Token-level confidence
Most chat models can tell you a pump is failing. InertialAI-0.1 also tells you how sure it is — not by claiming a confidence in prose, but through the probability of the answer tokens themselves. On live graded runs of held-out tasks, right answers average 0.97 token confidence and wrong ones 0.71, so a single threshold at 0.90 keeps 92% of the right answers while rejecting more than half of the wrong ones. That turns a chat completion into a decision-grade signal for alerting, escalation, and human-in-the-loop review of real-world data.
How it works
Add two OpenAI-standard fields to any request:
{ "logprobs": true, "top_logprobs": 5 }
Every generated token then carries its log-probability, plus up to 5
alternative tokens with theirs, in the standard OpenAI logprobs response
shape. There is no surcharge for logprobs.
exp(logprob) of the answer token is the model's probability for that
answer. For a one-word classification, that single number is your
confidence score.
The pattern: classify, then threshold
Constrain the answer to a known label set, then read the first answer token's probability:
import math
from openai import OpenAI
client = OpenAI(base_url="https://inertialai.com/api/v1", api_key="iai_...")
resp = client.chat.completions.create(
model="inertialai-0.1",
temperature=0,
max_tokens=2,
logprobs=True,
top_logprobs=5,
messages=[
{
"role": "user",
"content": (
"Vibration RMS (mm/s): 2.1, 2.0, 2.2, 4.8, 5.1, 5.0.\n"
"Answer with exactly one word: normal or anomaly."
),
}
],
)
tok = resp.choices[0].logprobs.content[0]
label = tok.token.strip()
confidence = math.exp(tok.logprob)
if confidence >= 0.90:
page_oncall(label) # act automatically
elif confidence >= 0.70:
queue_for_review(label) # human-in-the-loop
else:
log_only(label) # too uncertain to act on
The top_logprobs alternatives give you the full distribution over your
label set — useful for ROC curves, picking thresholds on your own holdout
data, and monitoring drift in production.
Why this works
Raw logprobs from general-purpose LLMs are notoriously overconfident. InertialAI-0.1 is trained against a proper scoring rule on physical data, so its answer-token probabilities separate right answers from wrong ones — which is what makes the thresholding pattern above safe to ship:
- Alert routing — page on high-confidence anomalies, queue the rest.
- Cost control — auto-accept high-confidence extractions; only pay humans to review the uncertain tail.
- Auditability — every automated decision has an attached probability you can log and defend.
Tips
- Set
temperature: 0for classification — you want the mode of the distribution, and its probability, not a sample. - Keep label sets to single tokens where possible (
normal/anomalyrather than multi-word phrases); if a label spans several tokens, use the first token's probability or sum the sequence logprobs. - Sum logprobs across tokens (or average per-token) to score longer extractions such as numeric readings.
- Calibration holds best on in-domain, real-world data; for your own domain's labels, a Chronicle finetune tightens it further and is evaluated against the base automatically.