gemini-agent-skills: Skill for Claude Code

.gemini/skills/slack-expert/SKILL.md

slack-expert is a skill for Claude Code, Gemini CLI from saeed-vayghan/gemini-agent-skills. It costs 55 tokens per session (1,092 once invoked), scanned A, original, MIT.

A Slack development guide for building apps, bots, commands, and interactive screens with Slack's APIs. It covers the Bolt framework, event handling, OAuth sign-in, and Block Kit, Slack's system for building interactive message layouts.

In plain words
What is it for?
Use it to build Slack bots and apps, handle messages and user actions, create slash commands and interactive forms, implement sign-in, and connect Slack with external APIs.
Why use it?
It helps avoid common integration mistakes such as insecure requests, leaked tokens, unsupported APIs, and unreliable error handling. It also provides patterns for connecting Slack to other systems.

Skill for Claude CodeGemini CLI

Written for Claude Code and Gemini CLI: allowed-tools in frontmatter, but also installed under .gemini/.

This is saeed-vayghan/gemini-agent-skills's own configuration. It tells Claude Code and Gemini CLI how to work on gemini-agent-skills itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything gemini-agent-skills configures →

Reuse

Borrowing it

Nothing to install: this file belongs to saeed-vayghan/gemini-agent-skills. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/saeed-vayghan/gemini-agent-skills/master/.gemini/skills/slack-expert/SKILL.md
Clone the repo
git clone --depth 1 https://github.com/saeed-vayghan/gemini-agent-skills

Made for: Claude Code, Gemini CLI.

Wrote 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.

agentmods badge for slack-expert

README.md
[![agentmods](https://agentmods.dev/badge/skills/saeed-vayghan/gemini-agent-skills/slack-expert/github.svg)](https://agentmods.dev/skills/saeed-vayghan/gemini-agent-skills/slack-expert)
Your own site
<a href="https://agentmods.dev/skills/saeed-vayghan/gemini-agent-skills/slack-expert"><img src="https://agentmods.dev/badge/skills/saeed-vayghan/gemini-agent-skills/slack-expert/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.

agentmods 80×15 button for slack-expert

Your own site · 80×15
<a href="https://agentmods.dev/skills/saeed-vayghan/gemini-agent-skills/slack-expert"><img src="https://agentmods.dev/badge/skills/saeed-vayghan/gemini-agent-skills/slack-expert.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 55 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,092 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00055 $0.01092
Opus 5 $0.00028 $0.00546
Sonnet 5 $0.00011 $0.00218
Haiku 4.5 $0.00006 $0.00109

Measured 8d ago against content hash d85b16f65a4a, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-11, from the pricing page.

Security

Grade A, and why

slack-expert 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 8d ago.

The scan reads SKILL.md. This mod also ships 1 executable file (references/event_handler_example.ts), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

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.

.gemini/skills/slack-expert/SKILL.md · 188 lines

How it starts

The opening of the file, as written. The whole thing — 188 lines — stays where its author put it; the contents beside it link to each section on GitHub.

You are an elite Slack Platform Expert and Developer Advocate with deep expertise in the Slack API ecosystem. You have extensive hands-on experience with @slack/bolt, the Slack Web API, Events API, and the latest platform features. You're genuinely passionate about Slack's potential to transform team collaboration.

When invoked:

  1. Query context for existing Slack code, configurations, and architecture
  2. Review current implementation patterns and API usage
  3. Analyze for deprecated APIs, security issues, and best practices
  4. Implement robust, scalable Slack integrations

Slack excellence checklist:

  • Request signature verification implemented
  • Rate limiting with exponential backoff
  • Block Kit used over legacy attachments
  • Proper error handling for all API calls
  • Token management secure (not in code)
  • OAuth 2.0 V2 flow implemented
  • Socket Mode for dev, HTTP for production
  • Response URLs used for deferred responses

Core Expertise Areas

Slack Bolt SDK (@slack/bolt)

  • Event handling patterns and best practices
  • Middleware architecture and custom middleware creation
  • Action, shortcut, and view submission handlers
  • Socket Mode vs. HTTP mode trade-offs
  • Error handling and graceful degradation
  • TypeScript integration and type safety

Slack APIs

  • Web API methods and rate limiting strategies
  • Events API subscription and verification
  • Conversations API for channel/DM management
  • Users API and user presence
  • Files API and file sharing
  • Admin APIs for Enterprise Grid

Block Kit & UI

  • Block Kit Builder patterns
  • Interactive components (buttons, select menus, overflow menus)
  • Modal workflows and multi-step forms
  • Home tab design and App Home best practices
  • Message formatting with mrkdwn
  • Attachment vs. Block Kit migration

Authentication & Security

  • OAuth 2.0 flows (V2 recommended)
  • Bot tokens vs. user tokens
  • Token rotation and secure storage
  • Scopes and principle of least privilege
  • Request signature verification

Modern Slack Features

  • Workflow Builder custom steps
  • Slack Canvas API
  • Slack Lists
  • Huddles integrations
  • Slack Connect for external collaboration

Read the full file on GitHub · 188 lines

Files

What ships with it

3 files 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.

Changes

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.

  1. 8d ago First seen · 188 lines · 55 tokens per session scan A d85b16f65a4a

Subscribe to this mod's changes

slack-expert is a skill published in the GitHub repository saeed-vayghan/gemini-agent-skills (34 stars, last pushed 7mo ago), licensed MIT. It adds 55 tokens to every session and 1,092 once invoked, about $0.0003 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 2026-09-03.