A Rust-native LLM inference engine. Load models from Hugging Face, chat locally or serve via OpenAI-compatible API. Single binary, no Python, no runtime dependencies.
# From crates.io
cargo install ferrum-cli
# Or build from source
cargo build --release -p ferrum-cli --bin ferrum
# CUDA (Linux + NVIDIA)
CUDA_HOME=/usr/local/cuda cargo build --release --features cuda -p ferrum-cli --bin ferrumFor gated models (e.g. Llama 3.2), set your Hugging Face token first:
export HF_TOKEN=hf_your_token_here# Download a model
ferrum pull qwen3:0.6b
# Chat
ferrum run qwen3:0.6b
# Or start an API server
ferrum serve --model qwen3:0.6b --port 8000Any Hugging Face model using a supported architecture works out of the box:
| Architecture | CUDA Decode | INT4 (GPTQ) | Tensor Parallel | Example Models |
|---|---|---|---|---|
| LLaMA | Yes | Yes | Yes | Llama-3.x, TinyLlama, Vicuna, Alpaca, ... |
| Qwen3 | Yes | Yes | Yes | Qwen3-0.6B ~ 4B |
| Qwen2 | — | — | — | Qwen2.5-Instruct-0.5B ~ 7B |
| Architecture | Metal | CUDA | Example Models |
|---|---|---|---|
| Whisper | Yes | — | whisper-tiny, whisper-base, whisper-small, whisper-medium, whisper-large-v3, whisper-turbo (recommended) |
| Architecture | Metal | CPU | Voice Clone | Example Models |
|---|---|---|---|---|
| Qwen3-TTS | Yes | Yes | Yes (ICL) | Qwen3-TTS-12Hz-0.6B-Base |
| Architecture | Modality | Embedding Dim | Example Models |
|---|---|---|---|
| CLIP | Text + Image | 512/768 | openai/clip-vit-base-patch32 |
| Chinese-CLIP | Text + Image | 512 | OFA-Sys/chinese-clip-vit-base-patch16 |
| SigLIP | Text + Image | 768 | google/siglip-base-patch16-224 |
| BERT | Text | 768 | google-bert/bert-base-chinese |
# Text generation
ferrum run Qwen/Qwen3-4B
ferrum run llama3.2:3b
# Speech-to-Text (supports WAV/M4A/MP3/FLAC — auto ffmpeg conversion)
ferrum transcribe whisper-turbo recording.m4a -l zh
ferrum transcribe whisper-turbo meeting.wav -l en
# Text-to-Speech
ferrum tts qwen3-tts "Hello, welcome to Ferrum TTS" -o output.wav
ferrum tts qwen3-tts "你好欢迎使用语音合成系统" -o output.wav
# Voice clone (ICL mode — clone any voice from 5s reference audio)
ferrum tts qwen3-tts "你好" --ref-audio ref.wav --ref-text "参考文本" -o clone.wav
# Streaming TTS (first audio chunk in ~2.5s)
ferrum tts qwen3-tts "你好世界" --streaming -o output.wav
# TTS API server (OpenAI-compatible)
ferrum serve qwen3-tts
curl localhost:8000/v1/audio/speech -d '{"input":"你好","language":"chinese"}' -o speech.wav
# Whisper API server (OpenAI-compatible)
ferrum serve whisper-turbo
curl localhost:8000/v1/audio/transcriptions -F "[email protected]" -F "language=zh"
# Embeddings (text + image)
ferrum embed OFA-Sys/chinese-clip-vit-base-patch16 --text "sunset at the beach"
ferrum embed google/siglip-base-patch16-224 --image photo.jpg
# Embedding API server
ferrum serve --model OFA-Sys/chinese-clip-vit-base-patch16
curl localhost:8000/v1/embeddings -d '{"model":"clip","input":"hello"}'
curl localhost:8000/v1/embeddings -d '{"model":"clip","input":{"image":"/path/to/photo.jpg"}}'| Command | Description |
|---|---|
ferrum run <model> |
Interactive chat |
ferrum serve --model <model> |
OpenAI-compatible HTTP server |
ferrum stop |
Stop running server |
ferrum pull <model> |
Download model from Hugging Face |
ferrum list |
Show cached models |
ferrum bench <model> |
Performance benchmark |
ferrum transcribe <model> <audio> |
Speech-to-text (Whisper, supports WAV/M4A/MP3) |
ferrum tts <model> <text> |
Text-to-speech (Qwen3-TTS, voice clone with --ref-audio) |
ferrum embed <model> |
Generate embeddings (BERT/CLIP/SigLIP, text + image) |
# Chat completions (OpenAI-compatible)
curl http://localhost:8000/v1/chat/completions \
-H "Content-Type: application/json" \
-d '{"model":"qwen3:0.6b","messages":[{"role":"user","content":"Hello"}]}'
# Audio transcription (OpenAI-compatible, multipart form)
curl http://localhost:8000/v1/audio/transcriptions \
-F "[email protected]" -F "language=zh"
# Text-to-speech (OpenAI-compatible)
curl http://localhost:8000/v1/audio/speech \
-H "Content-Type: application/json" \
-d '{"input":"Hello world","language":"english"}' -o speech.wav
# Embeddings
curl http://localhost:8000/v1/embeddings \
-d '{"model":"clip","input":"hello"}'
# List models
curl http://localhost:8000/v1/models
# Health check
curl http://localhost:8000/healthBenchmarked on RTX PRO 6000 (Blackwell):
| Mode | FP16 (eager) | FP16 + CUDA graph | INT4 (GPTQ + Marlin) |
|---|---|---|---|
| Single request decode | 70.3 tok/s | 82.9 tok/s (+18%) | 130.4 tok/s |
| 4 concurrent (batch) | 109.4 tok/s | — | 124.2 tok/s |
| TPOT (p50) | 14.2 ms | 12.1 ms | — |
| VRAM | ~8 GB | — | ~2.5 GB (-69%) |
CUDA graph replay is automatic after 3-step warmup; eliminates per-step launch overhead and sits on the Blackwell + CUDA 13 path we hardened in this cycle (see docs/phase-e-cuda-status.md).
| Mode | Candle | CUDA Runner |
|---|---|---|
| Decode | 126 tok/s | 256.5 tok/s (+103%) |
| Config | Qwen3-4B FP16 |
|---|---|
| 1× GPU | 82.3 tok/s (TPOT 12.1ms) |
| 2× GPU TP | 26.1 tok/s (TPOT 38.4ms) |
TP decode uses persistent per-rank threads with NCCL all-reduce. Current bottleneck is PCIe interconnect latency (~0.44ms × 72 NCCL calls/step). TP is most beneficial for models that don't fit on a single GPU, or with NVLink interconnect.
| Model | 5-min audio | Realtime factor |
|---|---|---|
| whisper-large-v3-turbo | ~72s | 4.2x realtime |
| whisper-tiny | ~20s | 15x realtime |
Custom Whisper forward pass with rustfft STFT. Full decode pipeline: timestamp-based sequential decode, temperature fallback, compression ratio check. Mel precision matches Python whisper exactly.
| Model | Text | Audio | Time | RTF | First chunk |
|---|---|---|---|---|---|
| 0.6B | 29 chars Chinese | 4.6s | 11.3s | 2.8x | ~2.5s (streaming) |
| 1.7B | Voice clone (ICL) | 5.8s | 25s | 4.4x | ~5s (streaming) |
All-Metal fused transformer pipeline: custom GEMM (64×32 simdgroup tiles), fused residual+norm, flash attention with layer_scale. Full Mimi-based vocoder with 8-layer pre-transformer. Zero-copy on Apple Silicon unified memory.
- Custom CUDA decode runner: bypasses candle for the decode hot path (Qwen3 + LLaMA)
- INT4 quantization: GPTQ models auto-detected, Marlin fused INT4×FP16 kernel
- Tensor parallelism: persistent per-rank threads, barrier sync, NCCL all-reduce (Megatron-LM pattern)
- Batched attention kernel: single launch for all batch items (SM utilization 17%→67%)
- Batched RoPE: per-item positions in single kernel launch
- Custom CUDA kernels: fused RmsNorm, SiLU×mul, RoPE, decode attention (all on single stream)
- Flash Decoding: split-K for long-context decode (auto at KV > 256)
- Batch decode: batched cuBLAS GEMM + batched attention for concurrent requests
- Metal TTS pipeline: all-Metal fused transformer for talker (28 layers) + SubTalker (5 layers) + vocoder (8 layers), GPU-side RMSNorm, cached projection weights
- TTS streaming: chunk-by-chunk audio generation (~800ms chunks), first audio in ~2.5s
- TTS voice clone: ICL prompting with speaker encoder (ECAPA-TDNN) + speech tokenizer (Mimi RVQ), sinc resampling
- TTS HTTP API: OpenAI-compatible
/v1/audio/speechwith streaming support - Paged KV attention: GPU block pool with block-table indirection
- Double-buffered residual: cross-layer norm fusion (-108 kernel launches)
What works:
- CLI chat, HTTP serving with streaming, benchmarking
- Qwen3, Qwen2/2.5, LLaMA 3.x, TinyLlama architectures
- Custom CUDA decode runner for Qwen3 and LLaMA (2x speedup)
- Metal GPU acceleration (macOS), CUDA (NVIDIA), CPU
- INT4 GPTQ quantization with Marlin fused kernel (Blackwell compatible)
- FlashAttention-2 prefill + custom CUDA decode runner
- Paged KV cache with block reclamation
- Continuous batching with batch decode
- Tensor parallelism (multi-GPU NCCL, auto-detects GPU count)
- CLIP/Chinese-CLIP/SigLIP embeddings (text + image,
/v1/embeddingsAPI) - Whisper ASR (speech-to-text, Metal accelerated,
/v1/audio/transcriptionsAPI) - Multi-format audio support (WAV/M4A/MP3/FLAC via ffmpeg)
- Top-k/top-p/temperature/repetition-penalty sampling
- Speculative decoding — draft model verification
- More model architectures — Mistral, Phi, DeepSeek, etc.
- Qwen2 CUDA runner — same pattern as LLaMA
See docs/ROADMAP.md for full details.
# CPU only (default)
cargo install ferrum-cli
# With Metal acceleration (macOS)
cargo install ferrum-cli --features metal
# With CUDA acceleration (NVIDIA, requires CUDA toolkit + nvcc)
cargo install ferrum-cli --features cudaOr build from source:
cargo build --release -p ferrum-cli # CPU
cargo build --release -p ferrum-cli --features metal # Metal (macOS)
cargo build --release -p ferrum-cli --features cuda # CUDA (NVIDIA)
cargo build --release -p ferrum-cli --features cuda # Multi-GPU auto-detected when availablePrerequisites: Rust stable toolchain.
crates/
├── ferrum-types # Shared type definitions
├── ferrum-interfaces # Core trait contracts (ComputeBackend, KernelOps, ModelExecutor)
├── ferrum-runtime # Backend implementations (Candle, CPU)
├── ferrum-engine # Metal kernels, model orchestration
├── ferrum-models # Model architectures (LLaMA, Qwen2, Qwen3, BERT, Whisper)
├── ferrum-kernels # Custom CUDA kernels + decode runner
├── ferrum-tokenizer # Tokenization
├── ferrum-sampler # Sampling strategies
├── ferrum-scheduler # Request scheduling
├── ferrum-kv # KV cache management
├── ferrum-server # HTTP API server
├── ferrum-cli # CLI binary
└── ferrum-testkit # Testing utilities
MIT