Just MCP Integration

Comprehensive MCP integration framework for Claude Code plugins that enables connecting to external services through stdio, SSE, HTTP, and WebSocket transports.

When to Use This MCP Server

Connect this server when you need to:

• Build Claude Code plugins that integrate with external services and APIs by exposing structured tool access through the Model Context Protocol
• Configure multi-server plugin architectures that combine local process servers with remote cloud endpoints in a single unified integration
• Implement OAuth authentication flows, token-based access, and complex credential management for MCP-connected external services

Consider alternatives when:

• You want to use a pre-built MCP server for a specific service like GitHub, Jira, or Slack rather than building custom integrations
• Your integration needs are limited to a single API call that can be handled by a simple HTTP request without MCP protocol overhead

Quick Start

Configuration

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name: just-mcp-integration
type: mcp
category: devtools

Example Connection

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claude mcp:connect just-mcp-integration

Available Tools

configure-server:    Set up a new MCP server connection with transport and auth configuration
discover-tools:      List all tools provided by a connected MCP server with their schemas
test-connection:     Verify connectivity and authentication to an MCP server endpoint
manage-credentials:  Handle OAuth flows, token refresh, and credential storage securely
debug-transport:     Diagnose transport-level issues with detailed connection logging

Core Concepts

MCP Integration Framework Overview

Aspect	Details
Transports	stdio (local process), SSE (server-sent events), HTTP (REST), WebSocket
Authentication	OAuth 2.0, API tokens, environment variables, and custom header schemes
Configuration	.mcp.json or inline plugin.json with environment variable expansion
Tool Naming	Automatic prefixing: mcp__plugin_<name>_<server>__<tool> for namespacing
Lifecycle	Automatic server startup, connection management, and graceful shutdown

Multi-Transport Architecture

Claude Code Plugin
    |
    v
[MCP Integration Layer]
    |
    +--[stdio]----> [Local MCP Server Process]
    |                    (custom servers, npx packages)
    |
    +--[SSE]-----> [Remote MCP Endpoint]
    |                    (OAuth, cloud services)
    |
    +--[HTTP]----> [REST API Backend]
    |                    (token auth, stateless)
    |
    +--[WS]------> [WebSocket Server]
                        (real-time, streaming)

Configuration

Parameter	Type	Default	Description
transport_type	string	stdio	MCP transport type: stdio, sse, http, or ws
server_command	string	none	Command to execute for stdio transport (e.g., npx, python, node)
server_url	string	none	URL for remote transports (SSE, HTTP, WebSocket)
auth_method	string	none	Authentication method: oauth, token, env, or none
env_vars	object	{}	Environment variables to pass to stdio server processes

Best Practices

1. Use stdio for Custom Local Servers - When building a custom MCP server, use stdio transport for simplicity and security. The server communicates via stdin/stdout without network exposure, and Claude Code manages the process lifecycle.

2. Prefer SSE for Cloud Service Integration - When connecting to hosted MCP endpoints from cloud providers (Asana, GitHub, etc.), use SSE transport. OAuth authentication is handled automatically, and no local installation is required.

3. Pre-Allow Specific Tools in Commands - In your plugin commands, explicitly list the MCP tools that each command is allowed to use. Avoid wildcard permissions that grant access to all tools from a server, as this increases the security surface.

4. Use Environment Variable Expansion - Reference credentials and configuration values using ${VARIABLE_NAME} syntax in your MCP configuration. This ensures portability across machines and prevents credential leakage in version control.

5. Validate Connections During Development - Use test-connection and debug-transport during development to verify MCP server connectivity before writing plugin logic. Early validation prevents frustrating debugging sessions with silent connection failures.

Common Issues

1. stdio Server Not Found - The command specified in server_command must be available on the system PATH. For npx-based servers, ensure Node.js and npm are installed. For Python servers, verify the Python interpreter path.

2. OAuth Flow Does Not Complete - SSE connections with OAuth require the user to authenticate in a browser. Ensure the browser can open and the OAuth redirect URI is correctly configured in the service provider's application settings.

3. Tool Names Do Not Match Expected Format - MCP tools are automatically prefixed with the plugin and server names. Use the discover-tools function to see the exact tool names as they appear in Claude Code, including the full prefix.