# Custom Pre-Tokenized Dataset

How to use a custom pre-tokenized dataset.

- Pass an empty `type:` in your axolotl config.
- Columns in Dataset must be exactly `input_ids`, `attention_mask`, `labels`
- To indicate that a token should be ignored during training, set its corresponding label to `-100`.
- You must add BOS and EOS, and make sure that you are training on EOS by not setting its label to -100.
- For pretraining, do not truncate/pad documents to the context window length.
- For instruction training, documents must be truncated/padded as desired.

Sample config:

    config.yml

    datasets:
      - path: /path/to/your/file.jsonl
        ds_type: json
        type:

Sample jsonl:

    {"input_ids":[271,299,99],"attention_mask":[1,1,1],"labels":[271,-100,99]}
    {"input_ids":[87,227,8383,12],"attention_mask":[1,1,1,1],"labels":[87,227,8383,12]}