VERDICT

Exit code 0 is not proof.

A 197 KB local model that reads a CLI tool call and returns
success, failure, blocked, or unknown.

Verdict is a research preview of a semantic outcome layer for coding agents, CI runners, and tool-using systems. It looks beyond the process exit code and reads the command, stdout, and stderr. Inference runs locally on CPU with no Python dependencies.

Important: Verdict is an advisory classifier, not proof that a task or environment mutation completed. Keep deterministic checks and authoritative state verification as the source of truth.

Why

A process can exit successfully while running zero tests, returning an HTTP 500, waiting for a worker, or producing incomplete output. Conversely, a non-zero exit can describe an environment blocker rather than a failed assertion. Agents need that distinction before they retry, stop, or claim completion.

Benchmark

Evaluated on 192 synthetic examples from 48 CLI families entirely absent from training. Training used 1,440 synthetic examples from 60 different families.

Model	Accuracy	Macro-F1	Size	Median inference
Verdict 0.1 (int8)	93.2%	93.2%	197 KB	0.54 ms
Exit-code baseline	47.9%	31.9%	—	—

Latency is the median of 576 predictions on Windows 11 / AMD64 / Python 3.12, including feature extraction and the Python API call. These are reproducibility measurements, not cross-hardware promises. See bench/results.json and reproduce with python training/train.py.

The corpus is synthetic and English-biased. The benchmark measures generalization across held-out templates, not reliability on production agent traces. Real-trace validation is the next milestone.

Install and run

git clone https://github.com/Balanov/verdict.git
cd verdict
python -m pip install .

from verdict_tiny import Verdict

model = Verdict()
result = model.predict(
    command="pytest tests/",
    exit_code=0,
    stdout="collected 0 items\nno tests ran in 0.01s",
)
print(result)

{
  "label": "unknown",
  "confidence": 0.999981,
  "probabilities": {
    "success": 0.000019,
    "failure": 0.0,
    "blocked": 0.0,
    "unknown": 0.999981
  },
  "advisory": true
}

CLI

printf 'collected 0 items\nno tests ran\n' | verdict \
  --command 'pytest tests/' --exit-code 0

Use --stdout output.log, --stderr error.log, and --weights /path/to/verdict-q8.bin when needed.

Browser demo

The project page runs the same quantized weights in your browser. Logs are not uploaded.

Output contract

Label	Meaning
success	Output contains positive evidence that the operation completed.
failure	The operation ran and reported a concrete failure.
blocked	Permissions, dependencies, network, quota, or environment prevented execution.
unknown	Evidence is absent, incomplete, skipped, dry-run-only, or otherwise inconclusive.

Probabilities come from a linear multiclass model and are not calibrated confidence in a safety-critical sense. Use thresholds and human or deterministic review for consequential actions.

Model

• Architecture: hashed character 3–5-grams and word 1–3-grams → multiclass logistic regression.
• Parameters: 196,608 int8 weights plus four biases and per-class scales.
• Input: command, exit code, stdout, stderr; UTF-8 text, bounded to 12,288 characters per output stream with explicit head/tail clipping.
• Runtime: pure Python standard library; no tokenizer files, GPU, network calls, or telemetry.
• Weights: weights/verdict-q8.bin, also on Hugging Face.

Verdict is deliberately narrow: it classifies observed CLI evidence; it does not judge task completion, code correctness, safety, or truthfulness.

Reproduce

python -m pip install -e '.[train,dev]'
python training/train.py
pytest -q

The training script regenerates the public corpus, trains from scratch, exports int8 weights, evaluates the quantized artifact, and writes benchmark metrics.

Repository layout

assets/              logo and editable vector source
bench/               measured metrics
data/                synthetic train and held-out test JSONL (CC0)
src/verdict_tiny/    zero-dependency inference and CLI
training/            corpus, features, training and export
weights/             release weights and config
site/                multilingual research page and browser demo

License

Code and model weights: Apache-2.0. Synthetic dataset: CC0-1.0. Fork it, modify it, ship it. See LICENSE and data/LICENSE.

Cite

@misc{balanov2026verdict,
  title  = {Verdict: Tiny Semantic Outcome Verification for AI Agents},
  author = {Balanov, Anton},
  year   = {2026},
  url    = {https://balanov.pro/research/verdict/}
}