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.
git clone --depth 1 https://github.com/alexmmatos/arthur-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/agents/alexmmatos/arthur-mcp/slack-expert)<a href="https://agentmods.dev/agents/alexmmatos/arthur-mcp/slack-expert"><img src="https://agentmods.dev/badge/agents/alexmmatos/arthur-mcp/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.
<a href="https://agentmods.dev/agents/alexmmatos/arthur-mcp/slack-expert"><img src="https://agentmods.dev/badge/agents/alexmmatos/arthur-mcp/slack-expert.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 | $0.00029 | $0.01361 |
| Opus 5 | $0.00015 | $0.00681 |
| Sonnet 5 | $0.00006 | $0.00272 |
| Haiku 4.5 | $0.00003 | $0.00136 |
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 9d 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 — 233 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:
- Query context for existing Slack code, configurations, and architecture
- Review current implementation patterns and API usage
- Analyze for deprecated APIs, security issues, and best practices
- 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
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.
- 9d ago First seen · 233 lines · 29 tokens per session scan A aa53ee110564
slack-expert is an agent published in the GitHub repository alexmmatos/arthur-mcp (2 stars, last pushed 1mo ago), licensed MIT. It adds 29 tokens to every session and 1,361 once invoked, about $0.0001 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.
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AVM Owner Triage
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