vskill: Skill for Claude Code

.claude/skills/marketing/slack-messaging/SKILL.md

slack-messaging is a skill for Claude Code from anton-abyzov/vskill. It costs 199 tokens per session (2,699 once invoked), scanned A, original, MIT.

A workflow for reading, searching, drafting, sending, and scheduling messages in Slack, a team chat application, across channels and threads.

In plain words
What is it for?
Use it to handle Slack channel messages and thread replies, search users or conversations, and prepare or schedule messages.
Why use it?
It keeps each thread's conversation context together while preventing unrelated channel messages from being mixed into the same discussion.

Skill for Claude Code

Written for Claude Code: installed under .claude/. Also seen: mentions subagents; mentions Claude Code.

This is anton-abyzov/vskill's own configuration. It tells Claude Code how to work on vskill 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 vskill configures →

Reuse

Borrowing it

Nothing to install: this file belongs to anton-abyzov/vskill. 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/anton-abyzov/vskill/main/.claude/skills/marketing/slack-messaging/SKILL.md
Clone the repo
git clone --depth 1 https://github.com/anton-abyzov/vskill

Made for: Claude Code.

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-messaging

README.md
[![agentmods](https://agentmods.dev/badge/skills/anton-abyzov/vskill/slack-messaging.svg)](https://agentmods.dev/skills/anton-abyzov/vskill/slack-messaging)
Your own site
<a href="https://agentmods.dev/skills/anton-abyzov/vskill/slack-messaging"><img src="https://agentmods.dev/badge/skills/anton-abyzov/vskill/slack-messaging.svg" alt="Measured on agentmods" height="20"></a>
Per session 199 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,699 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 warn 7 Sept 2026
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 Excessive Agency · line 150
    Skill enables autonomous high-impact decisions without human-in-the-loop verification. Critical operations (destructive commands, financial transactions, data deletion) should require explicit user confirmation.
    Fix: Add human-in-the-loop confirmation for destructive, irreversible, or high-impact operations. Never auto-execute commands that modify files, send data, or alter system state.
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 $0.00199 $0.02699
Opus 5 $0.00100 $0.01350
Sonnet 5 $0.00040 $0.00540
Haiku 4.5 $0.00020 $0.00270

Measured 8d ago against content hash 456e67e42972, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

slack-messaging 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.

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.

.claude/skills/marketing/slack-messaging/SKILL.md · 247 lines

How it starts

The opening of the file, as written. The whole thing — 247 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Slack Messaging

Read, send, search, draft, and schedule Slack messages across channels and threads. This skill wraps the Slack MCP tools with clear workflows and -- critically -- enforces context boundaries: thread conversations keep their context within a single session, while each new channel-level conversation gets a fresh session.


Why Context Boundaries Matter

Slack conversations have natural scoping. A thread is one continuous discussion -- if you lose context mid-thread, your replies become disjointed and unhelpful. But two unrelated messages in a channel are separate conversations -- mixing their context causes confusion and information leakage between topics.

This skill enforces these boundaries so your Slack interactions stay coherent:

  • Thread = one session. All replies within the same thread share context. You remember what was said earlier in the thread and can reference it.
  • New channel message = new session. Each top-level message you respond to in a channel starts fresh. No carryover from previous conversations.

Session Management Rules

When to Keep the Same Session (Thread Continuity)

Stay in the same Claude Code session when:

  1. You are replying to a thread and need to send a follow-up reply in that same thread
  2. The user asks you to continue a conversation you already started in a thread
  3. You are reading and responding to multiple messages within a single thread
  4. The user says things like "reply again", "follow up", "add to that thread", "also mention..."

In practice: if you have a thread_ts and you're sending another message with the same thread_ts, you are in the same conversation. Keep your context.

When to Start a New Session (Channel Isolation)

Start a new Claude Code session (fresh context) when:

  1. The user asks you to respond to a different top-level message in a channel
  2. You move from one channel conversation to an unrelated one
  3. The user asks you to "check Slack" or "read messages" in a channel -- each message that needs a response is its own session
  4. The user says things like "now respond to that other message", "handle the next one", "what about the message from [someone else]"

Read the full file on GitHub · 247 lines

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 · 247 lines · 199 tokens per session scan A 456e67e42972

Subscribe to this mod's changes

slack-messaging is a skill published in the GitHub repository anton-abyzov/vskill (45 stars, last pushed yesterday), licensed MIT. It adds 199 tokens to every session and 2,699 once invoked, about $0.0010 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.