TranslatePsy-AfriNano

TranslatePsy-AfriNano is a collection of compact multilingual machine translation models (17M–43M parameters) for African ↔ English translation optimized for browser, mobile, desktop, and edge-device deployment. TranslatePsy-AfriNano is made available by Tether Data, S.A. de C.V. (Tether AI Research, we, us, our) under the Apache 2.0 license for research and educational purposes. This repository contains multilingual translation models supporting 8 African languages and English in both directions:

• English → African Languages (en-xx)
• African Languages → English (xx-en)

The models are built using the Marian/Bergamot framework and are designed to provide an efficient balance between translation quality, deployment size, memory usage, and inference speed.

• TranslatePsy-AfriNano models retains upto 96.24% of NLLB-200 translation accuracy.
• Single checkpoint deployment size is smaller by 56.7×.
• Reduces peak RAM usage by 3.53× on CPU deployment

• Developed by: Tether AI Research (referred to Tether Data, S.A. de C.V.)
• Full blog post: Compact Multilingual Machine Translation for Resource-Constrained Edge Deployment

Supported Languages

Quick Start (QVAC SDK)

The INTGEMM packs run out of the box with the QVAC SDK using its built-in Bergamot NMT engine. The SDK runs on Node.js, Bare, and Expo, with native backends (Metal on macOS, Vulkan on Windows/Linux).

Requirements: Node.js >= 22.17.

1. Download the model

Grab the Base INTGEMM packs (both directions) with the HuggingFace CLI:

pip install -U "huggingface_hub[cli]"

huggingface-cli download qvac/TranslatePsy-AfriNano \
  --include "en-xx/Base/intgemm/*" "xx-en/Base/intgemm/*" \
  --local-dir ./TranslatePsy-AfriNano

This gives you:

TranslatePsy-AfriNano/
  en-xx/Base/intgemm/{model.intgemm.alphas.bin, vocab.spm}   # English -> African
  xx-en/Base/intgemm/{model.intgemm.alphas.bin, vocab.spm}   # African -> English

Swap Base for BaseMemory or Tiny to trade quality for size, or drop --include to fetch every variant.

2. Install the SDK

npm init -y && npm pkg set type=module
npm install @qvac/sdk

3. Translate

Save as quickstart.mjs:

import path from "node:path";
import { loadModel, translate, unloadModel } from "@qvac/sdk";

const ROOT = "./TranslatePsy-AfriNano";

// direction: "en-xx" (English -> African) or "xx-en" (African -> English)
function load(direction, from, to) {
  const dir = path.join(ROOT, direction, "Base", "intgemm");
  return loadModel({
    modelSrc: path.join(dir, "model.intgemm.alphas.bin"),
    modelType: "nmt",
    modelConfig: {
      engine: "Bergamot",
      from,
      to,
      srcVocabSrc: path.join(dir, "vocab.spm"),
      dstVocabSrc: path.join(dir, "vocab.spm"),
    },
  });
}

async function translateText(modelId, text) {
  const { text: out } = translate({ modelId, text, modelType: "nmt", stream: false });
  return (await out).trim();
}

// English -> Swahili: prepend the ##SW target tag (see Translation Directions).
const ende = await load("en-xx", "en", "sw");
console.log(await translateText(ensw, "##SW Good morning, how are you today?"));
await unloadModel({ modelId: ende });

// Swahili -> English: no tag needed.
const swen = await load("xx-en", "sw", "en");
console.log(await translateText(swen, "Habari za asubuhi, hujambo leo?"));
await unloadModel({ modelId: swen });

node quickstart.mjs

Notes

• English → African (en-xx): prepend the target tag (##SO, ##SW, ##YO, …) to the source text, as listed under "Supported Languages" section.
• African → English (xx-en): no tag required.
• African → African: pivot through English — run xx-en first, then feed the English output (with the target tag) into en-xx.
• Load a pack once and reuse the returned modelId for many translations; call unloadModel to free the memory when you're done.
• For token-by-token streaming, pass stream: true and iterate translate(...).tokenStream instead.

Model Details

Architecture

The models are based on Marian/Bergamot's deployment-oriented neural machine translation architecture.

Key characteristics:

• 6-layer Transformer encoder
• SSRU decoder
• Multi-head attention
• Shared multilingual SentencePiece vocabulary (32k)
• Language-tag controlled multilingual decoding
• CPU-optimized inference

Training Setup

Tokenization & Model

Training

Validation

Test evaluation

Model Variants

We train three model varinats:

Each trained model variant has FP32 and INTGEMM (INT8) versions for inference.

FP32 Models

The FP32 variants contain the original full-precision Marian model checkpoints (.npz) used during training and evaluation. These models provide the highest numerical precision and are primarily intended for research, fine-tuning, and framework-level inference using Marian.

Located under:

fp32/

Contains:

model.npz.best-chrf.npz
model.npz.best-chrf.npz.decoder.yml
vocab.spm

Advantages

• Full training precision
• Suitable for continued training and fine-tuning
• Reference checkpoints for reproducibility

Considerations

• Larger storage footprint
• Higher memory consumption during inference
• Not optimized for resource-constrained deployments

INTGEMM (INT8) Models

The INTGEMM variants are quantized inference models generated using Marian/Bergamot quantization tools. These models are optimized for CPU-based deployment and are compatible with Bergamot-style translation pipelines.

Located under:

intgemm/

Contains:

model.intgemm.alphas.bin
lex.50.50.*.s2t.bin
vocab.spm

Advantages

• Significantly smaller model size
• Reduced memory usage
• Faster CPU inference
• Well suited for browser, desktop, mobile, and edge-device deployment

Considerations

• Intended for inference only
• Minor translation quality differences may occur compared to FP32 models due to quantization

Across our evaluations, INTGEMM models retained translation quality close to their FP32 counterparts while substantially reducing deployment footprint and runtime memory requirements.

Translation Directions

English → African (en-xx)

Target language is selected using language tags prepended to the source sentence.

Examples:

##AM This is a multilingual translation model.

##SW This is a multilingual translation model.

##YO This is a multilingual translation model.

African → English (xx-en)

No language tags are required.

Input sentences may be written in any supported African language and are translated into English.

Repository Structure

TranslatePsy-AfriNano
├── en-xx
│   ├── Tiny
│   │   ├── fp32
│   │   └── intgemm
│   ├── BaseMemory
│   │   ├── fp32
│   │   └── intgemm
│   └── Base
│       ├── fp32
│       └── intgemm
│
└── xx-en
    ├── Tiny
    │   ├── fp32
    │   └── intgemm
    ├── BaseMemory
    │   ├── fp32
    │   └── intgemm
    └── Base
        ├── fp32
        └── intgemm

Training Data

The models were trained on multilingual corpora collected from publicly available resources including:

• OPUS-100
• MADLAD-400

Preprocessing

We filter parallel sample using:

• Length based filtering
• Token count ratio
• case/punctuation normalization
• language identification
• Adequacy score to see correctness of translation pairs

After filtering and deduplication, the final training corpus contains approximately:

Evaluation

Average COMET scores:

Our best model retains approximately 96.24% of NLLB-200 translation quality while requiring a fraction of the deployment footprint.

Performance on CPU

s/s: sentence per second, tok/s: token per second, T1: time to first sentence, Mem: RAM usage, Bundle: Size of en-xx and xx-en checkpoints pair for all 18 translation directions

Performance on Android device

Intended Use

These models are particularly suitable for:

• Browser translation
• Offline translation
• Mobile applications
• Desktop applications
• Edge devices
• CPU-only deployment
• Privacy-preserving local translation

Citation

@misc{translatepsyafrinano2026,
  title  = {TranslatePsy-AfriNano: Compact Multilingual Machine Translation for Resource-Constrained Edge Deployment},
  author = {Gupta, Kamal and Nambiar, Akshay and Nurman, Amril}
  institution = {Tether Data, S.A. de C.V. d.b.a. Tether AI Research},
  year   = {2026},
  note   = {Hugging Face model card}
}
}

Copyright

We will take appropriate actions in response to notices of copyright infringement. If you believe your work has been used or copied in a manner that infringes upon your intellectual property rights, please email data-apps@tether.io identifying and describing both the copyrighted work and alleged infringing content.