This Claude skill automates the conversion of Slack threads into well-formatted Markdown documents. It streamlines knowledge management by extracting chat history, resolving user identities, and generating organized files with descriptive names directly from Slack URLs, making ephemeral conversations searchable and permanent.

When should I use slack-to-md?

slack-to-md is useful in the following scenarios: • Knowledge Archiving: Transform ephemeral Slack technical discussions into permanent project documentation or wiki pages for future reference. • Meeting Summarization: Convert Slack-based brainstorming sessions or async stand-ups into structured meeting notes and action items. • Documentation Syncing: Automatically update existing Markdown files with the latest messages from their source Slack threads to keep local documentation in sync with live discussions. • Onboarding Support: Create a searchable local knowledge base from historical Slack conversations to help new team members quickly understand past decisions and context.

name	slack-to-md
description	Convert Slack thread URLs to markdown documents. Trigger on "slack-to-md" command or when user provides Slack URLs (https://.slack.com/archives//p*). Also handles updating existing markdown files from their source Slack threads.

Slack to Markdown Converter

Convert Slack thread URLs to well-formatted markdown documents.

Prerequisites

Before using this skill, the following setup is required:

Node.js 18+: Required for the Slack API script
Set up Slack Bot: Create a bot at https://api.slack.com/apps with these OAuth scopes:
- channels:history - Read messages from public channels
- channels:join - Auto-join channels when needed
- users:read - Resolve user IDs to names
Configure token: Copy .env to .env.local and add your bot token:
```
BOT_TOKEN=xoxb-your-token-here
```

Workflow

1. Parse Input

Slack URL format: https://{workspace}.slack.com/archives/{channel_id}/p{timestamp}

Extract:

workspace: subdomain
channel_id: after /archives/
thread_ts: convert p{digits} → {first10}.{rest} (e.g., p1234567890123456 → 1234567890.123456)

Existing .md file: Read and extract Slack URL from > Source: line.

2. Execute Conversion

Run the two scripts in a pipe:

node {SKILL_DIR}/scripts/slack-api.mjs <channel_id> <thread_ts> | \
  {SKILL_DIR}/scripts/slack-to-md.sh <channel_id> <thread_ts> <workspace> {PROJECT_ROOT}/slack-outputs/<output_file>.md [title]

{SKILL_DIR}: Shown at the top when skill is invoked as "Base directory for this skill: ..."
{PROJECT_ROOT}: Git root or current working directory (use absolute paths for reliability)
slack-api.mjs: Fetches thread data from Slack API, outputs JSON
slack-to-md.sh: Reads JSON from stdin, generates markdown file

3. Rename to Meaningful Filename

After fetching, read the generated markdown file and extract the first message content. Then rename the file to a meaningful name:

Read the markdown file to find the first message (after the header)
Extract a short, descriptive title from the first message (first 30-50 characters, or a key phrase)
Sanitize the title for use as filename:
- Convert to lowercase
- Replace spaces with hyphens
- Remove special characters (keep only alphanumeric, hyphens, Korean characters)
- Truncate to reasonable length (max 50 chars)
Rename the file: mv {old_file}.md {PROJECT_ROOT}/slack-outputs/{sanitized_title}.md
Report the new filename to the user

4. Handle Errors

The slack-api.mjs script automatically handles common errors:

not_in_channel: Automatically joins the channel and retries
missing_scope: Prints required OAuth scope to stderr

If errors persist, check:

Bot token is valid in .env.local
Bot has required OAuth scopes
Bot is added to the workspace

Resources

scripts/slack-api.mjs: Slack API wrapper (Node.js 18+, no external deps)
scripts/slack-to-md.sh: JSON to markdown converter (requires jq, perl)

slack-to-md

When & Why to Use This Skill

Use Cases