René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Bug Report: Incorrect Model Reference in Generated Paginated Envelope","articleBody":"# Bug Report: Incorrect Model Reference in Generated Paginated Envelope\n\n## Summary\n`openapi-python-client` incorrectly generates `PaginatedTransactionEnvelope` with `CustomerEntity` instead of `TransactionEntity`, despite the OpenAPI schema correctly specifying `TransactionEntity`.\n\n## Environment\n- **openapi-python-client version:** 0.28.1\n- **Python version:** 3.13\n- **Generation command:**\n  ```bash\n  openapi-python-client generate \\\n      --path schema.yaml \\\n      --output-path ./generated \\\n      --meta none\n  ```\n\n## Expected Behavior\nThe generated `PaginatedTransactionEnvelope` should use `TransactionEntity` based on this schema definition:\n\n```yaml\nPaginatedTransactionEnvelope:\n  allOf:\n  - $ref: '#/components/schemas/PaginatedSuccessEnvelope'\n  - type: object\n    properties:\n      data:\n        type: array\n        items:\n          $ref: '#/components/schemas/TransactionEntity'\n```\n\nExpected generated code:\n```python\nif TYPE_CHECKING:\n    from ..models.transaction_entity import TransactionEntity\n    from ..models.links import Links\n\n@_attrs_define\nclass PaginatedTransactionEnvelope:\n    timestamp: datetime.datetime\n    path: str\n    data: list[TransactionEntity]  # ✓ Correct\n    links: Links\n```\n\n## Actual Behavior\nThe generator produces code using `CustomerEntity` instead:\n\n```python\nif TYPE_CHECKING:\n    from ..models.customer_entity import CustomerEntity  # ✗ Wrong!\n    from ..models.links import Links\n\n@_attrs_define\nclass PaginatedTransactionEnvelope:\n    timestamp: datetime.datetime\n    path: str\n    data: list[CustomerEntity]  # ✗ Wrong!\n    links: Links\n    \n@classmethod\ndef from_dict(cls: type[T], src_dict: Mapping[str, Any]) -\u003e T:\n    from ..models.customer_entity import CustomerEntity  # ✗ Wrong!\n    from ..models.links import Links\n    \n    # ...\n    for data_item_data in _data:\n        data_item = CustomerEntity.from_dict(data_item_data)  # ✗ Wrong!\n        data.append(data_item)\n```\n\n## Impact\nThis causes runtime errors when parsing API responses:\n```python\nValueError: 'failed' is not a valid CustomerEntityStatus\n```\n\nThe parser attempts to deserialize transaction data as customer data, failing when transaction-specific status values don't exist in the `CustomerEntityStatus` enum.\n\n## Additional Context\nThe schema also defines `PaginatedCustomerEnvelope` (which correctly uses `CustomerEntity`). The generator may be incorrectly reusing or caching the entity type across similar paginated envelope structures.\n\nRelated schema definitions:\n```yaml\nPaginatedCustomerEnvelope:\n  allOf:\n  - $ref: '#/components/schemas/PaginatedSuccessEnvelope'\n  - type: object\n    properties:\n      data:\n        type: array\n        items:\n          $ref: '#/components/schemas/CustomerEntity'\n\nPaginatedTransactionEnvelope:\n  allOf:\n  - $ref: '#/components/schemas/PaginatedSuccessEnvelope'\n  - type: object\n    properties:\n      data:\n        type: array\n        items:\n          $ref: '#/components/schemas/TransactionEntity'\n```\n\n## Workaround\nWe've added a post-generation fix script:\n```bash\nsed -i '' 's/from ..models.customer_entity import CustomerEntity/from ..models.transaction_entity import TransactionEntity/g' \"$FILE\"\nsed -i '' 's/list\\[CustomerEntity\\]/list[TransactionEntity]/g' \"$FILE\"\nsed -i '' 's/CustomerEntity\\.from_dict/TransactionEntity.from_dict/g' \"$FILE\"\n```\n\n## Reproduction\nThe issue appears when:\n1. Multiple paginated envelopes are defined using `allOf` with shared base schemas\n2. Each envelope should use different entity types in the `data` array\n3. The generator confuses the entity types between envelopes\n","author":{"url":"https://github.com/thekashifmalik","@type":"Person","name":"thekashifmalik"},"datePublished":"2026-01-28T03:34:17.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":0},"url":"https://github.com/1390/openapi-python-client/issues/1390"}