x.split is not a function (it is undefined)

[lakpriya1s]

Describe the bug
I’m interested in using the Felladrin/Llama-160M-Chat-v1 model with react-native-transformers, which works best with ONNX models—ideally in INT8 for better performance on a Python notebook.

I used the following script to convert Felladrin/Llama-160M-Chat-v1 to ONNX:

!python3 /content/convert.py \
  --quantize \
  --task text-generation \
  --model_id Felladrin/Llama-160M-Chat-v1

After the conversion, it works on onnx optimum on python notebook. I tried loading the quantized model with react-native-transformers, but I encountered the following error:

x.split is not a function (it is undefined)
This error comes from the tokenizer.js file:

this.bpe_ranks = new Map(config.merges.map((x, i) => [x, i]));
this.merges = config.merges.map(x => x.split(this.BPE_SPLIT_TOKEN));

My goal is to fine-tune this model on my dataset, convert it to ONNX, and run it with eact-native-transformers — but I’m blocked on this issue. But it works perfectly on Python notebook using onnx optimum.

Could you help clarify what might be going wrong? Am I missing a step?

Thanks!

To Reproduce
Steps to reproduce the behavior:
Load the model.

Expected behavior
Load the model as expected

Screenshots

Smartphone (please complete the following information):

• Device: iPhone 16 Pro emu

[an-upfeat]

Got same error when trying to load:

export const MODEL_REPO = "onnx-community/Qwen3-0.6B-ONNX";
export const MODEL_FILE = "onnx/model_quantized.onnx";