aufklarer / Clef-flash-9B-MLX-4bit

Clef-flash 9B — MLX 4-bit

Clef-flash is a model from Cloudflare that helps your app choose what to do next. Give it some text and a list of options, and it returns a score for each option. For example, “Please turn the kitchen lights on” can map to “Turn lights on.” Your app can then use that choice to perform the action.

This version runs locally on Apple Silicon with MLX and supports text input.

The scores show how strongly the model favors each option; a high score does not guarantee a correct answer. Send one request at a time to each loaded model.

Files

Development measurements

Native MLX Swift, release build, compiled Metal shaders, Apple M5 Pro, 48 GB unified memory. One 303-token request with three fields: light action, factual-question check, and urgency. Model load is excluded; encoding through materialized probabilities is included.

This is a fidelity and timing smoke test, not a broad accuracy benchmark . No memory benchmark, p95 estimate, real robot test, or comparison with hosted inference is claimed. These measurements describe the native Swift implementation; other runtimes and requests can differ. Swift support is a development preview and was not yet released at the time of these measurements (2026-10-02).

Swift

Use the Clef library from speech-swift on Apple Silicon. Clef support is currently a development preview; it requires a checkout containing the Clef library and clef-decide product. Download this model's files into a local directory, then load it:

import Foundation
import Clef

let model = try Clef.load(
    from: URL(fileURLWithPath: "/path/to/Clef-flash-9B-MLX-4bit")
)

let result = try model.decide(
    state: "Please turn the kitchen lights on.",
    questions: [
        ClefQuestion(
            id: "action",
            instructions: "Which action was requested?",
            kind: .choice([
                "on": "Turn lights on",
                "off": "Turn lights off",
                "other": "Other request"
            ])
        )
    ]
)

for decision in result.decisions {
    print(decision.id, decision.selectedOption, decision.confidence)
    print(decision.probabilities)
}

Load the model once, then reuse it for each request. If the text and options are too long, the library returns an error rather than cutting them short.

Command line

swift build -c release --product clef-decide --disable-sandbox
scripts/build_mlx_metallib.sh release
.build/release/clef-decide /path/to/downloaded/model /path/to/downloaded/model/example-request.json

Sources

• Cloudflare's model and reference head

Links

• speech-swift — Apple SDK
• Installation and CLI docs
• soniqo.audio
• Blog