Winnr's Claude Code skills add cold email workflows on top of the Winnr MCP server. Eight slash commands: /winnr setup, /winnr connect, /winnr inbox, /winnr health, /winnr troubleshoot, /winnr scale, /winnr export and /winnr status. They are free, open source and install with one command. View on GitHub.
What are Claude Code skills?
Claude Code skills are Markdown files that give Claude a workflow for a specific job. When you type /winnr setup in Claude Code, Claude follows a written playbook: what to check first, which steps to run in which order, what defaults to use and what to do when something fails.
Skills are different from MCP tools. An MCP tool is a single API call: create a mailbox, check DNS, enable warming. A skill ties those calls together: check your plan's capacity, find and buy domains with your confirmation, wait for DNS to verify, create mailboxes with realistic names, turn on warming and write a report.
The MCP server gives Claude the tools. Skills give it the playbook.
MCP tools vs skills
The Winnr MCP server gives Claude 55 tools for domains, DNS, mailboxes, warming, inbox, export, jobs, the pre-warmed marketplace and webhooks. Skills sit on top of those tools:
| MCP tool (one API call) | Skill (workflow) | What the skill adds |
|---|---|---|
winnr_search_domains_bulk | /winnr setup | Capacity check, domain search and purchase with confirmation, DNS verification, mailboxes, warming and a setup report |
winnr_connect_domains | /winnr connect | Brings domains you already own, by pointing nameservers to Winnr or by adding records at your current DNS host |
winnr_list_inbox | /winnr inbox | Classifies replies (interested, question, unsubscribe, out-of-office, bounce) and drafts responses from the right mailbox |
winnr_get_warming_metrics | /winnr health | A 0 to 100 infrastructure score with a traffic-light report and prioritized fixes |
winnr_get_dns_status | /winnr troubleshoot | Diagnostic decision trees across DNS, warming and deliverability |
winnr_bulk_create_email_users | /winnr scale | Domain and mailbox math, plan-aware provisioning, or removing underperformers |
winnr_export_email_users | /winnr export | A readiness check before export |
winnr_get_account | /winnr status | A quick snapshot of plan, domains, mailboxes and warming |
You can use the MCP tools without the skills, and Claude will still manage your infrastructure. The skills make the results consistent: the same ratios, naming rules, warming period and readiness checks every time.
The eight commands
/winnr setup: infrastructure from scratch
Tell Claude how many mailboxes you need and your company or keyword. It checks your plan's capacity, suggests and buys domains after you confirm, waits for DNS to verify, creates mailboxes with realistic names, enables warming and saves a setup report. Domains bought through Winnr are a one-time purchase priced per extension at checkout (a .com is about $13), and warming is $0.60 per mailbox per month.
/winnr connect: bring your own domains
Connects domains registered anywhere (Namecheap, GoDaddy, Cloudflare and others). Two modes: point the nameservers to Winnr, which then manages MX, SPF, DKIM and DMARC, or keep your current DNS host and add the records there. It checks for existing mailboxes and DNSSEC before changing anything.
/winnr inbox: reply triage
Reads replies across every mailbox, classifies them, puts the ones that need a person first and drafts replies from the correct mailbox when you ask.
/winnr health: traffic-light report
Scores your infrastructure from 0 to 100 using four weighted categories: DNS health (30%), warming performance (40%), plan utilization (15%) and mailbox diversity, meaning 3 to 5 mailboxes per domain (15%). Problems are flagged red or yellow with what to do about each.
/winnr troubleshoot: diagnostics
Works through decision trees for DNS problems, warming problems, deliverability drops and provisioning failures, in that order, because problems upstream cause symptoms downstream. It ends with the fix and the order to apply it in.
/winnr scale: up or down
Adds capacity at 3 to 5 mailboxes per domain, checks your plan, buys domains and creates mailboxes, and staggers warming for large batches. Scaling down, it suggests which mailboxes to remove based on their metrics and asks before deleting anything.
/winnr export: to your sequencer
Exports mailbox credentials in the import format of the tool you name: Smartlead, Instantly, EmailBison, PlusVibe, Snov, Saleshandy, Woodpecker, Reply.io and the other formats Winnr supports, or a generic CSV. First it checks readiness: at least 14 days of warming, a health score above 75 and an inbox rate above 85%. Mailboxes that don't pass are listed with the reason, and you decide whether to include any that are almost ready.
/winnr status: quick snapshot
Plan, domains used, mailboxes used and warming averages, in a few lines.
Example: setting up 50 mailboxes
> /winnr setup I need 50 mailboxes for cold outreach. My company is Revfront.
Account check: Enterprise plan
Mailboxes: 120/200 used (80 available)
Domain slots: 20/40 used (20 available)
Capacity is enough for 50 new mailboxes.
Plan: 50 mailboxes across 13 new domains (3 to 4 per domain)Claude then searches for available names, shows each with its price and the order total, and waits for you to confirm. Then it buys the domains, waits for DNS to verify, creates the mailboxes and turns on warming:
Setup complete:
13 domains purchased, DNS verified
50 mailboxes created (3 to 4 per domain)
Warming enabled on all 50 ($30/mo)
Next steps:
Let warming run at least 2 weeks (4 on brand-new domains)
Run /winnr health in a week to check progress
Run /winnr export when mailboxes pass the readiness checkYour part takes a few minutes. Most of the wall-clock time is DNS verification, and then warming.
Installation
Skills need the MCP server (for the tools) and the skill files (for the workflows):
# Step 1: add the hosted MCP server (if you haven't already); it asks you to sign in to Winnr
claude mcp add --scope user --transport http winnr https://mcp.winnr.app/mcp
# Step 2: install the skills
curl -sL https://raw.githubusercontent.com/winnr-app/winnr-claude-skills/main/install.sh | bashThe script downloads eight skill files to ~/.claude/skills/. There is no build step and nothing to configure. Type /winnr status in Claude Code to check it works. To update, run the script again; it overwrites the files with the latest versions.
You also need a Winnr account. Creating one needs no card; buying domains and creating mailboxes need a paid plan. Winnr pricing: Startup is $69/mo for 50 mailboxes and Enterprise is $189/mo for 200, billed monthly.
What the skills encode
- Mailboxes per domain: 3 to 5. More concentrates risk on one domain; fewer means more domains to buy and manage.
- Domain names: keyword plus a short suffix (hq, team, labs, get, try), never your main brand's own domain. The skills prefer .com, then .net, .org and .co. See the TLD guide for how extensions affect deliverability.
- Mailbox names: realistic first.last style names with varied patterns, matched to the display name. No info@, sales@ or contact@.
- Warming before sending: no campaigns until mailboxes have warmed for at least 14 days. We recommend 4 weeks on brand-new domains.
- Sending volume: 10 to 15 cold emails per mailbox per day, and about 50 a day in total per mailbox including warming.
- Diagnostics in order: DNS, then warming, then deliverability.
- Readiness before export: 14+ days of warming, health above 75, inbox rate above 85%.
All of this lives in the skill Markdown files, not in the MCP server, so you can read it and change it. Fork the GitHub repo to adjust thresholds or add steps.
Related: build an AI SDR pipeline with Claude Code and Winnr, and vibe-code your own email sequencer.
Frequently Asked Questions
Do I need both the MCP server and the skills?
Yes, to use the skills. The skills contain the workflows, and the MCP server provides the 55 tools that carry out each step. You can use the MCP server on its own without the skills.
Can I use the skills outside Claude Code?
The skills are written for Claude Code. Other MCP clients, such as Claude Desktop, Cursor, Windsurf and VS Code, can connect to the Winnr MCP server and use its tools directly.
What happens if I don't have enough plan capacity?
The skills check capacity before creating anything and tell you what is available. Domain slots are free, so you can raise them in Settings, Subscription. Mailboxes beyond your plan are $1 each per month, or you can move from Startup to Enterprise.
Do the skills buy anything without asking?
No. The setup and scale skills show the domains and total and wait for your confirmation before buying. On the hosted MCP server you also choose whether Claude may make purchases at all when you sign in.
How do I update the skills?
Run the install script again. It overwrites the skill files in ~/.claude/skills/ with the latest versions. You can also clone the GitHub repo and pull updates.
Can I customize the skills?
Yes. They are plain Markdown files. Edit thresholds, add steps or write new skills in the same format, and fork the GitHub repo to keep your own version.
Get started
- GitHub repository: skill files, install script and docs
- Skills page: command reference and examples
- MCP server page: the tools the skills call, plus setup for other clients
- Create a Winnr account