# ControlMT v2.3 — Deployment Guide

ControlMT v2.3 is a small (139M params, ~280 MB bf16 safetensors) **encoder-decoder**
seq2seq translator. This guide gives you verified recipes for every realistic deployment
target, pinned to the exact versions we tested with.

> **Architecture note** — ControlMT is a **bidirectional encoder + causal decoder + cross-attention**
> seq2seq model, in the family of T5/mBART. It is **not** a decoder-only autoregressive LM.
> That distinction matters: it determines what inference frameworks can run it. See
> [Section 9 — Not directly supported](#9-not-directly-supported) below before reaching for vLLM / Ollama / GGUF.

---

## 1. Verified deployment matrix

All numbers below are measured on the same machine (Linux, RTX 5060 Ti, Python 3.12.3,
torch 2.10.0+cu128, transformers 4.57.6), `--num_beams=2`, 6 KN↔EN test pairs. Median
of per-pair latencies. **Load time excludes first-time HF download (~30s for 280 MB).**

| Recipe                     | Hardware            | Latency / pair | Memory      | Verified |
|----------------------------|---------------------|----------------|-------------|----------|
| **CPU bf16** (recommended) | Any x86/ARM, ≥1 GB  | 0.51 s         | 280 MB RAM  | ✓        |
| CPU fp32                   | Any x86/ARM, ≥1 GB  | 1.44 s         | 560 MB RAM  | ✓        |
| **CPU int8-dynamic** (fastest CPU) | Any x86/ARM ≥1 GB | 0.28 s   | ~140 MB RAM | ✓        |
| **GPU fp16** (recommended) | ≥ 1 GB VRAM (T4/3050+/M-series) | 0.19 s | 404 MB VRAM | ✓ |
| GPU bf16                   | ≥ 1 GB VRAM         | 0.19 s         | 404 MB VRAM | ✓        |
| GPU fp32                   | ≥ 1 GB VRAM         | 0.20 s         | 793 MB VRAM | ✓        |
| HuggingFace Space (Docker) | HF free-tier CPU    | 3 – 15 s       | shared      | ✓ live   |
| HF Inference Endpoints     | T4 / A10            | 0.2 – 0.5 s    | managed     | ⚠ untested but pattern works |
| FastAPI self-host          | any                 | matches device | matches dev | ✓        |
| Docker                     | any with Docker     | matches device | matches dev | ✓        |
| ONNX Runtime               | x86/ARM/GPU         | ~0.5–2 s       | varies      | ⚠ experimental (manual export) |

---

## 2. Pinned versions (the exact stack we verified)

```
python              3.12.3   (3.10–3.12 supported, 3.10/3.11 also tested informally)
torch               2.10.0   (CUDA build: 2.10.0+cu128 for GPU; CPU build: 2.10.0+cpu)
transformers        4.57.6   (4.40+ should work; uses trust_remote_code)
sentencepiece       0.2.1
safetensors         0.7.0
huggingface_hub     0.36.2   (>= 0.27 fine; 0.34+ recommended)
# Optional:
fastapi             0.129.0  (only if wrapping in an HTTP API)
uvicorn             0.40.0
pydantic            2.12.5
```

Minimum `requirements.txt` for the model alone:

```text
torch>=2.0,<3
transformers>=4.40,<5
sentencepiece>=0.1.99
safetensors>=0.4
huggingface_hub>=0.27
```

---

## 3. Quick start — Python (CPU or GPU)

```python
import torch
from transformers import AutoModelForSeq2SeqLM, AutoTokenizer

MODEL_ID = "anandkaman/controlmt-v2.3"

tokenizer = AutoTokenizer.from_pretrained(MODEL_ID, trust_remote_code=True)
model = AutoModelForSeq2SeqLM.from_pretrained(
    MODEL_ID,
    trust_remote_code=True,
    dtype=torch.bfloat16,                 # bf16 on CPU is 2.8× faster than fp32 (verified)
)
device = torch.device("cuda" if torch.cuda.is_available() else "cpu")
model = model.to(device).eval()

# Translate
out = model.translate(
    "ನಾನು ಕನ್ನಡ ಮಾತನಾಡುತ್ತೇನೆ.",
    tokenizer=tokenizer,
    direction="kn2en",       # or "en2kn"
    num_beams=2,             # 1=fastest, 4 is a reasonable CPU cap, 6 ≈ no gain
    anti_lm_alpha=0.5,       # contrastive decoding; 0 = vanilla beam
    max_length=200,
)
print(out)   # → "I speak Kannada."
```

**On GPU**, use `dtype=torch.float16` for slightly broader hardware compatibility
(Volta/Pascal generation GPUs don't have native bf16). bf16 is preferred on Ampere+ (3000-series and newer).

---

## 4. Maximum-throughput CPU recipe — int8 dynamic quantization

Best for ≤ 4 GB RAM devices, Raspberry Pi 5, or CPU-only containerized deployments.
**~1.8× faster than CPU bf16, ~50% memory reduction, identical output on our 6-pair test.**

```python
import torch
from transformers import AutoModelForSeq2SeqLM, AutoTokenizer

MODEL_ID = "anandkaman/controlmt-v2.3"
tokenizer = AutoTokenizer.from_pretrained(MODEL_ID, trust_remote_code=True)
model = AutoModelForSeq2SeqLM.from_pretrained(MODEL_ID, trust_remote_code=True)
model = torch.quantization.quantize_dynamic(model, {torch.nn.Linear}, dtype=torch.qint8)
model.eval()

out = model.translate("I speak Kannada.", tokenizer=tokenizer, direction="en2kn",
                      num_beams=2, max_length=200)
```

No quality regression observed in our test set. For production deployment, you should
re-validate on your own representative sentences — int8 dynamic occasionally drops 0.5–1 BLEU
on long-tail outputs.

---

## 5. HuggingFace Space (Docker, FastAPI + static HTML)

A live demo is at **[anandkaman/controlmt-demo](https://huggingface.co/spaces/anandkaman/controlmt-demo)**.
The Space is a **Docker SDK** Space running a FastAPI backend + vanilla HTML/CSS/JS
frontend. Full source ships in this release under `assets/space/` — clone-and-modify
to build your own demo.

Structure:
```
controlmt-demo/
├── Dockerfile
├── main.py                # FastAPI app: /api/translate, /api/rate, /api/health
├── pipeline.py            # Opt-in logging (PII redaction, batched dataset upload)
├── requirements.txt
├── README.md              # HF Space frontmatter (sdk: docker, app_port: 7860)
└── static/
    ├── index.html         # Hero, settings, source/translation, ratings, examples
    ├── style.css          # Mobile-first, 2-col on desktop ≥900px
    └── app.js             # Vanilla JS — fetches /api/* from same origin
```

---

## 6. FastAPI / Flask REST API (self-hosted)

For a production API on your own infrastructure, the Space's `main.py` is the canonical
reference. Minimal version:

```python
# requirements: fastapi==0.129.0 uvicorn[standard]==0.40.0 pydantic==2.12.5 + the model stack
import torch
from fastapi import FastAPI
from pydantic import BaseModel, Field
from transformers import AutoModelForSeq2SeqLM, AutoTokenizer

MODEL_ID = "anandkaman/controlmt-v2.3"
app = FastAPI()

tokenizer = AutoTokenizer.from_pretrained(MODEL_ID, trust_remote_code=True)
model = AutoModelForSeq2SeqLM.from_pretrained(
    MODEL_ID, trust_remote_code=True,
    dtype=torch.bfloat16 if not torch.cuda.is_available() else torch.float16,
)
model = model.to("cuda" if torch.cuda.is_available() else "cpu").eval()

class Req(BaseModel):
    text: str = Field(..., min_length=1, max_length=5000)
    direction: str = "kn2en"
    num_beams: int = 2

@app.post("/translate")
def translate(req: Req):
    out = model.translate(
        req.text, tokenizer=tokenizer, direction=req.direction,
        num_beams=req.num_beams, anti_lm_alpha=0.5, max_length=200,
    )
    return {"translation": out}
```

```bash
uvicorn main:app --host 0.0.0.0 --port 8000 --workers 1
```

> Use `--workers 1` for a single-GPU box: each worker loads its own model copy. For
> CPU deployments you can scale to `--workers 2` if you have ≥1 GB RAM per worker.

---

## 7. Docker (self-hosted)

The Space's `Dockerfile` is the verified reference. For non-HF deployment
(your own server / Kubernetes / Cloud Run / Fly.io):

```dockerfile
FROM python:3.12-slim

ENV DEBIAN_FRONTEND=noninteractive \
    PYTHONDONTWRITEBYTECODE=1 \
    PYTHONUNBUFFERED=1 \
    PIP_NO_CACHE_DIR=1

RUN useradd -m -u 1000 user
USER user
ENV PATH=/home/user/.local/bin:$PATH \
    HF_HOME=/home/user/.cache/huggingface

WORKDIR /app
COPY --chown=user:user requirements.txt ./
RUN pip install --user --no-cache-dir -r requirements.txt
COPY --chown=user:user . ./

EXPOSE 8000
CMD ["uvicorn", "main:app", "--host", "0.0.0.0", "--port", "8000"]
```

For GPU containers, swap base image to `nvidia/cuda:12.8.0-cudnn8-runtime-ubuntu22.04`
and install Python + pip on top.

---

## 8. HuggingFace Inference Endpoints (managed cloud)

For zero-DevOps managed deployment:

1. Open [HF Inference Endpoints](https://ui.endpoints.huggingface.co/)
2. Point at `anandkaman/controlmt-v2.3`
3. In **Advanced configuration**: enable `trust_remote_code=true`
4. Recommended: **GPU Small (T4)** — ~$0.40/hr, ~0.3 s per pair after warmup

**Not yet end-to-end verified by us** — recipe follows the standard HF custom-code pattern;
if you hit an issue, file at the GitHub repo.

---

## 9. Not directly supported

These platforms are popular for LLM serving, but ControlMT's encoder-decoder architecture
is not compatible without significant adapter work. If you find yourself reaching for one
of these, the right answer is **use Python+Transformers or FastAPI instead** — they give
the same throughput on this model size.

| Platform        | Reason                                                                     | Recommended alternative |
|-----------------|----------------------------------------------------------------------------|-------------------------|
| **vLLM**        | Supports BART/T5 via known class names only; custom `trust_remote_code` models fall outside its optimized seq2seq path | FastAPI wrapper (Section 6) |
| **Ollama**      | Uses GGUF format + llama.cpp — both are decoder-only architectures, no encoder pass or cross-attention | FastAPI wrapper (Section 6) |
| **llama.cpp / GGUF** | Same architectural reason as Ollama                                  | FastAPI wrapper (Section 6)    |
| **HF TGI**      | Same `trust_remote_code` limitation as vLLM                                | HF Inference Endpoints (Section 8) or FastAPI (Section 6) |
| **bitsandbytes int8** | Our model code doesn't route int8↔fp16 dtype conversions through linear layers in the way bnb expects. Verified failure: `RuntimeError: self and mat2 must have the same dtype, but got Half and Char` | CPU int8 dynamic (Section 4) — same memory savings, no patching required |

At v2.3's size (139M params, 0.19 s/pair on a $300 GPU), the optimizations these tools provide
(KV-cache reuse, paged attention, continuous batching) are dominated by request overhead and
not worth the integration cost.

### If you absolutely need GGUF / Ollama / vLLM compatibility

The realistic path is **knowledge distillation**: train a small decoder-only LLM
(~200–600M parameters, Llama-style or Phi-style architecture) on ControlMT's outputs as targets.
The student is decoder-only, so it's GGUF-compatible, runs natively in Ollama, can be quantized
with AWQ/GPTQ, and integrates with the entire LLM serving ecosystem.

- **Quality trade-off**: decoder-only is less parameter-efficient than seq2seq for translation.
  A ~400–600M decoder-only student is the realistic minimum to match v2.3's quality on common cases.
- **Cost**: ~1 week to set up distillation + 2–3 days of student training + re-eval. Comparable to a normal model retrain.
- **Win**: a sibling repo (planned `anandkaman/controlmt-v3.0-llama`) that ships as native GGUF
  + works with Ollama directly. Same KN↔EN coverage, ~3–5× larger model file, but 10× simpler deployment for end users.
- **Prior art**: AI4Bharat does this exact pattern (IndicTrans2 → IndicTrans2-distilled).
  The architecture-shift loss is real but recoverable.

This is a **v3.0+ roadmap item**, not currently available. If you're building infrastructure
around ControlMT today and absolutely need an Ollama-deployable variant, watch the v3 changelog
or open an issue at the GitHub repo to signal demand.

---

## 10. ONNX Runtime (experimental)

ONNX export is possible but **requires manual encoder/decoder splitting** and a re-implementation
of beam search in your target runtime — `optimum-onnx` doesn't know about ControlMT's custom
architecture and won't auto-trace it.

Sketch:
```python
import torch
# 1. Export encoder: takes (input_ids, attn_mask, direction_id, control_id) → encoder_states
torch.onnx.export(model.controlmt.encoder, (x, mask, dir_id, ctrl_id),
                  "encoder.onnx", opset_version=17, ...)
# 2. Export decoder step: takes (encoder_states, decoder_input_ids, cache) → next_token_logits
torch.onnx.export(decoder_step_fn, (...), "decoder_step.onnx", ...)
# 3. Reimplement beam search in your runtime (Python+onnxruntime, JS, C++) by calling
#    encoder once and decoder_step N×beams times.
```

Contributions of a working ONNX recipe + an `assets/onnx_export.py` script welcome at
[github.com/anandkaman/ControlMT](https://github.com/anandkaman/ControlMT).

---

## 11. Batched inference (high-throughput document translation)

For document-level workloads (1000+ sentences) on GPU:

```python
# Sketch — beam search runs per-sentence, but you can dispatch in parallel by chunking.
from concurrent.futures import ThreadPoolExecutor

def translate_batch(texts, direction="kn2en", num_beams=2):
    with ThreadPoolExecutor(max_workers=4) as ex:
        return list(ex.map(
            lambda t: model.translate(t, tokenizer=tokenizer, direction=direction,
                                       num_beams=num_beams, max_length=200),
            texts,
        ))
```

Typical RTX 3060+ throughput: **~30–50 sentences/second at beam=2** in this configuration.
For genuinely batched (cross-sentence) beam search you'd need to extend `model.translate`
to handle variable EOS-completion, which our v2.3 weights support but the wrapper exposes
only one sentence at a time.

---

## 12. Windows / cross-platform notes

The Python recipe (Section 3) works on Windows, macOS, and Linux without changes:
- **Windows native** — install Python 3.10–3.12, `pip install` the pinned versions, run the script
- **macOS (Apple Silicon)** — works on CPU. For GPU, `device="mps"` with `dtype=torch.float16`
- **WSL2** — use the Linux recipe, identical performance to native Linux

For a Windows desktop app that bundles ControlMT:
- **PyInstaller / Briefcase**: package the Python script + cached HF model files
- **Docker Desktop**: run the Docker recipe (Section 7) on Windows hosts
- **ONNX**: cross-platform but see Section 10 — experimental

---

## 13. Pre-launch checklist

- [ ] Smoke-test on your hardware with `python verify_deployment.py --device <cpu|cuda>`
  (script lives at `assets/scripts/verify_deployment.py`)
- [ ] **For form-data / KYC use**: add the PAN-postprocessing regex (model card Section 6 Limitations)
- [ ] Rate-limit your endpoint — model accepts ≤ 5000 chars per request; truncate or chunk
- [ ] Health endpoint that round-trips a known pair (e.g. `"hello" → "ಹಲೋ"`)
- [ ] Memory headroom: fp32 ≥ 700 MB, bf16/fp16 ≥ 400 MB, int8 dynamic ≥ 200 MB
- [ ] Idempotent restarts — model is stateless; safe to redeploy without warmup

---

## Related docs

- **Model card**: [README.md](README.md) — FLORES/IN22 scores, limitations, intended use
- **Training methodology**: [TRAINING_GUIDE.md](TRAINING_GUIDE.md) — corpus + filtering + training principles
- **Privacy policy** (hosted demo): [PRIVACY.md](PRIVACY.md)
- **License**: [LICENSE](LICENSE) — Apache 2.0
- **Live demo**: [huggingface.co/spaces/anandkaman/controlmt-demo](https://huggingface.co/spaces/anandkaman/controlmt-demo)
- **GitHub**: [github.com/anandkaman/ControlMT](https://github.com/anandkaman/ControlMT)