slack-skills-plugin is a plugin that connects coding agents to Slack through a Slack MCP server and provides Slack-focused skills for users and developers. It is used with Claude Code, Cursor, Codex, and other coding agents to work with Slack and build Slack applications. The catalogue entries are the plugin's included skills, commands, MCP server, instructions, and settings.
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 slackapi/slack-skills-plugin --skill create-slack-appgit clone --depth 1 https://github.com/slackapi/slack-skills-pluginWrote 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/slackapi/slack-skills-plugin/create-slack-app)<a href="https://agentmods.dev/skills/slackapi/slack-skills-plugin/create-slack-app"><img src="https://agentmods.dev/badge/skills/slackapi/slack-skills-plugin/create-slack-app/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/slackapi/slack-skills-plugin/create-slack-app"><img src="https://agentmods.dev/badge/skills/slackapi/slack-skills-plugin/create-slack-app.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector warn
SkillSpector: 1 finding, up to medium
These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →
- medium Data Exfiltration · line 53 Data is being sent to an external URL. This could be legitimate telemetry or data exfiltration. Manual review is recommended.Fix: Verify the destination URL is trusted and necessary. Remove or replace with documented APIs. Ensure no secrets, tokens, or PII are transmitted.
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 | $0.00076 | $0.03313 |
| Opus 5.5 | $0.00030 | $0.01325 |
| Sonnet 5.5 | $0.00015 | $0.00663 |
| Haiku 4.5 | $0.00008 | $0.00331 |
Grade A, and why
create-slack-app 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 3d 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 — 236 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Create Slack App
Help the developer create a Slack app or agent using Bolt. If $0 is exactly bolt-js or bolt-python, treat it as the chosen framework and skip asking. Otherwise (including if it's empty or any other value), ignore it and ask the developer which framework they want before continuing.
This skill walks through the full setup: prerequisites, authentication, choosing a workspace to install into, project scaffolding from a template, and running the app locally.
Step 1: Check Prerequisites
1a. Detect the Slack CLI command
Use the slack:slack-cli skill — Step 1: Detect the Slack CLI — to check whether the public Slack CLI is installed and resolve its command name. The fingerprint check, alias fallback, and install instructions all live there; do not duplicate them here.
Once resolved, use the detected command name for all CLI commands throughout the rest of this skill. We refer to it as SLACK_CMD below — substitute the actual resolved command name everywhere you see SLACK_CMD.
1b. Verify the CLI version
Run SLACK_CMD version and print the version to confirm everything is working before continuing.
1c. Check language runtime
- If
$0isbolt-js: Runnode --versionto verify Node.js is installed (v18+ required). If not installed, suggestbrew install nodeor point to https://nodejs.org. - If
$0isbolt-python: Runpython3 --versionto verify Python is installed (3.6+ required). If not installed, suggestbrew install python3or point to https://python.org.
Step 2: Authenticate with the Slack CLI
Use the slack:slack-cli skill — Step 5: Authentication (slack auth) — to check the developer's auth status and walk them through SLACK_CMD login if they're not already authenticated.
Wait for confirmation that authentication succeeded before proceeding.
Step 3: Choose Where to Install the App
The app needs a Slack workspace to install into. Three targets work and they are not equivalent. Use AskUserQuestion to let the developer pick, presenting them in this order:
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.
- 3d ago Changed · +1 lines 8d6b3da34db8
- 5d ago Changed · +2 lines 225cbdbb9cc4
- 9d ago Changed · +2 lines 3f65b3394309
- 24d ago Changed · -2 tokens per session 4b1b27837e50
- 1mo ago Changed · +44 lines · +4 tokens per session abff0f9f3690
- 1mo ago First seen · 187 lines · 74 tokens per session scan A 4ba2eb423948
create-slack-app is a skill published in the GitHub repository slackapi/slack-skills-plugin (150 stars, last pushed 3d ago), licensed MIT. It adds 76 tokens to every session and 3,313 once invoked, about $0.0003 per session on Opus 5.5. 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 2026-08-30.
Other skills, from other repositories
api-and-interface-design
Guides stable API and interface design. Use when designing APIs, module boundaries, or any public interface. Use when creating REST or GraphQL endpoints, defining type contracts between modules, or establishing boundaries between frontend and backend.
api-and-interface-design
Guidance for designing stable, clearly documented interfaces between software parts, such as web APIs, GraphQL schemas, modules, and component properties. It covers defining the contract first, limiting accidental dependencies, and planning safe changes.
deprecation-and-migration
A guide for retiring old code, systems, or interfaces and moving users to replacements. Deprecation means marking something as no longer preferred; migration means switching its users safely.
awesome-performance-audit
Read-only performance and reliability audit: event loop, backpressure, memory and CPU, timeouts, retries, queues, Core Web Vitals, bundles, with a verdict. Use when something is slow, memory climbs or latency spikes.
awesome-error-standards
Applies consistent error handling: typed errors, operational vs programmer errors, API error envelopes, HTTP status mapping, user-facing messages. Use when adding or refactoring error handling or designing an error contract.
awesome-api-design
Designs or reviews an HTTP API's shape before code: resources, versioning, pagination, idempotency, filtering. Use when asked to design an API or an endpoint.