#!/usr/bin/env bash
# Resources handler implementation.
# Error responses use JSON-RPC 2.0 codes (e.g., -32601 method not found,
# -32602 invalid params, -32603 internal error).
set -euo pipefail
# Sanitize a string for safe debug log output (escape newlines/carriage returns
# to prevent log injection attacks via malicious resource names/URIs).
_mcp_resources_sanitize_for_log() {
local value="$1"
value="${value//$'\n'/\\n}"
value="${value//$'\r'/\\r}"
printf '%s' "${value}"
}
mcp_resources_generate_subscription_id() {
if command -v uuidgen >/dev/null 2>&1; then
printf '%s' "sub-$(uuidgen 2>/dev/null | tr '[:upper:]' '[:lower:]')"
return
fi
printf 'sub-%s-%04d%04d' "$(date +%s)" "$RANDOM" "$RANDOM"
}
mcp_handle_resources() {
local method="$1"
local json_payload="$2"
local id
local logger="mcp.resources"
if ! id="$(mcp_json_extract_id "${json_payload}")"; then
id="null"
fi
if mcp_runtime_is_minimal_mode; then
local message
message=$(mcp_json_quote_text "Resources capability unavailable in minimal mode")
mcp_handler_error_response "${id}" "-32601" "${message}"
return 0
fi
case "${method}" in
resources/list)
local limit cursor list_json
limit="$(mcp_json_extract_limit "${json_payload}")"
cursor="$(mcp_json_extract_cursor "${json_payload}")"
if ! list_json="$(mcp_resources_list "${limit}" "${cursor}")"; then
local code
code="$(mcp_handler_normalize_error_code "${_MCP_RESOURCES_ERROR_CODE:-}")"
local message
message=$(mcp_json_quote_text "${_MCP_RESOURCES_ERROR_MESSAGE:-Unable to list resources}")
mcp_handler_error_response "${id}" "${code}" "${message}"
return 0
fi
mcp_handler_success_response "${id}" "${list_json}"
;;
resources/read)
local name uri result_json
name="$(mcp_json_extract_resource_name "${json_payload}")"
uri="$(mcp_json_extract_resource_uri "${json_payload}")"
if [ -z "${name}" ] && [ -z "${uri}" ]; then
local message
message=$(mcp_json_quote_text "Resource name or uri required")
mcp_handler_error_response "${id}" "-32602" "${message}"
return 0
fi
if ! mcp_resources_read "${name}" "${uri}"; then
local code
code="$(mcp_handler_normalize_error_code "${_MCP_RESOURCES_ERROR_CODE:-}")"
local message
message=$(mcp_json_quote_text "${_MCP_RESOURCES_ERROR_MESSAGE:-Unable to read resource}")
mcp_handler_error_response "${id}" "${code}" "${message}"
return 0
fi
result_json="${_MCP_RESOURCES_RESULT}"
mcp_handler_success_response "${id}" "${result_json}"
;;
resources/subscribe)
local name uri subscription_id result_json
name="$(mcp_json_extract_resource_name "${json_payload}")"
uri="$(mcp_json_extract_resource_uri "${json_payload}")"
mcp_logging_debug "${logger}" "Subscribe request name=${name:-<none>} uri=${uri:-<none>}"
if [ -n "${MCPBASH_STATE_DIR:-}" ]; then
# Sanitize name/uri to prevent log injection via newlines
local safe_name safe_uri
safe_name="$(_mcp_resources_sanitize_for_log "${name:-<none>}")"
safe_uri="$(_mcp_resources_sanitize_for_log "${uri:-<none>}")"
printf '%s %s\n' "subscribe-start" "${safe_name}:${safe_uri}" >>"${MCPBASH_STATE_DIR}/resources.debug.log"
fi
if [ -z "${name}" ] && [ -z "${uri}" ]; then
local message
message=$(mcp_json_quote_text "Resource name or uri required")
mcp_handler_error_response "${id}" "-32602" "${message}"
return 0
fi
subscription_id="$(mcp_resources_generate_subscription_id)"
if ! mcp_resources_read "${name}" "${uri}"; then
mcp_logging_error "${logger}" "Initial read failed code=${_MCP_RESOURCES_ERROR_CODE:-?} msg=${_MCP_RESOURCES_ERROR_MESSAGE:-?}"
local code
code="$(mcp_handler_normalize_error_code "${_MCP_RESOURCES_ERROR_CODE:-}")"
local message
message=$(mcp_json_quote_text "${_MCP_RESOURCES_ERROR_MESSAGE:-Unable to read resource}")
mcp_handler_error_response "${id}" "${code}" "${message}"
return 0
fi
result_json="${_MCP_RESOURCES_RESULT}"
mcp_logging_debug "${logger}" "Subscribe initial read ok subscription=${subscription_id}"
if [ -n "${MCPBASH_STATE_DIR:-}" ]; then
printf '%s %s\n' "subscribe-read-ok" "${subscription_id}" >>"${MCPBASH_STATE_DIR}/resources.debug.log"
fi
local effective_uri
effective_uri="$(printf '%s' "${result_json}" | "${MCPBASH_JSON_TOOL_BIN}" -r '.contents[0].uri // ""')" || effective_uri=""
if [ -z "${effective_uri}" ]; then
effective_uri="${uri}"
fi
mcp_resources_subscription_store_payload "${subscription_id}" "${name}" "${effective_uri}" "${result_json}"
local key
key="$(mcp_ids_key_from_json "${id}")"
if [ -n "${key}" ] && mcp_ids_is_cancelled_key "${key}"; then
mcp_logging_debug "${logger}" "Subscribe cancelled before response subscription=${subscription_id}"
if [ -n "${MCPBASH_STATE_DIR:-}" ]; then
rm -f "${MCPBASH_STATE_DIR}/resource_subscription.${subscription_id}"
fi
printf '%s' "${MCPBASH_NO_RESPONSE}"
return 0
fi
local response_payload response
# MCP 2025-11-25: resources/subscribe returns only {subscriptionId}.
response_payload="$("${MCPBASH_JSON_TOOL_BIN}" -n -c --arg sub "${subscription_id}" '{subscriptionId: $sub}')"
response="$(mcp_handler_success_response "${id}" "${response_payload}")"
mcp_logging_debug "${logger}" "Subscribe emitting response subscription=${subscription_id}"
rpc_send_line_direct "${response}"
if [ -n "${MCPBASH_STATE_DIR:-}" ]; then
printf '%s %s\n' "subscribe-response" "${subscription_id}" >>"${MCPBASH_STATE_DIR}/resources.debug.log"
fi
printf '%s' "${MCPBASH_NO_RESPONSE}"
;;
resources/unsubscribe)
local subscription_id
subscription_id="$(mcp_json_extract_subscription_id "${json_payload}")"
if [ -z "${subscription_id}" ]; then
local message
message=$(mcp_json_quote_text "subscriptionId required")
mcp_handler_error_response "${id}" "-32602" "${message}"
return 0
fi
rm -f "${MCPBASH_STATE_DIR}/resource_subscription.${subscription_id}"
mcp_handler_success_response "${id}" "{}"
;;
resources/templates/list)
local limit cursor list_json
limit="$(mcp_json_extract_limit "${json_payload}")"
cursor="$(mcp_json_extract_cursor "${json_payload}")"
if ! list_json="$(mcp_resources_templates_list "${limit}" "${cursor}")"; then
local code="${_MCP_RESOURCES_ERROR_CODE:--32603}"
# Special case: code 0 with cursor means invalid cursor, otherwise internal error
if [ "${code}" = "0" ]; then
if [ -n "${cursor}" ]; then
code="-32602"
else
code="-32603"
fi
fi
local message
local err_text="${_MCP_RESOURCES_ERROR_MESSAGE:-Unable to list resource templates}"
if [ "${code}" = "-32602" ] && [ -z "${_MCP_RESOURCES_ERROR_MESSAGE:-}" ]; then
err_text="Invalid cursor"
fi
message=$(mcp_json_quote_text "${err_text}")
mcp_handler_error_response "${id}" "${code}" "${message}"
return 0
fi
mcp_handler_success_response "${id}" "${list_json}"
;;
*)
local message
message=$(mcp_json_quote_text "Unknown resources method")
mcp_handler_error_response "${id}" "-32601" "${message}"
;;
esac
}
