Module: MCPClient::JsonRpcCommon::InputWaits

Included in:
MCPClient::JsonRpcCommon
Defined in:
lib/mcp_client/json_rpc_common/input_waits.rb

Overview

The host's hand on a multi round-trip request that waits on an interaction happening out of band (MCP 2026-07-28 client/elicitation "URL Mode": "Clients SHOULD provide manual controls that let the user retry or cancel the original request"): the pause before each retry of a requestState-only answer is the host's to steer, it never runs past the request timeout, and a stopped request resumes from the continuation its error carries. Mixed into MCPClient::JsonRpcCommon.

Defined Under Namespace

Classes: InputRequiredWait

Instance Method Summary collapse

Instance Method Details

#on_input_required_wait {|wait| ... } ⇒ void

This method returns an undefined value.

Register the host's control over an out-of-band wait (MCP 2026-07-28 client/elicitation "URL Mode": "Clients SHOULD provide manual controls that let the user retry or cancel the original request"). The block is called with an InputRequiredWait before each paced retry of a continuation that asked for nothing; it returns :retry to retry at once, :cancel to stop with an Errors::InputRequiredError the host can hand to #resume_input_required later, or anything else to wait the pace and retry.

Yield Parameters:

Yield Returns:

  • (Symbol, Object) —

    :retry, :cancel, or anything else to wait



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# File 'lib/mcp_client/json_rpc_common/input_waits.rb', line 54

def on_input_required_wait(&block)
  @input_required_wait_callback = block
end

#reject_input_required_discover!(result) ⇒ void

This method returns an undefined value.

An InputRequiredResult is defined only for tools/call, resources/read and prompts/get (MCP 2026-07-28 basic/patterns/mrtr "Supported Requests"). server/discover is not one of them, so an input_required discover answer is invalid and MUST NOT be applied or cached: the probe would otherwise adopt a protocol version out of an unfinished result and hand that result back as the first heartbeat. The rejection is a ModernServerError, not an InvalidResultError, because a server answering server/discover with a 2026-07-28-only discriminator is modern: the era is settled, so it must never be retried with the initialize handshake, and MCPClient.connect must not send it on to the legacy SSE and HTTP+POST transports either.

Parameters:

  • result (Hash) —

    the server/discover result

Raises:



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# File 'lib/mcp_client/json_rpc_common/input_waits.rb', line 35

def reject_input_required_discover!(result)
  return unless MCPClient::JsonRpcCommon.result_type(result) == 'input_required'

  raise MCPClient::Errors::ModernServerError,
        'Server answered server/discover with an input_required result; multi round-trip requests are ' \
        "only valid for #{MRTR_METHODS.join(', ')}"
end

#resume_input_required(error, timeout: nil) ⇒ Object

Resume a multi round-trip request from the continuation an Errors::InputRequiredError carries: the original request goes out again as a new request with the server's requestState echoed and no inputResponses, and the round trip continues from there.

Parameters:

Returns:

  • (Object) —

    the final (complete) result

Raises:

  • (ArgumentError) —

    if the error carries no continuation



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# File 'lib/mcp_client/json_rpc_common/input_waits.rb', line 66

def resume_input_required(error, timeout: nil)
  unless error.is_a?(MCPClient::Errors::InputRequiredError) && error.resumable?
    raise ArgumentError, 'the error carries no continuation to resume'
  end

  params = error.request_params.is_a?(Hash) ? error.request_params.dup : {}
  %w[inputResponses requestState].each do |key|
    params.delete(key)
    params.delete(key.to_sym)
  end
  params['requestState'] = error.request_state unless error.request_state.nil?
  ensure_initialized if respond_to?(:ensure_initialized, true)
  rpc_request(error.request_method, params, timeout: timeout)
end