#!/usr/bin/env bash
# Elicitation state, request routing, and worker coordination.
set -euo pipefail
# Track client elicitation capability (SEP-1036: form vs URL modes)
MCPBASH_CLIENT_SUPPORTS_ELICITATION="${MCPBASH_CLIENT_SUPPORTS_ELICITATION:-0}"
MCPBASH_CLIENT_ELICIT_FORM="${MCPBASH_CLIENT_ELICIT_FORM:-0}"
MCPBASH_CLIENT_ELICIT_URL="${MCPBASH_CLIENT_ELICIT_URL:-0}"
mcp_elicitation_support_flag_path() {
printf '%s/elicitation.support' "${MCPBASH_STATE_DIR}"
}
mcp_elicitation_modes_flag_path() {
printf '%s/elicitation.modes' "${MCPBASH_STATE_DIR}"
}
mcp_elicitation_write_support_flag() {
local value="$1"
printf '%s' "${value}" >"$(mcp_elicitation_support_flag_path 2>/dev/null)" 2>/dev/null || true
}
mcp_elicitation_write_modes_flag() {
local form="$1"
local url="$2"
printf '%s %s' "${form}" "${url}" >"$(mcp_elicitation_modes_flag_path 2>/dev/null)" 2>/dev/null || true
}
mcp_elicitation_init() {
local client_caps="${1:-{}}"
MCPBASH_CLIENT_SUPPORTS_ELICITATION=0
MCPBASH_CLIENT_ELICIT_FORM=0
MCPBASH_CLIENT_ELICIT_URL=0
if ! mcp_json_has_key "${client_caps}" "elicitation"; then
# Fallback for environments without JSON tooling: string match
case "${client_caps}" in
*\"elicitation\"*)
MCPBASH_CLIENT_SUPPORTS_ELICITATION=1
# Legacy format without modes → assume form support
MCPBASH_CLIENT_ELICIT_FORM=1
;;
esac
else
MCPBASH_CLIENT_SUPPORTS_ELICITATION=1
# SEP-1036: Check for form/url mode support
# New format: {"elicitation": {"form": {}, "url": {}}}
# Legacy format: {"elicitation": {}} → implies form
local elicit_caps
elicit_caps="$(printf '%s' "${client_caps}" | "${MCPBASH_JSON_TOOL_BIN}" -c '.elicitation // {}' 2>/dev/null || printf '{}')"
if mcp_json_has_key "${elicit_caps}" "form"; then
MCPBASH_CLIENT_ELICIT_FORM=1
fi
# "url" or "oob" both mean URL mode
if mcp_json_has_key "${elicit_caps}" "url" || mcp_json_has_key "${elicit_caps}" "oob"; then
MCPBASH_CLIENT_ELICIT_URL=1
fi
# Legacy: empty elicitation object → assume form support
if [ "${MCPBASH_CLIENT_ELICIT_FORM}" = "0" ] && [ "${MCPBASH_CLIENT_ELICIT_URL}" = "0" ]; then
MCPBASH_CLIENT_ELICIT_FORM=1
fi
fi
mcp_elicitation_write_support_flag "${MCPBASH_CLIENT_SUPPORTS_ELICITATION}"
mcp_elicitation_write_modes_flag "${MCPBASH_CLIENT_ELICIT_FORM}" "${MCPBASH_CLIENT_ELICIT_URL}"
}
mcp_elicitation_is_supported() {
if [ "${MCPBASH_CLIENT_SUPPORTS_ELICITATION}" = "1" ]; then
return 0
fi
local flag
flag="$(cat "$(mcp_elicitation_support_flag_path 2>/dev/null)" 2>/dev/null || true)"
[ "${flag}" = "1" ]
}
mcp_elicitation_form_supported() {
if [ "${MCPBASH_CLIENT_ELICIT_FORM}" = "1" ]; then
return 0
fi
local modes
modes="$(cat "$(mcp_elicitation_modes_flag_path 2>/dev/null)" 2>/dev/null || true)"
[ "${modes%% *}" = "1" ]
}
mcp_elicitation_url_supported() {
if [ "${MCPBASH_CLIENT_ELICIT_URL}" = "1" ]; then
return 0
fi
local modes
modes="$(cat "$(mcp_elicitation_modes_flag_path 2>/dev/null)" 2>/dev/null || true)"
[ "${modes##* }" = "1" ]
}
mcp_elicitation_clear_request_id() {
local request_id="$1"
local id_file
for id_file in "${MCPBASH_STATE_DIR}"/elicit.*.id; do
[ -f "${id_file}" ] || continue
if [ "$(cat "${id_file}")" = "${request_id}" ]; then
rm -f "${id_file}"
break
fi
done
}
mcp_elicitation_response_path_for_worker() {
local key="$1"
printf '%s/elicit.%s.response' "${MCPBASH_STATE_DIR}" "${key}"
}
mcp_elicitation_request_path_for_worker() {
local key="$1"
printf '%s/elicit.%s.request' "${MCPBASH_STATE_DIR}" "${key}"
}
mcp_elicitation_request_id_path_for_worker() {
local key="$1"
printf '%s/elicit.%s.id' "${MCPBASH_STATE_DIR}" "${key}"
}
mcp_elicitation_request_id_for_worker() {
local key="$1"
local path
path="$(mcp_elicitation_request_id_path_for_worker "${key}")"
if [ -f "${path}" ]; then
cat "${path}"
fi
}
mcp_elicitation_process_requests() {
local listing key request_file
listing="$(mcp_ids_list_active_workers 2>/dev/null || true)"
[ -z "${listing}" ] && return 0
while IFS= read -r key || [ -n "${key}" ]; do
[ -z "${key}" ] && continue
request_file="$(mcp_elicitation_request_path_for_worker "${key}")"
[ -f "${request_file}" ] || continue
mcp_elicitation_handle_tool_request "${key}" "${request_file}"
done <<<"${listing}"
}
mcp_elicitation_handle_tool_request() {
local key="$1"
local request_file="$2"
local response_file
response_file="$(mcp_elicitation_response_path_for_worker "${key}")"
local request_json
# The tool may time out and clean up the request file before the poller can
# read it (seen intermittently on Windows runners). Handle the race
# gracefully instead of crashing the server under set -e.
if [ ! -f "${request_file}" ]; then
return 0
fi
request_json="$(cat "${request_file}" 2>/dev/null || true)"
if [ -z "${request_json}" ]; then
rm -f "${request_file}"
return 0
fi
rm -f "${request_file}"
# If client doesn't support elicitation, respond immediately so tool can proceed
if ! mcp_elicitation_is_supported; then
printf '{"action":"decline","content":null}' >"${response_file}"
return 0
fi
local message mode
message="$(printf '%s' "${request_json}" | "${MCPBASH_JSON_TOOL_BIN}" -r '.message')" || message=""
mode="$(printf '%s' "${request_json}" | "${MCPBASH_JSON_TOOL_BIN}" -r '.mode // "form"')" || mode="form"
# SEP-1036: Check if client supports the requested mode
if [ "${mode}" = "form" ] && ! mcp_elicitation_form_supported; then
printf '{"action":"decline","content":null}' >"${response_file}"
return 0
fi
if [ "${mode}" = "url" ] && ! mcp_elicitation_url_supported; then
printf '{"action":"decline","content":null}' >"${response_file}"
return 0
fi
local request_id
request_id="$(mcp_rpc_next_outgoing_id)"
local message_json
message_json="$(mcp_json_quote_text "${message}")"
# SEP-1036: Build elicitation request based on mode
local elicit_request
if [ "${mode}" = "url" ]; then
# URL mode: send url field instead of requestedSchema
local url
url="$(printf '%s' "${request_json}" | "${MCPBASH_JSON_TOOL_BIN}" -r '.url // ""')" || url=""
local url_json
url_json="$(mcp_json_quote_text "${url}")"
elicit_request="$(printf '{"jsonrpc":"2.0","id":%s,"method":"elicitation/create","params":{"mode":"url","message":%s,"url":%s}}' \
"${request_id}" "${message_json}" "${url_json}")"
else
# Form mode: send requestedSchema
local schema
schema="$(printf '%s' "${request_json}" | "${MCPBASH_JSON_TOOL_BIN}" -c '.schema')" || schema='{"type":"object","properties":{}}'
elicit_request="$(printf '{"jsonrpc":"2.0","id":%s,"method":"elicitation/create","params":{"mode":"form","message":%s,"requestedSchema":%s}}' \
"${request_id}" "${message_json}" "${schema}")"
fi
printf '%s' "${request_id}" >"$(mcp_elicitation_request_id_path_for_worker "${key}")"
mcp_rpc_register_pending "${request_id}" "${response_file}"
mcp_io_send_line "${elicit_request}"
}
mcp_elicitation_cancel_for_worker() {
local key="$1"
[ -n "${key}" ] || return 0
local request_file
local response_file
request_file="$(mcp_elicitation_request_path_for_worker "${key}")"
response_file="$(mcp_elicitation_response_path_for_worker "${key}")"
rm -f "${request_file}"
printf '{"action":"cancel","content":null}' >"${response_file}"
local request_id
request_id="$(mcp_elicitation_request_id_for_worker "${key}")"
if [ -n "${request_id}" ]; then
mcp_rpc_unregister_pending "${request_id}"
fi
rm -f "$(mcp_elicitation_request_id_path_for_worker "${key}")"
}
mcp_elicitation_cleanup_for_worker() {
local key="$1"
[ -n "${key}" ] || return 0
rm -f "$(mcp_elicitation_request_path_for_worker "${key}")" "$(mcp_elicitation_response_path_for_worker "${key}")"
local request_id
request_id="$(mcp_elicitation_request_id_for_worker "${key}")"
if [ -n "${request_id}" ]; then
mcp_rpc_unregister_pending "${request_id}"
fi
rm -f "$(mcp_elicitation_request_id_path_for_worker "${key}")"
}
