Models
What Is Joey-1? Baseten’s Penny-a-Million Decision Model, Explained
Joey-1 is Baseten’s 2B open-weights decision model, released October 29, 2026. It picks answers for $0.01 per million tokens. What it does and how to try it.
Joey-1 (written joey-1 by Baseten, and sometimes searched as "joey 1" or "Baseten Joey") is a tiny AI model that does not chat. You hand it a question and a few possible answers. It hands back the answer it picks and how sure it is.
Baseten released it on October 29, 2026, and the headline number is the price: one cent per million tokens. Here is what joey-1 is, who made it, what it costs, how to try it, and how it stacks up against the other "decision models" that arrived this month.
What is joey-1?
Joey-1 is the smallest member of Baseten’s decision model family. A decision model is a narrow AI that only answers closed questions. Think "Is this email spam?" or "Which team should get this ticket: billing, shipping or tech?" It does not write a reply. It gives one answer and a confidence score, in a single quick step.
Baseten says joey-1 handles three kinds of questions:
- Yes or no. It returns the chance the answer is yes.
- Pick one. It chooses from a list of named options and gives a probability for each.
- Scores. It rates something on an ordered scale, like 1 to 5 against a rubric.
It reads text and images. The training also included an "I don’t know" option, so the model can say it is unsure instead of guessing. Baseten pitches it as a first-line model: joey-1 takes the easy, high-volume calls, and its bigger siblings take over when it is not confident.
Joey-1 at a glance
| Question | Answer |
|---|---|
| Who made it? | Base Labs, the in-house research lab of Baseten, an AI inference company |
| Released | October 29, 2026 |
| Size | 2B parameters (Baseten’s figure) |
| Built on | Alibaba’s open-weight Qwen3.5-2B, post-trained by Base Labs |
| What it returns | An answer plus a calibrated probability, not free text |
| Inputs | Text and images |
| API price | $0.01 per million input tokens |
| Speed | About 20 ms median for a 2,000-token request, per Baseten |
| Context | 16K tokens on Baseten’s shared API; Baseten says dedicated deployments go up to 262K |
| License | MIT, weights on Hugging Face as baselabs/joey-1 |
Joey-1 vs elephant-1 vs mammoth-1
Joey-1 is the third model in a family. A week earlier, on October 21, Baseten shipped two bigger siblings. All three use the same training data and the same API, so a developer can switch between them by changing one line.
| Model | Size | Price per 1M tokens | Role |
|---|---|---|---|
| joey-1 | 2B | $0.01 | Fastest and cheapest, first line |
| elephant-1 | 9B | $0.035 | The balanced default |
| mammoth-1 | 27B | $0.10 | Most accurate |
Baseten gives a simple cost example. Sorting 10 million support tickets a month, at about 500 tokens each, is 5 billion tokens. That comes to about $50 a month on joey-1, versus $500 on mammoth-1. On speed, Baseten says joey-1 is about 2.5 times faster than elephant-1 (20 ms against 49 ms).
Is joey-1 any good?
Baseten calls joey-1 the strongest decision model with 3 billion or fewer parameters. Baseten says those internal tests are "coming soon," so that claim cannot be checked yet.
The one public number is on the Jev Decision Index 0.4, a leaderboard for decision models. On its public split, the model card lists these scores:
| Model | Jev Decision Index 0.4 (public split) |
|---|---|
| elephant-1 (Baseten, 9B) | 72.24 |
| joey-1 (Baseten, 2B) | 63.30 |
| Cloudflare Clef | 61.71 |
| Jev 1.14 | 60.70 |
| Perplexity Decider Flash v1.2 | 60.06 |
That puts joey-1 at number 37 of 230 models and first among models under 4B, per Baseten. These are figures Baseten reported, so treat them like any launch-day benchmark. The fair reading: joey-1 trails its bigger sibling everywhere, but it beats several better-known decision models while costing a fraction as much.
Joey-1 vs other decision models
October 2026 turned decision models into a crowded category. Microsoft Decision-1 costs $0.042 per million input tokens. The OpenAI Decisions API charges $0.10. Perplexity Decider is open-weight too and can run on a Mac. Joey-1’s angle is plain: the smallest and cheapest of the bunch, with an MIT license that lets companies run and change it however they like.
How to try joey-1
- Baseten Model APIs. Developers call it through Baseten’s decision endpoint with the model ID
decision-models/baseten-joey-2b-latest. Baseten says zero data retention is on by default. - Download the weights. The model is on Hugging Face at
baselabs/joey-1. The model card says self-hosting needs one CUDA GPU. - Fine-tune it. Baseten says joey-1 can be post-trained on its Training Jobs product, and it published a cookbook for that.
There is no chat app. Joey-1 is a building block for software, not something you open on your phone.
What this means for you
You will probably never call joey-1 yourself. But you will feel models like it. Every AI agent makes hundreds of tiny choices while it works: which tool next, did that step succeed, is this message safe. When those choices cost a cent per million tokens instead of dollars, agents get faster and cheaper to run.
The part a normal person cares about is the finished task, not the plumbing. That is the point of agentic AI: expert agents that plan, check and finish real work. Agentic AI puts a team of up to four of them on your iPhone and iPad, with no account and no model shopping.
Quick answers
What is joey-1? A 2B open-weights decision model from Baseten, released October 29, 2026. It answers yes-or-no, pick-one and scoring questions with a probability instead of writing text.
Is joey-1 free? The weights are free under the MIT license. Using it on Baseten’s API costs $0.01 per million input tokens.
Is Baseten joey-1 open source? It is open-weights under the MIT license, so you can download, run, change and use it commercially.
What model is joey-1 based on? Alibaba’s Qwen3.5-2B, post-trained by Base Labs with the same data and recipe as elephant-1 and mammoth-1.
Can I chat with joey-1? No. It only picks answers. For an AI that writes, researches and plans, use an assistant or an AI agent app on iPhone.
New to these terms? Our agentic AI glossary explains decision models, inference and more.
Sources: Baseten: Introducing joey-1 · Hugging Face: baselabs/joey-1 · Baseten model library · The Next Web · Unite.AI
