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What is MCP?

MCP (Model Context Protocol) is how agents access external tools. An MCP server exposes a set of tools (functions) that the agent can call during a run. muxAI manages which MCP servers each agent can access.

Built-in servers

muxAI ships with several MCP servers out of the box:
ServerToolsPurpose
news-analystRSS feeds, CoinMarketCap newsFetch and analyze crypto news
chart-analystChart image analysisAnalyze trading charts from URLs
orchestratorrun_team, ask_reporterCoordinate team members (lead agents only)
contractorask_contractor, list_contractorsConsult external LLM contractors
walletwallet_address, wallet_fetchAgent wallet access and x402 payments
docssearch_docs, get_doc_pageSearch and read muxAI platform documentation
Built-in servers are registered in config/mcp-registry.json and automatically available when an agent uses Built-in MCP mode.

Custom servers

Add your own MCP servers through the MCP Servers page. Two transport types are supported:

stdio

Runs as a local process. You provide the command and arguments. The agent communicates over stdin/stdout.Example: a Python script that wraps a proprietary API.

HTTP

Connects to a remote server via URL. Optionally include authentication headers.Example: an MCP server running on another machine or cloud service.

Adding a custom server

Paste a standard MCP config JSON block. muxAI parses it, shows a preview, and imports all servers at once.
{
  "mcpServers": {
    "my-server": {
      "command": "node",
      "args": ["path/to/server.js"]
    }
  }
}

MCP modes

Each agent is configured with one of two MCP modes:
ModeBehavior
Built-in (default)Agent gets only the built-in servers plus any custom servers from the database. Uses --mcp-config and --strict-mcp-config flags for full isolation.
GlobalAgent inherits MCP servers from your global Claude CLI config (~/.claude). No isolation flags.
Built-in mode is recommended. It prevents global MCP servers from leaking into agent runs and ensures reproducible behavior.

How it works at runtime

When an agent runs in Built-in mode, muxAI:
  1. Reads the built-in registry (config/mcp-registry.json)
  2. Loads custom servers from the database
  3. Merges them into a single MCP config JSON
  4. Passes it to the Claude CLI via --mcp-config <path> --strict-mcp-config
The agent can only call tools from servers in that config. Nothing else.

Guides

Add a Custom MCP Server

Connect an existing MCP server through the portal UI. No code changes required.

Build a Built-in MCP Server

Create a new MCP server package that ships with your muxAI installation.