Exception: MCP::Server::ResourceNotFoundError

Inherits:
RequestHandlerError show all
Defined in:
lib/mcp/server.rb

Overview

Raised when a requested resource URI does not exist. Per SEP-2164, resource-not-found errors use the standard JSON-RPC Invalid Params code (-32602) with the requested URI in the error ‘data` member. Raise this from a `resources_read_handler` block for unknown URIs:

server.resources_read_handler do |params|
  raise MCP::Server::ResourceNotFoundError.new(params[:uri], params) unless known?(params[:uri])
  do_something(params[:uri])
end

github.com/modelcontextprotocol/modelcontextprotocol/pull/2164

Instance Attribute Summary

Attributes inherited from RequestHandlerError

#error_code, #error_data, #error_type, #original_error

Instance Method Summary collapse

Constructor Details

#initialize(uri, request = nil) ⇒ ResourceNotFoundError

Returns a new instance of ResourceNotFoundError.



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# File 'lib/mcp/server.rb', line 73

def initialize(uri, request = nil)
  # The explicit `error_code` keeps the descriptive message in the JSON-RPC
  # error response; `error_type: :invalid_params` alone would replace it
  # with the generic "Invalid params" string.
  super(
    "Resource not found: #{uri}",
    request,
    error_type: :invalid_params,
    error_code: JsonRpcHandler::ErrorCode::INVALID_PARAMS,
    error_data: { uri: uri },
  )
end