Does Clef-flash support zero data retention?

Yes. Clef-flash is available with zero data retention on Berget, Cloudflare, Melious, Regolo through the Opper gateway.

Where is Clef-flash hosted?

Clef-flash runs on EU hosting routes through the Opper gateway, with contractually enforced residency on supported providers.

Is Clef-flash trained on prompts and outputs?

No. Every hosting route for Clef-flash is configured so customer prompts and outputs are not used to train models by default.

Is a GDPR DPA available for Clef-flash?

Yes. A GDPR Data Processing Agreement is available on at least one route serving Clef-flash. Contact hello@opper.ai to receive it.

Clef-flash

by Cloudflare

Clef-flash is the smaller of Cloudflare's two decision models, post-trained from Alibaba's Qwen3.5-9B with the same joint schema head as Clef. You send a state (text or any JSON value) and named questions, and it returns typed answers: the probability that a statement is true, a choice among options you define, or a position on your own rubric, each with a full probability distribution. It generates no text, so answers cannot fall outside the options given. It speaks the same request and response format as TypeSafe's System One API, so code written for Jev can switch models by changing the model name, and several questions can be asked about one state in a single request. Use it where decisions sit on a hot path: routing every incoming message, gating tool calls in an agent loop, or filtering at volume. Clef, the 27B sibling, is the choice when accuracy matters more than speed. Weights are published by Cloudflare under Apache-2.0 at https://huggingface.co/Cloudflare/clef-flash.

Call Clef-flash on Opper through the System One evaluation API. Sign up without a credit card. Get started

Get your API key Evaluate via API Compare

Key info

Input

Output

Features

Context window

16K

Max output

—

Input price

$0.05 /1M

Output price

$0 /1M

EU residency available
Zero data retention on pay-as-you-go
No training by default
GDPR DPA available

Available routes

Clef-flash runs on 4 different routes through the Opper gateway. Compare residency, zero data retention and training posture at a glance, with full data-handling detail per route below. In the EU it is served by Berget (Sweden), Melious (Finland) and Regolo (Italy). See every model hosted in the EU.

Provider	Region	Training	Input	Output	Cache read
Berget	EU	No	$0.05	$0	Input price
Cloudflare	Multi	No	$0.04	$0	Input price
Melious	EU	No	$0.03	$0	Input price
Regolo	EU	No	$0.17	$0	Input price

Live routes and prices as JSON: api.opper.ai/v3/models?q=berget%2FCloudflare%2Fclef-flash

Uptime and availability

One of Clef-flash's 4 routes is on the monitoring board, so the figure below is that provider's availability rather than the model's.

99.87%route uptime, last 30 days

Its other routes aren't measured here yet.

Name a second model in the same request and the gateway tries it on retriable errors, so a busy hour never has to reach your users. Set up a fallback chain.

Measured over the last 30 days from each provider's official status feed via StatusGator. Refreshed hourly. 3 further routes are not on the board yet. See uptime for every provider Opper monitors.

Data handling per route

Each route hosting Clef-flash has its own privacy posture, residency, and GDPR terms. Postures are maintained by Opper with a last-verification timestamp.

Berget — Sweden🇸🇪

Zero data retention: nothing is logged, held for abuse monitoring or used for training. No training on customer data. EU; DPA available.

Zero data retention: Yes. Nothing is logged, held for abuse monitoring or used for training.
Training: No training on customer data.
Logging: None
Abuse monitoring: No classifier
Caching: Content cached for replay
Subprocessor access: No subprocessor reads content
GDPR DPA: DPA available
Transfer mechanism: Not applicable — data stays in EU

Cloudflare — Multi-region

Zero data retention: nothing is logged, held for abuse monitoring or used for training. No training on customer data. GLOBAL; dpf sccs; DPA available.

Zero data retention: Yes. Nothing is logged, held for abuse monitoring or used for training.
Training: No training on customer data.
Logging: None
Abuse monitoring: No classifier
Subprocessor access: Subprocessors may read content
GDPR DPA: DPA available
Transfer mechanism: dpf sccs

Melious — Finland🇫🇮

Zero data retention: nothing is logged, held for abuse monitoring or used for training. No training on customer data. EU; DPA available.

Zero data retention: Yes. Nothing is logged, held for abuse monitoring or used for training.
Training: No training on customer data.
Logging: None
Abuse monitoring: No classifier
Caching: Content cached for replay
Subprocessor access: Subprocessors may read content
GDPR DPA: DPA available
Transfer mechanism: Not applicable — data stays in EU

Regolo — Italy🇮🇹

Zero data retention: nothing is logged, held for abuse monitoring or used for training. No training on customer data. EU; DPA available.

Zero data retention: Yes. Nothing is logged, held for abuse monitoring or used for training.
Training: No training on customer data.
Logging: None
Abuse monitoring: No classifier
Subprocessor access: No subprocessor reads content
GDPR DPA: DPA available
Transfer mechanism: Not applicable — data stays in EU

Benchmarks

Clef-flash played 100 games of Pac-Man against the four arcade ghosts.

JevMan: the Pac-Man benchmark for AI decision models

Rank in our runs8 of 15

Mean score2,538

Best game4,260

Games100

See the JevMan benchmark →Compare all decision modelsScores from Opper's own runs. Updated Oct 24, 2026.

Get started

Call Clef-flash through the Opper gateway with one API key. Evaluate state against typed questions using TypeSafe’s System One API for yes/no decisions, classification, and rubric scoring.

See the Opper evaluation guide and the TypeSafe API reference for question types and response formats. Compare every decision model, on one API.

Clef-flash is a premium model on Opper. Sign up needs no credit card: you get an API key straight away and the free models work in the playground and the API. Add a card to use premium models, pay-as-you-go with no minimum.

Set it up with your agent

Copy this and paste it into a coding agent like Claude Code, Cursor or Codex and it'll wire up Opper for you.

Or call it directly

1curl https://api.opper.ai/v3/compat/v1/systemone \
2  -H "Authorization: Bearer $OPPER_API_KEY" \
3  -H "Content-Type: application/json" \
4  -d '{
5    "model": "berget/Cloudflare/clef-flash",
6    "state": "The customer cannot sign in and needs help immediately.",
7    "questions": {
8      "is_urgent": {
9        "type": "noul",
10        "instructions": "Does the customer need urgent help?"
11      }
12    }
13  }'