clef

cloudflare/clef
Decisionsapache-2.0
Cloudflare|Released Sep 2026 · Updated Oct 2026

clef (cloudflare/clef) is a decision 27.4B-parameter model from Cloudflare with a 16,384-token context window, priced at $0.24/1M input and $0.00/1M output tokens. Returns predicate, choice, or score answers via the haimaker.ai decision API.

Parameters
27.4B
Context Window
16K
tokens
Input Price
$0.24
/1M tokens
Output Price
Free
/1M tokens

Overview

Clef is a decision model by Cloudflare. It returns structured predicate, choice, or score answers through the non-streaming decision API. It has 27.4B parameters. It supports a 16K token context window.

Model Card

Clef

Clef is a 27B multimodal model that turns a state and a schema of typed questions into decisions. It reads the state as text, JSON, images, or video, and returns a probability for every allowed option of every question in a single forward pass. There is no free-form text generation and no output parsing.

The Clef API is fully compatible with Jev and SystemOne.

Clef is post-trained from Qwen/Qwen3.8-27B. See
Clef-Flash for the
smaller, faster variant.

Model

  • Backbone: Qwen/Qwen3.8-27B with its vision encoder, stored as standard sharded safetensors.
  • Joint schema head: a small transformer head that reads the backbone's final hidden states,
routes evidence from the state to each question, and scores all options of all questions jointly.
  • Output: one logit per allowed option for each question. Apply a softmax per question to get
probabilities.

Files

| File | Purpose |
|---|---|
| model-*.safetensors, model.safetensors.index.json, config.json, generation_config.json | Backbone, including the vision encoder |
| joint_head.safetensors, joint_head_config.json | Joint schema head |
| joint_schema_model.py | Record encoding, batching, the model, load_release_model, and systemone |
| tokenizer.json, tokenizer_config.json, chat_template.jinja, processor_config.json | Tokenizer and image/video processor |
| LICENSE | Apache-2.0 license |

Usage

Tested with torch 2.11 and transformers 5.10.2 on a single H200. Image and video inputs also
need pillow.

import sys

import torch
from huggingface_hub import snapshot_download

path = snapshot_download("Cloudflare/clef")
sys.path.insert(0, path)
from joint_schema_model import collate_records, encode_record, load_release_model

model, processor = load_release_model(path, device="cuda")

record = {
"state": {"invoice": {"vendor": "Acme", "total": 1250.0, "currency": "USD", "status": "overdue"}},
"questions": {
"status": {
"type": "choice",
"instructions": "What is the invoice status?",
"criteria": {"paid": "Invoice is paid.", "overdue": "Invoice is past due.", "draft": "Not sent."},
},
"large": {"type": "noul", "instructions": "Is the total above 1000 USD?"},
},
}

encoded = encode_record(processor.tokenizer, record, processor=processor)
batch = collate_records([encoded], processor.tokenizer.pad_token_id, torch.device("cuda"))
with torch.inference_mode():
logits = model(batch)[0]

for question, question_logits in zip(encoded.questions, logits):
probabilities = question_logits.float().softmax(-1).tolist()
print(question.question_id, dict(zip(question.option_ids, probabilities)))

SGLang

Clef can be served with SGLang. See the SGLang cookbook for
launch commands on H200, B200, and B300. On a single H200:

docker run --gpus all \
  --shm-size 32g \
  -p 30000:30000 \
  -v ~/.cache/huggingface:/root/.cache/huggingface \
  --ipc=host \
  lmsysorg/sglang:dev-clef \
  sglang serve \
    --model-path Cloudflare/clef \
    --host 0.0.0.0 \
    --port 30000

The server answers Jev/SystemOne requests at /v1/systemone:

curl http://localhost:30000/v1/systemone \
  -H 'Content-Type: application/json' \
  -d '{"model":"Cloudflare/clef","state":"My Stripe integration keeps failing. Please help ASAP.","questions":{"urgency":{"type":"noul","instructions":"Does this message express urgency?"}}}'

Jev / SystemOne API

systemone takes a Jev/SystemOne POST /v1/systemone request body and returns the same response
body: model, answers keyed by question ID, and usage. A choice answer has choice,
confidence, and probabilities; a score answer has the expected score, confidence, legend,
and probabilities; a noul answer has the probability of true. instructions is optional, and
images and videos may be added to the request.

from joint_schema_model import systemone

response = systemone(model, processor, {
"model": "clef",
"state": "Our checkout started returning errors and orders are blocked.",
"questions": {
"department": {
"type": "choice",
"instructions": "Which team should handle the message?",
"criteria": {"billing": "Payments or invoices", "technical": "Bugs or outages"},
},
"urgency": {"type": "score", "criteria": ["Can wait", "This week", "Today"]},
"outage": {"type": "noul", "instructions": "Is a service down?"},
},
})
print(response["answers"])

Images and video

Add images (PIL images) or videos (frame arrays) to the record and pass the processor to
encode_record. Optional processor arguments go in media_kwargs.

from PIL import Image

record = {
"state": {"task": "Review the attached receipt."},
"images": [Image.open("receipt.jpg")],
"questions": {
"legible": {"type": "noul", "instructions": "Is the receipt total legible?"},
},
}
encoded = encode_record(processor.tokenizer, record, processor=processor)

Text-only and multimodal records can be mixed in the same batch.

Input format

| Field | Description |
|---|---|
| state | Any string or JSON value describing the situation to decide on |
| images, videos | Optional lists of images or video frame arrays |
| media_kwargs | Optional keyword arguments for the image/video processor |
| questions | Mapping of question ID to question |

Each question has:

  • type: noul (true/false), choice (named options), or score (ordered options)
  • instructions: what to decide; optional, and the question ID is used when it is omitted
  • criteria: for choice, a mapping of option ID to description; for score, a list of option
descriptions indexed from 0; for noul, optional descriptions for true and false

encode_record accepts max_length (default 16,384 tokens) and max_state_tokens to bound the input.

Results

Decision Index

Per-benchmark results from our internal run of the Decision Index 0.2.1 suite. Scores are percentages; ForecastBench is a Brier score, where lower is better. The last two rows are request latency in milliseconds, where lower is better. The best value in each row is in bold.

| Benchmark | Clef | Clef-flash | Jev | DiffusionGemma Jev | Kev 9B | Laya |
|---|---|---|---|---|---|---|
| BFCL (case exact accuracy) | 98.5 | 98.8 | 95.8 | 96.5 | 94.5 | 38.1 |
| ToolRet (nDCG@10) | 69.2 | 66.4 | 65.3 | 61.2 | 64.3 | 12.8 |
| API-Bank (accuracy) | 91.9 | 93.1 | 88.2 | 83.7 | 56.3 | 11.5 |
| BANKING77 (macro-F1) | 94.2 | 90.9 | 79.7 | 74.3 | 84.8 | 14.3 |
| CLINC150+OOS (macro-F1) | 97.4 | 66.8 | 89.3 | 83.5 | 79.0 | 3.2 |
| RouterBench (selected quality) | 79.7 | 79.9 | 79.9 | 79.0 | 80.0 | 57.1 |
| Home appliance simulator (case exact accuracy) | 83.0 | 97.7 | 52.3 | 42.0 | 25.0 | 0.0 |
| SGD/SGD-X (macro-F1) | 43.8 | 34.2 | 43.0 | 40.6 | 64.0 | 42.4 |
| ContractNLI (macro-F1) | 81.4 | 84.3 | 71.7 | 76.0 | 57.8 | 29.0 |
| ANLI (macro-F1) | 69.8 | 59.1 | 74.8 | 66.4 | 56.3 | 48.7 |
| BPoMP (accuracy) | 96.9 | 95.4 | 90.6 | 86.9 | 67.0 | 51.6 |
| Humicroedit (accuracy) | 66.7 | 75.1 | 61.9 | 63.0 | 55.8 | 47.2 |
| POP909-CL (accuracy) | 15.8 | 1.6 | 18.1 | 2.5 | 10.8 | 5.1 |
| cfcolor (accuracy) | 66.0 | 65.8 | 64.7 | 58.2 | 56.3 | 52.3 |
| MMLU (accuracy) | 90.3 | 91.8 | 91.7 | 79.3 | 75.3 | 30.7 |
| GPQA Diamond (accuracy) | 48.0 | 51.0 | 78.3 | 44.9 | 38.8 | 27.6 |
| ARC-Easy (accuracy) | 99.0 | 99.5 | 99.3 | 98.2 | 97.7 | 47.0 |
| ARC-Challenge (accuracy) | 97.7 | 98.3 | 97.8 | 94.5 | 93.7 | 28.6 |
| WinoGrande (accuracy) | 93.5 | 97.5 | 92.0 | 73.6 | 73.2 | 50.5 |
| HellaSwag (accuracy) | 98.2 | 98.6 | 94.5 | 83.3 | 81.9 | 33.1 |
| GSM8K (accuracy) | 80.8 | 67.3 | 79.9 | 50.3 | 48.7 | 21.6 |
| ChessBench (accuracy) | 24.7 | 23.0 | 17.2 | 14.2 | 11.2 | 7.7 |
| MuSR (accuracy) | 83.5 | 86.0 | 66.1 | 61.2 | 57.9 | 43.2 |
| SATA-Bench (case exact accuracy) | 33.8 | 36.7 | 26.4 | 27.5 | 26.7 | 0.3 |
| BRIGHT (nDCG@10) | 45.9 | 39.3 | 47.5 | 42.9 | 38.5 | 19.9 |
| Amazon ESCI (macro-F1) | 57.5 | 57.4 | 55.2 | 53.4 | 49.2 | 24.4 |
| ACOS (per-review F1) | 33.3 | 25.9 | 29.5 | 24.5 | 18.3 | 3.5 |
| FinEntity (macro-F1) | 96.2 | 97.1 | 87.0 | 89.0 | 88.4 | 61.0 |
| VAST (macro-F1) | 59.5 | 49.6 | 64.6 | 55.7 | 55.4 | 40.5 |
| NLI4CT (macro-F1) | 82.9 | 78.6 | 84.1 | 78.4 | 74.9 | 47.7 |
| CRUXEval (accuracy) | 86.7 | 86.1 | 73.0 | 64.7 | 51.2 | 40.2 |
| CLadder (accuracy) | 94.0 | 97.7 | 72.6 | 67.8 | 62.0 | 52.9 |
| ForecastBench (Brier, lower is better) | 13.9 | 10.6 | 17.4 | 29.6 | 17.6 | 41.1 |
| Habermas Machine (accuracy) | 68.7 | 71.8 | 45.9 | 45.0 | 39.4 | 33.4 |
| PhishNChips (accuracy) | 79.6 | 75.0 | 62.5 | 85.4 | 50.7 | 50.1 |
| MMLU-Pro (accuracy) | 65.9 | 65.3 | 82.7 | 56.9 | 51.1 | 13.6 |
| BBH (accuracy) | 73.7 | 68.9 | 92.9 | 70.7 | 65.2 | 34.1 |
| RAGTruth (hallucination F1) | 79.4 | 35.6 | 76.5 | 70.4 | 46.2 | 48.8 |
| HoVer (accuracy) | 65.2 | 61.2 | 72.9 | 70.9 | 58.8 | 55.8 |
| When2Call MCQ (accuracy) | 72.4 | 65.6 | 81.0 | 75.4 | 49.6 | 11.9 |
| New Yorker (accuracy) | 69.5 | 66.1 | 70.1 | 63.6 | 58.1 | 27.1 |
| Median latency (ms) | 209.3 | 38.8 | 524.1 | 84.4 | 51.4 | 5.8 |
| p95 latency (ms) | 238.6 | 122.4 | 536.0 | 211.2 | 187.9 | 222.5 |

Workflow evals

Decision accuracy on four end-to-end business workflows from Typesafe Evals, scored against consensus reference labels. All models are scored on the same dataset revision and case cohort.

| Workflow | Metric | Clef | Clef-flash | Jev |
|---|---|---:|---:|---:|
| Invoice processing | Exact actions | 64.7 | 57.1 | 61.8 |
| Invoice processing | Primary action | 86.2 | 73.3 | 83.1 |
| Customer service | Exact actions | 76.3 | 77.0 | 76.0 |
| Security incidents | Exact actions | 62.9 | 61.7 | 61.7 |
| Agent trace observability | Primary action | 68.5 | 69.8 | 71.6 |

License

Released under the Apache-2.0 license, following the base model
Qwen/Qwen3.8-27B.

Features & Capabilities

ModeDecisions
Context Window16,384 tokens
Function CallingNot supported
VisionNot supported
ReasoningNot supported
Web SearchNot supported
Url ContextNot supported

Technical Details

ArchitectureQwen3_5ForConditionalGeneration
Model Typeqwen3_5
Base ModelQwen/Qwen3.8-27B
Librarytransformers

API Usage

Send text or structured JSON with 1–128 questions to /v1/decisions. Questions request predicate, choice, or score answers. Responses are non-streaming. For state-based requests, use /v1/systemone with state and a named questions object.

import requests

response = requests.post(
    "https://api.haimaker.ai/v1/decisions",
    headers={"Authorization": "Bearer YOUR_API_KEY"},
    json={
        "model": "cloudflare/clef",
        "input": "Please refund my duplicate payment.",
        "questions": [{
            "type": "predicate",
            "name": "needs_refund",
            "instructions": "Is the customer requesting a refund?"
        }],
    },
    timeout=30,
)
response.raise_for_status()
print(response.json()["answers"])

Frequently Asked Questions

What is the context window of clef?

clef (cloudflare/clef) has a 16,384-token context window.

How much does clef cost?

clef is priced at $0.24 per 1M input tokens and $0.00 per 1M output tokens when accessed via the haimaker.ai decision API.

How do I use clef via API?

Send a non-streaming POST to https://api.haimaker.ai/v1/decisions with model "cloudflare/clef", input (text or structured JSON), and a questions array. Questions can request predicate, choice, or score answers; read the answers field in the response. Alternatively, POST to https://api.haimaker.ai/v1/systemone with state and a named questions object for noul, choice, or score answers. Authentication uses a Bearer API key from https://app.haimaker.ai.

What does clef return?

Decision models return structured predicate, choice, or score answers instead of chat messages. The decision API accepts 1–128 questions per request and supports text and structured JSON inputs. Responses are non-streaming.

Use clef with the haimaker API

Returns predicate, choice, or score answers via the haimaker.ai decision API.

Get API Access

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