Files
LocalAI/backend/README.md
localai-org-maint-bot 9bfd71387b feat(stores): add Valkey Search vector store backend (#11196)
* feat: add Valkey Search vector store backend

Add a new built-in Go gRPC store backend 'valkey-store' that implements the
four Stores RPCs (Set/Get/Delete/Find) against the Valkey Search module (FT.*)
using the pure-Go github.com/valkey-io/valkey-go client. It is selected via the
existing per-request 'backend' field on /stores, so there is no proto or HTTP
API change, and it mirrors the in-memory local-store while adding persistence
across restarts and opt-in HNSW.

Each vector is a Valkey HASH keyed by hex(little-endian float32); the index is
created lazily on first Set (FLAT+COSINE by default), cosine similarity is
derived as 1-distance, and namespaces get a collision-resistant token. Includes
unit tests (valkey-go mock) and env-gated integration tests against
valkey/valkey-bundle, plus build/matrix/gallery wiring and docs.

Assisted-by: Kiro:claude-opus-4.8 golangci-lint
Signed-off-by: Daria Korenieva <daric2612@gmail.com>

* Address review feedback: recover persisted index dimension, harden Find

- Load now recovers the persisted vector DIM from FT.INFO (not just index
  existence), so a post-restart Set/Find validates against the real DIM
  instead of silently re-learning a wrong one and dropping mismatched
  vectors from the index. This also restores Find's dimension check after
  a restart.
- StoresFind treats a dropped/missing index as an empty store (empty
  result, no error) and clears the stale indexCreated flag, matching
  local-store's empty-store behaviour.
- StoresSet reuses checkDims for its per-key length check so the four RPCs
  share one dimension-guard implementation.
- Add unit tests for FT.INFO dimension recovery, loadIndexState, and the
  dropped-index Find path.

Assisted-by: Kiro:claude-opus-4.8
Signed-off-by: Daria Korenieva <daric2612@gmail.com>

* Address review feedback: TLS ServerName/CA, Find nil-check, config fail-fast

Addresses external review comments on the valkey-store backend:

- StoresFind now rejects a nil/empty query Key before dereferencing it,
  so a malformed gRPC request can no longer panic the backend.
- TLS: derive ServerName (SNI) from the VALKEY_ADDR host so certificate
  verification works for IP-addressed endpoints, and add VALKEY_TLS_CA_CERT
  (custom CA bundle) and VALKEY_TLS_SKIP_VERIFY (testing-only) knobs.
- Config integer parsing now fails fast on a malformed value (e.g.
  VALKEY_HNSW_M=1x6) instead of silently defaulting, matching the
  fail-fast behaviour of the index-algo/distance-metric validation.
- Add VALKEY_DB (SELECT n) support for logical-DB isolation.
- Cap the human-readable part of a namespace token at 64 chars so a very
  long model name cannot produce an unbounded key prefix / index name
  (the appended short hash keeps distinct namespaces collision-free).
- Document the KNN-query injection-safety invariant (fields are constants)
  and why StoresGet uses a single aggregate DoMulti deadline for reads.
- Unit tests for the Find nil/empty-key guard, fail-fast HNSW parsing,
  and VALKEY_DB parsing/validation; docs + .env updated for the new vars.

Assisted-by: Kiro:claude-opus-4.8 golangci-lint
Signed-off-by: Daria Korenieva <daric2612@gmail.com>

* Address review feedback: configure valkey-store via model config

richiejp asked that the valkey-store backend take its configuration from
a model config rather than process-wide VALKEY_* environment variables,
so multiple stores can each have their own Valkey config within one
LocalAI process. This removes every env access from the backend and
routes config through the model-config seam every other backend uses.

- config.go: loadConfig(opts *pb.ModelOptions) now parses the model
  config `options:` list (key:value strings, split on the first ':')
  instead of os.Getenv. Option keys mirror the old VALKEY_* names without
  the prefix (addr, index_algo, distance_metric, ...). Defaults, fail-fast
  validation and the mandatory client name are unchanged.
- store.go: Load threads opts into loadConfig; TLS comments/errors renamed
  off the VALKEY_* names.
- core/backend/stores.go: StoreBackend and NewVectorStore take a
  *config.ModelConfigLoader, resolve the per-store ModelConfig by store
  name, and pass its Options (and Backend when unset) to the backend via
  WithLoadGRPCLoadModelOpts. No config -> default backend + built-in
  defaults, preserving the zero-config experience.
- Endpoints/routes/application: thread the config loader to StoreBackend.
- Unit + integration tests: configure via options; the integration test
  passes addr through the model-config path (VALKEY_ADDR is now only the
  test harness locating the server).
- docs + .env: document the model-config options, drop the env var table.

Assisted-by: Kiro:claude-opus-4.8
Signed-off-by: Daria Korenieva <daric2612@gmail.com>

* Remove valkey-store informational comment from .env The backend is configured via model config, not env vars — the comment was unnecessary noise in .env. The configuration is already documented in docs/content/features/stores.md.

Signed-off-by: Daria Korenieva <daric2612@gmail.com>

* feat(valkey-store): gate Load on NamespacePrefix to refuse autoload probing Mirror local-store's pattern: reject model names without store.NamespacePrefix so the model loader's greedy autoload probe cannot bind an arbitrary model name to the vector store backend (the #9287 failure mode). Also adds unit tests for the gate covering: prefixed namespace, prefix alone, unprefixed model name, empty model, and nil opts.

Signed-off-by: Daria Korenieva <daric2612@gmail.com>

* feat(valkey-store): add username_env/password_env credential indirection Add support for resolving Valkey credentials from environment variables named in the model config, mirroring cloud-proxy's api_key_env pattern. This keeps secrets out of model YAML files and lets distinct store configs each reference their own credentials. Options: username_env / password_env name the env var holding the value. The direct username / password options still work and take precedence when both are set (backward compatible). Includes 5 unit tests and updated stores.md documentation.

Signed-off-by: Daria Korenieva <daric2612@gmail.com>

* fix: correct rebase artifacts in backend-matrix.yml and Makefile Fix two issues introduced by the conflict-resolution script during the rebase onto master: 1. .github/backend-matrix.yml: valkey-store entries were merged INTO the cloud-proxy entries (duplicate keys in same YAML map items) instead of being separate list items. This broke cloud-proxy Linux builds and the cloud-proxy darwin entry lost its build-type/lang. Fixed by making them standalone entries and restoring cloud-proxy exactly as on master. 2. Makefile: duplicated .NOTPARALLEL and docker-build-backends lines. Collapsed to single lines that are master's current content plus the valkey-store additions. Also adds the three optional pickups from #10801: - /valkey-store in .gitignore (the built binary) - valkey-store row in docs/content/reference/compatibility-table.md - valkey-store line in backend/README.md

Signed-off-by: Daria Korenieva <daric2612@gmail.com>

---------

Signed-off-by: Daria Korenieva <daric2612@gmail.com>
Co-authored-by: Daria Korenieva <daric2612@gmail.com>
2026-07-29 20:12:29 +02:00

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Markdown

# LocalAI Backend Architecture
This directory contains the core backend infrastructure for LocalAI, including the gRPC protocol definition, multi-language Dockerfiles, and language-specific backend implementations.
## Overview
LocalAI uses a unified gRPC-based architecture that allows different programming languages to implement AI backends while maintaining consistent interfaces and capabilities. The backend system supports multiple hardware acceleration targets and provides a standardized way to integrate various AI models and frameworks.
## Architecture Components
### 1. Protocol Definition (`backend.proto`)
The `backend.proto` file defines the gRPC service interface that all backends must implement. This ensures consistency across different language implementations and provides a contract for communication between LocalAI core and backend services.
#### Core Services
- **Text Generation**: `Predict`, `PredictStream` for LLM inference
- **Embeddings**: `Embedding` for text vectorization
- **Image Generation**: `GenerateImage` for stable diffusion and image models
- **Audio Processing**: `AudioTranscription`, `TTS`, `SoundGeneration`
- **Video Generation**: `GenerateVideo` for video synthesis
- **Object Detection**: `Detect` for computer vision tasks
- **Vector Storage**: `StoresSet`, `StoresGet`, `StoresFind` for RAG operations
- **Reranking**: `Rerank` for document relevance scoring
- **Voice Activity Detection**: `VAD` for audio segmentation
#### Key Message Types
- **`PredictOptions`**: Comprehensive configuration for text generation
- **`ModelOptions`**: Model loading and configuration parameters
- **`Result`**: Standardized response format
- **`StatusResponse`**: Backend health and memory usage information
### 2. Multi-Language Dockerfiles
The backend system provides language-specific Dockerfiles that handle the build environment and dependencies for different programming languages:
- `Dockerfile.python`
- `Dockerfile.golang`
- `Dockerfile.llama-cpp`
### 3. Language-Specific Implementations
#### Python Backends (`python/`)
- **transformers**: Hugging Face Transformers framework
- **vllm**: High-performance LLM inference
- **mlx**: Apple Silicon optimization
- **diffusers**: Stable Diffusion models
- **longcat-video**: CUDA text/image-to-video and speech-driven avatar generation
- **Audio**: coqui, faster-whisper, kitten-tts
- **Vision**: mlx-vlm, rfdetr
- **Specialized**: rerankers, chatterbox, kokoro
#### Go Backends (`go/`)
- **whisper**: OpenAI Whisper speech recognition in Go with GGML cpp backend (whisper.cpp)
- **stablediffusion-ggml**: Stable Diffusion in Go with GGML Cpp backend
- **piper**: Text-to-speech synthesis Golang with C bindings using rhaspy/piper
- **local-store**: Vector storage backend
- **valkey-store**: Durable vector storage backend backed by Valkey Search (FT.*)
#### C++ Backends (`cpp/`)
- **llama-cpp**: Llama.cpp integration
- **grpc**: GRPC utilities and helpers
## Hardware Acceleration Support
### CUDA (NVIDIA)
- **Versions**: CUDA 12.x, 13.x
- **Features**: cuBLAS, cuDNN, TensorRT optimization
- **Targets**: x86_64, ARM64 (Jetson)
### ROCm (AMD)
- **Features**: HIP, rocBLAS, MIOpen
- **Targets**: AMD GPUs with ROCm support
### Intel
- **Features**: oneAPI, Intel Extension for PyTorch
- **Targets**: Intel GPUs, XPUs, CPUs
### Vulkan
- **Features**: Cross-platform GPU acceleration
- **Targets**: Windows, Linux, Android, macOS
### Apple Silicon
- **Features**: MLX framework, Metal Performance Shaders
- **Targets**: M1/M2/M3 Macs
## Backend Registry (`index.yaml`)
The `index.yaml` file serves as a central registry for all available backends, providing:
- **Metadata**: Name, description, license, icons
- **Capabilities**: Hardware targets and optimization profiles
- **Tags**: Categorization for discovery
- **URLs**: Source code and documentation links
## Building Backends
### Prerequisites
- Docker with multi-architecture support
- Appropriate hardware drivers (CUDA, ROCm, etc.)
- Build tools (make, cmake, compilers)
### Build Commands
Example of build commands with Docker
```bash
# Build Python backend
docker build -f backend/Dockerfile.python \
--build-arg BACKEND=transformers \
--build-arg BUILD_TYPE=cublas12 \
--build-arg CUDA_MAJOR_VERSION=12 \
--build-arg CUDA_MINOR_VERSION=0 \
-t localai-backend-transformers .
# Build Go backend
docker build -f backend/Dockerfile.golang \
--build-arg BACKEND=whisper \
--build-arg BUILD_TYPE=cpu \
-t localai-backend-whisper .
# Build C++ backend
docker build -f backend/Dockerfile.llama-cpp \
--build-arg BACKEND=llama-cpp \
--build-arg BUILD_TYPE=cublas12 \
-t localai-backend-llama-cpp .
```
For ARM64/Mac builds, docker can't be used, and the makefile in the respective backend has to be used.
### Build Types
- **`cpu`**: CPU-only optimization
- **`cublas12`**, **`cublas13`**: CUDA 12.x, 13.x with cuBLAS
- **`hipblas`**: ROCm with rocBLAS
- **`intel`**: Intel oneAPI optimization
- **`vulkan`**: Vulkan-based acceleration
- **`metal`**: Apple Metal optimization
## Backend Development
### Creating a New Backend
1. **Choose Language**: Select Python, Go, or C++ based on requirements
2. **Implement Interface**: Implement the gRPC service defined in `backend.proto`
3. **Add Dependencies**: Create appropriate requirements files
4. **Configure Build**: Set up Dockerfile and build scripts
5. **Register Backend**: Add entry to `index.yaml`
6. **Test Integration**: Verify gRPC communication and functionality
### Backend Structure
```
backend-name/
├── backend.py/go/cpp # Main implementation
├── requirements.txt # Dependencies
├── Dockerfile # Build configuration
├── install.sh # Installation script
├── run.sh # Execution script
├── test.sh # Test script
└── README.md # Backend documentation
```
### Required gRPC Methods
At minimum, backends must implement:
- `Health()` - Service health check
- `LoadModel()` - Model loading and initialization
- `Predict()` - Main inference endpoint
- `Status()` - Backend status and metrics
## Integration with LocalAI Core
Backends communicate with LocalAI core through gRPC:
1. **Service Discovery**: Core discovers available backends
2. **Model Loading**: Core requests model loading via `LoadModel`
3. **Inference**: Core sends requests via `Predict` or specialized endpoints
4. **Streaming**: Core handles streaming responses for real-time generation
5. **Monitoring**: Core tracks backend health and performance
## Performance Optimization
### Memory Management
- **Model Caching**: Efficient model loading and caching
- **Batch Processing**: Optimize for multiple concurrent requests
- **Memory Pinning**: GPU memory optimization for CUDA/ROCm
### Hardware Utilization
- **Multi-GPU**: Support for tensor parallelism
- **Mixed Precision**: FP16/BF16 for memory efficiency
- **Kernel Fusion**: Optimized CUDA/ROCm kernels
## Troubleshooting
### Common Issues
1. **GRPC Connection**: Verify backend service is running and accessible
2. **Model Loading**: Check model paths and dependencies
3. **Hardware Detection**: Ensure appropriate drivers and libraries
4. **Memory Issues**: Monitor GPU memory usage and model sizes
## Contributing
When contributing to the backend system:
1. **Follow Protocol**: Implement the exact gRPC interface
2. **Add Tests**: Include comprehensive test coverage
3. **Document**: Provide clear usage examples
4. **Optimize**: Consider performance and resource usage
5. **Validate**: Test across different hardware targets