hasura/graphql-engine · error · CommandsIssue::InvalidCommandOutputType

Command '{command_name}' has an invalid output type '{output

Error message

Command '{command_name}' has an invalid output type '{output_type}'

What it means

Indicates a command's declared output TypeReference is not a valid output type (must be an object type usable as a GraphQL output).

Source

Thrown at v3/crates/metadata-resolve/src/stages/commands/types.rs:93

        command_name: Qualified<CommandName>,
        function_name: FunctionName,
        issue: ArgumentMappingIssue,
    },
    #[error(
        "An issue occurred while mapping arguments in the command {command_name:} to the procedure {procedure_name:} in the data connector {data_connector_name:}: {issue:}"
    )]
    ProcedureArgumentMappingIssue {
        data_connector_name: Qualified<DataConnectorName>,
        command_name: Qualified<CommandName>,
        procedure_name: ProcedureName,
        issue: ArgumentMappingIssue,
    },
    #[error("Cannot add the command {command_name:} to GraphQL schema: {error:}")]
    GraphQlRootFieldAlreadyInUse {
        command_name: Qualified<CommandName>,
        error: DuplicateRootFieldError,
    },
    #[error("Command '{command_name}' has an invalid output type '{output_type}'")]
    InvalidCommandOutputType {
        command_name: Qualified<CommandName>,
        output_type: TypeReference,
    },
}

impl ShouldBeAnError for CommandsIssue {
    fn should_be_an_error(&self, flags: &open_dds::flags::OpenDdFlags) -> bool {
        match self {
            CommandsIssue::GraphQlRootFieldAlreadyInUse { .. } => {
                flags.contains(open_dds::flags::Flag::RequireUniqueCommandGraphqlNames)
            }
            CommandsIssue::InvalidCommandOutputType { .. } => {
                flags.contains(open_dds::flags::Flag::RequireValidCommandOutputType)
            }
            CommandsIssue::FunctionArgumentMappingIssue { issue, .. }
            | CommandsIssue::ProcedureArgumentMappingIssue { issue, .. } => {
                issue.should_be_an_error(flags)

View on GitHub (pinned to 724551b9ae)

Solutions

1. Change the command's output type to a valid object type defined in metadata
2. Verify the referenced type exists and is an object type
3. Rebuild

// Verify the command's output type resolves to an object type
assert!(matches!(lookup(&output_type), Some(t) if t.is_object()));

Catch InvalidCommandOutputType and report the command name and offending type.

When it happens

Trigger: Setting a command's output type to a scalar/enum-only type, an undefined type, or a type not permitted as command output.

Common situations: Hand-editing metadata to point a command at a scalar type, or deleting a type still referenced as a command output.

Related errors

• Cannot add the command {command_name:} to GraphQL schema: {e
• error in getting server feature flags %w
• parsing 'admin_secrets' from config.yaml / environment varia
• Field mapping not found for the field {field_name:} of type
• Object type '{type_name}' not found

AI-assisted analysis of hasura/graphql-engine@724551b9ae (2026-08-28). Data as JSON: /api/errors/95a50bfd5ba1cd9e. Report an issue: GitHub.