[2ynn]

Why

UnrecognizedStr and UnrecognizedInt hold values of open enums (x-speakeasy-unknown-values: allow) that the SDK does not know. They had no serialization schema, so:

• dumping a model holding an unknown enum value emitted Pydantic serialization warnings;
• in an optional nullable open enum field, the unknown value was serialized by the Unset member of the union and then dropped: {"stringOrNull": "future"} was sent as {}.

This affects every Python SDK with open enums and needs no configuration.

What changed

• Give both types an explicit serializer:
  • Python-mode dumps return the original object, so type(...) is UnrecognizedStr still holds;
  • JSON-mode dumps return a plain str or int;
  • values of another type raise PydanticSerializationUnexpectedValue, so union serialization moves on to the remaining members.
• Add the open-enum-scalar-unions primary fragment: an open string or integer enum combined with number, boolean or null. The number and boolean cases guard that values of other types still keep their JSON type now that the enum types serialize themselves.
• Review SDK: only types/basemodel.py changes.

Stack

1. This PR: unrecognized enum serialization
2. fix(python): honour include/exclude filters in model dumps #149: honour include/exclude filters in model dumps
3. feat(python): add preserveUnknownFields option #146: preserveUnknownFields
4. feat(python): add modelSerializationMethods option #147: modelSerializationMethods

Together these contain the change from #133, split into two fixes and two independent options.

Testing

• TARGET=primary make test-pythonv2: 679 passed, including the new open-enum cases with warnings raised as errors.
• With the previous basemodel.py, the unknown-value cases fail: two on warnings, and stringOrNull serializes to {}.
• TARGET=review make build-pythonv2: integrity validation passes; only types/basemodel.py and gen.lock change.
• git diff --check passes.

Public-safety check

• This change contains no credentials, customer documents, private repository URLs, private filesystem paths, or unredacted private logs.
• Title, body, comments, and commit messages name no customers or customer-derived identifiers, private paths or trackers, or workflow provenance, and are understandable without private context (.claude/skills/public-repo-communication/SKILL.md).
• Generated fixtures and review SDK changes are public-safe.
• I reviewed git diff --check.

[cubic-dev-ai]

No issues found across 6 files

Confidence score: 5/5

• Automated review surfaced no issues in the provided summaries.
• No files require special attention.

<sub>Shadow auto-approve: would auto-approve. Fixes Python SDK serialization of unrecognized open enum values by adding an explicit serializer that preserves python-mode values and emits plain str/int in JSON, with new tests covering enum-scalar unions; bounded bug fix with tests.

View guided diff | Turn on auto-fix | Re-trigger cubic</sub>

[cubic-dev-ai]

0 issues found across 5 reviewed files. 1 file intentionally excluded from review.

Confidence score: 5/5

• Automated review surfaced no issues in the provided summaries.
• No files require special attention.

<sub>Shadow auto-approve: would auto-approve. Adds explicit serialization for unrecognized open enum values in the Python SDK so dumps emit plain str/int without Pydantic warnings and unknown values survive in nullable union fields; a focused, tested template bug fix.

View guided diff | Turn on auto-fix | Re-trigger cubic</sub>

[speakeasy-generator-bot]

Generator Snapshot Testing

Selector(s)	Result	Summary
snapshot-python	✅	Snapshot run completed

Snapshot results: https://github.com/speakeasy-api/openapi-generation-snapshots/issues/134#issuecomment-6369044276

Snapshot results are summarized above. Additional run context is linked for maintainers with access.