slack

slack is a skill for Claude Code, Codex from laude-institute/headlong. It costs 20 tokens per session (527 once invoked), scanned A, original, Apache-2.0.

A Slack connection for receiving messages from people and replying to them in direct messages or channel threads. Slack is a workplace chat service.

In plain words
What is it for?
It helps read who sent a Slack message and where it was posted, then continue the conversation or send a follow-up later.
Why use it?
It removes the need to manually route replies through Slack’s API or find the right conversation. Replies go back to the sender or thread they came from.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit It helps read who sent a Slack message and where it was posted, then continue the conversation or send a follow-up later.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/laude-institute/headlong/slack
About the project

Headlong is a Bash-based agent microharness for running language-model agents in persistent, self-directed loops. People use it to create agents that maintain ongoing interests and projects, interact through shell commands, and share one stream of conversations across a team and chat services.

laude-institute/headlong · 1,135 stars · on GitHub · headlong.ai

Install

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.

Any agent
npx skills add laude-institute/headlong --skill slack
Clone the repo
git clone --depth 1 https://github.com/laude-institute/headlong

Made for: Claude Code, Codex.

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

README.md
[![agentmods](https://agentmods.dev/badge/skills/laude-institute/headlong/slack.svg)](https://agentmods.dev/skills/laude-institute/headlong/slack)
Your own site
<a href="https://agentmods.dev/skills/laude-institute/headlong/slack"><img src="https://agentmods.dev/badge/skills/laude-institute/headlong/slack.svg" alt="Measured on agentmods" height="20"></a>
Per session 20 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 527 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. Third-party audits
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
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 $0.00020 $0.00527
Opus 5 $0.00010 $0.00264
Sonnet 5 $0.00004 $0.00105
Haiku 4.5 $0.00002 $0.00053

Measured 2d ago against content hash b3adfee0e7fa, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

slack 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 2d 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.

skills/slack/SKILL.md · 62 lines

What it actually says

slack

Instructions

A Slack bridge forwards messages between your mind log and the org's Slack workspace. You do not need to call the Slack API — the bridge handles delivery in both directions.

Recognizing Slack messages

Messages from Slack arrive as normal message steps whose from looks like:

  • slack-U07AB12CD-D09XYZ123 — a direct message
  • slack-U07AB12CD-C09XYZ123-1722400000.123456 — a channel thread

The parts are Slack IDs: user, channel, and (for channels) the thread timestamp. The message content starts with a readable header like (Slack: Dana Kim in #eng) telling you who is talking and where.

Replying

Reply exactly as you would to any other sender — the bridge delivers it to the right Slack conversation (in-thread for channels, top-level for DMs):

chat reply slack-U07AB12CD-C09XYZ123-1722400000.123456 "On it — deploy is green."

Always use the sender's full slack-… name verbatim as the reply target. Do not shorten it or substitute the person's display name.

Reacting

Add an emoji reaction to the Slack message you are answering. Use the Slack short name (thumbsup, eyes, +1), not unicode:

chat react slack-U07AB12CD-C09XYZ123-1722400000.123456 thumbsup
chat react --reply-to <inbound-step-id> slack-U07AB12CD-C09XYZ123-1722400000.123456 eyes

--reply-to copies that inbound step's source_url so the reaction lands on the specific message, not just the thread root. Needs the Slack app's reactions:write scope (reinstall after it lands).

Following up proactively

To continue a Slack conversation later (e.g. after finishing a task someone asked about), chat reply to the same slack-… name from the earlier message. The bridge posts it into that conversation.

Formatting

Write normal markdown; the bridge converts it for Slack (bold, links, headings, code blocks). Long messages are split automatically. Prefer concise messages — it is chat, not a report.

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. 2d ago Changed · +14 lines b3adfee0e7fa
  2. 9d ago First seen · 48 lines · 20 tokens per session scan A 8034be6f8dca

Subscribe to this mod's changes

slack is a skill published in the GitHub repository laude-institute/headlong (1,135 stars, last pushed 3d ago), licensed Apache-2.0. It adds 20 tokens to every session and 527 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 2026-08-30.