The Anthropic Marketplace is where you find and install plugins for Claude. systemprompt.io publishes plugins there that give Claude personalized skills — your brand voice, your processes, your expertise. This guide walks you through installing your first plugin and making it work for your business.

Prerequisites

  • A Claude Pro or Team account at claude.ai
  • Access to Claude Cowork (available on Pro and Team plans)
  • A systemprompt.io account (free tier works)

Step 1: Find the systemprompt.io Plugin in the Marketplace

Open Claude Cowork and click Marketplace in the sidebar. Search for "systemprompt" to find the systemprompt.io plugin.

Click Install to add it to your workspace. Claude will ask you to authorize the connection — this lets the plugin read your skills and configuration from systemprompt.io.

Step 2: Create Your First Skill

Skills are what make Claude useful for your specific business. A skill is a set of instructions that tells Claude how to handle a particular task — writing in your brand voice, following your code review checklist, or drafting emails the way your team expects.

Go to systemprompt.io/admin and log in. From the dashboard:

  1. Click My Skills in the sidebar
  2. Click Create Skill
  3. Give your skill a name like "Brand Voice" or "Code Review"
  4. Write the instructions in plain language — describe what you want Claude to do, how you want it to sound, and any rules it should follow
  5. Click Save

Your skill is now available to Claude through the plugin.

Step 3: Use Your Skill in Cowork

Back in Claude Cowork, start a new conversation. The systemprompt.io plugin is now active, which means Claude has access to your skills.

You can reference a skill directly:

"Use my Brand Voice skill to draft a LinkedIn post about our new feature launch."

Or Claude will automatically apply relevant skills when it recognizes the context matches.

Step 4: Add More Skills with Claude Code

If you use Claude Code (the CLI), you can create skills even faster using the Skill Manager MCP server:

claude --mcp-server systemprompt

Then ask Claude to create a skill:

"Create a skill for writing technical documentation in our house style. We use active voice, short paragraphs, and always include code examples."

Claude will walk you through a guided interview to capture your requirements, then create the skill automatically.

Verification

To confirm everything is working:

  1. Open Claude Cowork
  2. Start a new conversation
  3. Ask: "What systemprompt.io skills do I have available?"
  4. Claude should list your skills by name

If Claude doesn't see your skills, check that the plugin is installed and authorized in your Marketplace settings.

Next Steps