OpenAI Fine-tuning JSONL Validator

Chat fine-tuning examples use a messages array. Validate message roles and dataset consistency before uploading a training file.

{"messages":[{"role":"user","content":"What is JSONL?"},{"role":"assistant","content":"One JSON value per line."}]}

What this catches

• Missing messages arrays and unsupported roles.
• Schema drift between examples.
• Possible email addresses or API keys in training text.
• Approximate token volume for planning.

This preflight checker does not upload your data. Confirm the supported training formats in the OpenAI fine-tuning guide.