Class: Raix::MCP::SseClient

Inherits:
Object
  • Object
show all
Defined in:
lib/mcp/sse_client.rb

Overview

Client for communicating with MCP servers via Server-Sent Events (SSE).

Constant Summary collapse

PROTOCOL_VERSION = 
"2024-11-05".freeze
CONNECTION_TIMEOUT = 
10
OPEN_TIMEOUT = 
30

Instance Method Summary collapse

Constructor Details

#initialize(url, headers: {}) ⇒ SseClient

Creates a new client and establishes SSE connection to discover the JSON-RPC endpoint.

Parameters:

  • url (String) —

    the SSE endpoint URL



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# File 'lib/mcp/sse_client.rb', line 19

def initialize(url, headers: {})
  @url = url
  @endpoint_url = nil
  @sse_thread = nil
  @event_queue = Thread::Queue.new
  @buffer = ""
  @closed = false
  @headers = headers

  # Start the SSE connection and discover endpoint
  establish_sse_connection
end

Instance Method Details

#call_tool(name, **arguments) ⇒ Object

Executes a tool with given arguments. Returns text content directly, or JSON-encoded data for other content types.



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# File 'lib/mcp/sse_client.rb', line 48

def call_tool(name, **arguments)
  request_id = SecureRandom.uuid
  send_json_rpc(request_id, "tools/call", name:, arguments:)

  # Wait for response through SSE
  response = wait_for_response(request_id)
  content = response[:content]
  return "" if content.nil? || content.empty?

  # Handle different content formats
  first_item = content.first
  case first_item
  when Hash
    case first_item[:type]
    when "text"
      first_item[:text]
    when "image"
      # Return a structured response for images
      {
        type: "image",
        data: first_item[:data],
        mime_type: first_item[:mimeType] || "image/png"
      }.to_json
    else
      # For any other type, return the item as JSON
      first_item.to_json
    end
  else
    first_item.to_s
  end
end

#close ⇒ Object

Closes the connection to the server.



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# File 'lib/mcp/sse_client.rb', line 81

def close
  @closed = true
  @sse_thread&.kill
  @connection&.close
end

#tools ⇒ Object

Returns available tools from the server.



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# File 'lib/mcp/sse_client.rb', line 33

def tools
  @tools ||= begin
    request_id = SecureRandom.uuid
    send_json_rpc(request_id, "tools/list", {})

    # Wait for response through SSE
    response = wait_for_response(request_id)
    response[:tools].map do |tool_json|
      Tool.from_json(tool_json)
    end
  end
end

#unique_key ⇒ Object 



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# File 'lib/mcp/sse_client.rb', line 87

def unique_key
  parametrized_url = @url.parameterize.underscore.gsub("https_", "")
  Digest::SHA256.hexdigest(parametrized_url)[0..2]
end