feat: Add Sherpa ONNX backend for ASR and TTS

.github/workflows/backend.yml

@@ -2877,6 +2877,49 @@ jobs:
             dockerfile: "./backend/Dockerfile.python"
             context: "./"
             ubuntu-version: '2404'
+          # sherpa-onnx CPU
+          - build-type: ''
+            cuda-major-version: ""
+            cuda-minor-version: ""
+            platforms: 'linux/amd64,linux/arm64'
+            tag-latest: 'auto'
+            tag-suffix: '-cpu-sherpa-onnx'
+            runs-on: 'ubuntu-latest'
+            base-image: "ubuntu:24.04"
+            skip-drivers: 'false'
+            backend: "sherpa-onnx"
+            dockerfile: "./backend/Dockerfile.golang"
+            context: "./"
+            ubuntu-version: '2404'
+          # sherpa-onnx CUDA 12
+          - build-type: 'cublas'
+            cuda-major-version: "12"
+            cuda-minor-version: "8"
+            platforms: 'linux/amd64'
+            tag-latest: 'auto'
+            tag-suffix: '-gpu-nvidia-cuda-12-sherpa-onnx'
+            runs-on: 'ubuntu-latest'
+            base-image: "ubuntu:24.04"
+            skip-drivers: 'false'
+            backend: "sherpa-onnx"
+            dockerfile: "./backend/Dockerfile.golang"
+            context: "./"
+            ubuntu-version: '2404'
+          # sherpa-onnx CUDA 13 — requires onnxruntime 1.24.x+ for the
+          # gpu_cuda13 tarball; sherpa-onnx SHERPA_COMMIT pins to v1.12.39.
+          - build-type: 'cublas'
+            cuda-major-version: "13"
+            cuda-minor-version: "0"
+            platforms: 'linux/amd64'
+            tag-latest: 'auto'
+            tag-suffix: '-gpu-nvidia-cuda-13-sherpa-onnx'
+            runs-on: 'ubuntu-latest'
+            base-image: "ubuntu:24.04"
+            skip-drivers: 'false'
+            backend: "sherpa-onnx"
+            dockerfile: "./backend/Dockerfile.golang"
+            context: "./"
+            ubuntu-version: '2404'
   backend-jobs-darwin:
     uses: ./.github/workflows/backend_build_darwin.yml
     strategy:

.github/workflows/test-extra.yml

@@ -40,6 +40,7 @@ jobs:
       kokoros: ${{ steps.detect.outputs.kokoros }}
       insightface: ${{ steps.detect.outputs.insightface }}
       speaker-recognition: ${{ steps.detect.outputs.speaker-recognition }}
+      sherpa-onnx: ${{ steps.detect.outputs.sherpa-onnx }}
     steps:
       - name: Checkout repository
         uses: actions/checkout@v6
@@ -506,6 +507,72 @@ jobs:
       - name: Build llama-cpp backend image and run audio transcription gRPC e2e tests
         run: |
           make test-extra-backend-llama-cpp-transcription
+  # Realtime e2e with sherpa-onnx driving VAD + STT + TTS against a mocked LLM.
+  # Builds the sherpa-onnx Docker image, extracts the rootfs so the e2e suite
+  # can discover the backend binary + shared libs, downloads the three model
+  # bundles (silero-vad, omnilingual-asr, vits-ljs) and drives the realtime
+  # websocket spec end-to-end.
+  tests-sherpa-onnx-realtime:
+    needs: detect-changes
+    if: needs.detect-changes.outputs.sherpa-onnx == 'true' || needs.detect-changes.outputs.run-all == 'true'
+    runs-on: ubuntu-latest
+    timeout-minutes: 90
+    steps:
+      - name: Clone
+        uses: actions/checkout@v6
+        with:
+          submodules: true
+      - name: Setup Go
+        uses: actions/setup-go@v5
+        with:
+          go-version: '1.25.4'
+      - name: Setup Node.js
+        uses: actions/setup-node@v6
+        with:
+          node-version: '22'
+      - name: Build sherpa-onnx backend image and run realtime e2e tests
+        run: |
+          make test-extra-e2e-realtime-sherpa
+  # Streaming ASR via the sherpa-onnx online recognizer (zipformer
+  # transducer). Exercises both AudioTranscription (buffered) and
+  # AudioTranscriptionStream (real-time deltas) on the e2e-backends
+  # harness.
+  tests-sherpa-onnx-grpc-transcription:
+    needs: detect-changes
+    if: needs.detect-changes.outputs.sherpa-onnx == 'true' || needs.detect-changes.outputs.run-all == 'true'
+    runs-on: ubuntu-latest
+    timeout-minutes: 90
+    steps:
+      - name: Clone
+        uses: actions/checkout@v6
+        with:
+          submodules: true
+      - name: Setup Go
+        uses: actions/setup-go@v5
+        with:
+          go-version: '1.25.4'
+      - name: Build sherpa-onnx backend image and run streaming ASR gRPC e2e tests
+        run: |
+          make test-extra-backend-sherpa-onnx-transcription
+  # VITS TTS via the sherpa-onnx backend. Drives both TTS (file write) and
+  # TTSStream (PCM chunks) on the e2e-backends harness.
+  tests-sherpa-onnx-grpc-tts:
+    needs: detect-changes
+    if: needs.detect-changes.outputs.sherpa-onnx == 'true' || needs.detect-changes.outputs.run-all == 'true'
+    runs-on: ubuntu-latest
+    timeout-minutes: 90
+    steps:
+      - name: Clone
+        uses: actions/checkout@v6
+        with:
+          submodules: true
+      - name: Setup Go
+        uses: actions/setup-go@v5
+        with:
+          go-version: '1.25.4'
+      - name: Build sherpa-onnx backend image and run TTS gRPC e2e tests
+        run: |
+          make test-extra-backend-sherpa-onnx-tts
   tests-ik-llama-cpp-grpc:
     needs: detect-changes
     if: needs.detect-changes.outputs.ik-llama-cpp == 'true' || needs.detect-changes.outputs.run-all == 'true'

.github/workflows/test.yml

@@ -195,7 +195,7 @@ jobs:
         run: go version
       - name: Dependencies
         run: |
-          brew install protobuf grpc make protoc-gen-go protoc-gen-go-grpc libomp llvm opus
+          brew install protobuf grpc make protoc-gen-go protoc-gen-go-grpc libomp llvm opus ffmpeg
           pip install --user --no-cache-dir grpcio-tools grpcio
       - name: Setup Node.js
         uses: actions/setup-node@v6

Makefile

@@ -1,5 +1,5 @@
 # Disable parallel execution for backend builds
-.NOTPARALLEL: backends/diffusers backends/llama-cpp backends/turboquant backends/outetts backends/piper backends/stablediffusion-ggml backends/whisper backends/faster-whisper backends/silero-vad backends/local-store backends/huggingface backends/rfdetr backends/insightface backends/speaker-recognition backends/kitten-tts backends/kokoro backends/chatterbox backends/llama-cpp-darwin backends/neutts build-darwin-python-backend build-darwin-go-backend backends/mlx backends/diffuser-darwin backends/mlx-vlm backends/mlx-audio backends/mlx-distributed backends/stablediffusion-ggml-darwin backends/vllm backends/vllm-omni backends/sglang backends/moonshine backends/pocket-tts backends/qwen-tts backends/faster-qwen3-tts backends/qwen-asr backends/nemo backends/voxcpm backends/whisperx backends/ace-step backends/acestep-cpp backends/fish-speech backends/voxtral backends/opus backends/trl backends/llama-cpp-quantization backends/kokoros backends/sam3-cpp backends/qwen3-tts-cpp backends/tinygrad
+.NOTPARALLEL: backends/diffusers backends/llama-cpp backends/turboquant backends/outetts backends/piper backends/stablediffusion-ggml backends/whisper backends/faster-whisper backends/silero-vad backends/local-store backends/huggingface backends/rfdetr backends/insightface backends/speaker-recognition backends/kitten-tts backends/kokoro backends/chatterbox backends/llama-cpp-darwin backends/neutts build-darwin-python-backend build-darwin-go-backend backends/mlx backends/diffuser-darwin backends/mlx-vlm backends/mlx-audio backends/mlx-distributed backends/stablediffusion-ggml-darwin backends/vllm backends/vllm-omni backends/sglang backends/moonshine backends/pocket-tts backends/qwen-tts backends/faster-qwen3-tts backends/qwen-asr backends/nemo backends/voxcpm backends/whisperx backends/ace-step backends/acestep-cpp backends/fish-speech backends/voxtral backends/opus backends/trl backends/llama-cpp-quantization backends/kokoros backends/sam3-cpp backends/qwen3-tts-cpp backends/tinygrad backends/sherpa-onnx
 
 GOCMD=go
 GOTEST=$(GOCMD) test
@@ -750,6 +750,44 @@ test-extra-backend-speaker-recognition-ecapa: docker-build-speaker-recognition
 test-extra-backend-speaker-recognition-all: \
 	test-extra-backend-speaker-recognition-ecapa
 
+## Realtime e2e with sherpa-onnx driving VAD + STT + TTS against a mocked
+## LLM. Extracts the sherpa-onnx Docker image rootfs, downloads the three
+## gallery-referenced model bundles (silero-vad, omnilingual-asr, vits-ljs),
+## writes the corresponding model config YAMLs, and runs the realtime
+## websocket spec in tests/e2e with REALTIME_* env vars wiring the sherpa
+## slots into the pipeline. The LLM slot stays on the in-repo mock-backend
+## registered unconditionally by tests/e2e/e2e_suite_test.go. See
+## tests/e2e/run-realtime-sherpa.sh for the full orchestration.
+test-extra-e2e-realtime-sherpa: build-mock-backend docker-build-sherpa-onnx protogen-go react-ui
+	bash tests/e2e/run-realtime-sherpa.sh
+
+## Streaming ASR via the sherpa-onnx online recognizer. Uses the streaming
+## zipformer English model (encoder/decoder/joiner int8 + tokens) from the
+## sherpa-onnx gallery entry. Drives both AudioTranscription and
+## AudioTranscriptionStream via the e2e-backends gRPC harness; streaming
+## emits real partial deltas during decode. Each file is renamed on download
+## to the shape sherpa-onnx's online loader expects (encoder.int8.onnx etc.).
+test-extra-backend-sherpa-onnx-transcription: docker-build-sherpa-onnx
+	BACKEND_IMAGE=local-ai-backend:sherpa-onnx \
+	BACKEND_TEST_MODEL_URL='https://huggingface.co/csukuangfj/sherpa-onnx-streaming-zipformer-en-2023-06-26/resolve/main/encoder-epoch-99-avg-1-chunk-16-left-128.int8.onnx#encoder.int8.onnx' \
+	BACKEND_TEST_EXTRA_FILES='https://huggingface.co/csukuangfj/sherpa-onnx-streaming-zipformer-en-2023-06-26/resolve/main/decoder-epoch-99-avg-1-chunk-16-left-128.int8.onnx#decoder.int8.onnx|https://huggingface.co/csukuangfj/sherpa-onnx-streaming-zipformer-en-2023-06-26/resolve/main/joiner-epoch-99-avg-1-chunk-16-left-128.int8.onnx#joiner.int8.onnx|https://huggingface.co/csukuangfj/sherpa-onnx-streaming-zipformer-en-2023-06-26/resolve/main/tokens.txt' \
+	BACKEND_TEST_AUDIO_URL=https://github.com/ggml-org/whisper.cpp/raw/master/samples/jfk.wav \
+	BACKEND_TEST_CAPS=health,load,transcription \
+	BACKEND_TEST_OPTIONS=subtype=online \
+	$(MAKE) test-extra-backend
+
+## VITS TTS via the sherpa-onnx backend. Pulls the individual files from
+## HuggingFace (the vits-ljs release tarball lives on the k2-fsa github
+## but is also mirrored as discrete files on HF). Exercises both
+## TTS (write-to-file) and TTSStream (PCM chunks + WAV header) via the
+## e2e-backends gRPC harness.
+test-extra-backend-sherpa-onnx-tts: docker-build-sherpa-onnx
+	BACKEND_IMAGE=local-ai-backend:sherpa-onnx \
+	BACKEND_TEST_MODEL_URL='https://huggingface.co/csukuangfj/vits-ljs/resolve/main/vits-ljs.onnx#vits-ljs.onnx' \
+	BACKEND_TEST_EXTRA_FILES='https://huggingface.co/csukuangfj/vits-ljs/resolve/main/tokens.txt|https://huggingface.co/csukuangfj/vits-ljs/resolve/main/lexicon.txt' \
+	BACKEND_TEST_CAPS=health,load,tts \
+	$(MAKE) test-extra-backend
+
 ## sglang mirrors the vllm setup: HuggingFace model id, same tiny Qwen,
 ## tool-call extraction via sglang's native qwen parser. CPU builds use
 ## sglang's upstream pyproject_cpu.toml recipe (see backend/python/sglang/install.sh).
@@ -887,6 +925,7 @@ BACKEND_VOXTRAL = voxtral|golang|.|false|true
 BACKEND_ACESTEP_CPP = acestep-cpp|golang|.|false|true
 BACKEND_QWEN3_TTS_CPP = qwen3-tts-cpp|golang|.|false|true
 BACKEND_OPUS = opus|golang|.|false|true
+BACKEND_SHERPA_ONNX = sherpa-onnx|golang|.|false|true
 
 # Python backends with root context
 BACKEND_RERANKERS = rerankers|python|.|false|true
@@ -999,12 +1038,13 @@ $(eval $(call generate-docker-build-target,$(BACKEND_LLAMA_CPP_QUANTIZATION)))
 $(eval $(call generate-docker-build-target,$(BACKEND_TINYGRAD)))
 $(eval $(call generate-docker-build-target,$(BACKEND_KOKOROS)))
 $(eval $(call generate-docker-build-target,$(BACKEND_SAM3_CPP)))
+$(eval $(call generate-docker-build-target,$(BACKEND_SHERPA_ONNX)))
 
 # Pattern rule for docker-save targets
 docker-save-%: backend-images
 	docker save local-ai-backend:$* -o backend-images/$*.tar
 
-docker-build-backends: docker-build-llama-cpp docker-build-ik-llama-cpp docker-build-turboquant docker-build-rerankers docker-build-vllm docker-build-vllm-omni docker-build-sglang docker-build-transformers docker-build-outetts docker-build-diffusers docker-build-kokoro docker-build-faster-whisper docker-build-coqui docker-build-chatterbox docker-build-vibevoice docker-build-moonshine docker-build-pocket-tts docker-build-qwen-tts docker-build-fish-speech docker-build-faster-qwen3-tts docker-build-qwen-asr docker-build-nemo docker-build-voxcpm docker-build-whisperx docker-build-ace-step docker-build-acestep-cpp docker-build-voxtral docker-build-mlx-distributed docker-build-trl docker-build-llama-cpp-quantization docker-build-tinygrad docker-build-kokoros docker-build-sam3-cpp docker-build-qwen3-tts-cpp docker-build-insightface docker-build-speaker-recognition
+docker-build-backends: docker-build-llama-cpp docker-build-ik-llama-cpp docker-build-turboquant docker-build-rerankers docker-build-vllm docker-build-vllm-omni docker-build-sglang docker-build-transformers docker-build-outetts docker-build-diffusers docker-build-kokoro docker-build-faster-whisper docker-build-coqui docker-build-chatterbox docker-build-vibevoice docker-build-moonshine docker-build-pocket-tts docker-build-qwen-tts docker-build-fish-speech docker-build-faster-qwen3-tts docker-build-qwen-asr docker-build-nemo docker-build-voxcpm docker-build-whisperx docker-build-ace-step docker-build-acestep-cpp docker-build-voxtral docker-build-mlx-distributed docker-build-trl docker-build-llama-cpp-quantization docker-build-tinygrad docker-build-kokoros docker-build-sam3-cpp docker-build-qwen3-tts-cpp docker-build-insightface docker-build-speaker-recognition docker-build-sherpa-onnx
 
 ########################################################
 ### Mock Backend for E2E Tests

backend/go/sherpa-onnx/.gitignore

@@ -0,0 +1,11 @@
+.cache/
+sources/
+build*/
+package/
+backend-assets/
+sherpa-onnx
+*.so
+compile_commands.json
+sherpa-onnx-whisper-*
+vits-ljs/
+streaming-zipformer-en/

backend/go/sherpa-onnx/Makefile

@@ -0,0 +1,120 @@
+CURRENT_DIR=$(abspath ./)
+GOCMD=go
+
+ONNX_VERSION?=1.24.4
+# v1.12.39 — includes upstream's onnxruntime 1.24.4 bump (#3501). Earlier
+# pinned commits only support onnxruntime 1.23.2, which has no CUDA 13
+# pre-built tarball, blocking the -gpu-nvidia-cuda-13 build matrix entry.
+SHERPA_COMMIT?=7288d15e3e31a7bd589b2ba88828d521e7a6b140
+ONNX_ARCH?=x64
+ONNX_OS?=linux
+
+ifneq (,$(findstring aarch64,$(shell uname -m)))
+	ONNX_ARCH=aarch64
+endif
+
+ifeq ($(OS),Darwin)
+	ONNX_OS=osx
+	ifneq (,$(findstring aarch64,$(shell uname -m)))
+		ONNX_ARCH=arm64
+	else ifneq (,$(findstring arm64,$(shell uname -m)))
+		ONNX_ARCH=arm64
+	else
+		ONNX_ARCH=x86_64
+	endif
+endif
+
+# Upstream onnxruntime ships CUDA 12 and CUDA 13 variants under different
+# names: -gpu-<ver>.tgz for CUDA 12, -gpu_cuda13-<ver>.tgz for CUDA 13
+# (note underscore vs dash). CUDA 13 tarballs only exist from 1.24.x onward.
+ifeq ($(BUILD_TYPE),cublas)
+	SHERPA_GPU=ON
+	ONNX_PROVIDER=cuda
+	ifeq ($(CUDA_MAJOR_VERSION),13)
+		ONNX_VARIANT=-gpu_cuda13
+	else
+		ONNX_VARIANT=-gpu
+	endif
+else
+	ONNX_VARIANT=
+	SHERPA_GPU=OFF
+	ONNX_PROVIDER=cpu
+endif
+
+JOBS?=$(shell nproc --ignore=1 2>/dev/null || sysctl -n hw.ncpu 2>/dev/null || echo 4)
+
+sources/onnxruntime:
+	mkdir -p sources/onnxruntime
+	curl -L https://github.com/microsoft/onnxruntime/releases/download/v$(ONNX_VERSION)/onnxruntime-$(ONNX_OS)-$(ONNX_ARCH)$(ONNX_VARIANT)-$(ONNX_VERSION).tgz \
+	  -o sources/onnxruntime/onnxruntime.tgz
+	cd sources/onnxruntime && tar -xf onnxruntime.tgz --strip-components=1 && rm onnxruntime.tgz
+
+sources/sherpa-onnx: sources/onnxruntime
+	git clone https://github.com/k2-fsa/sherpa-onnx.git sources/sherpa-onnx
+	cd sources/sherpa-onnx && git checkout $(SHERPA_COMMIT)
+	mkdir -p sources/sherpa-onnx/build
+	# sherpa-onnx's cmake detects a pre-installed onnxruntime via the
+	# SHERPA_ONNXRUNTIME_{INCLUDE,LIB}_DIR env vars (not via -D flags).
+	# Point them at our locally-downloaded Microsoft tarball — without
+	# this, sherpa-onnx falls through to download_onnxruntime() which
+	# fetches from csukuangfj/onnxruntime-libs. For the GPU 1.24.4
+	# build that release mirror publishes `-patched.zip` instead of the
+	# expected `.tgz`, so the download 404s and the build fails.
+	cd sources/sherpa-onnx/build && \
+	SHERPA_ONNXRUNTIME_INCLUDE_DIR=$(CURRENT_DIR)/sources/onnxruntime/include \
+	SHERPA_ONNXRUNTIME_LIB_DIR=$(CURRENT_DIR)/sources/onnxruntime/lib \
+	cmake \
+	  -DCMAKE_BUILD_TYPE=Release \
+	  -DCMAKE_C_FLAGS="-Wno-error=format-security" \
+	  -DCMAKE_CXX_FLAGS="-Wno-error=format-security" \
+	  -DSHERPA_ONNX_ENABLE_GPU=$(SHERPA_GPU) \
+	  -DSHERPA_ONNX_ENABLE_TTS=ON \
+	  -DSHERPA_ONNX_ENABLE_BINARY=OFF \
+	  -DSHERPA_ONNX_ENABLE_PYTHON=OFF \
+	  -DSHERPA_ONNX_ENABLE_TESTS=OFF \
+	  -DSHERPA_ONNX_ENABLE_C_API=ON \
+	  -DBUILD_SHARED_LIBS=ON \
+	  -DSHERPA_ONNX_USE_PRE_INSTALLED_ONNXRUNTIME_IF_AVAILABLE=ON \
+	  ..
+	cd sources/sherpa-onnx/build && make -j$(JOBS)
+
+backend-assets/lib: sources/sherpa-onnx sources/onnxruntime
+	mkdir -p backend-assets/lib
+	cp -rfLv sources/onnxruntime/lib/* backend-assets/lib/
+	cp -rfLv sources/sherpa-onnx/build/lib/*.so* backend-assets/lib/ 2>/dev/null || true
+	cp -rfLv sources/sherpa-onnx/build/lib/*.dylib backend-assets/lib/ 2>/dev/null || true
+
+# libsherpa-shim wraps sherpa-onnx's nested config structs and TTS
+# callback plumbing behind a purego-friendly API: opaque handles plus
+# fixed-signature setters/getters/trampoline. Plain C compile — no cgo.
+SHIM_EXT=so
+ifeq ($(OS),Darwin)
+	SHIM_EXT=dylib
+endif
+
+backend-assets/lib/libsherpa-shim.$(SHIM_EXT): csrc/shim.c csrc/shim.h backend-assets/lib
+	$(CC) -shared -fPIC -O2 \
+	  -I$(CURRENT_DIR)/sources/sherpa-onnx/sherpa-onnx/c-api \
+	  -o $@ csrc/shim.c \
+	  -L$(CURRENT_DIR)/backend-assets/lib \
+	  -lsherpa-onnx-c-api \
+	  -Wl,-rpath,'$$ORIGIN'
+
+sherpa-onnx: backend-assets/lib backend-assets/lib/libsherpa-shim.$(SHIM_EXT)
+	CGO_ENABLED=0 $(GOCMD) build \
+	  -ldflags "$(LD_FLAGS) -X main.onnxProvider=$(ONNX_PROVIDER)" \
+	  -tags "$(GO_TAGS)" -o sherpa-onnx ./
+
+package:
+	bash package.sh
+
+build: sherpa-onnx package
+
+clean:
+	rm -rf sherpa-onnx sources/ backend-assets/ package/ vits-ljs/ sherpa-onnx-whisper-*/
+
+test: sherpa-onnx
+	LD_LIBRARY_PATH=$(CURRENT_DIR)/backend-assets/lib \
+	bash test.sh
+
+.PHONY: build package clean test