Model Context Protocol Tools

Spice can find and use tools from Model Context Protocol (MCP) servers. This includes both:

1. Running stdio-based MCP servers internally
2. Connecting to MCP servers over SSE protocol.

Usage

tools:
  - name: google_maps
    from: mcp:npx
    params:
      mcp_args: -y @modelcontextprotocol/server-google-maps

Spice as an MCP server

The tools available, or loaded into, Spice can be connected to over the MCP protocol. Spice exposes the necessary SSE endpoints. For example, connecting to the tools of another Spice instance can be configured like any other MCP server.

tools:
  - name: another_spice_instance
    from: mcp:http://localhost:8090/v1/mcp/sse

Configuration

from

The from field is used to specify the tool to use. The value to use is based on the transport mechanism:

• SSE: Specify the HTTP URL where to connect over, including the /sse path, e.g. http://localhost::8090/v1/mcp/sse.
• stdio: Specify the command to run to initialise the MCP server. E.g. from: mcp:docker, from: mcp:npx. Additional arguments to the command are specified in params (specifically params.mcp_args).

name

The name field is used to specify the name of tool group. This name is used:

• To reference the tool in the model's params.tools field
• To make HTTP requests to the tool via the API, i.e. v1/tools/{name}/{tool_name}. where tool_name is the name of the tool from within the MCP server. e.g v1/tools/google_maps/maps_geocode.
• Provided to any language model that uses the tool.

description

The description field is used to provide a description of the tool. This description is provided to any language model that uses the tool.

params

The following parameters are supported for configuring the connection to the MCP server:

Parameter Name	Definition
mcp_args	Only for stdio MCP servers. Specify the additional arguments to instantiate the MCP server. e.g. -y @modelcontextprotocol/server-google-maps (for from: mcp:npx).