/new-client

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🚨 EXECUTION NOTICE FOR CLAUDE

When you invoke this command via SlashCommand, the system returns THESE INSTRUCTIONS below.

YOU are the executor. This is NOT an autonomous subprocess.

• ✅ The phases below are YOUR execution checklist
• ✅ YOU must run each phase immediately using tools (Bash, Read, Write, Edit, TodoWrite)
• ✅ Complete ALL phases before considering this command done
• ❌ DON't wait for "the command to complete" - YOU complete it by executing the phases
• ❌ DON't treat this as status output - it IS your instruction set

Immediately after SlashCommand returns, start executing Phase 0, then Phase 1, etc.

See @CLAUDE.md section "SlashCommand Execution - YOU Are The Executor" for detailed explanation.

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Security Requirements

CRITICAL: All generated files must follow security rules:

@docs/security/SECURITY-RULES.md

Key requirements:

• Never hardcode API keys or secrets
• Use placeholders: your_service_key_here
• Protect .env files with .gitignore
• Create .env.example with placeholders only
• Document key acquisition for users

Arguments: $ARGUMENTS

Goal: Create a FastMCP client project for connecting to and interacting with MCP servers. Supports both Python and TypeScript.

Core Principles:

• Ask language preference first (Python or TypeScript)
• Route to correct setup agent based on language
• Follow FastMCP Client SDK patterns
• Create functional client code with proper transport configuration

Phase 1: Discovery & Education Goal: Understand what the user wants to build through interactive conversation

Actions:

• Parse $ARGUMENTS for project name

• Load FastMCP documentation: @plugins/fastmcp/docs/fastmcp-documentation.md

• Have an interactive conversation to understand the client:

  Start with Purpose:

  • "What MCP server(s) will this client connect to?"
  • "What will this client do? (e.g., 'call tools', 'fetch resources', 'automated workflows')"

  Explain Transport Types:

  • STDIO: For local MCP servers (like Claude Desktop uses)
    • Reference: https://gofastmcp.com/clients/client-transports
  • HTTP: For remote MCP servers over HTTP/HTTPS
  • In-Memory: For testing or embedded servers
  • Ask which transport they need and explain the differences

  Explain Client Capabilities:

  • Show them how clients call tools: client.call_tool("tool_name", {...})
  • Show them how to fetch resources: client.read_resource("uri://resource")
  • Explain callback handlers for server notifications
  • Reference: https://gofastmcp.com/clients/client-usage

  Language Selection:

  • Use AskUserQuestion for language (Python or TypeScript)
  • Explain: Python for scripts/automation, TypeScript for applications

  Connection Strategy:

  • Will they connect to multiple servers? Explain connection management
  • Do they need authentication? Explain client-side auth

• Store all choices for Phase 3

Phase 2: Validation Goal: Verify project doesn't exist and environment is ready

Actions:

• Check if directory already exists
• If Python chosen:
  • Verify Python is installed (Python 3.10+)
  • Check if uv or pip is available
• If TypeScript chosen:
  • Verify Node.js is installed (Node 18+)
  • Check if npm/yarn/pnpm is available
• Confirm project location

Phase 3: Implementation Goal: Create client project with language-specific agent

Actions:

If Python was chosen in Phase 1:

Invoke the fastmcp-client-setup agent to create the FastMCP client application.

The agent should:

• Create Python project structure
• Set up pyproject.toml with FastMCP client dependencies
• Generate starter client code with transport configuration
• Include examples for tool calls, resource fetching
• Create README with setup instructions
• Add .gitignore for Python projects
• Create .env.example if needed

Provide the agent with:

• Context: Client requirements and transport type
• Target: $ARGUMENTS (project name)
• Expected output: Working FastMCP client application

If TypeScript was chosen in Phase 1:

Invoke the fastmcp-client-setup-ts agent to create the FastMCP client application.

The agent should:

• Create Node.js/TypeScript project structure
• Set up package.json with FastMCP client TypeScript dependencies
• Create tsconfig.json with ES modules support
• Generate starter client code with TypeScript types and transport configuration
• Include examples for tool calls, resource fetching
• Create README with setup and TypeScript build instructions
• Add .gitignore for Node.js/TypeScript projects
• Create .env.example if needed

Provide the agent with:

• Context: Client requirements and transport type
• Target: $ARGUMENTS (project name)
• Expected output: Working FastMCP client application with TypeScript

Phase 4: Summary Goal: Guide user on next steps

Actions:

• Show project location and structure
• Display how to connect to MCP servers
• Explain transport configuration
• Provide FastMCP Client documentation links