---
license: mit
language:
- en
task_categories:
- question-answering
- text-generation
size_categories:
- n<1K
configs:
- config_name: forgebench_full
  data_files:
  - split: tasks
    path: data/forgebench_full.jsonl
- config_name: schema_example
  data_files:
  - split: examples
    path: data/schema_example.jsonl
tags:
- minecraft
- neoforge
- forge
- mixin
- code
- benchmark
pretty_name: ForgeBench v1
---

Check the newer (v4) version

# ForgeBench v1 — independent benchmark for Minecraft-modding LLMs

Contamination-free evaluation benchmark for models fine-tuned on the
`ComerX/forge-neoforge-sft-*` dataset family. Targets **NeoForge 1.21.1** and
**Forge 1.20.1** (Mojang mappings). 100 tasks, 5 modules × 20.

## Data files (what the Dataset Viewer loads)

| Config | Split | File | Rows |
|---|---|---|---|
| `forgebench_full` | `tasks` | `data/forgebench_full.jsonl` | 100 |
| `schema_example` | `examples` | `data/schema_example.jsonl` | 3 |

Both files are UTF-8 JSONL, one task object per line — loadable with
`load_dataset("ComerX/forgebench-v1", "forgebench_full")` or line-by-line with
`json.loads`. Everything else in the repo (`harness/`, `template/`, reports) is
tooling, not data.

## Task schema (strict)

```json
{
  "task_id": "MIXIN_014",
  "module": "api | mixin | migration | debug | build",
  "instruction": "prompt given to the evaluated LLM",
  "context": "vanilla snippet / crash log / legacy code (may be empty)",
  "golden_reference": "reference answer",
  "eval_criteria": {
    "must_compile": true,
    "required_annotations": ["@Inject"],
    "forbidden_apis": ["net.minecraft.util.text"],
    "gametest_required": false
  }
}
```

`context` is `""` for tasks that need no reference material (e.g. pure API
registration drills); it contains vanilla/legacy code or FML log excerpts for
`mixin`, `migration` and `debug` tasks.

## Modules

| Module | Count | Task type | Grading |
|---|---|---|---|
| `api` (API & registration) | 20 | instruction→code | compile + AST gate |
| `mixin` (Mojmap targets) | 20 | FIM / translation | compile + AST gate |
| `migration` (1.20.1→1.21.1) | 20 | refactoring | compile + AST gate (legacy APIs forbidden) |
| `debug` (FML crash logs) | 20 | log analysis → JSON | judge + JSON-shape gate |
| `build` (Gradle KTS / mods.toml) | 20 | config generation | judge + required-token gate |

## Layout

```
data/
  forgebench_full.jsonl    # 100 tasks (single JSONL, one task per line)
  schema_example.jsonl     # 3 complete examples (Mixin / Migration / Crash log)
harness/
  Dockerfile               # sandbox image: JDK 21 + Gradle 8.9 + prebuilt MDK template
  sandbox_runner.py        # injects answer into MDK -> ./gradlew build -x test -> Pass@1
  ast_eval.py              # javalang AST gate: syntax, forbidden APIs, hallucinated
                           # imports, required annotations, version-mix penalties
  gametest_runner.py       # GameTest template generation + headless run
  judge_prompt.txt         # strict LLM-as-a-judge rubric for debug/build tasks
  run_benchmark.py         # driver: aggregates sandbox + AST + judge into a report
  requirements.txt
template/                  # minimal NeoForge 1.21.1 MDK (NeoGradle 7 userdev)
VERIFICATION.md            # benchmark self-verification results (19/19)
verification_result.json   # machine-readable check log
SHA256SUMS.txt             # integrity manifest (sha256 of every repo file)
```

## Running

```bash
# 0. build the sandbox image (once)
docker build -t forgebench-sandbox:1.21.1 .

# 1. produce answers.jsonl: {"task_id": ..., "answer": ...} per row

# 2a. offline static gate only
python3 harness/run_benchmark.py --data data/forgebench_full.jsonl \
    --answers answers.jsonl --skip-compile --out report.json

# 2b. full compile evaluation (inside Docker)
python3 harness/run_benchmark.py --data data/forgebench_full.jsonl \
    --answers answers.jsonl --out report.json

# 3. judge-graded tasks (debug/build): run your judge LLM with harness/judge_prompt.txt
#    and pass scores via --scores '{"DEBUG_004": {"score": 9, "verdict": "pass"}, ...}'
```

## Contamination status

Golden references and instructions were screened against the public SFT corpus
(`ComerX/forge-neoforge-sft-v2.1.0-rc2` + `-rc1`, sampled shards): **0 hits**
(normalized 300-char prefix containment). The benchmark tasks are synthetic
examples, not derived from any corpus repository.

## Integrity

- Frozen artifact: `SHA256SUMS.txt` (sha256 of every file in this repo).
- The benchmark is immutable once published; changes require a new version tag.

## License

MIT — applies to the benchmark data (`data/`), the harness (`harness/`), and the
MDK template (`template/`).