verdict

from verdict import Verdict

v = Verdict()                                                      # verdict-small: 118M params, 100+ languages, CPU is fine
v.choose("Billed twice, refund or we cancel", ["billing", "technical", "sales"])   # -> billing  p=0.71
v.score("Great product, slow delivery", scale=(1, 5))                             # -> 4  expected 3.6
v.check("Can I talk to a person?", claim="the user asks for a human")             # -> True p=0.84

Three question kinds, one mechanism. No text generation, no schema errors, no hallucinated labels: the answer is always one of the options you gave.

Why another one

TypeSafe's Jev (closed, hosted) and Laya (open, 421M ModernBERT) made "System One" decision models a category in September 2026. Both have the same three gaps, and Verdict is built around closing them:

	Jev	Laya	kev	Verdict
Zero-shot, Banking77 (77 intents)	0.80-0.87	0.425	0.425 (third-party)	0.594 base, 0.556 trained
Trained on your labels	not possible	4-5 h on 2xT4	delta fine-tune, GPU	0.9 s on a laptop CPU (16 labels/class)
Accuracy after training, Banking77	0.80-0.87 (zero-shot only)	0.425	not reported	0.858 with 16 labels/class, 0.913 full
Calibration (ECE, lower is better)	0.144-0.246	0.466 as shipped	"still a bit overconfident" (author)	0.014-0.030
"I don't know"	opaque confidence	act_probability always 1.0	threshold on confidence	conformal abstain with a coverage guarantee
Max options	255	~20 before degrading	collapses past ~20	unbounded (options embedded once, cached)
Languages	English first	English ckpt fails silently on non-Latin	English	100+ (multilingual encoder)
Latency	70-500 ms network	33 ms GPU, 329 ms+ CPU	12-26 ms H100, 780 ms M5	0.5 ms/example batched (M-series), single-digit ms CPU
Weights, data, training code	closed	weights only	all open	all open, Apache-2.0
Wire format	/v1/systemone	/v1/systemone	/v1/systemone	/v1/systemone compatible + native API + MCP
Option order changes the answer	yes, log-odds shift 0.3-0.5	yes, flip rate up to 0.23	yes, 13.75 pp in a third-party test	no, by construction

Jev, Laya and kev numbers are from their own docs and published third-party evals; see docs/RESEARCH.md. Verdict numbers are from bench/ and reproducible with one command below.

The honest-probability part

Every answer carries a Confidence:

a = d("the courier lost my parcel")
a.confidence.probability     # temperature-scaled, so 0.9 means right ~90% of the time
a.confidence.abstain         # True when the model cannot commit at your chosen coverage
a.confidence.conformal_set   # ["shipping"] or ["shipping", "refund"]: the labels it cannot rule out

calibrate() fits a temperature and a conformal threshold on held-out data. After that, on data like your held-out set, the true label is inside conformal_set at least coverage of the time. That is a distribution-free guarantee, not a heuristic. The number you actually care about comes out of evaluate():

Banking77, 16 labels per class, coverage 0.90:
  automation_rate 0.76   accuracy_when_committed 0.947   accuracy overall 0.858   ECE 0.020

Read: at 90% coverage Verdict commits on 76% of tickets, is right 94.7% of the time when it does, and hands the rest to a human or an LLM. The cascade is one object:

from verdict.cascade import Cascade

route = Cascade(d, fallback=lambda text, answer: llm_router(text, shortlist=answer.confidence.conformal_set))
route("where is my parcel")   # Verdict's label when it commits, the LLM's otherwise
route.stats()                 # calls, committed share, average ms on each path

Teach it your decision

from verdict import Verdict, Question
from verdict.types import options_from

v = Verdict()
d = v.compile(Question(kind="choose", options=options_from(["refund", "shipping", "account", "other"])))

d.fit(train_pairs)                       # [(text, label), ...]  seconds on a CPU
d.calibrate(held_out_pairs, coverage=0.9)
d.evaluate(test_pairs)                   # accuracy, ECE, automation_rate, accuracy_when_committed
d.save("support.verdict")                # one JSON file

fit trains a head on frozen embeddings: a prototype head from as little as one example per class, a logistic head (initialised at the zero-shot solution, shrunk towards it) when you have more. Nothing is fine-tuned, so it is fast, deterministic and cheap to redo.

Distill your LLM's decisions

Your router, judge or classifier has been logging (input, answer) for months. That is a training set.

verdict distill traces.jsonl support.verdict --coverage 0.9

traces 12,400 · fit 8,680 · calibrate 2,480 · test 1,240
agreement_with_llm 0.94 · agreement_when_committed 0.98 · automation_rate 0.81 · ece 0.02

Read: Verdict now answers 81% of that traffic itself, agreeing with the LLM 98% of the time on those, and escalates the rest. The question kind is inferred from the answers (labels, small integer range, or booleans) or given with --question q.json.

Drop-in for Jev / Laya clients

pip install "verdictml[serve]"
verdict serve --port 8000

Then point any Jev, Laya or impossibl client at http://localhost:8000/v1/systemone. The choice / score / noul question shapes are accepted unchanged; answers add an abstain flag. The native POST /v1/decide returns full Choice / Score / Check objects.

No PyTorch? Use the ONNX engine

pip install "verdictml[onnx]"

v = Verdict(engine="onnx")     # int8 weights from the Hub, ~120 MB, onnxruntime + tokenizers only

Same model, same numbers, 0.7 ms per example batched and under 2 ms single on a laptop CPU. These are the exact weights the browser playground runs.

Long inputs

Inputs longer than the encoder window are chunked with overlap, embedded, mean-pooled and re-normalised. A twenty-page document becomes one vector instead of a silently truncated one.

As an agent tool (MCP)

pip install "verdictml[mcp]"
verdict mcp

{"mcpServers": {"verdict": {"command": "verdict", "args": ["mcp"]}}}

Three tools, choose, score, check, for Claude Desktop, Claude Code, Cursor or any MCP client. Give an agent a fast, calibrated judgement call instead of another LLM round trip.

CLI

verdict ask "I want my money back" -o refund -o shipping -o account
verdict ask "Can I speak to someone?" --claim "the user asks for a human"
verdict fit question.json train.jsonl support.verdict --calibrate heldout.jsonl
verdict evaluate support.verdict test.jsonl
verdict bench banking77 --shots 0,16,-1

Benchmarks

Protocol: heads fit on train minus a fixed 1,000-row calibration slice; temperature and conformal threshold fit on that slice only; every number on the untouched test split. python -m bench.run all --shots 0,16,-1 reproduces the table.

suite	shots/class	accuracy	ECE	automation @0.9	acc. when committed	ms/example
Banking77 (77 intents)	0	0.594	0.054	0.10	0.979	0.8
Banking77	16	0.860	0.036	0.76	0.960	0.6
Banking77	all (8,993)	0.920	0.032	0.98	0.929	0.6
CLINC150 (150 intents)	0	0.536	0.048	0.16	0.957	0.5
CLINC150	16	0.928	0.018	1.00	0.928	0.5
CLINC150	all (14,000)	0.953	0.015	1.00	0.953	0.5
MASSIVE en (60 intents)	0	0.612	0.111	0.12	0.898	0.5
MASSIVE en	16	0.789	0.034	0.55	0.956	0.5
MASSIVE en	all (10,514)	0.881	0.030	0.85	0.933	0.5
MASSIVE Hindi (English option names)	0	0.494	0.068	0.02		0.5
MASSIVE Hindi	16	0.742	0.053	0.41		0.5
MASSIVE Hindi	all	0.863	0.043	0.69		0.5
SST-5 (score 1-5)	0	0.274	0.097			0.9
SST-5	16	0.381	0.032			0.9
SST-5	all (7,544)	0.462	0.029			1.2
ToxicChat (check, 7% positive)	0	AUROC 0.59				2.7
ToxicChat	16	AUROC 0.86	0.016	0.77		2.8
ToxicChat	all (9,082)	AUROC 0.955, acc 0.936	0.011			2.3
Banking77, + deberta-v3-base-zeroshot-v2.0 reranker (top-8)	0	0.650	0.103	0.22	0.950	~30
SST-5, + mDeBERTa-v3-base-xnli reranker	0	0.349				98
ToxicChat, + deberta-v3-base-zeroshot-v2.0 reranker	0	AUROC 0.69				127
ToxicChat, + mDeBERTa-v3-base-xnli reranker	0	AUROC 0.46				59
verdict-small (trained encoder), Banking77, full test 3,076	0	0.556	0.030	0.07	0.985	0.6
verdict-small, Banking77	16	0.842	0.020	0.75	0.944	0.6
verdict-small, SST-5, full test 2,210	0	0.403	0.024			0.9
verdict-small, ToxicChat, full test 5,083	0	AUROC 0.892, acc 0.894	0.015			2.5
verdict-small, ToxicChat	16	AUROC 0.939	0.014	0.93		2.5
Banking77, ONNX int8, CPU only	0	0.604	0.062	0.10		0.7 idle*
Banking77, ONNX int8, CPU only	16	0.858	0.030	0.74		0.7 idle*

typed-decisions (the benchmark Laya and Jev are compared on: 4 workflows, JSON states, 2,000 test decisions labelled by Jev; random 0.318, majority 0.461):

model	protocol	accuracy
Jev 1.13	zero-shot	0.727
Laya base	zero-shot	0.362
Laya typed-decisions	fine-tuned on the train split	0.766
Verdict e5-small	zero-shot, raw JSON state	0.323
Verdict step-1,000 checkpoint	zero-shot, raw JSON state	0.386
Verdict e5-small + heads	fitted on the train split, raw JSON state	0.625
Verdict e5-small, full fine-tune with soft targets, 3 epochs	Laya's protocol	0.689 (0.693 through the Verdict path, 52% automation at 0.81 accuracy when committed)
Verdict e5-base (278M), full fine-tune, 3 epochs	Laya's protocol	0.706

On jevbench's public tiers (mostly knowledge and multi-hop items) verdict-small scores 0.94 / 0.49 / 0.40 on easy / original / hard: routing and intent items are fine, reasoning items are not. Full table in docs/BENCHMARKS.md.

We are behind here and we know why. These states are JSON records, and the label depends on reading fields together with the options ("constraint_violations: 0" plus "harmful"). A bi-encoder scores each option against one vector of the state, by design: that is what buys unbounded options, cached inputs and the browser build. A listwise cross-encoder variant for structured states is the v2 item on the roadmap. train/finetune_typed.py reproduces both rows.

Reference points from published evals: Jev zero-shot Banking77 0.80-0.87, CLINC150 0.87; Laya Banking77 0.425, SST-5 0.372, MASSIVE non-English mean 0.451, ToxicChat 0.755.

verdict-small is multilingual-e5-small trained for 2,000 steps on the typed-decision mix in train/ (Banking77, SST-5 and ToxicChat never in the mix). Load it with Verdict(model="verdict-small"). Zero-shot check went from AUROC 0.59 to 0.89 and score from 0.27 to 0.40; intent zero-shot dipped from 0.594 to 0.556, which the next run addresses with a lower learning rate.

Where we lose, in plain words: zero-shot on score and check questions is weak with the default bi-encoder (SST-5 0.27, ToxicChat AUROC 0.59). A cross-encoder reranker helps (Verdict(reranker=...): Banking77 zero-shot 0.594 to 0.650, at ~30 ms instead of 0.6 ms); the trained-encoder track in docs/PLAN.md is the real answer. Sixteen labels per class fixes all of it, and the full ToxicChat train set reaches AUROC 0.955.

* ONNX rows were measured while a training run occupied the machine (16 ms/example then); 0.7 ms/example batched on an idle M5 CPU.

* zero-shot probabilities are uncalibrated by definition; calibrate() fixes ECE without changing accuracy. Apple M5, intfloat/multilingual-e5-small, batched.

We publish the rows we lose too. Zero-shot on fine-grained intent sets is where a bigger cross-encoder still wins; that is the trained-encoder track in docs/PLAN.md.

How it works

input ──► bi-encoder (options embedded once, cached) ──► logits
                  └─ optional cross-encoder rerank of top-k ─┘
          head: none | prototype | logistic   ◄── fit(examples)
          temperature scaling                 ◄── calibrate(held_out)
          conformal set (LAC)  ──► commit or abstain

Options are scored independently, so option order cannot change an answer (Jev shifts log-odds by 0.3-0.5 when you reorder) and P(true) + P(false) is exactly 1 (Jev's ranges 0.71-1.42). Both are tests in tests/test_invariance.py.

The default encoder is intfloat/multilingual-e5-small (118M, MIT). Swap any sentence-transformers model with Verdict(model=...). Add an NLI cross-encoder reranker with Verdict(reranker="MoritzLaurer/mDeBERTa-v3-base-xnli-multilingual-nli-2mil7") for check questions and subtle option sets.

Install

pip install verdictml                  # import verdict
pip install "verdictml[serve,onnx,mcp]"  # + server, ONNX engine, MCP
pip install "verdictml[bench]"         # + datasets for the benchmark suite

Roadmap

1. ONNX int8 export and a browser playground (ORT Web).
2. TypeScript SDK with literal-union return types from the options array.
3. Trained multilingual encoder on an open, commercially clean typed-decision mix (open data list, open script, open weights).
4. Long inputs: chunk + max-pool.

License

Apache-2.0.