Open-weight model
kodiak-large-v2-preview
by Cortex Agent LLC cortex-agent-llc/kodiak-large-v2-preview
kodiak-large-v2-preview is an open-weight model from Cortex Agent LLC, released under Apache License 2.0. It has 400M parameters. At 16-bit it needs about 1 GB of GPU memory, which fits on 1x MI300X from $1.85 an hour, at the lowest prices in the SAVRN Index.
Kodiak is an encoder-only "System One" decision model by Cortex Agent LLC: a state (text, list of texts, or JSON) plus typed questions in, calibrated answers out, in one forward pass.
Runs On
What it takes to serve kodiak-large-v2-preview (400M parameters): the memory its weights need at each precision, and the cheapest way to rent enough data-center GPUs to hold them.
| Precision | Weights | Memory needed | Cheapest setup | Per hour | Also fits |
|---|---|---|---|---|---|
| 16-bit | 0.8 GB | 1.0 GB | 1x MI300X (192 GB) Vultr |
$1.85 | 1x H100 $1.99 · 1x MI325X $2.00 |
| 8-bit | 0.4 GB | 0.5 GB | 1x MI300X (192 GB) Vultr |
$1.85 | 1x H100 $1.99 · 1x MI325X $2.00 |
| 4-bit | 0.2 GB | 0.2 GB | 1x MI300X (192 GB) Vultr |
$1.85 | 1x H100 $1.99 · 1x MI325X $2.00 |
Memory is the weights at that precision plus 20% for the runtime and a short context; a long context needs more. Prices are the lowest on-demand hourly rates in the SAVRN Index, read Oct 19, 2026.
kodiak-large-v2-preview on every accelerator the SAVRN Index prices, at every precision
Model Card
By Cortex Agent LLC, published under apache-2.0, revision a16f3499b9ed.
Kodiak is an encoder-only "System One" decision model by Cortex Agent LLC: a state (text, list of texts, or JSON) plus typed questions in, calibrated answers out, in one forward pass. Choice answers are always one of your labels, scores stay inside your range, and every question can come back as "not answerable from this state" with its own probability. The large model beats every open zero-shot classifier we tested on never-seen tasks (release criterion 1; decision D33). Details: - Run b-base-s1-v2-s1 (seed 1 of three, chosen by validation loss, not the eval set), step 6000. ModernBERT-large backbone (Apache-2.0). Calibration temperatures baked in; default abstain threshold from…
Read Cortex Agent LLC's full model card
Kodiak large — research preview v2
Research preview. The quality tier of Kodiak, shared while we build in public. It's more accurate than the small model, especially on tasks it has never seen, and less reliable at saying "I can't tell" (see Known weaknesses). Code, docs and evaluation: https://github.com/grizzlypeaksoftware/kodiak · Fast tier: kodiak-small-v2-preview · Feedback and failure cases welcome as GitHub issues.
Kodiak is an encoder-only "System One" decision model by Cortex Agent LLC: a state (text, list of texts, or JSON) plus typed questions in, calibrated answers out, in one forward pass. Choice answers are always one of your labels, scores stay inside your range, and every question can come back as "not answerable from this state" with its own probability.
# pip install "kodiak-s1[infer] @ git+https://github.com/grizzlypeaksoftware/kodiak"
from kodiak_s1.hub import Kodiak
kodiak = Kodiak.from_pretrained("cortex-agent-llc/kodiak-large-v2-preview") # GPU if available, else CPU
kodiak.decide("Hi, I ordered the walnut desk two weeks ago. Tracking has said 'label created' for 10 days. "
"If it can't arrive by Monday, please cancel and refund me.",
[{"type": "choice", "id": "intent", "text": "What does the customer want?",
"labels": ["delivery status or expedite", "cancel and refund", "product question"]}])
Large vs. small (eval set v0.2, averaged over three training runs each)
| small v2 (152M) | large v2 (~400M) | |
|---|---|---|
| Never-seen tasks (12 tasks), forced accuracy, choice questions | 55.3% | 60.9% |
| Best open zero-shot classifier on the same questions | 57.9% | 57.9% |
| Familiar tasks | 81.7% | 85.5% |
| Occupation from a biography (never seen) | 63.3% | 77.2% |
| When it abstains, how often it's right | 91% | 84% |
| Latency, GPU / 8 ARM CPU cores | 8 ms / ~80 ms | 16 ms / ~250 ms |
The large model beats every open zero-shot classifier we tested on never-seen tasks (release criterion 1; decision D33). Details: STRATEGY.md §4.
This checkpoint
- Run
b-base-s1-v2-s1(seed 1 of three, chosen by validation loss, not the eval set), step 6000. ModernBERT-large backbone (Apache-2.0). Calibration temperatures baked in; default abstain threshold fromcalibration.json(override per request withnull_threshold). - Eval v0.2: overall 67.2%, familiar tasks 85.4%, never-seen tasks 56.8% (61.0% forced), ECE 0.088. (Eval v0.1: overall 81.8%, ECE 0.049.)
- Includes
handler.pyfor Hugging Face Inference Endpoints. - Includes
model.onnx(fp32, calibration baked in) for self-hosting without Python: the Node.js + Docker server inserver/answers in ~80 ms per request on 8 CPU threads. Download this repo into a folder and pointKODIAK_MODELat it.
Known weaknesses (read before using)
- Abstention is weaker than the small model's. On a message that never names a carrier, it answered "FedEx" (0.46) where the small model
abstains. If a trustworthy "I can't tell" matters more than accuracy, use the small model, or require a higher
min_confidence. - Confidence is less reliable on unfamiliar inputs (calibration error ~0.13 on never-seen tasks; true of both sizes). A long-horizon test (text adventures) showed Kodiak can be confidently wrong on inputs unlike its training data; escalate low-confidence answers.
- Judgment scores on new scales are weak for both sizes (e.g. it rates "I was charged twice and nobody answers!" around 4/10 for urgency).
- Some intent calls are wrong where the small model is right (e.g. "box arrived crushed, lamp broken" → "delivery status").
- States longer than 512 tokens are truncated; English only.
- Not for high-stakes decisions about people without human review. Bias in Bios (occupation) is a held-out task with known gender bias.
Identity and Version
- Repository
- cortex-agent-llc/kodiak-large-v2-preview
- Publisher
- Cortex Agent LLC
- Task
- Not stated by the source
- Modality
- Other
- Library
- kodiak
- Parameters
- 400M parameters
- Languages
- en
- Revision
- a16f3499b9ed873213f140199f316dfc0fc37159
- First published
- 2026-09-27
- Last updated
- 2026-09-27
Files and Weights
8 files, 1.6 GB in total. The weights are 1 file totalling 1.6 GB in safetensors.
Every file
| File | Type | Size | SHA-256 |
|---|---|---|---|
| model.safetensors | Weights | 1.6 GB | cfce427237fd |
| calibration.json | Configuration | 586 B | — |
| handler.py | Configuration | 948 B | — |
| model_config.json | Configuration | 457 B | — |
| README.md | Documentation | 4.3 KB | — |
| requirements.txt | Other | 69 B | — |
| .gitattributes | Repository | 1.5 KB | — |
| tokenizer.json | Tokenizer | 2.1 MB | — |
License and Download
- License
- apache-2.0
- Access
- Open weights, no gate
- Download size
- 1.6 GB
Released by Cortex Agent LLC through its official repository on Hugging Face. Read the license.
Built From
- Derived from answerdotai/ModernBERT-large
Memory Requirements
| Precision | Weights in memory |
|---|---|
| As published | 1.6 GB |
| 16-bit | 0.8 GB |
| 8-bit | 0.4 GB |
| 4-bit | 0.2 GB |
Weights only, from the published parameter count; the key-value cache and runtime add to this.
Questions About kodiak-large-v2-preview
How much GPU memory does kodiak-large-v2-preview need?
About 1 GB at 16-bit and 0.2 GB at 4-bit: the weights (400M parameters) plus a working margin. A long context needs more.
What is the cheapest GPU to run kodiak-large-v2-preview on?
At 16-bit, 1x MI300X from $1.85 an hour; at 4-bit, 1x MI300X from $1.85 an hour, at the lowest on-demand prices the SAVRN Index lists.
Can I use kodiak-large-v2-preview commercially?
Yes. kodiak-large-v2-preview is released under Apache License 2.0. The Apache License 2.0 is a permissive open-source license. It permits commercial use, modification and redistribution. It requires keeping the license and copyright notices and any NOTICE file, stating significant changes, and it includes an express patent grant from contributors.