module Riffer::Mcp::ToolFactory

Generates anonymous Riffer::Tool subclasses from MCP tool definitions.

Each generated class:

Has .name, .description, and .parameters_schema derived from the MCP tool definition.
Delegates call to the MCP client’s tools_call method.
Skips Riffer’s param validation — the MCP server validates inputs.

Public Class Methods

build (manifest_name, client, tool_defs)

Source

# File lib/riffer/mcp/tool_factory.rb, line 20
def self.build(manifest_name, client, tool_defs)
  tool_defs.map { |td| build_tool_class(manifest_name, client, td) }
end

Builds one Riffer::Tool subclass per tool definition.

Tool names are prefixed with the manifest name to avoid collisions across MCP servers (e.g. +“jira__search”+). The original server-side name is available via .mcp_server_tool_name.

build_tool_class (manifest_name, client, td)

Source

# File lib/riffer/mcp/tool_factory.rb, line 31
                     def self.build_tool_class(manifest_name, client, td)
  prefixed = "#{sanitize_name_component(manifest_name)}__#{sanitize_name_component(td[:name])}"

  # steep cannot type the body of a dynamically created anonymous class:
  # its ivars and `self` inside define_method are unresolvable, so the
  # block is ignored wholesale (cf. AuthenticatedTool.wrap_one).
  Class.new(Riffer::Tool) do
    # steep:ignore:start
    @mcp_client = client
    @mcp_server_tool_name = td[:name]
    # Set @identifier directly so .identifier does not fall back to
    # class_name_to_path(nil) on this anonymous class.
    @identifier = prefixed

    define_singleton_method(:name) { prefixed }
    define_singleton_method(:mcp_server_tool_name) { td[:name] }
    define_singleton_method(:description) { td[:description] }
    define_singleton_method(:parameters_schema) { |strict: false| td[:input_schema] || Riffer::Tool.send(:empty_schema) }

    define_method(:call) do |context:, **kwargs|
      result = self.class.instance_variable_get(:@mcp_client).tools_call(
        self.class.instance_variable_get(:@mcp_server_tool_name), kwargs
      )
      text(result)
    end
    # steep:ignore:end
  end
end