* feat(backend): add moss-tts-cpp text-to-speech backend Add a Go + purego backend wrapping the moss-tts.cpp ggml port of the OpenMOSS MOSS-TTS-Local v1.5 text-to-speech model (GPT-J local transformer decoded through MOSS-Audio-Tokenizer-v2), producing 48 kHz stereo audio with optional reference-audio voice cloning. Mirrors the qwen3-tts-cpp backend: dlopen the static-ggml shared library, bind the moss-tts.cpp C-API via purego, and serve the gRPC TTS method. A thin C shim holds the pipeline handle and copies engine PCM into a Go-freeable buffer. Wires the CI registration: backend-matrix.yml (CPU, CUDA 12/13, Intel SYCL f16/f32, Vulkan, ROCm, NVIDIA L4T, plus Darwin metal), backend/index.yaml metas and image entries pointing at mudler/MOSS-TTS-Local-Transformer-v1.5-GGUF, the root Makefile build targets, and the changed-backends.js path mapping. Assisted-by: Claude:claude-opus-4-8 [Claude Code] Signed-off-by: Ettore Di Giacinto <mudler@localai.io> * docs: list the moss-tts-cpp backend among the LocalAI-maintained engines Add moss-tts.cpp to the README "Backends built by us" table, the Text-to-Speech compatibility table, and the reference-audio voice-cloning backend list, so the new backend is documented alongside its peers. Assisted-by: Claude:claude-opus-4-8 [Claude Code] Signed-off-by: Ettore Di Giacinto <mudler@localai.io> * backend(moss-tts-cpp): pin moss-tts.cpp to the squashed single-commit release moss-tts.cpp history was collapsed to a single commit; repoint MOSSTTS_CPP_VERSION to ee722b8e9205ee9b1b1c398a4e87e4e393e9be41. Assisted-by: Claude:claude-opus-4-8 [Claude Code] Signed-off-by: Ettore Di Giacinto <mudler@localai.io> * backend(moss-tts-cpp): add the moss-tts-cpp-development gallery meta The gallery had the -development image entries but no matching -development meta anchor (as locate-anything-cpp and depth-anything-cpp have), so the master build was not installable as a gallery backend. Add moss-tts-cpp-development mirroring the production meta with the -development capability image names. Assisted-by: Claude:claude-opus-4-8 [Claude Code] Signed-off-by: Ettore Di Giacinto <mudler@localai.io> --------- Signed-off-by: Ettore Di Giacinto <mudler@localai.io> Co-authored-by: Ettore Di Giacinto <mudler@localai.io>
MOSS-TTS C++ backend
This backend runs the OpenMOSS MOSS-TTS-Local (v1.5) GGUF model through moss-tts.cpp, a from-scratch C++/ggml port with no Python at inference time. It generates 48 kHz stereo speech and supports reference-audio voice cloning.
The engine loads three GGUFs: the local transformer (the model), the
MOSS-Audio-Tokenizer neural codec, and the text tokenizer. It is loaded via
purego (cgo-less dlopen) exactly like qwen3-tts-cpp.
Model configuration
The model path points at the local transformer GGUF. The codec and text tokenizer are auto-discovered as siblings of the model:
- codec: a
*.ggufwhose name containsaudio+tokenizer(orcodec), e.g.moss-audio-tokenizer-v2-f32.gguf - tokenizer: the other
*.ggufwhose name containstokenizer, e.g.moss-tokenizer-v1_5.gguf
name: moss-tts-cpp
backend: moss-tts-cpp
parameters:
model: moss-tts-local-v1_5-q8_0.gguf
known_usecases:
- tts
tts:
audio_path: voices/default-reference.wav # optional model-wide clone reference
Override discovery when the filenames are non-standard:
options:
- "codec:moss-audio-tokenizer-v2-f32.gguf"
- "tokenizer:moss-tokenizer-v1_5.gguf"
- "seed:42"
GGUFs for the Local v1.5 model (plus its codec and tokenizer) live at mudler/MOSS-TTS-Local-Transformer-v1.5-GGUF.
Voice cloning
MOSS-TTS-Local has no named speakers; cloning is driven purely by a
reference-audio path. Request precedence is: a request voice that ends in
a known audio extension (.wav, .flac, .mp3, .ogg, .m4a), then
tts.audio_path. The engine decodes the reference itself, so no client-side
resampling is required.
API example
curl http://localhost:8080/v1/audio/speech \
-H 'Content-Type: application/json' \
-d '{
"model": "moss-tts-cpp",
"input": "This request uses a saved reference voice.",
"voice": "/path/to/reference.wav"
}' \
--output speech.wav
Native end-to-end test
The labeled test loads real GGUFs, synthesizes a 48 kHz stereo WAV, and streams audio:
make -C backend/go/moss-tts-cpp moss-tts-cpp
MOSSTTS_MODEL=/path/to/moss-tts-local-v1_5-q8_0.gguf \
MOSSTTS_CODEC=/path/to/moss-audio-tokenizer-v2-f32.gguf \
MOSSTTS_TOKENIZER=/path/to/moss-tokenizer-v1_5.gguf \
MOSSTTS_LIBRARY=backend/go/moss-tts-cpp/libgomosstts-cpp-fallback.so \
go test ./backend/go/moss-tts-cpp -ginkgo.label-filter=e2e