Module: ActionMCP::Server::Capabilities

Included in:
TransportHandler
Defined in:
lib/action_mcp/server/capabilities.rb

Instance Method Summary collapse

Instance Method Details

#send_capabilities(request_id, params = {}) ⇒ Hash

Handles the 'initialize' request. Validates parameters, checks protocol version, stores client info, initializes the session, and returns the server capabilities payload or an error payload.

Parameters:

  • request_id (String, Integer) —

    The JSON-RPC request ID.

  • params (Hash) (defaults to: {}) —

    The JSON-RPC parameters.

Returns:

  • (Hash) —

    A hash representing the JSON-RPC response (success or error).



12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
 
# File 'lib/action_mcp/server/capabilities.rb', line 12

def send_capabilities(request_id, params = {})
  client_protocol_version = params["protocolVersion"]
  client_info = params["clientInfo"]
  client_capabilities = params["capabilities"]
  unless client_protocol_version.is_a?(String)
    return send_jsonrpc_error(request_id, :invalid_params, "Missing or invalid 'protocolVersion'")
  end

  unless client_info.is_a?(Hash) && client_info["name"].is_a?(String) && client_info["version"].is_a?(String)
    return send_jsonrpc_error(request_id, :invalid_params, "Missing or invalid 'clientInfo'")
  end
  unless client_capabilities.is_a?(Hash)
    return send_jsonrpc_error(request_id, :invalid_params, "Missing or invalid 'capabilities'")
  end

  negotiated_version = if ActionMCP::SUPPORTED_VERSIONS.include?(client_protocol_version)
                         client_protocol_version
  else
                         ActionMCP::LATEST_VERSION
  end

  session.store_client_info(client_info)
  session.store_client_capabilities(client_capabilities)
  session.set_protocol_version(negotiated_version)

  unless session.begin_initialization!
    return send_jsonrpc_error(request_id, :invalid_request, "Session has already started initialization")
  end

  capabilities_payload = session.server_capabilities_payload
  capabilities_payload[:protocolVersion] = negotiated_version

  send_jsonrpc_response(request_id, result: capabilities_payload)
end