OpenAPITools/openapi-generator · error · IllegalArgumentException

Invalid param naming '{name}'. Must be 'original', 'camelCas

Error message

Invalid param naming '{name}'. Must be 'original', 'camelCase', 'PascalCase' or 'snake_case'

What it means

Error "Invalid param naming '{name}'. Must be 'original', 'camelCase', 'PascalCase' or 'snake_case'" thrown in OpenAPITools/openapi-generator.

Source

Thrown at modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractTypeScriptClientCodegen.java:911

                    .collect(Collectors.joining(", "));

            String msg = String.format(Locale.ROOT, "Invalid parameter naming '%s'. Must be one of %s.", naming, values);
            throw new IllegalArgumentException(msg);
        }
    }

    private String getNameUsingParamNaming(String name) {
        switch (getParamNaming()) {
            case original:
                return name;
            case camelCase:
                return camelize(name, LOWERCASE_FIRST_LETTER);
            case PascalCase:
                return camelize(name);
            case snake_case:
                return underscore(name);
            default:
                throw new IllegalArgumentException("Invalid param naming '" +
                        name + "'. Must be 'original', 'camelCase', " +
                        "'PascalCase' or 'snake_case'");
        }

    }

    private String getNameUsingModelPropertyNaming(String name) {
        switch (getModelPropertyNaming()) {
            case original:
                additionalProperties.put("modelPropertyNamingOriginal", true);
                return name;
            case camelCase:
                return camelize(name, LOWERCASE_FIRST_LETTER);
            case PascalCase:
                return camelize(name);
            case snake_case:
                return underscore(name);
            default:

View on GitHub (pinned to fcec517be3)

Solutions

1. Set parameterNaming to one of 'original', 'camelCase', 'PascalCase' or 'snake_case'.

When it happens

Trigger: Thrown when the 'paramNaming' option is set to a value other than 'original', 'camelCase', 'PascalCase' or 'snake_case' for a TypeScript client generator.

Common situations: See trigger scenarios.

AI-assisted analysis of OpenAPITools/openapi-generator@fcec517be3 (2026-08-22). Data as JSON: /api/errors/c794f5b1df53b01a. Report an issue: GitHub.