MLX-Knife 2.0

Current Stable Version: 2.0.1

Features

Core Functionality

• List & Manage Models: Browse your HuggingFace cache with MLX-specific filtering
• Model Information: Detailed model metadata including quantization info
• Download Models: Pull models from HuggingFace with progress tracking
• Run Models: Native MLX execution with streaming and chat modes
• Health Checks: Verify model integrity and MLX runtime compatibility
• Cache Management: Clean up and organize your model storage
• Privacy & Network: No background network or telemetry; only explicit Hugging Face interactions when you run pull or the experimental push.

Requirements

• macOS with Apple Silicon
• Python 3.9+ (native macOS version or newer)
• 8GB+ RAM recommended + RAM to run LLM

Python Compatibility

MLX Knife has been comprehensively tested and verified on:

✅ Python 3.9.6 (native macOS) - Primary target ✅ Python 3.10-3.13 - Fully compatible

Installation

Via PyPI (Recommended)

# Install stable release from PyPI
pip install mlx-knife

# Verify installation
mlxk --version  # → mlxk 2.0.1

Development Installation

# Clone and install from source
git clone https://github.com/mzau/mlx-knife.git
cd mlx-knife

# Install with all development dependencies (required for testing and code quality)
pip install -e ".[dev,test]"

# Verify installation
mlxk --version  # → mlxk 2.0.1

# Run tests and quality checks (before committing)
pytest -v
ruff check mlxk2/ --fix
mypy mlxk2/

Note: For minimal user installation without dev tools: pip install -e .

Migrating from 1.x

If you're upgrading from MLX Knife 1.x, see MIGRATION.md for important information about the license change (MIT → Apache 2.0) and behavior changes.

Quick Start

# List models (human-readable)
mlxk list
mlxk list --health
mlxk list --verbose --health

# Check cache health
mlxk health

# Show model details
mlxk show "mlx-community/Phi-3-mini-4k-instruct-4bit"

# Pull a model
mlxk pull "mlx-community/Llama-3.2-3B-Instruct-4bit"

# Run interactive chat
mlxk run "Phi-3-mini" -c

# Start OpenAI-compatible server
mlxk serve --port 8080

Commands

Command	Description
server/serve	OpenAI-compatible API server; SIGINT-robust (Supervisor); SSE streaming
run	Interactive and single-shot model execution with streaming/batch modes
list	Model discovery with JSON output
health	Corruption detection and cache analysis
show	Detailed model information with --files, --config
pull	HuggingFace model downloads with corruption detection
rm	Model deletion with lock cleanup and fuzzy matching
🔒 push	Alpha feature - Upload to HuggingFace Hub; requires MLXK2_ENABLE_ALPHA_FEATURES=1
🔒 clone	Alpha feature - Model workspace cloning; requires MLXK2_ENABLE_ALPHA_FEATURES=1

JSON API

📋 Complete API Specification: See JSON API Specification for comprehensive schema, error codes, and examples.

All commands support both human-readable and JSON output (--json flag) for automation and scripting, enabling seamless integration with CI/CD pipelines and cluster management systems.

Command Structure

All commands support JSON output via --json flag:

mlxk list --json | jq '.data.models[].name'
mlxk health --json | jq '.data.summary'
mlxk show "Phi-3-mini" --json | jq '.data.model'

Response Format:

{
    "status": "success|error",
    "command": "list|health|show|pull|rm|clone|version|push|run|server",
    "data": { /* command-specific data */ },
    "error": null | { "type": "...", "message": "..." }
}

Examples

List Models

mlxk list --json
# Output:
{
  "status": "success",
  "command": "list",
  "data": {
    "models": [
      {
        "name": "mlx-community/Phi-3-mini-4k-instruct-4bit",
        "hash": "a5339a41b2e3abcdef1234567890ab12345678ef",
        "size_bytes": 4613734656,
        "last_modified": "2024-10-15T08:23:41Z",
        "framework": "MLX",
        "model_type": "chat",
        "capabilities": ["text-generation", "chat"],
        "health": "healthy",
        "runtime_compatible": true,
        "reason": null,
        "cached": true
      }
    ],
    "count": 1
  },
  "error": null
}

Health Check

mlxk health --json
# Output:
{
  "status": "success",
  "command": "health",
  "data": {
    "healthy": [
      {
        "name": "mlx-community/Phi-3-mini-4k-instruct-4bit",
        "status": "healthy",
        "reason": "Model is healthy"
      }
    ],
    "unhealthy": [],
    "summary": { "total": 1, "healthy_count": 1, "unhealthy_count": 0 }
  },
  "error": null
}

Show Model Details

mlxk show "Phi-3-mini" --json --files
# Output (simplified):
{
  "status": "success",
  "command": "show",
  "data": {
    "model": {
      "name": "mlx-community/Phi-3-mini-4k-instruct-4bit",
      "hash": "a5339a41b2e3abcdefgh1234567890ab12345678",
      "size_bytes": 4613734656,
      "framework": "MLX",
      "model_type": "chat",
      "capabilities": ["text-generation", "chat"],
      "last_modified": "2024-10-15T08:23:41Z",
      "health": "healthy",
      "runtime_compatible": true,
      "reason": null,
      "cached": true
    },
    "files": [
      {"name": "config.json", "size": "1.2KB", "type": "config"},
      {"name": "model.safetensors", "size": "2.3GB", "type": "weights"}
    ],
    "metadata": null
  },
  "error": null
}

Hash Syntax Support

All commands support @hash syntax for specific model versions:

mlxk health "Qwen3@e96" --json     # Check specific hash
mlxk show "model@3df9bfd" --json   # Short hash matching
mlxk rm "Phi-3@e967" --json --force  # Delete specific version

Integration Examples

Broke-Cluster Integration

# Get available model names for scheduling
MODELS=$(mlxk list --json | jq -r '.data.models[].name')

# Check cache health before deployment
HEALTH=$(mlxk health --json | jq '.data.summary.healthy_count')
if [ "$HEALTH" -eq 0 ]; then
    echo "No healthy models available"
    exit 1
fi

# Download required models
mlxk pull "mlx-community/Phi-3-mini-4k-instruct-4bit" --json

CI/CD Pipeline Usage

# Verify model integrity in CI
mlxk health --json | jq -e '.data.summary.unhealthy_count == 0'

# Clean up CI artifacts
mlxk rm "test-model-*" --json --force

# Pre-warm cache for deployment
mlxk pull "production-model" --json

Model Management Automation

# Find models by pattern
LARGE_MODELS=$(mlxk list --json | jq -r '.data.models[] | select(.name | contains("30B")) | .name')

# Show detailed info for analysis
for model in $LARGE_MODELS; do
    mlxk show "$model" --json --config | jq '.data.model_config'
done

Human Output

MLX Knife provides rich human-readable output by default (without --json flag).

Basic Usage

mlxk list
mlxk list --health
mlxk health
mlxk show "mlx-community/Phi-3-mini-4k-instruct-4bit"

List Filters

• list: Shows MLX chat models only (compact names, safe default)
• list --verbose: Shows all MLX models (chat + base) with full org/names and Framework column
• list --all: Shows all frameworks (MLX, GGUF, PyTorch)
• Flags are combinable: --all --verbose, --all --health, --verbose --health

Health Status Display (--health flag)

The --health flag adds health status information to the output:

Compact mode (default, --all):

• Shows single "Health" column with values:
  • healthy - File integrity OK and MLX runtime compatible
  • healthy* - File integrity OK but not MLX runtime compatible (use --verbose for details)
  • unhealthy - File integrity failed or unknown format

Verbose mode (--verbose --health):

• Splits into "Integrity" and "Runtime" columns:
  • Integrity: healthy / unhealthy
  • Runtime: yes / no / - (dash = gate blocked by failed integrity)
  • Reason: Explanation when problems detected (wrapped at 26 chars for readability)

Examples:

# Compact health view
mlxk list --health
# Output:
# Name                    | Hash    | Size   | Modified | Type | Health
# Llama-3.2-3B-Instruct   | a1b2c3d | 2.1GB  | 2d ago   | chat | healthy
# Qwen2-7B-Instruct       | 1a2b3c4 | 4.8GB  | 3d ago   | chat | healthy*

# Verbose health view with details
mlxk list --verbose --health
# Output:
# Name                    | Hash    | Size   | Modified | Framework | Type | Integrity | Runtime | Reason
# Llama-3.2-3B-Instruct   | a1b2c3d | 2.1GB  | 2d ago   | MLX       | chat | healthy   | yes     | -
# Qwen2-7B-Instruct       | 1a2b3c4 | 4.8GB  | 3d ago   | PyTorch   | chat | healthy   | no      | Incompatible: PyTorch

# All frameworks with health status
mlxk list --all --health
# Output:
# Name                    | Hash    | Size   | Modified | Framework | Type    | Health
# Llama-3.2-3B-Instruct   | a1b2c3d | 2.1GB  | 2d ago   | MLX       | chat    | healthy
# llama-3.2-gguf-q4       | b2c3d4e | 1.8GB  | 3d ago   | GGUF      | unknown | healthy*
# broken-download         | -       | 500MB  | 1h ago   | Unknown   | unknown | unhealthy

Design Philosophy:

• unhealthy is a catch-all for anything not understood/supported (broken downloads, unknown formats, creative HuggingFace structures)
• healthy guarantees the model will work with mlxk2 run
• healthy* means files are intact but MLX runtime can't execute them (e.g., GGUF/PyTorch models, incompatible model_type, or mlx-lm version too old)

Note: JSON output is unaffected by these human-only filters and always includes full health/runtime data.

Logging & Debugging

MLX Knife 2.0 provides structured logging with configurable output formats and levels.

Log Levels

Control verbosity with --log-level (server mode):

# Default: Show startup, model loading, and errors
mlxk serve --log-level info

# Quiet: Only warnings and errors
mlxk serve --log-level warning

# Silent: Only errors
mlxk serve --log-level error

# Verbose: All logs including HTTP requests
mlxk serve --log-level debug

Log Level Behavior:

• debug: All logs + Uvicorn HTTP access logs (GET /v1/models, etc.)
• info: Application logs (startup, model switching, errors) + HTTP access logs
• warning: Only warnings and errors (no startup messages, no HTTP access logs)
• error: Only error messages

JSON Logs (Machine-Readable)

Enable structured JSON output for log aggregation tools:

# JSON logs (recommended - CLI flag)
mlxk serve --log-json

# JSON logs (alternative - environment variable)
MLXK2_LOG_JSON=1 mlxk serve

Note: --log-json also formats Uvicorn access logs as JSON for consistent output.

JSON Format:

{"ts": 1760830072.96, "level": "INFO", "msg": "MLX Knife Server 2.0 starting up..."}
{"ts": 1760830073.14, "level": "INFO", "msg": "Switching to model: mlx-community/...", "model": "..."}
{"ts": 1760830074.52, "level": "ERROR", "msg": "Model type bert not supported.", "logger": "root"}

Fields:

• ts: Unix timestamp
• level: Log level (INFO, WARN, ERROR, DEBUG)
• msg: Log message (HF tokens and user paths automatically redacted)
• logger: Source logger (mlxk2 = application, root = external libraries like mlx-lm)
• Additional fields: model, request_id, detail, duration_ms (context-dependent)

Security: Automatic Redaction

Sensitive data is automatically removed from logs:

• HuggingFace tokens (hf_...) → [REDACTED_TOKEN]
• User home paths (/Users/john/...) → ~/...

Example:

# Original (unsafe):
Using token hf_AbCdEfGhIjKlMnOpQrStUvWxYz123456 from /Users/john/models

# Logged (safe):
Using token [REDACTED_TOKEN] from ~/models

Environment Variables

• MLXK2_LOG_JSON=1: Enable JSON log format (alternative to --log-json flag)
• MLXK2_LOG_LEVEL: Override log level (used internally for subprocess mode)

HuggingFace Cache Safety

MLX-Knife 2.0 respects standard HuggingFace cache structure and practices:

Best Practices for Shared Environments

• Read operations (list, health, show) always safe with concurrent processes
• Write operations (pull, rm) coordinate during maintenance windows
• Lock cleanup automatic but avoid during active downloads
• Your responsibility: Coordinate with team, use good timing

Example Safe Workflow

# Check what's in cache (always safe)
mlxk list --json | jq '.data.count'

# Maintenance window - coordinate with team
mlxk rm "corrupted-model" --json --force
mlxk pull "replacement-model" --json

# Back to normal operations
mlxk health --json | jq '.data.summary'

Hidden Alpha Features: clone and push

clone - Model Workspace Creation

mlxk clone is a hidden alpha feature. Enable with MLXK2_ENABLE_ALPHA_FEATURES=1. It creates a local workspace from a cached model for modification and development.

• Creates isolated workspace from cached models
• Supports APFS copy-on-write optimization on same-volume scenarios
• Includes health check integration for workspace validation
• Use case: Fork-modify-push workflows

Example:

# Enable alpha features
export MLXK2_ENABLE_ALPHA_FEATURES=1

# Clone model to workspace
mlxk clone org/model ./workspace

push - Upload to Hub

mlxk push is a hidden alpha feature. Enable with MLXK2_ENABLE_ALPHA_FEATURES=1. It uploads a local folder to a Hugging Face model repository using huggingface_hub/upload_folder.

• Requires HF_TOKEN (write-enabled).
• Default branch: main (explicitly override with --branch).
• Safety: --private is required to avoid accidental public uploads.
• No validation or manifests. Basic hard excludes are applied by default: .git/**, .DS_Store, __pycache__/, common virtualenv folders (.venv/, venv/), and *.pyc.
• .hfignore (gitignore-like) in the workspace is supported and merged with the defaults.
• Repo creation: use --create if the target repo does not exist; harmless on existing repos. Missing branches are created during upload.
• JSON output: includes commit_sha, commit_url, no_changes, uploaded_files_count (when available), local_files_count (approx), change_summary and a short message.
• Quiet JSON by default: with --json (without --verbose) progress bars/console logs are suppressed; hub logs are still captured in data.hf_logs.
• Human output: derived from JSON; add --verbose to include extras such as the commit URL or a short message variant. JSON schema is unchanged.
• Local workspace check: use --check-only to validate a workspace without uploading. Produces workspace_health in JSON (no token/network required).
• Dry-run planning: use --dry-run to compute a plan vs remote without uploading. Returns dry_run: true, dry_run_summary {added, modified:null, deleted}, and sample added_files/deleted_files.
• Testing: see TESTING.md ("Push Testing (2.0)") for offline tests and opt-in live checks with markers/env.
• Intended for early testers only. Carefully review the result on the Hub after pushing.
• Responsibility: You are responsible for complying with Hugging Face Hub policies and applicable laws (e.g., copyright/licensing) for any uploaded content.

Example:

# Enable alpha features
export MLXK2_ENABLE_ALPHA_FEATURES=1

# Use push command
mlxk push --private ./workspace org/model --create --commit "init"

These features are not final and may change or be removed in future releases.

Testing

The 2.0 test suite runs by default (pytest discovery points to tests_2.0/):

# Run 2.0 tests (default)
pytest -v

# Explicitly run legacy 1.x tests (not maintained on this branch)
pytest tests/ -v

# Test categories (2.0 example):
# - ADR-002 edge cases
# - Integration scenarios
# - Model naming logic
# - Robustness testing

# Current status: all current 2.0 tests pass (some optional schema tests may be skipped without extras)

Test Architecture:

• Isolated Cache System - Zero risk to user data
• Atomic Context Switching - Production/test cache separation
• Mock Models - Realistic test scenarios
• Edge Case Coverage - All documented failure modes tested

Compatibility Notes

• Streaming note: Some UIs buffer SSE; verify real-time with curl -N. Server sends clear interrupt markers on abort.

Contributing

This branch follows the established MLX-Knife development patterns:

# Run quality checks
python test-multi-python.sh  # Tests across Python 3.9-3.13
./run_linting.sh             # Code quality validation

# Key files:
mlxk2/                       # 2.0.0 implementation
tests_2.0/                   # 2.0 test suite
docs/ADR/                    # Architecture decision records

See CONTRIBUTING.md for detailed guidelines.

Support & Feedback

• Issues: GitHub Issues
• Discussions: GitHub Discussions
• API Specification: JSON API Specification
• Documentation: See docs/ directory for technical details
• Security Policy: See SECURITY.md

License

Apache License 2.0 — see LICENSE (root) and mlxk2/NOTICE.

Acknowledgments

• Built for Apple Silicon using the MLX framework
• Models hosted by the MLX Community on HuggingFace
• Inspired by ollama's user experience

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Made with ❤️ by The BROKE team
Version 2.0.1 | November 2025
🔮 Next: BROKE Cluster for multi-node deployments