TL;DR

Winnr Claude Code Skills add cold email operational expertise on top of the MCP server. 6 slash commands — /winnr setup, /winnr health, /winnr troubleshoot, /winnr scale, /winnr export, and /winnr status — that turn Claude into an email infrastructure expert. Free, open source, and installed in 30 seconds. View on GitHub.

What Are Claude Code Skills?

Claude Code Skills are slash commands that give Claude domain-specific expertise. When you type /winnr setup in Claude Code, you're not just calling an API — you're activating a guided workflow that knows the right order of operations, the best practices, and the edge cases for cold email infrastructure.

Skills are different from MCP tools. MCP tools are individual API calls — "create a mailbox," "check DNS," "enable warming." Skills are the operational knowledge that ties those calls together into something useful: "set up 50 mailboxes across the right number of domains with professional names, verify DNS, enable warming, and generate a report."

Think of it this way: the MCP server gives Claude hands. Skills give it a brain.

MCP Tools vs. Skills: Plumbing vs. Expertise

The Winnr MCP server gives Claude 36 API tools — raw capabilities for managing domains, mailboxes, warming, and inbox. Skills layer cold email operational knowledge on top of those tools, turning individual API calls into guided multi-step workflows.

Here's the difference in practice:

MCP Tool (Raw API Call)Skill (Guided Workflow)What Changes
winnr_search_domains/winnr setupSearches, purchases, creates mailboxes, verifies DNS, enables warming — entire infrastructure in one command
winnr_get_warming_metrics/winnr healthScores every mailbox 0-100, flags problems, gives prioritized recommendations
winnr_get_dns_status/winnr troubleshootRuns diagnostic decision trees across DNS, warming, and deliverability
winnr_list_email_users/winnr scaleCalculates optimal ratios, suggests domains, handles the math
winnr_export_credentials/winnr exportRuns readiness checks before export — blocks if health is too low
winnr_get_account/winnr statusQuick snapshot with utilization percentages and warnings

You can use MCP tools without skills — Claude will still help manage your infrastructure. But skills encode the expertise that separates a good setup from a great one: the right domain-to-mailbox ratios, TLD selection strategy, warming timelines, and readiness thresholds that experienced cold email operators know by heart.

The Six Commands

/winnr setup — Full Infrastructure Wizard

The flagship skill. Tell Claude how many mailboxes you need and a keyword, and it handles everything: account capacity check, domain search and purchase (with your confirmation), DNS verification, mailbox creation with professional naming conventions, warming activation, and a final summary report. One command replaces 30 minutes of dashboard clicking.

/winnr health — Traffic-Light Health Report

Generates a scored health report for every mailbox in your account. Each mailbox gets a 0-100 score based on four weighted factors: DNS configuration (30%), warming performance (40%), utilization (15%), and infrastructure diversity (15%). Color-coded output flags critical issues in red, warnings in yellow, and healthy metrics in green. Includes prioritized action items.

/winnr troubleshoot — DNS and Deliverability Diagnostics

When something's wrong, this skill runs systematic diagnostic decision trees. It checks DNS records (MX, SPF, DKIM, DMARC), warming health, inbox placement rates, and infrastructure distribution. Instead of dumping raw data, it walks through the problem step by step and tells you exactly what to fix and in what order.

/winnr scale — Scale Up or Down with Best-Practice Ratios

Need more mailboxes? Fewer? This skill calculates the optimal number of new domains based on 3-5 mailboxes per domain, suggests TLDs that avoid spam-associated extensions, and handles the provisioning. Scaling down? It identifies which mailboxes to decommission based on health scores and warming age.

/winnr export — Export to 15+ Sequencer Formats

Exports your mailbox credentials to Smartlead, Instantly, Snov, Lemlist, Woodpecker, Reply, Mailshake, GMass, and more. But first, it runs readiness checks: account health must be above 75, inbox rate above 85%, and mailboxes must have been warming for at least 14 days. If any check fails, it tells you why and what to fix before exporting.

/winnr status — Quick Account Snapshot

A fast overview of your account: total domains, mailboxes, warming status, plan utilization, and any immediate issues. Takes seconds and gives you the numbers you need without digging through dashboards.

Real Example: Setting Up 50 Mailboxes

Here's what a real /winnr setup session looks like:

> /winnr setup — I need 50 mailboxes for cold outreach. My keyword is "revfront".

Claude checks your account first:

Account check: Growth plan
  Domains: 12/100 used (88 remaining)
  Mailboxes: 36/500 used (464 remaining)
  ✓ Capacity sufficient for 50 new mailboxes

Then it calculates the infrastructure needed:

Plan: 50 mailboxes across 13 new domains (3-4 per domain)
  Domain search: "revfront" keyword across .com, .io, .co, .xyz, .dev

  Found 18 available domains:
    revfront.io         $14.99
    revfront.co         $11.99
    getrevfront.com     $10.99
    revfrontapp.com     $10.99
    tryrevfront.com     $10.99
    revfronthq.com      $10.99
    userevfront.io      $14.99
    revfront.xyz        $5.99
    revfrontmail.com    $10.99
    gorevfront.com      $10.99
    revfront.dev        $12.99
    meetrevfront.com    $10.99
    revfrontteam.com    $10.99

  Purchasing 13 domains... confirm? (y/n)

After you confirm, Claude purchases the domains, waits for DNS propagation, creates mailboxes with professional names (first.last format), enables warming on each one, and generates a summary:

Setup complete:
  ✓ 13 domains purchased and DNS verified
  ✓ 50 mailboxes created (3-4 per domain)
  ✓ Warming enabled on all 50 mailboxes

  Next steps:
  - Warming will ramp up over 14-21 days
  - Run /winnr health in 7 days to check progress
  - Run /winnr export when ready to load into your sequencer

The entire process takes about 5 minutes of your time, most of it waiting for DNS propagation. Without the skill, you'd be clicking through domain searches, mailbox creation forms, and warming toggles for an hour or more.

Installation in 30 Seconds

Skills require the MCP server (for the API tools) and the skill files (for the workflow knowledge). Two commands:

# Step 1: Add the MCP server (if you haven't already)
claude mcp add winnr -- env WINNR_API_TOKEN=wnr_xxx uvx winnr-mcp

# Step 2: Install skills
curl -sL https://raw.githubusercontent.com/winnr-app/winnr-claude-skills/main/install.sh | bash

The install script copies 6 skill files to ~/.claude/skills/. That's it — no build step, no dependencies, no configuration. Open Claude Code and type /winnr to see all available commands.

Already have the MCP server?

If you set up the Winnr MCP server from our previous post, you only need the second command. Skills layer on top of your existing MCP installation.

What's Built Into Each Skill

Skills aren't just convenience wrappers. Each one encodes cold email operational knowledge that would otherwise live in your head (or in a forgotten Notion doc):

This knowledge is encoded in the skill Markdown files, not in the MCP server. That means you can read it, modify it, or extend it. Fork the GitHub repo and adjust the thresholds to match your operation.

Frequently Asked Questions

Do I need both the MCP server and skills?

Yes. Skills are the brain, the MCP server is the hands. Skills contain the workflow logic — what to do and in what order. The MCP server provides the 36 API tools that actually execute each step (create domains, enable warming, check DNS, etc.). Install both: the MCP server for the tools, the skills for the expertise.

Can I use skills with Cursor or Windsurf?

Not yet. Claude Code Skills are specific to the Claude Code CLI. Cursor and Windsurf support MCP servers (so you can use the 36 winnr-mcp tools), but they don't support the slash command / skills format. If your IDE adds skills support in the future, Winnr skills will work there too.

What happens if I don't have enough plan capacity?

Skills check your account capacity before creating any resources. If you ask for 50 mailboxes but only have room for 30, the skill tells you exactly what's available and suggests options: upgrade your plan, reduce the request, or proceed with what you have. No surprise failures or partial setups.

How do skills handle errors?

Each skill has built-in error handling and recovery logic. If a domain purchase fails, it moves to the next one and reports what happened. If DNS verification times out, it tells you which records are missing and suggests fixes. If warming fails to activate, it retries and explains the issue. Skills never silently fail — they explain what went wrong and what to do about it.

Are skills updated automatically?

Skills are installed as local Markdown files in your ~/.claude/skills/ directory. To update, re-run the install script:

curl -sL https://raw.githubusercontent.com/winnr-app/winnr-claude-skills/main/install.sh | bash

It overwrites existing files with the latest versions. You can also git clone the repo and pull updates manually.

Can I customize or extend the skills?

Absolutely. Skills are plain Markdown files — no compiled code, no binary dependencies. Open any skill file in your editor, adjust the thresholds, add steps, or change the workflow logic. You can also create entirely new skills by following the same format. Fork the GitHub repo to maintain your own version.

Get Started

Winnr Claude Code Skills are live and ready to use:

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