Implement first TTS plugin using new Plugin Architecture:
- plugins/kokoro/: Plugin package with manifest and entry point
- plugins/kokoro/engine.py: KokoroEngine and KokoroSession adapters
- Wraps existing KokoroBackend without modifying it
- Implements VoiceLister capability
- Satisfies Engine/EngineSession protocol
- Passes all 163 contract tests
Tests:
- Plugin loading through Plugin Loader
- Manifest validation
- Engine creation and lifecycle
- Session synthesis and dispose
- VoiceLister capability
15 new tests for Kokoro plugin.
Implement plugin loading and validation:
- loader.py: discover, import, validate plugins
- validate PLUGIN_MANIFEST, MODEL_REQUIREMENTS, create_engine
- validate api_version compatibility (major must match)
- validate capabilities (reject unknown)
- diagnostic messages for all error cases
- no partial registration after error
Test plugins:
- fake_plugin: minimal valid plugin for testing
- missing_manifest: no PLUGIN_MANIFEST
- invalid_api_version: major version mismatch
- invalid_capabilities: unknown capabilities
- missing_create_engine: no create_engine function
- import_error: raises ImportError during import
- missing_model_requirements: no MODEL_REQUIREMENTS
39 new tests covering all loader functionality.
Create public API structure for TTS Plugin Architecture:
- types.py: immutable value objects (AudioFormat, Duration, VoiceSelection, etc.)
- errors.py: EngineError hierarchy (7 typed exceptions)
- manifest.py: plugin manifest dataclasses (PluginManifest, EngineManifest, etc.)
- engine.py: Engine and EngineSession protocols
- capabilities.py: optional capability interfaces (VoiceLister, PreviewGenerator, etc.)
- host_context.py: HostContext and HttpClient protocol
- plugin.py: plugin contract (create_engine signature)
- __init__.py: public API exports
All interfaces are fully defined but contain no business logic.
API is frozen and ready for implementation in subsequent PRs.
- Add resolve_backend_for_voice() to TTSBackendRegistry
- Add module-level wrapper resolve_backend_for_voice()
- Simplify _infer_provider_from_spec() to use registry API
- Simplify _supertonic_voice_from_spec() to only normalize
- Add 11 test cases for the new method
Resolution rules:
1. Empty spec -> fallback
2. Kokoro formula (* or +) -> kokoro
3. Exact voice ID match -> backend id
4. Unknown voice -> fallback
Add TTSBackendRegistry.is_registered() and module-level
is_registered_backend() to validate backend IDs dynamically.
Replace all Category A hardcoded sets (validation-only) in
voice_profiles, api routes, conversion_runner, and form utils.
Make the Kokoro voice list an internal implementation detail of the
backend instead of a shared constant. The rest of the project already
accesses voices via get_metadata('kokoro').voices.
- Move VOICES_INTERNAL from constants.py to kokoro.py as _VOICES_INTERNAL
- Update tests to use get_metadata('kokoro').voices instead of importing
the constant directly
Replace direct VOICES_INTERNAL imports with get_metadata('kokoro').voices
from tts_backend_registry in all PyQt modules:
- abogen/pyqt/gui.py
- abogen/pyqt/predownload_gui.py
- abogen/pyqt/voice_formula_gui.py
- Add get_default_voice() helper to tts_backend_registry
- Replace all VOICES_INTERNAL imports in WebUI with get_metadata().voices
- Replace all DEFAULT_SUPERTONIC_VOICES imports in conversion_runner with get_metadata().voices
- Remove unused VOICES_INTERNAL import from voices.py
Core modules (voice_profiles, voice_formulas, voice_cache) already used
get_metadata(). This completes the WebUI migration.
Replace direct imports of VOICES_INTERNAL and DEFAULT_SUPERTONIC_VOICES
in voice_profiles, voice_formulas, and voice_cache with get_metadata()
from TTSBackendRegistry. Adds get_metadata() top-level function to
tts_backend_registry as symmetric counterpart to register_backend() and
create_backend().
Add voices field to TTSBackendMetadata so each backend's supported
voice list is part of its metadata rather than external constants.
- Add voices: tuple[str, ...] = () to TTSBackendMetadata
- Create _KOKORO_METADATA / _SUPERTONIC_METADATA as single source
of truth for both metadata property and registry registration
- Update KokoroBackend.get_available_voices() to use self.metadata.voices
- Update SupertonicBackend.get_available_voices() to use self.metadata.voices
- Add tests for voices field, metadata voice content, and unified instance identity
- Create KokoroBackend class implementing TTSBackend protocol
- Move all KPipeline interaction inside KokoroBackend
- Update LoadPipelineThread to create backend via create_backend()
- Update ConversionThread and VoicePreviewThread to accept backend
- Replace np_module/kpipeline_class parameters with single backend
- Add 24 unit tests for KokoroBackend
- KPipeline is now an internal implementation detail of KokoroBackend
Encapsulate SupertonicPipeline as an internal detail of
SupertonicBackend. The factory create_supertonic_backend() now
returns a SupertonicBackend instance instead of a raw
SupertonicPipeline, satisfying the TTSBackend protocol with
metadata, synthesize, get_available_voices, get_supported_formats,
and get_info methods. Backward-compatible __call__ delegates to
the internal pipeline.
Migrate all preview/debug/conversion pipeline creation to use
TTSBackendRegistry.create_backend() instead of direct imports:
- debug_tts_runner._load_pipeline(): Kokoro via registry
- preview.get_preview_pipeline(): Kokoro via registry
- preview.generate_preview_audio(): Supertonic via registry
- voice.get_preview_pipeline(): Kokoro via registry
- conversion_runner._load_pipeline(): both backends via registry
- conversion_runner inline pipeline creation: both via registry
- test: update mock to target tts_backend_registry.create_backend
- Add create_kokoro_backend() factory in kokoro.py
- Add create_supertonic_backend() factory in supertonic.py
- Auto-discover backend modules in __init__.py via pkgutil
- Both backends register themselves on import
- Tests verify registration and factory callables
- TTSBackendRegistry class with register(), list_backends(), get_metadata(), create_backend()
- Global registry singleton with register_backend() and create_backend() convenience functions
- Unit tests for registry operations
Moved SupertonicPipeline from abogen/tts_supertonic.py to
abogen/tts_backends/supertonic.py and load_numpy_kpipeline from
abogen/utils.py to abogen/tts_backends/kokoro.py.
Git correctly detects the Supertonic file as a rename (R),
preserving full commit history.
- New package: abogen/tts_backends/
- __init__.py (package marker)
- supertonic.py (SupertonicPipeline, moved from tts_supertonic.py)
- kokoro.py (load_numpy_kpipeline, moved from utils.py)
- abogen/utils.py: re-exports load_numpy_kpipeline for backward compat
- All imports updated to new canonical paths
- Create TTSBackend abstract base class with minimal contract
- Implement KokoroTTSBackend that maintains existing behavior
- Update conversion_runner.py to use new interface
- No behavioral changes, GUI unchanged, no new features
Artem Akymenko