Your model already knows it's wrong. Asking costs 0.06 seconds and zero tokens.

Ask a language model how confident it is and you get 0.5000 — a coin flip, measured across 2,018 items.

Read its internal state instead and you get 0.8801.

Same model. Same questions. The verdict was already there; nobody was reading it.

Zero-Token Confidence (ZTC) reads it. One forward pass, zero generated tokens, a calibrated probability out the other side. It ships today on Hugging Face.

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#1 on the board — against verifiers that generate

A shared benchmark, 2,018 items, one harness, every verifier scored on the same rows.

Two numbers deserve a second look.

0.5000. That is the model answering "how sure are you?" It is exactly a coin. Every product that routes on self-reported confidence is routing on noise.

0.7036. That is a baseline that reads nothing but answer length and formatting. Two published verifiers score below it — they are not reading content at all.

ZTC tops the board while emitting not a single token.

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The gap over asking the model: +0.22

On 539 held-out items, self-readout mode — the model judging its own answer:

Every number clears a permutation null at z = 9 to 13 — the probe is refit on shuffled labels 200 times, and the real fit sits nine to thirteen standard deviations above that distribution.

And it holds when we make it hard: under leave-one-domain-out, where the probe never sees the domain it is tested on and every hyperparameter is chosen inside the training domains only, Darwin-397B still returns 0.7572.

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0.0615 seconds

Measured on four B200s, 27B, 2,000 items:

Generate one candidate answer     1.631 s
ZTC gate                          0.0615 s     ← 26× cheaper than the work it guards

Darwin-397B scored 2,018 items in 270 seconds across eight B200s — 0.13 s each, forward pass included.

A verifier that generates tokens competes with your agent for the same budget. A verifier that reads costs about as much as a rounding error, which means you can gate every action instead of a sampled few.

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Bigger is not better — and we have the receipt

Same 400 items, same harness, judge mode:

A 180B-class model lands last, below a 27B, on identical rows.

Its hidden width is 2560 and 36 of its 48 layers use linear attention. The probe reads one vector: a narrow hidden state has less room to carry the verdict, and linear-attention layers compress away the global comparison the judgement needs.

What predicts ZTC quality is hidden width and full-attention share — not parameter count. Pick your gate model accordingly.

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Ships today: 45 KB and four lines

FINAL-Bench/Darwin-397B-ZTC carries a deployable probe — a 45 KB .npz holding the weight vector, standardisation terms and calibration constants. No training data, no extra dependency, no service to call.

z = np.load("ztc/ztc_probe_darwin397b.npz")
h = model.model(**inputs).last_hidden_state[0, -1].float().cpu().numpy()
s = ((h - z["mu"]) / z["sd"]) @ z["w"]
p = 1 / (1 + np.exp(-(z["cal_A"] * (s - z["s_mean"]) / z["s_std"] + z["cal_B"])))

That is the whole integration. FINAL-Bench/ZTC-Judge-27B does the same job over other models' answers, across five domains.

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Watch it decide — in your browser

We wired these constants into a live arcade. Three lanes get the same stream of proposed actions — delete three rows, charge a payment, run the deploy script — and the same time budget. One has no gate and must execute everything. One uses a text-reading verifier. One uses ZTC.

Right action +1 · Wrong action −1 · Hold 0.

Over 400 matches:

No gate            −3.9
Text verifier     +13.0
ZTC               +29.1        98% of matches won

Gating lifts executed accuracy from 49% → 65%. And in the same 300 seconds ZTC handles 2.2× more actions than the text verifier, because its gate is nearly free.

You can take the ungated lane yourself. The only cue on screen is the model's self-reported confidence — and you now know exactly what that number is worth.

👉 huggingface.co/spaces/FINAL-Bench/gate-tetris

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Get it

Zero-Token Confidence is developed by VIDRAFT. FINAL-Bench · vidraft.net