Deprecation & API Stability

How the SDK manages deprecations, version bumps, and backward compatibility.

The OpenHands SDK enforces a structured deprecation lifecycle to keep the public API stable while allowing it to evolve. Two CI checks run automatically on every release to enforce these policies.

Public API Surface

Each published package defines its public API via __all__ in its top-level __init__.py. The following packages are currently covered:

Package	Distribution	__all__
openhands.sdk	openhands-sdk	✅
openhands.workspace	openhands-workspace	✅

openhands-tools does not yet define __all__ and is not covered by the automated breakage checks. This is tracked in #2074.

Deprecation Helpers

The SDK provides two canonical ways to mark something as deprecated, both in openhands.sdk.utils.deprecation:

@deprecated decorator

Use on classes and functions that will be removed in a future release:

from openhands.sdk.utils.deprecation import deprecated

@deprecated(deprecated_in="1.10.0", removed_in="1.12.0")
class OldThing:
    ...

warn_deprecated() function

Use for runtime deprecation warnings on dynamic access paths (e.g., property accessors, conditional branches):

from openhands.sdk.utils.deprecation import warn_deprecated

class MyModel:
    @property
    def old_field(self):
        warn_deprecated("MyModel.old_field", deprecated_in="1.10.0", removed_in="1.12.0")
        return self._new_field

Both helpers emit a DeprecationWarning so users see the message during development, and record metadata that CI tooling can detect.

Policy 1: Deprecation Before Removal

Any symbol removed from a package’s __all__ must have been marked as deprecated for at least one release before removal.

This is enforced by check_sdk_api_breakage.py, which AST-scans the previous PyPI release looking for @deprecated decorators or warn_deprecated() calls. If a removed symbol was never deprecated, CI flags it as an error.

1. Mark the symbol as deprecated

   Add @deprecated(...) or warn_deprecated(...) in the current release. The symbol stays in __all__ and continues to work — users just see a warning.

2. Release with the deprecation marker

   The deprecation is now recorded in the published package on PyPI.

3. Remove the symbol in a subsequent release

   Remove it from __all__ (and the code). CI will verify the prior release had the deprecation marker and allow the removal.

Policy 2: MINOR Version Bump for Breaking Changes

Any breaking change — removal of an exported symbol or structural change to a public class/function — requires at least a MINOR version bump (e.g., 1.11.x → 1.12.0).

This applies to all structural breakages detected by Griffe, including:

• Removed symbols from __all__
• Removed attributes from exported classes
• Changed function signatures

A PATCH bump (e.g., 1.11.3 → 1.11.4) with breaking changes will fail CI.

Event Field Deprecation (Special Case)

Event types (Pydantic models used in event serialization) have an additional constraint: old events must always load without error, because production systems may resume conversations containing events from older SDK versions.

When removing a field from an event type:

1. Never use extra="forbid" without a deprecation handler — old events containing removed fields would fail to deserialize.
2. Add a permanent model validator using handle_deprecated_model_fields:

from openhands.sdk.utils.deprecation import handle_deprecated_model_fields

class MyEvent(BaseModel):
    model_config = ConfigDict(extra="forbid")

    _DEPRECATED_FIELDS: ClassVar[tuple[str, ...]] = ("old_field_name",)

    @model_validator(mode="before")
    @classmethod
    def _handle_deprecated_fields(cls, data: Any) -> Any:
        return handle_deprecated_model_fields(data, cls._DEPRECATED_FIELDS)

Deprecated field handlers on events are permanent and must never be removed. They ensure old conversations can always be loaded regardless of when they were created.

CI Checks

Two scripts enforce these policies automatically:

Script	Runs on	What it checks
check_sdk_api_breakage.py	Release PRs (rel-* branches)	Deprecation-before-removal + MINOR bump
check_deprecations.py	Every PR	Deprecation deadline enforcement

Together they ensure that:

• Users always get advance warning before APIs are removed
• Breaking changes are properly versioned
• Deprecated code is eventually cleaned up