Quick Reference
Messages Format (Default)
OpenAI-compatible messages format for fine-tuning GPT models.ChatML Format
ChatML format with special tokens.Q&A Format
Question-answer format with ground truth labels for evaluation.LangSmith Format
Format compatible with LangSmith evaluation datasets.Langfuse Format
Format compatible with Langfuse evaluation datasets.Tool Call Format
Format for function/tool calling training.BERT Format
Format for BERT and encoder models.Classification
Extractive QA
Custom Tasks
Register custom BERT task formatters:Pretty Print
Add indentation for human-readable output:Direct Formatter Usage
For advanced use cases, use formatters directly:HuggingFace Export
All formats work with HuggingFace export:Format Comparison
| Format | Use Case | Structure |
|---|---|---|
messages | OpenAI fine-tuning | Chat messages array |
chatml | Alternative chat format | Single text with tokens |
qa | Evaluation datasets | Question/answer pairs |
langsmith | LangSmith integration | Inputs/outputs/metadata |
langfuse | Langfuse integration | Input/expected_output |
tool_call | Function calling | Messages with tool_calls |
bert | Encoder classification | Text/label pairs |
bert:qa | Extractive QA | Question/context/answer |