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Get tools from MCP servers

Source: R/tools-mcp.R
tools_mcp.Rd

Fetches ellmer-compatible tools from configured MCP servers using the mcptools package for use with deputy agents.

MCP (Model Context Protocol) allows agents to access tools from external services like GitHub, Slack, Google Drive, and more. Tools are discovered dynamically from running MCP servers.

Usage

tools_mcp(config = NULL, servers = NULL)

Arguments

config

Path to MCP configuration file. If NULL (default), uses the mcptools default location (~/.config/mcptools/config.json).

servers

Optional character vector of server names to load tools from. If NULL (default), loads tools from all configured servers. Filtering is performed on exact configuration names before connecting servers.

Value

A list of tool definitions compatible with Agent$register_tools(). tool_metadata() reports exact MCP origin, supplied annotations, and gaps. The metadata bridge is qualified for mcptools 1.0.2; other versions fail explicitly rather than silently losing annotations. Reconnecting a server invalidates tools loaded from its previous connection. Reload and explicitly replace those tools on the Agent. Load failures warn and return an empty list. Returns an empty list if mcptools is not installed or no tools are available.

Details

The MCP configuration file follows the Claude Desktop format:

{
  "mcpServers": {
    "github": {
      "command": "npx",
      "args": ["-y", "@modelcontextprotocol/server-github"],
      "env": {"GITHUB_TOKEN": "..."}
    }
  }
}

See also

mcptools package for configuration

Examples

if (FALSE) { # \dontrun{
# Get all MCP tools from default config
mcp_tools <- tools_mcp()

# Create agent with MCP tools
agent <- Agent$new(
  chat = ellmer::chat_anthropic(),
  tools = c(tools_file(), mcp_tools)
)

# Use custom config file
mcp_tools <- tools_mcp(config = "path/to/config.json")

# Load tools from specific servers only
mcp_tools <- tools_mcp(servers = c("github", "slack"))
} # }