Build a Career Agent in Claude Desktop — 15-Minute Setup

What You Will Build

By the end of this tutorial, you will have Claude Desktop working as a career agent. You will paste a job posting URL or text into the chat, and Claude will:

• Analyze the job posting and extract what the recruiter actually needs
• Match your CV against the role and find your strongest angle
• Generate a story-driven cover letter using a narrative archetype that fits
• Score the result and tell you what to improve

All of this happens through StoryLenses MCP — five tools that Claude can call automatically. You just talk to it like you would talk to a career coach.

Prerequisites

• Claude Desktop — the desktop app from Anthropic (not the web version). Download it at claude.ai/download if you do not have it.
• A StoryLenses API key — free, takes 30 seconds. Go to storylenses.app/developers, sign in with your email, and create a key. You get 10 free generations per month.

Step 1: Get Your API Key

Go to storylenses.app/developers. Enter your email. Click the magic link in your inbox. On the developer portal, click "Create New Key". The key will be copied to your clipboard automatically — it looks like sl_live_abc123.... Save it somewhere safe.

Step 2: Configure Claude Desktop

Open Claude Desktop. Go to Settings (Claude menu → Settings → Developer → Edit Config). This opens a file called claude_desktop_config.json. Replace its contents with:

{
  "mcpServers": {
    "storylenses": {
      "command": "npx",
      "args": ["-y", "@storylenses/mcp-server"],
      "env": {
        "STORYLENSES_API_KEY": "sl_live_YOUR_KEY_HERE"
      }
    }
  }
}

Replace sl_live_YOUR_KEY_HERE with the API key you copied in Step 1. Save the file. Restart Claude Desktop.

Step 3: Verify It Works

Open a new conversation in Claude Desktop. You should see a small tools icon (hammer) indicating MCP tools are available. Type:

"List the available narrative archetypes for cover letters."

Claude should call storylenses_list_archetypes and show you 10+ narrative styles like The Golden Fleece, The Problem-Solver, and The Fool Triumphant. If you see this, everything is connected.

Step 4: Generate Your First Cover Letter

Now the fun part. Paste a job posting into the chat and ask:

"Analyze this job posting, match it against my CV below, and write me a cover letter. Here is my CV: [paste your CV text]"

Claude will automatically call the StoryLenses tools in sequence: analyze the job, match your profile, choose an archetype, and generate a letter. The whole process takes about 30 seconds.

You can also just paste a job URL:

"Write me a cover letter for this job: https://linkedin.com/jobs/view/12345"

Step 5: Refine and Iterate

After getting the first letter, you can ask Claude to:

• "Make it more confident" — Claude will regenerate with a different tone
• "Use the Problem-Solver archetype instead" — changes the narrative structure
• "Score this letter" — calls quality_check to see how it rates
• "Make it shorter" — regenerates with the short length option

This is the power of having tools in a conversation: you iterate naturally, and each iteration uses the same deep job analysis and profile matching.

What Is Happening Under the Hood

When you ask Claude to write a cover letter, it calls five tools:

1. storylenses_analyze_job — extracts 15+ structured fields from the job posting
2. storylenses_match_profile — matches your CV against the job requirements
3. storylenses_generate_letter — generates the letter using narrative science
4. storylenses_quality_check — scores the result across four dimensions
5. storylenses_list_archetypes — lets you browse narrative styles

The first four happen automatically. The fifth is available whenever you want to explore different styles.

Download the Config

You can download the ready-made config file at storylenses.app/configs/claude-desktop-career-agent.json. Just replace the API key placeholder with your own.

Next Steps

This is Part 1 of a tutorial series. In Part 2, we will add job search to the mix — chaining a job search MCP with StoryLenses so Claude can find jobs AND write letters in one conversation. In Part 3, we will build a standalone CLI agent that automates the entire workflow.

Get your free API key at storylenses.app/developers. Ten generations per month, no credit card required.