#3926·FastChat

Would an EvalPort-format export of MT-Bench be welcome?

Author: adhabnr-uxCreated Aug 22, 2026Updated Aug 22, 2026

Hi FastChat team — I maintain EvalPort, an open, framework-agnostic JSON spec for portable LLM eval datasets (Apache 2.0, TestCase/Suite schema with a real JSON Schema validator). It has a benchmarks/ directory converting well-known public benchmarks into validated EvalPort suites, each with attribution and license preserved, so someone using a different harness can still run the same questions without a bespoke converter.

I read the actual data files rather than guessing at fields. fastchat/llm_judge/data/mt_bench/question.jsonl:

{"question_id": 81, "category": "writing", "turns": ["Compose an engaging travel blog post about a recent trip to Hawaii...", "Rewrite your previous response. Start every sentence with the letter A."]}

plus fastchat/llm_judge/data/mt_bench/reference_answer/gpt-4.jsonl (reference answers keyed by question_id), and fastchat/llm_judge/data/judge_prompts.jsonl for the LLM-judge rubric.

This maps onto EvalPort cleanly: turns → a multi-turn TestCase.input list, question_id/categorymetadata, the matching reference_answer entry → expected_output where present, and the judge prompt → an EvalPort llm_judge grader definition (MT-Bench's pairwise/single-answer grading is exactly the kind of grader EvalPort's spec has a slot for).

Would your maintainers be open to an EvalPort-format export of MT-Bench (and/or Vicuna-Bench, same structure) living in EvalPort's benchmarks/ directory, with attribution to this repo/paper and the Apache-2.0 license preserved? I'd do the conversion work and validate it against EvalPort's real schema — filing this as a heads-up issue first rather than sending a PR out of nowhere. Also happy to link back to FastChat from EvalPort's benchmark listing either way. Let me know if this is of interest, or not a priority right now — no worries either way.