OpenAPITools/openapi-generator · error · RuntimeException

Error! Failed to process getPydanticType when getting the co

Error message

Error! Failed to process getPydanticType when getting the content: {cp}

What it means

In AbstractPythonPydanticV1Codegen's getPydanticType for parameters, content-bearing parameters are resolved by looping the media-type map and returning on the first non-null CodegenMediaType schema. If content is non-null but no usable entry exists (empty map or all-null values), the loop completes and this RuntimeException fires — the content definition is degenerate and unmappable.

Source

Thrown at modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractPythonPydanticV1Codegen.java:1299

        } else if (cp.isFreeFormObject) { // type: object
            typingImports.add("Dict");
            typingImports.add("Any");
            return "Dict[str, Any]";
        } else if (!cp.isPrimitiveType) {
            // add model prefix
            hasModelsToImport = true;
            modelImports.add(cp.dataType);
            exampleImports.add(cp.dataType);
            return cp.dataType;
        } else if (cp.getContent() != null) {
            LinkedHashMap<String, CodegenMediaType> contents = cp.getContent();
            for (String key : contents.keySet()) {
                CodegenMediaType cmt = contents.get(key);
                // TODO process the first one only at the moment
                if (cmt != null)
                    return getPydanticType(cmt.getSchema(), typingImports, pydanticImports, datetimeImports, modelImports, exampleImports, postponedModelImports, postponedExampleImports, classname);
            }
            throw new RuntimeException("Error! Failed to process getPydanticType when getting the content: " + cp);
        } else {
            throw new RuntimeException("Error! Codegen Parameter not yet supported in getPydanticType: " + cp);
        }
    }


    /*
     * Gets the pydantic type given a Codegen Property
     *
     * @param cp codegen property
     * @param typingImports typing imports
     * @param pydantic pydantic imports
     * @param datetimeImports datetime imports
     * @param modelImports model imports
     * @param exampleImports example imports
     * @param postponedModelImports postponed model imports
     * @param postponedExampleImports postponed example imports
     * @param classname class name

View on GitHub (pinned to fcec517be3)

Solutions

  1. Give the content at least one media type with a schema: content: { application/json: { schema: { type: object } } }
  2. Delete empty content blocks so the parameter follows the normal typed path
  3. If the spec is well-formed, upgrade openapi-generator and report the issue with the operation

Example fix

# before
requestBody:
  content: {}

# after
requestBody:
  content:
    application/json:
      schema:
        type: object
Defensive patterns

Strategy: validation

Validate before calling

// JS: no empty content maps in request bodies
for (const item of Object.values(spec.paths || {})) {
  for (const op of Object.values(item)) {
    const c = op && op.requestBody && op.requestBody.content;
    if (c && Object.keys(c).length === 0) fail('empty requestBody.content');
  }
}

Try / catch

try { generator.generate(); } catch (RuntimeException e) { if (String.valueOf(e.getMessage()).contains("when getting the content")) { /* fill or remove the empty content block */ } throw e; }

Prevention

When it happens

Trigger: A requestBody-style content block that is empty (content: {}) or whose media-type entries carry no schema, when generating with the python-pydantic-v1 generator. Only the first media type is ever processed (source TODO).

Common situations: Placeholder content blocks left in hand-edited specs; spec transformers that strip inner schemas; media-type keys with null values after preprocessing.

Related errors

AI-assisted analysis of OpenAPITools/openapi-generator@fcec517be3 (2026-08-22). Data as JSON: /api/errors/0d1092a3ab9244e0. Report an issue: GitHub.