instructure/canvas-lms · error · ArgumentError

Missing required asset parameter #

Error message

Missing required asset parameter #{asset_param_name}

What it means

Guard in Lti::Pns::LtiAssetProcessorContributionNoticeBuilder#validate_params!: an entry in params[:assets] is missing one of the REQUIRED_ASSETS_PARAMS keys, so ArgumentError is raised while constructing a Caliper/asset-processor notification. It's a constructor-time input validation for the notice payload.

Solutions

1. Ensure every entry in params[:assets] contains all REQUIRED_ASSETS_PARAMS keys with truthy values
2. Normalize asset hashes (symbolize keys, default-fill known values) before constructing the builder
3. Filter out assets missing required fields upstream, or validate the array before calling initialize

Example fix

// before
params[:assets] = [{ id: 1 }] # missing other required asset params
// after
req = Lti::Pns::LtiAssetProcessorContributionNoticeBuilder::REQUIRED_ASSETS_PARAMS
params[:assets] = raw_assets.select { |a| req.all? { |k| a[k] } }

req = Lti::Pns::LtiAssetProcessorContributionNoticeBuilder::REQUIRED_ASSETS_PARAMS
bad = params[:assets].to_a.reject { |a| req.all? { |k| a[k] } }
raise "invalid assets" unless bad.empty?

def valid_asset?(a) = Lti::Pns::LtiAssetProcessorContributionNoticeBuilder::REQUIRED_ASSETS_PARAMS.all? { |k| a[k] }

begin
  Builder.new(params)
rescue ArgumentError => e
  Rails.logger.error("PNS builder: #{e.message}")
end

When it happens

Trigger: Passing params[:assets] where at least one asset hash is missing one of the REQUIRED_ASSETS_PARAMS keys (or holds nil/false).

Common situations: Building asset arrays from partial records (some assets lack the field); symbol vs string key mismatches in the asset hashes; schema drift between producer and builder.

Understand the failure class

Background: "missing required argument" and "the following required arguments were not provided": what required-argument errors mean and how to fix them — this error's family across 20 libraries.

Related errors

• Missing required parameter: asset_report_service_url when…
• Missing required parameter: #
• Invalid contribution_status: #
• Access token expired
• Access token invalid - signature likely incorrect

AI-assisted analysis of instructure/canvas-lms@1c9f0bb801 (2026-09-15). Data as JSON: /api/errors/ebff7afa3f75d045. Report an issue: GitHub.

Appendix: source

Thrown at app/models/lti/pns/lti_asset_processor_contribution_notice_builder.rb:58

        SUBMITTED,
        DELETED,
        HIDDEN
      ].freeze

      def initialize(params)
        validate_params!(params)
        @params = params
        ensure_lti_ids
        super()
      end

      def validate_params!(params)
        REQUIRED_PARAMS.each do |param_name|
          raise ArgumentError, "Missing required parameter: #{param_name}" unless params[param_name]
        end
        params[:assets].each do |asset|
          REQUIRED_ASSETS_PARAMS.each do |asset_param_name|
            raise ArgumentError, "Missing required asset parameter #{asset_param_name}" unless asset[asset_param_name]
          end
        end
        if params[:assets].any? && params[:asset_report_service_url].blank?
          raise ArgumentError, "Missing required parameter: asset_report_service_url when assets are present"
        end
        unless VALID_CONTRIBUTION_STATUSES.include?(params[:contribution_status])
          raise ArgumentError, "Invalid contribution_status: #{params[:contribution_status]}. Must be one of: #{VALID_CONTRIBUTION_STATUSES.join(", ")}"
        end
      end

      def notice_type
        NoticeTypes::ASSET_PROCESSOR_CONTRIBUTION
      end

      def custom_ims_claims(_tool)
        discussion_entry_version = @params[:discussion_entry_version]
        discussion_entry = discussion_entry_version.discussion_entry
        {

View on GitHub (pinned to 1c9f0bb801)