mlx-community/FLUX.2-klein-base-4B-bf16

MLX (bf16) snapshot of black-forest-labs/FLUX.2-klein-base-4B (Apache-2.0) for Apple Silicon — the quality tier companion to the distilled FLUX.2-klein-4B-bf16. Same compact rectified-flow MMDiT (5 double + 20 single blocks) + Qwen3-4B 3-layer-tap conditioner + FLUX.2 VAE, but the base checkpoint is not guidance-distilled: it runs classic two-pass classifier-free guidance (guidance ~4.0) + negative prompts over ~28 steps for stronger prompt adherence (dense scenes, text, fine attributes) at ~2× the forward cost. Standard diffusers tree; int8/int4 produced at load (int4 DiT ~2.35 GB → q4 pipeline fits a 16 GB Mac).

4B only — the 9B klein variants are FLUX Non-Commercial; this Apache-2.0 4B is the wrapped tier.

Use (Swift / MLXEngine)

import MLXKlein
import MLXToolKit
let pkg = Klein4BBaseT2IPackage(configuration: .base(quant: .int4, snapshotPath: "<this repo dir>"))
try await pkg.load()
let r = try await pkg.run(T2IRequest(
    prompt: "a rustic picnic table with a chalkboard sign reading 'PICNIC', three green apples, "
          + "sunflowers, sunny meadow, photorealistic",
    negativePrompt: "blurry, deformed, extra objects",
    guidanceScale: 4.0, width: 1024, height: 1024, seed: 42)) as! T2IResponse

Code: https://github.com/xocialize/flux2-klein-swift