plugin slack-messaging --agent gemini-cliProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/slackapi/slack-skills-plugin.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/skills/slack-messaging .gemini/skills/slack-messaging && rm -rf skills-srcUse ~/.gemini/skills/ instead of .gemini/skills for a personal install, then run /skills reload.
Gemini CLI skills documentation · loads skills from .gemini/skills/, .agents/skills/
Install the "slack-messaging" agent skill from https://github.com/slackapi/slack-skills-plugin/tree/main/skills/slack-messaging into .gemini/skills/slack-messaging/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "slack-messaging", then confirm the skill loads.Gemini CLI copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gh skill install slackapi/slack-skills-plugin slack-messagingInstalls for Copilot at project scope by default; add --scope user for a personal install. Preview a skill first with gh skill preview. Needs GitHub CLI 2.90.0 or later (public preview).
$ npx skills add slackapi/slack-skills-plugin --skill slack-messaging -a github-copilotProject install goes to .agents/skills/; add -g for ~/.copilot/skills/.
$ git clone --depth 1 https://github.com/slackapi/slack-skills-plugin.git skills-src && mkdir -p .github/skills && cp -r skills-src/skills/slack-messaging .github/skills/slack-messaging && rm -rf skills-srcUse ~/.copilot/skills/ instead of .github/skills for a personal install. Commit .github/skills so cloud agent and code review can use it.
GitHub Copilot skills documentation · loads skills from .github/skills/, .claude/skills/, .agents/skills/
Install the "slack-messaging" agent skill from https://github.com/slackapi/slack-skills-plugin/tree/main/skills/slack-messaging into .github/skills/slack-messaging/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "slack-messaging", then confirm the skill loads.GitHub Copilot copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add slackapi/slack-skills-plugin --skill slack-messaging -a opencodeOpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.
$ gh skill install slackapi/slack-skills-plugin slack-messaging --agent opencodeProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/slackapi/slack-skills-plugin.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/skills/slack-messaging .opencode/skills/slack-messaging && rm -rf skills-srcUse ~/.config/opencode/skills/ instead of .opencode/skills for a personal install.
OpenCode skills documentation · loads skills from .opencode/skills/, .claude/skills/, .agents/skills/
Install the "slack-messaging" agent skill from https://github.com/slackapi/slack-skills-plugin/tree/main/skills/slack-messaging into .opencode/skills/slack-messaging/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "slack-messaging", then confirm the skill loads.OpenCode copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
Facts
- Skill name
slack-messaging- GitHub stars
- 144
- Token cost
- ~1.3k tokens
- SKILL.md length
- 618 words
- Files
- 1
- Skills in repo
- 7
- Repo updated
- First seen
- Licence
- MIT
At a glance
A skill your agent uses when writing, drafting, scheduling, or improving a Slack message, announcement, or reply sent via the Slack MCP tools (slacksendmessage, slacksendmessagedraft…
- Improving a Slack message
- SKILL.md covers When to Use, Formatting, Message Structure Guidelines and Thread vs. Channel Etiquette, plus 3 more sections
- Instructions only: no scripts, shell commands, URLs or credentials in SKILL.md
- Reply sent via the Slack MCP tools (slacksendmessage
What it does
Slack Messaging is an agent skill from slackapi/slack-skills-plugin, published by the product's own GitHub organization. Use when writing, drafting, scheduling, or improving a Slack message, announcement, or reply sent via the Slack MCP tools (slacksendmessage, slacksendmessagedraft, slackschedulemessage). Covers Slack markdown formatting, message structure, thread etiquette, reactions, and scheduling, and points to the right dialect for canvases and Block Kit.
Its SKILL.md is about 1.3k tokens, which your agent loads only when the skill is triggered. It is a single SKILL.md file with no bundled scripts.
It sits in Documents & Office, covering Markdown and MCP servers. It works with Slack. The repository describes itself as: Claude Code, Codex, Cursor, and npx skills plugin that enables your AI tools with a Slack MCP Server and Slack Developer Skills. The licence is MIT.
When your agent uses it
- Improving a Slack message
- Reply sent via the Slack MCP tools (slacksendmessage
- Slacksendmessagedraft
- Slackschedulemessage)
Example prompts
- “/slack-messaging”
Requirements
- Python 3
What it can do on your machine
Read from SKILL.md and the folder at commit 64c3f33. It shows what the files ask for, not the result of running them.
Tool permissions
Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.
From allowed-tools in the SKILL.md frontmatter.
Runs code
No scripts in the folder and no shell commands in SKILL.md.
From the folder's file list and the shell code blocks in SKILL.md.
Network
No URLs in SKILL.md.
From URLs in SKILL.md, links to its own repository left out.
Credentials
Names no API keys, tokens, secrets or passwords.
From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.
Context cost
Slack Messaging loads about 1.3k tokens when it runs. Until then it costs about 92 tokens; SKILL.md has 618 words of instructions outside code blocks.
Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.
Safety
Auto-check passed
The automated check found no risky patterns in SKILL.md.
Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.
SKILL.md
The full file from slackapi/slack-skills-plugin at commit 64c3f33, republished under its MIT licence (© slackapi). 618 words, ~1,293 tokens.
Download SKILL.mdSave it as
.claude/skills/slack-messaging/SKILL.md (or your agent's skills folder).- name
- slack-messaging
- description
- Use when writing, drafting, scheduling, or improving a Slack message, announcement, or reply sent via the Slack MCP tools (slack_send_message, slack_send_message_draft, slack_schedule_message). Covers Slack markdown formatting, message structure, thread etiquette, reactions, and scheduling, and points to the right dialect for canvases and Block Kit.
Slack Messaging Best Practices
This skill provides guidance for composing well-formatted, effective Slack messages.
When to Use
Apply this skill whenever composing, drafting, or helping the user write a Slack message, including when using slack_send_message, slack_send_message_draft, or slack_schedule_message. The formatting rules below cover these message tools. slack_create_canvas uses a different, richer markdown dialect — see the Canvas note below.
Formatting
The message tools (slack_send_message, slack_send_message_draft, slack_schedule_message) accept standard markdown and convert it to Slack formatting on send. Write normal markdown. Do not use Slack's legacy mrkdwn syntax (*bold*, ~strike~); those single-character forms mean something different in standard markdown. Each text element is limited to ~5000 characters.
| Format | Syntax |
|---|---|
| Bold | **text** |
| Italic | _text_ (or *text*) |
| Strikethrough | ~~text~~ |
| Code (inline) | `code` |
| Quote | > text |
| Link | [display text](url) |
| Bulleted list | - item |
| Numbered list | 1. item |
Block elements also work. Write them as literal markdown:
Code block with an optional language for syntax highlighting:
text ```python print("hello") ```Table with
|delimiters (escape a literal pipe inside a cell as\|):text | Feature | Status | |---------|--------| | Tables | works |Headers with
#/##/###:text ## Section title
The one thing that does not embed in a message: inline images () typically render as a plain link rather than an inline image. For rich embedded layouts (buttons, images, structured cards) you need Block Kit; for a document-style surface where images do embed, use a canvas. See the Notes below.
Message Structure Guidelines
- Lead with the point. Put the most important information in the first line. Many people read Slack on mobile or in notifications where only the first line shows.
- Keep it short. Aim for 1-3 short paragraphs (the ~5000-character limit is a ceiling, not a target). If the message is long or structured, consider a Canvas instead.
- Use line breaks generously. Walls of text are hard to read. Separate distinct thoughts with blank lines.
- Use bullet points for lists. Anything with 3+ items should be a list, not a run-on sentence.
- Bold key information. Use
**bold**for names, dates, deadlines, and action items so they stand out when scanning.
Thread vs. Channel Etiquette
- Reply in threads when responding to a specific message to keep the main channel clean.
- Use
reply_broadcast(also post to channel) only when the reply contains information everyone needs to see. - Post in the channel (not a thread) when starting a new topic, making an announcement, or asking a question to the whole group.
- Don't start a new thread to continue an existing conversation; find and reply to the original message.
Show full SKILL.md (220 more words)Show less
Tone and Audience
- Match the tone to the channel:
#generalis usually more formal than#random. - For simple acknowledgments, add an emoji reaction with
slack_add_reactioninstead of a reply message (useslack_get_reactionsto read existing reactions). - When writing announcements, use a clear structure: context, key info, call to action.
Scheduling
- Use
slack_schedule_messageto post later.post_atis a Unix timestamp that must be at least 2 minutes in the future and at most 120 days out; the message body uses the same standard markdown as above. - Scheduled messages can't be edited via the API once set — the user manages them from Drafts & sent in Slack.
Notes
- Canvas formatting is different.
slack_create_canvasuses Canvas-flavored Markdown, a richer dialect than the message tools: headers, tables, checklists, and inline images () all embed, and it also supports user/channel reference cards, callouts, and columns. Do not assume the message rules above apply — follow theslack_create_canvastool's own formatting guidance when composing a canvas. - Scope: this skill owns composing and formatting the text of messages sent through the Slack MCP message tools. For interactive layouts (buttons, menus, modals, Home tabs, or any Block Kit JSON), use the
slack:block-kitskill, which composes and validates the block payload. For calling the Slack Web API directly (chat.postMessageand friends) rather than the MCP tools, use theslack:slack-apiskill.
© slackapi, MIT. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file
Files
Just SKILL.md in skills/slack-messaging of slackapi/slack-skills-plugin.
Open the folder on GitHubat commit 64c3f33
Compare with similar skills
Slack Messaging next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.
| Skill | Stars | Used in | Tokens | Auto-check | Licence | Repo updated |
|---|---|---|---|---|---|---|
| Slack Messaging this skillslackapi/slack-skills-plugin | 144 | — | ~1.3k | Automated safety check: Pass | MIT | |
| Open Knowledgeojowwalker77/BonsAI | 145 | — | ~5.1k | Automated safety check: Pass | Custom licence | |
| Markdown To Confluencetestdouble/han | 279 | — | ~2.4k | Automated safety check: Pass | MIT | |
| Microsoft 365 Agents ToolkitOfficeDev/microsoft-365-agents-toolkit | 781 | — | ~2.8k | Automated safety check: Notes | Custom licence | |
| Gdoc To Markdowniurykrieger/claude-bedrock | 105 | 1 repos | ~3.8k | Automated safety check: Notes | MIT | |
| Delivery Routinggrandamenium/cortextos | 100 | — | ~1.5k | Automated safety check: Pass | MIT |
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Markdown To Confluence
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Publishes a local Markdown file to a user-specified Confluence location, creating a new page or updating an existing one through the Atlassian MCP server.
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Builds, tests, and deploys Microsoft 365 apps and agents for Teams and Copilot.
Gdoc To Markdown
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Internal fetcher module for Google Docs and Sheets. An agent skill from iurykrieger/claude-bedrock.
Delivery Routing
grandamenium/cortextos
Route research summaries to local markdown, Telegram, or Slack with approval gates and delivery-state updates.
Outline
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Conventions and efficient workflows for Outline knowledge bases via mcp-outline tools.
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Works with
Categories
Questions about Slack Messaging
What does Slack Messaging do?
A skill your agent uses when writing, drafting, scheduling, or improving a Slack message, announcement, or reply sent via the Slack MCP tools (slacksendmessage, slacksendmessagedraft…. Slack Messaging is an agent skill from slackapi/slack-skills-plugin, published by the product's own GitHub organization. Use when writing, drafting, scheduling, or improving a Slack message, announcement, or reply sent via the Slack MCP tools (slacksendmessage, slacksendmessagedraft, slackschedulemessage).
When should I use Slack Messaging?
Slack Messaging fits situations like: improving a Slack message; reply sent via the Slack MCP tools (slacksendmessage; slacksendmessagedraft; slackschedulemessage).
How do I install Slack Messaging in Claude Code?
Run `npx skills add slackapi/slack-skills-plugin --skill slack-messaging -a claude-code`. Or copy the skill folder (skills/slack-messaging in slackapi/slack-skills-plugin) into .claude/skills/slack-messaging in your project. Claude Code loads it when a task matches its description.
How do I install Slack Messaging in Codex?
Run `npx skills add slackapi/slack-skills-plugin --skill slack-messaging -a codex`. Or copy the skill folder (skills/slack-messaging in slackapi/slack-skills-plugin) into .agents/skills/slack-messaging in your project. Codex loads it when a task matches its description.
Can I use Slack Messaging in Cursor, Gemini CLI or GitHub Copilot?
Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add slackapi/slack-skills-plugin --skill slack-messaging -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/slack-messaging, .gemini/skills/slack-messaging, .github/skills/slack-messaging and .opencode/skills/slack-messaging in your project.
What does Slack Messaging need to run?
SKILL.md names no scripts, command-line tools or credentials: Slack Messaging is instructions for the agent only. Our summary lists: Python 3.
Does Slack Messaging access the network?
SKILL.md contains no URLs. Any network use would come from the scripts or tools the agent runs. This is read from the text; nothing was executed.
Is Slack Messaging safe to install?
Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.
What licence does Slack Messaging use?
Slack Messaging is published under the MIT licence (the repository's licence). It allows redistribution, so the full SKILL.md is shown on this page.
How many tokens does Slack Messaging use?
About 1.3k tokens (SKILL.md is roughly 5.2k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full.
What are the alternatives to Slack Messaging?
Skills that share tags, products or a category with Slack Messaging: Open Knowledge (ojowwalker77/BonsAI, 145 stars), Markdown To Confluence (testdouble/han, 279 stars), Microsoft 365 Agents Toolkit (OfficeDev/microsoft-365-agents-toolkit, 781 stars) and Gdoc To Markdown (iurykrieger/claude-bedrock, 105 stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.
Who maintains Slack Messaging?
slackapi (a GitHub organization, an official publisher) maintains it in slackapi/slack-skills-plugin, which has 144 GitHub stars. The repository holds 7 skills in this directory. The repository was last updated on October 6, 2026.
Source: slackapi/slack-skills-plugin on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.