MicroDCS

MicroDCS: An Open-Standards-Based Framework for Distributed Sequence Control Applications.

MicroDCS is a Python framework for building distributed sequence control applications for OT and manufacturing. It uses MQTT v5, CloudEvents, JSON Schema, OPC UA companion specifications, and OpenTelemetry to support event-driven control flows with typed data models, protocol abstraction, and open-standard interoperability.

Quickstart

Get the framework installed, run the unit tests, and start the example application:

# Install dependencies
uv sync

# Run unit tests
uv run pytest tests/ --ignore=tests/test_mqtt_integration.py --ignore=tests/test_msgpack_integration.py

# Run the example app
# Requires a reachable MQTT broker and Redis server.
uv run python -m app

Features

• Open-standards foundation built around MQTT v5, CloudEvents, JSON Schema, OPC UA companion specifications, and OpenTelemetry
• Protocol abstraction for MQTT v5 and MessagePack-RPC transports with a shared event-processing model
• Outgoing CloudEvents over MessagePack-RPC via server-to-client notification frames
• Typed application models generated from JSON Schema and serialized to JSON or MessagePack
• Event-driven processor architecture for handling commands, data, events, and metadata
• Distributed operation features including MQTT shared subscriptions, deduplication, and message expiry handling
• Redis-backed persistence for job state, responses, and delivery coordination
• Built-in support for OPC UA Machinery Job Management patterns, including hierarchical state-machine execution
• Observability support through OpenTelemetry auto-instrumentation and internal tracing and metrics hooks

Usage

Initialize a new project

Create a new MicroDCS application with the init command. It scaffolds the project structure, pins Python 3.14, and prepares the dependencies needed to build a distributed sequence control application.

# Initialize in the current directory
uvx --from git+https://github.com/aschamberger/microdcs microdcs init

# Initialize in a new directory
uvx --from git+https://github.com/aschamberger/microdcs microdcs init my-app

The generated project includes:

1. A uv project pinned to Python ≥ 3.14
2. The microdcs package and core development dependencies
3. A starter project structure:

   app/
     __init__.py
     __main__.py       # wiring of handlers, bindings and processors
     models/           # place for generated and hand-written model mixins
     processors/       # place for CloudEventProcessor implementations
   schemas/            # JSON Schema input files for dataclassgen
   deploy/
     k8s.yaml          # Kubernetes deployment manifest
   tests/
   .vscode/
     settings.json
     tasks.json
   .github/
     copilot-instructions.md
   Dockerfile
   

4. Build-system and pytest configuration in pyproject.toml

After initialization, generate typed application models from your JSON Schema files:

uv run microdcs dataclassgen dataclasses my-schema.schema.json

Additional Documentation

• Your First Processor
• Overall Design
• Development