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Gemini Decisions API

On 11 November 2026 Google launched the Gemini Decisions API, powered by a new model called Gemini Decision 1. Instead of generating text token by token, it evaluates one input — text, images, audio, video, or PDFs — against up to 1,000 bounded questions in a single pass, and returns answers with a confidence score. It's the third decision-focused model from a major lab in two months. Here's what's confirmed, and how it lines up against Jev, which defined this category in September.

The Gemini Decisions API is Google's entry into the decision-layer category: a bounded interface for software that needs an answer it can act on, not prose to parse. You send a shared input plus a set of questions with fixed answer shapes — yes/no, multiple choice, or a rating on a scale you define — and it returns a selected answer for each, with a confidence score. Google positions it for the high-frequency decisions inside apps and agents: routing, tool selection, safety checks, and grading, without the latency or output-token cost of full text generation.

What's confirmed

context Jev purpose-built parallel sampler typed answer RLCD-calibrated context + questions Gemini Decision 1 Google's decision model, multimodal answer + score ~150–250ms, AI Studio
Same decision shape, different builds: Jev is a from-scratch System One model in one non-autoregressive pass; Gemini Decision 1 is Google's new decision model, with multimodal input across the Gemini stack.

Why this matters: the category is now a three-way race

Google shipping a decision model is the clearest signal yet that "decision API" is a real category, not one startup's framing. TypeSafe AI defined the shape with Jev in September — context plus a finite answer space, one typed answer out — OpenAI followed with its Decisions API the next month, and now Google has joined with Gemini Decision 1. Whichever you end up using, the takeaway is the same: for the small, frequent decisions inside routing, grading, and agent loops, a purpose-shaped decision call beats prompting a chat model and parsing the reply.

Pricing

Google lists Gemini Decision 1 at $0.10 per million input tokens with output tokens free, and calls it roughly five times cheaper than Gemini 3.5 Flash-Lite. Jev also charges nothing for output and bills a fraction of a cent per decision — notably, Google's own launch benchmark (vendor-reported) called Jev slightly more cost-efficient even though its sticker input price is higher, because a decision rarely spends many input tokens. For exact Jev figures see the pricing page; on both products the real cost driver is how much context each decision carries, not the headline per-million rate.

Gemini Decisions API vs Jev, in brief

Gemini Decisions APIJev (TypeSafe)
ApproachGoogle's new decision model (Gemini Decision 1)Purpose-built System One model
AvailabilityAI Studio + limited free tierGenerally available, self-serve
Speed~150–250ms end-to-end~70–500ms, 40–200x faster than a frontier LLM
Questions/requestUp to 1,000 against one inputMultiple questions in one decide call
InputText, images, audio, video, PDFText state (convert evidence to text)
OutputAnswer + confidence scorechoice · score · noul + confidence
CalibrationConfidence score (Google claims lowest calibration error)RLCD-calibrated probabilities
WeightsClosed, hosted onlyClosed, hosted (API + browser playground)

The honest read: Gemini Decision 1 brings real multimodal input (images, audio, video, PDFs) and Google's distribution, and Google's own benchmark puts it ahead of Jev on seven of nine tests — those are vendor-reported numbers with no independent verification yet, and the same benchmark called Jev slightly more cost-efficient. Jev's bet is different: a model designed only for decisions, emitting a typed value in a single non-autoregressive pass and trained end-to-end with RLCD so its confidence numbers track real outcomes. If your decision hinges on visual or audio context, Gemini's multimodal input is a genuine advantage; if it hinges on a calibrated threshold you route on, a model built and trained for calibrated decisions is a meaningfully different thing.

Does this site support the Gemini Decisions API?

Not directly — this site runs on Jev, and Gemini Decision 1 is Google's own hosted model with no open weights. The two share the category shape (an input plus a bounded question set, a typed answer plus confidence out), so if you build your decision on Jev today you're not locked in: the request is portable, and we'd add other providers as options behind the same decide call rather than making you rewrite your logic.

Ship a decision call today

Jev is generally available and takes the same kind of request — a finite answer space in, one typed answer plus confidence out — so you can build the decision into your app now:

// A decision call to Jev — same category shape as Gemini Decision 1
const res = await fetch("https://jevtypesafeai.com/api/v1/decide", {
  method: "POST",
  headers: {
    "Content-Type": "application/json",
    Authorization: `Bearer ${process.env.JEV_KEY}`, // jv_live_...
  },
  body: JSON.stringify({
    state: { message: text },
    questions: {
      intent: { type: "choice", instructions: "Classify the message.",
                criteria: { question: "a question", bug: "a bug report", billing: "a billing issue", spam: "spam" } },
      urgent: { type: "noul", instructions: "Does this need a human within the hour?" },
    },
  }),
});
const { answers } = await res.json();
if (answers.urgent.noul > 0.8) escalate(answers.intent.choice); // both answers, one round trip

FAQ

What is the Gemini Decisions API?

An API Google launched on 11 November 2026, powered by its new Gemini Decision 1 model. It scores one input — text, images, audio, video, or PDFs — against up to 1,000 bounded questions (yes/no, multiple choice, or a rating scale) in a single pass, returning each answer with a confidence score instead of generating text token by token.

How much does the Gemini Decisions API cost?

Google lists Gemini Decision 1 at $0.10 per million input tokens with output tokens free, which it calls about five times cheaper than Gemini 3.5 Flash-Lite. Because a single decision usually carries few input tokens, the effective cost per decision is a small fraction of a cent.

How does it compare to Jev?

Both return a typed answer from a bounded set with a confidence score. Gemini Decision 1 adds multimodal input (images, audio, video, PDFs) and Google's own benchmark claims it leads Jev on seven of nine tests — vendor-reported, unverified, and that same benchmark called Jev slightly more cost-efficient. Jev is a purpose-built, text-state model calibrated with RLCD and generally available self-serve today.

Is Gemini Decision 1 open source?

No. It's a closed, hosted model available only through the Gemini Decisions API and a limited free tier in Google AI Studio; Google has not released open weights.

Can I use the Gemini Decisions API on this site?

No — this site runs on Jev. The two share the same category shape (an input plus a bounded question set in, a typed answer plus confidence out), so you can build your decision call on Jev today and keep it portable.

See also: What is a decision API · OpenAI Decisions API explained · Microsoft-Decision-1 explained · Jev alternatives · Playground

Ship a decision call today

Jev is generally available and takes the same category shape. Try one free in the browser, then grab a jv_live_ key.

▶ Try Jev freeGet an API key →
Gemini Decisions API — what it is & how it compares to Jev · Jev by TypeSafe AI